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Burden of diabetes mellitus and prediabetes in tribal population of India: A systematic review
diabetes research and clinical practice 102 (2013) 1–7
Contents available at Sciverse ScienceDirect
Diabetes Research and Clinical Practice journ al h ome pa ge : www .elsevier.co m/lo cate/diabres
Review
Burden of diabetes mellitus and prediabetes in tribal population of India: A systematic review Ravi Prakash Upadhyay a,*, Puneet Misra b, Vinoth G. Chellaiyan a, Timiresh K. Das a, Mrinmoy Adhikary a, Palanivel Chinnakali c, Kapil Yadav b, Smita Sinha d a
Department of Community Medicine, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India Center for Community Medicine, All India Institute of Medical Sciences, New Delhi, India c Department of Community Medicine, Indira Gandhi Medical College and Research Institute, Puducherry, India d Department of Community Medicine School of Public Health, PGIMER, Chandigarh, India b
article info
abstract
Article history:
Objective: To estimate the burden of diabetes mellitus and pre-diabetes in tribal populations
Received 25 January 2013
of India.
Received in revised form
Methods: The authors reviewed studies from 2000 to 2011 that documented the prevalence
5 March 2013
of diabetes mellitus in various tribal populations of India. The search was performed using
Accepted 10 June 2013
electronic and manual methods. Meta-analysis of data on point prevalence was performed.
Available online 19 July 2013
Results: A total of seven studies were retrieved. The prevalence of diabetes mellitus ranged from 0.7% to 10.1%. The final estimate of diabetes prevalence obtained after pooling of data
Keywords:
from individual studies, was 5.9% (95% CI; 3.1–9.5%). The prevalence for impaired fasting
Diabetes mellitus
glucose (IFG) varied from 5.1% to 13.5% and impaired glucose tolerance (IGT), from 6.6% to
Burden
12.9%.
Tribal population
Conclusion: Chronic disease research in tribal populations is limited. The reported preva-
India
lence of IFG/IGT was higher than the prevalence of diabetes and this observation could be
Review
suggestive of a potential increase in diabetes in the coming years. Given that lifestyle changes have occurred in the tribal populations, there is a need to synthesize evidence(s) relating to diabetes and other chronic diseases in these marginalized populations and inform policy makers. # 2013 Elsevier Ireland Ltd. All rights reserved.
Contents 1. 2.
Introduction . . . . . . . . . . . . . . . . . . . . . . . . Methodology . . . . . . . . . . . . . . . . . . . . . . . 2.1. Data sources and search strategy . . 2.2. Study selection and data extraction 2.3. Statistical analysis . . . . . . . . . . . . . .
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* Corresponding author at: Department of Community Medicine, Vardhman Mahavir Medical College and Safdarjang Hospital, New Delhi 110029, India. Tel.: +91 9911645513. E-mail address: [email protected] (R.P. Upadhyay). 0168-8227/$ – see front matter # 2013 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.diabres.2013.06.011
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diabetes research and clinical practice 102 (2013) 1–7
3.
4. 5.
1.
Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1. Methodological issues . . . . . . . . . . . 3.2. Prevalence of diabetes mellitus, IFG Discussion . . . . . . . . . . . . . . . . . . . . . . . . . Conclusions . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . .
....... ....... and IGT ....... ....... .......
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Introduction
The high burden of diabetes mellitus presents a formidable challenge not only to developed nations but also to developing countries. Currently there are 366 million people living with diabetes mellitus globally and this number is expected to increase to 552 million by 2030 i.e. a 51% increase [1]. A further 23.8 million people had impaired glucose tolerance (IGT) and this will increase to 38.6 million by 2030 [2]. In 2011 there were 71.4 million people with diabetes in the South East Asia region and this is further expected to increase to 120.9 million by 2030 (around 70% increase) [1]. India alone had 61.3 million people living with diabetes placing India second to China [1,2]. Further, India was the largest contributor to the noted mortality due to diabetes in South East Asia region with 983,000 deaths attributable to diabetes [2]. The primary driver of this epidemic of diabetes is the rapid epidemiological transition associated with changes in dietary patterns and decreased physical activity [3–5]. The established criteria for specification of a community as scheduled tribes used by the government of India, Ministry of Tribal Affairs, include indications of primitive traits, distinctive culture, geographical isolation, shyness of contact with the community at large, and backwardness [6]. Tribal communities reside in hilly areas or forests and have well demarcated geographical territory. They tend to cluster and concentrate in a few pockets within an environmental setting which is largely averse to intensive settled cultivation [7]. These communities have their own culture, religion, belief system, folklore and strong ethnic identity [6,7]. In India as per the 2001 census, the tribal population constituted about 8.2% of the total population of India (figures from the recent 2011 census are not yet available) [8]. There were about 635 tribal groups and subgroups including 75 communities who have been designated as ‘primitive’ [9,10]. In spite of constituting a considerable proportion in total population, the health of the inhabitants of these tribal areas has not been given enough focus. They are mostly exploited, neglected, and highly vulnerable to diseases with a high degree of malnutrition, morbidity and mortality [9,11]. These communities do not have adequate access to basic health facilities. The tribal populations in India face considerable disparity compared with urban, semi-urban and rural populations in terms of health facilities, education and economic pursuits [9,12–14]. In recent years, the tribal population in India has undergone a marked lifestyle transition due to socio-economic growth and there is a high possibility that these communities become affected by chronic diseases, diabetes mellitus in particular, as has been observed in the tribal communities of America, northern Sudan, Taiwan and in aborigines of
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Australia [15–19]. In India, although more studies have been conducted in urban than rural areas, there is little epidemiological data on diabetes in tribal communities where the prevalence of diabetes may be different from that seen in urban and rural population [20,21]. With this in mind, this review was undertaken to provide a cogent estimate of the burden of diabetes mellitus in tribal population of India which could possibly guide future policy and programs.
2.
Methodology
2.1.
Data sources and search strategy
A systematic search was performed by three of the authors independently (VGC, TKD and RPU) using an electronic as well as manual method. The electronic search was done with Pubmed, Google scholar, Medline, Embase, WHO and Biomed central databases. Search strategies used subject headings and key words (diabetes mellitus, impaired fasting glucose, impaired glucose tolerance, metabolic syndrome, diabetic complications, population based study, community based study, tribal, India) with no language restrictions. The bibliographies of relevant guidelines, reviews and reports were also inspected to identify further relevant primary reports. A manual search was done from B.B. Dikshit Library of All India Institute of Medical Sciences, New Delhi; Central Library of Vardhman Mahavir Medical College, New Delhi and National Medical Library, New Delhi. For studies with data missing or requiring clarification, principal investigators were contacted. Online searches of major conference proceedings were also conducted in order to identify unpublished literature.
2.2.
Study selection and data extraction
Community based studies conducted in tribal populations and those that provided information on study setting, age group studied, diagnostic criteria, sample size and the prevalence of any of the three outcome(s) of interest i.e. diabetes mellitus, impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) were included in the review. Studies documenting prevalence based on ‘‘self reporting’’ by the study participants were excluded as this measure was considered not useful for estimating the prevalence and moreover, it depends on the awareness level of the people. In order to capture the current picture of the prevalence of diabetes mellitus in the tribal population, only studies published from 2000 to 2011 were included. Articles in any language were considered for the review. After initial screening of titles and abstracts, full-text publications of possible studies were reviewed. Data from
diabetes research and clinical practice 102 (2013) 1–7
abstracts were used if the full text of the article could not be acquired. Discrepancies about inclusion of studies and interpretation of data were resolved by discussion among the reviewers. Data from all studies meeting the inclusion criteria were abstracted into a tabular form. Study quality was assessed by two authors (RPU and VGC) independently using the STROBES checklist [22]. Differences were discussed and consensus reached.
2.3.
Statistical analysis
Meta-analysis of data on point prevalence from studies conducted in tribal populations in different parts of the country was performed using a random effects model. The overall prevalence was calculated as a weighted average of individual summary statistics. The results were displayed as a forest plot. ‘‘StatsDirect’’ software was used to perform metaanalysis and generate the forest plot [23].
3.
Results
On initial searches 452 citations were identified of which 118 were duplicates, thus yielding 334 unique citations. Of these, 318 were excluded on title/abstract alone and a further 11 were excluded following initial full-text review (Fig. 1). Consequently, a total of seven studies were included in the review. On screening by STROBES checklist, all seven studies were found to contain the required essentials of observational studies. The majority of studies were from the north-west region of India (n = 3) followed by two studies in the north-eastern parts (Table 1) [24,26,27,29,30]. One study was conducted in both the north-east and eastern part of the country while another was from the central part of the country [25,28]. Table 2 presents the information on the tribal communities studied by each of the included studies. Most of the studies were conducted after 2005 (n = 5) which might reflect the recent increase in concern
Databases searched: Pubmed, Google scholar, Medline, Embase, WHO database, Biomed Central database Key words used: 1. “diabetes mellitus” OR “impaired fasting glucose “OR “impaired glucose tolerance” OR “metabolic syndrome” OR “diabetic complications” 2. “population based study,” OR “community based study” OR “tribal” OR “primitive” OR “India” 3. Combined terms 1 AND 2
Studies published from 2000 to 2011 were included
Citations identified (n=452) Duplicates (n=118) Stage 1: abstract screening (n=334)
Studies excluded on abstract (n=318) Study did not include tribal population (164) Did not provide prevalence of diabetes mellitus/IFG or IGT (69) Study was conducted outside India (57)
Stage 2: full text screening (n=16)
Review article/editorial (28)
Excluded on full text review (n=11) Study done in peri-urban/rural setup (4) All the required information was not available/authors did not respond to inquiry (3) Potentially eligible articles for reference list/citation checking (n=5)
3
Self-reported prevalence of diabetes documented (2) Review article (2) New articles identified from cross reference list/snowballing (n=2)
Articles included in review (n=7) Fig. 1 – Flow chart depicting the selection process of articles to be included in the review.
4
diabetes research and clinical practice 102 (2013) 1–7
Table 1 – Studies documenting the prevalence of diabetes mellitus in tribal population of India (2000–2011). Author(s)
Year of study
Location
Agrawal et al.a [24]
2002
Sarkar et al. [25]
2002–2003 Bhutan, Sikkim and West Bengal
Lau et al. [26]
2007
Sachdev [27] 2009
Rajasthan
Response rate (%)
Age group (years)
Diagnostic criteria
Sample size
Sampling strategy
Prevalence Prevalence of diabetes of IFG/IGT (%) (%)
78.2%
>20
Symptom based plus FBG > 140 mg/dl or PPBG >200 mg/dl or RBG >200 mg/dl
605
Stratified sampling
0.7% (T)
5.1% (IFG) 12.9% (IGT)
NR
>12
FBG >110 mg/dl
588
All eligible participants included
10.1 (T)
–
West Tripura 97.9
>25
FBG > 126 mg/dl; RBG > 200 mg/dl
144
Simple random 9% (T) sampling
9% (IGT)
Rajasthan
NR
>18
RBG > 200 mg/dl
173
Not mentioned
5.2% (T)
__
Madhya Pradesh
NR
18–60
RBG > 140 mg/dl
364
Not mentioned
7.9% (T) 8.9% (M) 7.1% (F)
__
159
Cluster sampling
7.4% (T)
13.5% (IFG) 8.3% (IGT)
1296
Snowball sampling
3.9% (T) 5.2% (M) 2.9% (F)
IGT 6.6%(T) 5.3%(M) 7.6%(F)
Kapoor et al. [28]
2010
Singh et al. [29]
2010–2011 Arunachal Pradesh
98.7%
>25
FBG > 126 mg/dl or on medications
Sachdev [30]
2010–2011 Rajasthan
NR
>18
RBG > 200 mg/dl
NR, not reported; FBG, fasting blood sugar; RBG, random blood sugar; PPBG, postprandial blood glucose; IFG, impaired fasting glucose; IGT, impaired glucose tolerance. a Only the data for ‘‘Raica’’ (tribal community) considered, M – males, F – females, T – total.
of researchers about the health of the tribal communities with regard to chronic diseases.
3.1.
Methodological issues
Of the studies included in the review, only three reported response rate(s) which ranged from 78.2 to 98.7% (Table 1) [24,27,29]. Most of the studies focussed on young adults and the elderly population. There was considerable heterogeneity in the diagnostic criteria used. A number of methods such as
fasting blood glucose, post-prandial blood glucose and random blood glucose levels were used with different studies using different cut-off values. In one study, those who were on ‘‘anti-diabetic’’ medications were labeled as have diabetes while one used ‘‘symptom based approach’’ along with blood sugar levels for labeling as diabetes [22,27]. There was substantial variation in the number of study subjects which ranged from 144 to 1296. Most of the studies (n = 5) reported the sampling strategy adopted. Random sampling methods were adopted by three studies and all eligible participants
Table 2 – Characteristics of the tribal communities that formed the study population in the studies included in the review (2000–2011). Author(s) Agrawal et al. [24] Sarkar et al. [25]
Lau et al. [26] Sachdev [27] Kapoor et al. [28]
Singh et al. [29]
Sachdev [30]
Tribal communities studied and their characteristics Raica is a tribal community of North-West Rajasthan who not only habitually cares for the camel but also consumes its milk Two tribal groups – Toto and Bhutia. They share a common ancestry and live in a similar ecological habitat (rural subHimalayan region). The Toto are geographically localized in a single village (Totopara) of Jalpaiguri district of West Bengal, bordering Bhutan. The Bhutia are geographically widely distributed – throughout Bhutan and Sikkim, as well as in the hill subdivisions of Darjeeling district of West Bengal Tribal population in the Khowai district in West Tripura in North East India. Despite being only 3 h away from the capital city of Agartala, many tribal people live in relative isolation because of restricted facilities for travel Tribal population covering Natt, Sapera and the Banjara communities in Jhunjhunu district of Rajasthan Saharia – a primitive tribal group in Madhya Pradesh. They have a lower level of literacy, primitive form of agricultural practices and economic backwardness. Although traditionally Saharias practiced shifting cultivation, hunting gathering, etc., due to lack of cultivated land and scarcity of rain, most of the Saharias have become daily wage earners The study covered the areas of the Palizi, Trizino in West Kameng district, and Bana in East kameng district in the north-eastern state of Arunachal Pradesh. The population covered belonged to the Aka tribes consisting of the Hrusso Aka of the East Kameng district and the Koro Akas of the West Kameng district Tribal populations of three districts of Rajasthan state in India, namely Natt, Sapera, Banjara, Bawariya, Sansui, Bhopa and Gujjar communities
5
diabetes research and clinical practice 102 (2013) 1–7
Proportion meta-analysis plot [random effects]
% Weights
Sarkar S et al
0.100 (0.077, 0.128)
15.08
Lau SL et al
0.090 (0.049, 0.149)
13.01
Kapoor S et al
0.080 (0.054, 0.112)
14.61
Sachdev B et al
0.052 (0.024, 0.096)
13.41
Singh A et al
0.075 (0.040, 0.128)
13.23
Agarwal RP et al
0.007 (0.002, 0.017)
15.10
Sachdev B et al
0.039 (0.029, 0.051)
15.52
0.059 (0.031, 0.095)
100
combined 0.00
0.05
0.10
0.15
proportion (95% confidence interval)
Fig. 2 – Forest plot of studies on prevalence of diabetes mellitus in tribal population of India.
were included in one study. Only one study used snow ball sampling to recruit participants [30].
3.2.
Prevalence of diabetes mellitus, IFG and IGT
The overall prevalence ranged from 0.7% to 10.1%. Studies from Rajasthan, located in north-west part of India, reported prevalence in the range of 0.7–5.2% while those from the north eastern parts reported prevalence from 7.4% to 9.0% [24,26,27,29,30]. The study from Madhya Pradesh, a state in central India, reported a prevalence of 7.9%. Sarkar et al. in their multicentre study encompassing both the north eastern (Sikkim) and eastern regions (West Bengal) of the country reported a prevalence of around 10% [25]. Only two studies reported sex-based prevalence of diabetes and the prevalence in males was higher than in females in both the studies [28,30]. The prevalence in males varied from 5.2% to 8.9% whereas in females the range was from 2.9% to 7.1% whereas in females the range was from 2.9% to 7.1%.
Standard error 0.00
Bias assessment plot
0.01
0.02
0.03 -0.02
0.03
0.08
0.13 Proportion
Fig. 3 – Funnel plot of studies on the prevalence of diabetes mellitus in tribal population of India.
The overall estimate of the prevalence of diabetes in tribal population obtained after pooling of data from individual studies was 5.9% (95% CI; 3.1–9.5%) (Fig. 2). The funnel plot (Fig. 3) was skewed and asymmetrical. Normal statistical testing confirmed the presence of publication bias (Egger test P < 0.001). The value of I2 was >90%, so a random effects model was used. The prevalence for IFG varied from 5.1% to 13.5% and for IGT the range was from 6.6% to 12.9%. The reported prevalence of IFG/IGT was higher than the prevalence of diabetes and this observation could be suggestive of a potential increase in diabetes in the coming years.
4.
Discussion
The current review was done to estimate the burden of diabetes in tribal populations of India. There were just seven studies over a span of 12 years underscoring the fact that chronic disease in tribal population is a neglected problem. The point estimate for diabetes prevalence was around 6% and in a country with a population of more than one billion, of which the tribal population is around 8%, this translates into more than four million people with diabetes in these tribal communities [8]. Our review also demonstrates a high prevalence of pre-diabetic states among people living in tribal areas which point toward the imminent threat of increased number of diabetes in near future. Changes in lifestyle, including those of diet as well as physical activity could be an important contributors. The problem is further compounded by the lack of health care facilities in these areas. This high prevalence of diabetes in the tribal population corroborates well with that reported in the urban and rural population. Misra et al. reported an increase in diabetes prevalence among the rural population at a rate of 2.02 per 1000 population per year [20]. The overall point estimate for the period 1994–2009 was reported to be 2.96% [20]. Gupta et al. documented that since the 1990s reported prevalence rates
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diabetes research and clinical practice 102 (2013) 1–7
varied from 5 to 15% among urban populations and 2–5% in rural populations [21]. Thus, although the burden of diabetes in tribal population is comparable to its urban and rural counterparts, the attention received by these marginalized population in terms of health care services, especially in context to non-communicable diseases, has been minuscule. In recent years, there has been a noticeable change in the life style pattern of the tribal communities [15]. Migration to urban areas has often been suggested to be an important cause for this change in lifestyle [15,30–32]. The tribal ancestral lifestyle was dependent mainly on hunting and gathering food together with cultivation of food crops. With increasing urbanization and migration to urban areas, they have started adopting a lifestyle largely based on low-wage livelihoods. This has resulted in unhealthy dietary pattern, sedentary lifestyle and stress, all of which could predispose to the development of diabetes [30]. Studies have shown that the tribal communities are generally ignorant about diabetes which has implications for the course of disease and outcomes. Moreover, as per the 2001 census, the literacy rate of the Schedule Tribes (STs) was 47.1%, far below the national literacy rate of 64.8% [8,33,34]. Singh et al. in their study in tribal communities of Arunachal Pradesh found that only around one-fifth of the study population had heard about diabetes, out of which only 7% were aware of the symptoms of the disease [29]. Lau et al. in Tripura documented that although most participants had heard about diabetes, at least a third of the population lacked basic knowledge about risk factors and treatment [26]. Considering this low level of awareness, it is necessary to create awareness through wellstructured information, education and communication packages specifically tailored to the tribal population. Factors such as geographic isolation, poor socio-economic status and provider inadequacy have led to a lack of access to quality health care services in tribal populations [14,33]. This is further aggravated by the lack of adequate infrastructure and human resources in these areas [33]. The government of India has established the norms of having a primary health center (PHC) for every 20,000 population and a sub-center for every 3000 population in tribal areas but in reality, the number of these health centers falls short of this recommendation [33] with almost 25% of the tribal population not having access to adequate health services [14]. Around 20% of the PHCs in tribal areas are not staffed with doctors and 15% of paramedical workers posts are vacant [14]. In order to improve the health care delivery in these areas, apart from ensuring availability of trained staff and infrastructure development, the government should consider innovative approaches such as those demonstrated by the ‘‘Tribal Health Initiative’’, a public charitable trust located in Tamil Nadu [34]. Also, public-private partnerships could be utilized as has been seen in three World Bank-supported state health systems projects – in Rajasthan, Karnataka, and Tamil Nadu where a number of ingenious strategies were adopted to improve the health of tribal groups and almost all these initiatives were provided through public–private partnerships [35]. This current review provides an overview of diabetes prevalence in tribal populations of India, a south Asian
developing country. The findings have important global public health implications as the south Asian countries of Nepal, India, Pakistan, Bangladesh and Sri Lanka account for about a quarter of the world’s population and contribute a high proportion of atherosclerotic heart disease and diabetes compared with other regions of the world. There are some limitations of this study. The paucity of studies documenting the prevalence of diabetes in tribal population and individual studies not being representative of the whole country might lead to inappropriate estimates of diabetes prevalence. Most of the studies did not provide prevalence based on sex, therefore sex based estimates could not be calculated and the authors could not determine if any significant difference existed between males and females. Also there may be confounding bias in individual studies which may affect the true estimate.
5.
Conclusions
There is a lack of reliable data on the burden of diabetes in the tribal population of India. Efforts should be directed toward generating adequate data which could influence future policy and planning. Nevertheless, the findings of this review point to a high burden of diabetes and pre-diabetes in tribal populations. Considering the current lack of adequate health care facilities in these areas, the magnitude of mortality and morbidity due to diabetes could be quite high. Programs should be implemented to educate the community regarding the disease, its signs/symptoms, importance of early detection and treatment along with ensuring availability of trained staff and well equipped health facilities.
Author’s contributions RPU, VGC, TKD and MA conceived the idea and planned the study. VGC, TKD and RPU did the review of literature. VGC, MA and TKD performed data extraction and tabulation. RPU and VGC prepared the manuscript. PM, KY, PC and SS provided technical suggestions and supervised the study. All the authors read and approved the final manuscript.
Funding No funding was required.
Conflict of interest The authors declare that they have no conflict of interest.
references
[1] Whiting DR, Guariguata L, Weil C, Shaw J. IDF Diabetes Atlas: global estimates of the prevalence of diabetes for 2011 and 2030. Diabetes Res Clin Pract 2011;94:311–21.
diabetes research and clinical practice 102 (2013) 1–7
[2] International Diabetes Federation. IDF Diabetes Atlas, 5th edn., Brussels, Belgium: International Diabetes Federation; 2011, http://www.idf.org/diabetesatlas [accessed 12.08.12]. [3] Mohan V, Sandeep S, Deepa R, Shah B, Varghese C. Epidemiology of type 2 diabetes: India scenario. Indian J Med Res 2007;125(3):217–30. [4] Ramachandran A, Snehalatha C, Baskar AD, Mary S, Kumar CK, Selvam S, et al. Temporal changes in prevalence of diabetes and impaired glucose tolerance associated with lifestyle transition occurring in the rural population in India. Diabetologia 2004;47:860–5. [5] Chan JC, Malik V, Jia W, Kadowaki T, Yajnik CS, Yoon KH, et al. Diabetes in Asia: epidemiology, risk factors, and pathophysiology. J Am Med Assoc 2009;301(20):2129–40. [6] Ministry of Tribal Affairs, Government of India. http:// tribal.nic.in/index3.asp?subsublinkid=303&langid=1 [accessed 05.03.13]. [7] Saikia S, Medhi B, Medhi BK. Spatial distribution of tribal population and inter tribal differences in population growth: a critical review on demography and immigration in Assam. IOSR J Human Soc Sci 2012;3(3):23–30. [8] Census of India. Register General and Census Commissioner, Government of India; 2001. http:// censusindia.gov.in/Census_And_You/scheduled_castes_ and_ sceduled_tribes.aspx [accessed 13.08.12]. [9] Balgir RS. Tribal health problems, disease burden and ameliorative challenges in tribal communities with special emphasis on tribes of Orissa. In: Proceeding of national symposium on tribal health; 2013, http://www.rmrct.org/ files_rmrc_web/centre’s_publications/NSTH_06/ NSTH06_22.RS. Balgir.pdf [accessed 15.08.12]. [10] New Delhi, India: Govt of India, Ministry of Home Affairs, Office of the Register General and Census Commissioner; 2001. Census of India 2001: Table A10 – State Primary Census Abstract for Individual Scheduled Caste and State Primary Census Abstract for Individual Scheduled Tribe. [11] Luxmi Y, Sachdeva MP. Prevalence of malnutrition among the Chiru children of Manipur, India. Int J Hum Sci 2012;2(9):405–16. [12] Rao KS. Heath care services in tribal areas of Andhra Pradesh: a public policy perspective. Econ Polit Week 1998;33(9):481–6. [13] Planning Commission of India. Eleventh five year plan, vol. 1(6). Oxford University Press; 2008. p. 113. [14] Bala SM, Thiruselvakumar D. Overcoming problems in the practice of public health among tribals of India. Indian J Commun Med 2009;34(4):283–7. [15] Khongsdier R. Increasing urbanisation in tribal states of Northeast India: implications for the prevalence of chronic diseases. Tribes Tribals 2008;2:25–33. [16] Greenlund KJ, Valde`z R, Casper ML, Rith-Najarian S, Croft JB. Prevalence and correlates of the insulin resistance syndrome among Native Americans: the Inter-Tribal Heart Project. Diabetes Care 1999;22(3):441–7. [17] Elbagir MN, Eltom MA, Elmahadi EM, Kadam IM, Berne C. A high prevalence of diabetes mellitus and impaired glucose tolerance in the Danagla community in northern Sudan. Diabet Med 1998;15:164–9. [18] Chen HD, Shaw CK, Tseng WP, Chen HI, Lee ML. Prevalence of diabetes mellitus and impaired glucose tolerance in
[19]
[20]
[21] [22]
[23] [24]
[25]
[26]
[27]
[28]
[29]
[30]
[31]
[32]
[33]
[34]
[35]
Aborigines and Chinese in eastern Taiwan. Diabetes Res Clin Pract 1997;38:199–205. Rowley KG, Iser DM, Best JD, O’Dea K, Leonard D, McDermott R. Albuminuria in Australian Aboriginal people: prevalence and associations with components of the metabolic syndrome. Diabetologia 2000;43:1397–403. Misra P, Upadhyay RP, Misra A, Anand K. A review of the epidemiology of diabetes in rural India. Diabetes Res Clin Pract 2011;92(3):303–11. Gupta R, Misra A. Type 2 diabetes in India: regional disparities. Br J Diabetes Vasc Dis 2007;7:12–6. STROBE Statement. Strengthening the reporting of observational studies in epidemiology; 2013 Available from:http://www.strobe-statement.org/ index.php?id=available-checklists [accessed 25.08.12]. StatsDirect Ltd. StatsDirect statistical software. England: StatsDirect Ltd.; 2008, http://www.statsdirect.com. Agrawal RP, Singh G, Nayak KC, Kochar DK, Sharma RC, Beniwal R, et al. Prevalence of diabetes in camel milk consuming ‘Raica’ rural community of north-west Rajasthan. Int J Diab Dev Ctries 2004;24:109–14. Sarkar S, Das M, Mukhopadhyay B, Chakrabarti CS, Majumder PP. High prevalence of metabolic syndrome and its correlates in two tribal populations of India and the impact of urbanization. Indian J Med Res 2006;123(5):679–86. Lau SL, Debarm R, Thomas N, Asha HS, Vasan KS, Alex RG, et al. Healthcare planning in north-east India: a survey on diabetes awareness, risk factors and health attitudes in a rural community. J Assoc Physicians India 2009;57:305–9. Sachdev B. Community based study on incidence of type 2 diabetes and hypertension among nomad tribal population of Rajasthan, India. Int J Sci Nat 2011;2(2):296–301. Kapoor S, Tyagi R, Saluja K, Chaturvedi A, Kapoor AK. Emerging health threats among a primitive tribal group of Central India. J Public Health Epidemiol 2010;2(2):13–9. Singh A, Milton PE, Nanaiah A, Samuel P, Thomas N. Awareness and attitude toward diabetes in the rural population of Arunachal Pradesh, Northeast India. Indian J Endocrinol Metab 2012;16(Suppl. 1):S83–6. Sachdev B. Screening of type 2 diabetes mellitus and its associated risk factors among select tribes of Rajasthan. Int J Health Sci Res 2012;2(1):33–44. Kulkarni P, Das KC, Pardeshi V. Understanding mobility among tribal population: a study in Andhra Pradesh, India; 2013 Available from:http://epc2010.princeton.edu/papers/ 100159 [accessed 10.09.12]. Migration of tribal women: its socioeconomic effects – an in-depth study of Chhatisgarh, Jharkhand, M.P. and Orissa. Society for Regional Research and Analysis; 2010, Available from: http://planningcommission.nic.in/reports/sereport/ ser/ser_mig.pdf [accessed 21.09.12]. Statistical profile of scheduled tribes in India. Ministry of Tribal Affairs, Statistics Division, Government of India; 2010, Available from: http://tribal.nic.in/writereaddata/ mainlinkfile/File1386.pdf [accessed 22.09.12].. Prabhakar H, Manoharan R. The Tribal Health Initiative model for healthcare delivery: a clinical and epidemiological approach. Natl Med J India 2005;18(4):197–204. URL: http://go.worldbank.org/81QRIZ0QG0 [accessed 28.09.12].
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Contents available at Sciverse ScienceDirect
Diabetes Research and Clinical Practice journ al h ome pa ge : www .elsevier.co m/lo cate/diabres
Review
Burden of diabetes mellitus and prediabetes in tribal population of India: A systematic review Ravi Prakash Upadhyay a,*, Puneet Misra b, Vinoth G. Chellaiyan a, Timiresh K. Das a, Mrinmoy Adhikary a, Palanivel Chinnakali c, Kapil Yadav b, Smita Sinha d a
Department of Community Medicine, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India Center for Community Medicine, All India Institute of Medical Sciences, New Delhi, India c Department of Community Medicine, Indira Gandhi Medical College and Research Institute, Puducherry, India d Department of Community Medicine School of Public Health, PGIMER, Chandigarh, India b
article info
abstract
Article history:
Objective: To estimate the burden of diabetes mellitus and pre-diabetes in tribal populations
Received 25 January 2013
of India.
Received in revised form
Methods: The authors reviewed studies from 2000 to 2011 that documented the prevalence
5 March 2013
of diabetes mellitus in various tribal populations of India. The search was performed using
Accepted 10 June 2013
electronic and manual methods. Meta-analysis of data on point prevalence was performed.
Available online 19 July 2013
Results: A total of seven studies were retrieved. The prevalence of diabetes mellitus ranged from 0.7% to 10.1%. The final estimate of diabetes prevalence obtained after pooling of data
Keywords:
from individual studies, was 5.9% (95% CI; 3.1–9.5%). The prevalence for impaired fasting
Diabetes mellitus
glucose (IFG) varied from 5.1% to 13.5% and impaired glucose tolerance (IGT), from 6.6% to
Burden
12.9%.
Tribal population
Conclusion: Chronic disease research in tribal populations is limited. The reported preva-
India
lence of IFG/IGT was higher than the prevalence of diabetes and this observation could be
Review
suggestive of a potential increase in diabetes in the coming years. Given that lifestyle changes have occurred in the tribal populations, there is a need to synthesize evidence(s) relating to diabetes and other chronic diseases in these marginalized populations and inform policy makers. # 2013 Elsevier Ireland Ltd. All rights reserved.
Contents 1. 2.
Introduction . . . . . . . . . . . . . . . . . . . . . . . . Methodology . . . . . . . . . . . . . . . . . . . . . . . 2.1. Data sources and search strategy . . 2.2. Study selection and data extraction 2.3. Statistical analysis . . . . . . . . . . . . . .
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* Corresponding author at: Department of Community Medicine, Vardhman Mahavir Medical College and Safdarjang Hospital, New Delhi 110029, India. Tel.: +91 9911645513. E-mail address: [email protected] (R.P. Upadhyay). 0168-8227/$ – see front matter # 2013 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.diabres.2013.06.011
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diabetes research and clinical practice 102 (2013) 1–7
3.
4. 5.
1.
Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1. Methodological issues . . . . . . . . . . . 3.2. Prevalence of diabetes mellitus, IFG Discussion . . . . . . . . . . . . . . . . . . . . . . . . . Conclusions . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . .
....... ....... and IGT ....... ....... .......
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Introduction
The high burden of diabetes mellitus presents a formidable challenge not only to developed nations but also to developing countries. Currently there are 366 million people living with diabetes mellitus globally and this number is expected to increase to 552 million by 2030 i.e. a 51% increase [1]. A further 23.8 million people had impaired glucose tolerance (IGT) and this will increase to 38.6 million by 2030 [2]. In 2011 there were 71.4 million people with diabetes in the South East Asia region and this is further expected to increase to 120.9 million by 2030 (around 70% increase) [1]. India alone had 61.3 million people living with diabetes placing India second to China [1,2]. Further, India was the largest contributor to the noted mortality due to diabetes in South East Asia region with 983,000 deaths attributable to diabetes [2]. The primary driver of this epidemic of diabetes is the rapid epidemiological transition associated with changes in dietary patterns and decreased physical activity [3–5]. The established criteria for specification of a community as scheduled tribes used by the government of India, Ministry of Tribal Affairs, include indications of primitive traits, distinctive culture, geographical isolation, shyness of contact with the community at large, and backwardness [6]. Tribal communities reside in hilly areas or forests and have well demarcated geographical territory. They tend to cluster and concentrate in a few pockets within an environmental setting which is largely averse to intensive settled cultivation [7]. These communities have their own culture, religion, belief system, folklore and strong ethnic identity [6,7]. In India as per the 2001 census, the tribal population constituted about 8.2% of the total population of India (figures from the recent 2011 census are not yet available) [8]. There were about 635 tribal groups and subgroups including 75 communities who have been designated as ‘primitive’ [9,10]. In spite of constituting a considerable proportion in total population, the health of the inhabitants of these tribal areas has not been given enough focus. They are mostly exploited, neglected, and highly vulnerable to diseases with a high degree of malnutrition, morbidity and mortality [9,11]. These communities do not have adequate access to basic health facilities. The tribal populations in India face considerable disparity compared with urban, semi-urban and rural populations in terms of health facilities, education and economic pursuits [9,12–14]. In recent years, the tribal population in India has undergone a marked lifestyle transition due to socio-economic growth and there is a high possibility that these communities become affected by chronic diseases, diabetes mellitus in particular, as has been observed in the tribal communities of America, northern Sudan, Taiwan and in aborigines of
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Australia [15–19]. In India, although more studies have been conducted in urban than rural areas, there is little epidemiological data on diabetes in tribal communities where the prevalence of diabetes may be different from that seen in urban and rural population [20,21]. With this in mind, this review was undertaken to provide a cogent estimate of the burden of diabetes mellitus in tribal population of India which could possibly guide future policy and programs.
2.
Methodology
2.1.
Data sources and search strategy
A systematic search was performed by three of the authors independently (VGC, TKD and RPU) using an electronic as well as manual method. The electronic search was done with Pubmed, Google scholar, Medline, Embase, WHO and Biomed central databases. Search strategies used subject headings and key words (diabetes mellitus, impaired fasting glucose, impaired glucose tolerance, metabolic syndrome, diabetic complications, population based study, community based study, tribal, India) with no language restrictions. The bibliographies of relevant guidelines, reviews and reports were also inspected to identify further relevant primary reports. A manual search was done from B.B. Dikshit Library of All India Institute of Medical Sciences, New Delhi; Central Library of Vardhman Mahavir Medical College, New Delhi and National Medical Library, New Delhi. For studies with data missing or requiring clarification, principal investigators were contacted. Online searches of major conference proceedings were also conducted in order to identify unpublished literature.
2.2.
Study selection and data extraction
Community based studies conducted in tribal populations and those that provided information on study setting, age group studied, diagnostic criteria, sample size and the prevalence of any of the three outcome(s) of interest i.e. diabetes mellitus, impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) were included in the review. Studies documenting prevalence based on ‘‘self reporting’’ by the study participants were excluded as this measure was considered not useful for estimating the prevalence and moreover, it depends on the awareness level of the people. In order to capture the current picture of the prevalence of diabetes mellitus in the tribal population, only studies published from 2000 to 2011 were included. Articles in any language were considered for the review. After initial screening of titles and abstracts, full-text publications of possible studies were reviewed. Data from
diabetes research and clinical practice 102 (2013) 1–7
abstracts were used if the full text of the article could not be acquired. Discrepancies about inclusion of studies and interpretation of data were resolved by discussion among the reviewers. Data from all studies meeting the inclusion criteria were abstracted into a tabular form. Study quality was assessed by two authors (RPU and VGC) independently using the STROBES checklist [22]. Differences were discussed and consensus reached.
2.3.
Statistical analysis
Meta-analysis of data on point prevalence from studies conducted in tribal populations in different parts of the country was performed using a random effects model. The overall prevalence was calculated as a weighted average of individual summary statistics. The results were displayed as a forest plot. ‘‘StatsDirect’’ software was used to perform metaanalysis and generate the forest plot [23].
3.
Results
On initial searches 452 citations were identified of which 118 were duplicates, thus yielding 334 unique citations. Of these, 318 were excluded on title/abstract alone and a further 11 were excluded following initial full-text review (Fig. 1). Consequently, a total of seven studies were included in the review. On screening by STROBES checklist, all seven studies were found to contain the required essentials of observational studies. The majority of studies were from the north-west region of India (n = 3) followed by two studies in the north-eastern parts (Table 1) [24,26,27,29,30]. One study was conducted in both the north-east and eastern part of the country while another was from the central part of the country [25,28]. Table 2 presents the information on the tribal communities studied by each of the included studies. Most of the studies were conducted after 2005 (n = 5) which might reflect the recent increase in concern
Databases searched: Pubmed, Google scholar, Medline, Embase, WHO database, Biomed Central database Key words used: 1. “diabetes mellitus” OR “impaired fasting glucose “OR “impaired glucose tolerance” OR “metabolic syndrome” OR “diabetic complications” 2. “population based study,” OR “community based study” OR “tribal” OR “primitive” OR “India” 3. Combined terms 1 AND 2
Studies published from 2000 to 2011 were included
Citations identified (n=452) Duplicates (n=118) Stage 1: abstract screening (n=334)
Studies excluded on abstract (n=318) Study did not include tribal population (164) Did not provide prevalence of diabetes mellitus/IFG or IGT (69) Study was conducted outside India (57)
Stage 2: full text screening (n=16)
Review article/editorial (28)
Excluded on full text review (n=11) Study done in peri-urban/rural setup (4) All the required information was not available/authors did not respond to inquiry (3) Potentially eligible articles for reference list/citation checking (n=5)
3
Self-reported prevalence of diabetes documented (2) Review article (2) New articles identified from cross reference list/snowballing (n=2)
Articles included in review (n=7) Fig. 1 – Flow chart depicting the selection process of articles to be included in the review.
4
diabetes research and clinical practice 102 (2013) 1–7
Table 1 – Studies documenting the prevalence of diabetes mellitus in tribal population of India (2000–2011). Author(s)
Year of study
Location
Agrawal et al.a [24]
2002
Sarkar et al. [25]
2002–2003 Bhutan, Sikkim and West Bengal
Lau et al. [26]
2007
Sachdev [27] 2009
Rajasthan
Response rate (%)
Age group (years)
Diagnostic criteria
Sample size
Sampling strategy
Prevalence Prevalence of diabetes of IFG/IGT (%) (%)
78.2%
>20
Symptom based plus FBG > 140 mg/dl or PPBG >200 mg/dl or RBG >200 mg/dl
605
Stratified sampling
0.7% (T)
5.1% (IFG) 12.9% (IGT)
NR
>12
FBG >110 mg/dl
588
All eligible participants included
10.1 (T)
–
West Tripura 97.9
>25
FBG > 126 mg/dl; RBG > 200 mg/dl
144
Simple random 9% (T) sampling
9% (IGT)
Rajasthan
NR
>18
RBG > 200 mg/dl
173
Not mentioned
5.2% (T)
__
Madhya Pradesh
NR
18–60
RBG > 140 mg/dl
364
Not mentioned
7.9% (T) 8.9% (M) 7.1% (F)
__
159
Cluster sampling
7.4% (T)
13.5% (IFG) 8.3% (IGT)
1296
Snowball sampling
3.9% (T) 5.2% (M) 2.9% (F)
IGT 6.6%(T) 5.3%(M) 7.6%(F)
Kapoor et al. [28]
2010
Singh et al. [29]
2010–2011 Arunachal Pradesh
98.7%
>25
FBG > 126 mg/dl or on medications
Sachdev [30]
2010–2011 Rajasthan
NR
>18
RBG > 200 mg/dl
NR, not reported; FBG, fasting blood sugar; RBG, random blood sugar; PPBG, postprandial blood glucose; IFG, impaired fasting glucose; IGT, impaired glucose tolerance. a Only the data for ‘‘Raica’’ (tribal community) considered, M – males, F – females, T – total.
of researchers about the health of the tribal communities with regard to chronic diseases.
3.1.
Methodological issues
Of the studies included in the review, only three reported response rate(s) which ranged from 78.2 to 98.7% (Table 1) [24,27,29]. Most of the studies focussed on young adults and the elderly population. There was considerable heterogeneity in the diagnostic criteria used. A number of methods such as
fasting blood glucose, post-prandial blood glucose and random blood glucose levels were used with different studies using different cut-off values. In one study, those who were on ‘‘anti-diabetic’’ medications were labeled as have diabetes while one used ‘‘symptom based approach’’ along with blood sugar levels for labeling as diabetes [22,27]. There was substantial variation in the number of study subjects which ranged from 144 to 1296. Most of the studies (n = 5) reported the sampling strategy adopted. Random sampling methods were adopted by three studies and all eligible participants
Table 2 – Characteristics of the tribal communities that formed the study population in the studies included in the review (2000–2011). Author(s) Agrawal et al. [24] Sarkar et al. [25]
Lau et al. [26] Sachdev [27] Kapoor et al. [28]
Singh et al. [29]
Sachdev [30]
Tribal communities studied and their characteristics Raica is a tribal community of North-West Rajasthan who not only habitually cares for the camel but also consumes its milk Two tribal groups – Toto and Bhutia. They share a common ancestry and live in a similar ecological habitat (rural subHimalayan region). The Toto are geographically localized in a single village (Totopara) of Jalpaiguri district of West Bengal, bordering Bhutan. The Bhutia are geographically widely distributed – throughout Bhutan and Sikkim, as well as in the hill subdivisions of Darjeeling district of West Bengal Tribal population in the Khowai district in West Tripura in North East India. Despite being only 3 h away from the capital city of Agartala, many tribal people live in relative isolation because of restricted facilities for travel Tribal population covering Natt, Sapera and the Banjara communities in Jhunjhunu district of Rajasthan Saharia – a primitive tribal group in Madhya Pradesh. They have a lower level of literacy, primitive form of agricultural practices and economic backwardness. Although traditionally Saharias practiced shifting cultivation, hunting gathering, etc., due to lack of cultivated land and scarcity of rain, most of the Saharias have become daily wage earners The study covered the areas of the Palizi, Trizino in West Kameng district, and Bana in East kameng district in the north-eastern state of Arunachal Pradesh. The population covered belonged to the Aka tribes consisting of the Hrusso Aka of the East Kameng district and the Koro Akas of the West Kameng district Tribal populations of three districts of Rajasthan state in India, namely Natt, Sapera, Banjara, Bawariya, Sansui, Bhopa and Gujjar communities
5
diabetes research and clinical practice 102 (2013) 1–7
Proportion meta-analysis plot [random effects]
% Weights
Sarkar S et al
0.100 (0.077, 0.128)
15.08
Lau SL et al
0.090 (0.049, 0.149)
13.01
Kapoor S et al
0.080 (0.054, 0.112)
14.61
Sachdev B et al
0.052 (0.024, 0.096)
13.41
Singh A et al
0.075 (0.040, 0.128)
13.23
Agarwal RP et al
0.007 (0.002, 0.017)
15.10
Sachdev B et al
0.039 (0.029, 0.051)
15.52
0.059 (0.031, 0.095)
100
combined 0.00
0.05
0.10
0.15
proportion (95% confidence interval)
Fig. 2 – Forest plot of studies on prevalence of diabetes mellitus in tribal population of India.
were included in one study. Only one study used snow ball sampling to recruit participants [30].
3.2.
Prevalence of diabetes mellitus, IFG and IGT
The overall prevalence ranged from 0.7% to 10.1%. Studies from Rajasthan, located in north-west part of India, reported prevalence in the range of 0.7–5.2% while those from the north eastern parts reported prevalence from 7.4% to 9.0% [24,26,27,29,30]. The study from Madhya Pradesh, a state in central India, reported a prevalence of 7.9%. Sarkar et al. in their multicentre study encompassing both the north eastern (Sikkim) and eastern regions (West Bengal) of the country reported a prevalence of around 10% [25]. Only two studies reported sex-based prevalence of diabetes and the prevalence in males was higher than in females in both the studies [28,30]. The prevalence in males varied from 5.2% to 8.9% whereas in females the range was from 2.9% to 7.1% whereas in females the range was from 2.9% to 7.1%.
Standard error 0.00
Bias assessment plot
0.01
0.02
0.03 -0.02
0.03
0.08
0.13 Proportion
Fig. 3 – Funnel plot of studies on the prevalence of diabetes mellitus in tribal population of India.
The overall estimate of the prevalence of diabetes in tribal population obtained after pooling of data from individual studies was 5.9% (95% CI; 3.1–9.5%) (Fig. 2). The funnel plot (Fig. 3) was skewed and asymmetrical. Normal statistical testing confirmed the presence of publication bias (Egger test P < 0.001). The value of I2 was >90%, so a random effects model was used. The prevalence for IFG varied from 5.1% to 13.5% and for IGT the range was from 6.6% to 12.9%. The reported prevalence of IFG/IGT was higher than the prevalence of diabetes and this observation could be suggestive of a potential increase in diabetes in the coming years.
4.
Discussion
The current review was done to estimate the burden of diabetes in tribal populations of India. There were just seven studies over a span of 12 years underscoring the fact that chronic disease in tribal population is a neglected problem. The point estimate for diabetes prevalence was around 6% and in a country with a population of more than one billion, of which the tribal population is around 8%, this translates into more than four million people with diabetes in these tribal communities [8]. Our review also demonstrates a high prevalence of pre-diabetic states among people living in tribal areas which point toward the imminent threat of increased number of diabetes in near future. Changes in lifestyle, including those of diet as well as physical activity could be an important contributors. The problem is further compounded by the lack of health care facilities in these areas. This high prevalence of diabetes in the tribal population corroborates well with that reported in the urban and rural population. Misra et al. reported an increase in diabetes prevalence among the rural population at a rate of 2.02 per 1000 population per year [20]. The overall point estimate for the period 1994–2009 was reported to be 2.96% [20]. Gupta et al. documented that since the 1990s reported prevalence rates
6
diabetes research and clinical practice 102 (2013) 1–7
varied from 5 to 15% among urban populations and 2–5% in rural populations [21]. Thus, although the burden of diabetes in tribal population is comparable to its urban and rural counterparts, the attention received by these marginalized population in terms of health care services, especially in context to non-communicable diseases, has been minuscule. In recent years, there has been a noticeable change in the life style pattern of the tribal communities [15]. Migration to urban areas has often been suggested to be an important cause for this change in lifestyle [15,30–32]. The tribal ancestral lifestyle was dependent mainly on hunting and gathering food together with cultivation of food crops. With increasing urbanization and migration to urban areas, they have started adopting a lifestyle largely based on low-wage livelihoods. This has resulted in unhealthy dietary pattern, sedentary lifestyle and stress, all of which could predispose to the development of diabetes [30]. Studies have shown that the tribal communities are generally ignorant about diabetes which has implications for the course of disease and outcomes. Moreover, as per the 2001 census, the literacy rate of the Schedule Tribes (STs) was 47.1%, far below the national literacy rate of 64.8% [8,33,34]. Singh et al. in their study in tribal communities of Arunachal Pradesh found that only around one-fifth of the study population had heard about diabetes, out of which only 7% were aware of the symptoms of the disease [29]. Lau et al. in Tripura documented that although most participants had heard about diabetes, at least a third of the population lacked basic knowledge about risk factors and treatment [26]. Considering this low level of awareness, it is necessary to create awareness through wellstructured information, education and communication packages specifically tailored to the tribal population. Factors such as geographic isolation, poor socio-economic status and provider inadequacy have led to a lack of access to quality health care services in tribal populations [14,33]. This is further aggravated by the lack of adequate infrastructure and human resources in these areas [33]. The government of India has established the norms of having a primary health center (PHC) for every 20,000 population and a sub-center for every 3000 population in tribal areas but in reality, the number of these health centers falls short of this recommendation [33] with almost 25% of the tribal population not having access to adequate health services [14]. Around 20% of the PHCs in tribal areas are not staffed with doctors and 15% of paramedical workers posts are vacant [14]. In order to improve the health care delivery in these areas, apart from ensuring availability of trained staff and infrastructure development, the government should consider innovative approaches such as those demonstrated by the ‘‘Tribal Health Initiative’’, a public charitable trust located in Tamil Nadu [34]. Also, public-private partnerships could be utilized as has been seen in three World Bank-supported state health systems projects – in Rajasthan, Karnataka, and Tamil Nadu where a number of ingenious strategies were adopted to improve the health of tribal groups and almost all these initiatives were provided through public–private partnerships [35]. This current review provides an overview of diabetes prevalence in tribal populations of India, a south Asian
developing country. The findings have important global public health implications as the south Asian countries of Nepal, India, Pakistan, Bangladesh and Sri Lanka account for about a quarter of the world’s population and contribute a high proportion of atherosclerotic heart disease and diabetes compared with other regions of the world. There are some limitations of this study. The paucity of studies documenting the prevalence of diabetes in tribal population and individual studies not being representative of the whole country might lead to inappropriate estimates of diabetes prevalence. Most of the studies did not provide prevalence based on sex, therefore sex based estimates could not be calculated and the authors could not determine if any significant difference existed between males and females. Also there may be confounding bias in individual studies which may affect the true estimate.
5.
Conclusions
There is a lack of reliable data on the burden of diabetes in the tribal population of India. Efforts should be directed toward generating adequate data which could influence future policy and planning. Nevertheless, the findings of this review point to a high burden of diabetes and pre-diabetes in tribal populations. Considering the current lack of adequate health care facilities in these areas, the magnitude of mortality and morbidity due to diabetes could be quite high. Programs should be implemented to educate the community regarding the disease, its signs/symptoms, importance of early detection and treatment along with ensuring availability of trained staff and well equipped health facilities.
Author’s contributions RPU, VGC, TKD and MA conceived the idea and planned the study. VGC, TKD and RPU did the review of literature. VGC, MA and TKD performed data extraction and tabulation. RPU and VGC prepared the manuscript. PM, KY, PC and SS provided technical suggestions and supervised the study. All the authors read and approved the final manuscript.
Funding No funding was required.
Conflict of interest The authors declare that they have no conflict of interest.
references
[1] Whiting DR, Guariguata L, Weil C, Shaw J. IDF Diabetes Atlas: global estimates of the prevalence of diabetes for 2011 and 2030. Diabetes Res Clin Pract 2011;94:311–21.
diabetes research and clinical practice 102 (2013) 1–7
[2] International Diabetes Federation. IDF Diabetes Atlas, 5th edn., Brussels, Belgium: International Diabetes Federation; 2011, http://www.idf.org/diabetesatlas [accessed 12.08.12]. [3] Mohan V, Sandeep S, Deepa R, Shah B, Varghese C. Epidemiology of type 2 diabetes: India scenario. Indian J Med Res 2007;125(3):217–30. [4] Ramachandran A, Snehalatha C, Baskar AD, Mary S, Kumar CK, Selvam S, et al. Temporal changes in prevalence of diabetes and impaired glucose tolerance associated with lifestyle transition occurring in the rural population in India. Diabetologia 2004;47:860–5. [5] Chan JC, Malik V, Jia W, Kadowaki T, Yajnik CS, Yoon KH, et al. Diabetes in Asia: epidemiology, risk factors, and pathophysiology. J Am Med Assoc 2009;301(20):2129–40. [6] Ministry of Tribal Affairs, Government of India. http:// tribal.nic.in/index3.asp?subsublinkid=303&langid=1 [accessed 05.03.13]. [7] Saikia S, Medhi B, Medhi BK. Spatial distribution of tribal population and inter tribal differences in population growth: a critical review on demography and immigration in Assam. IOSR J Human Soc Sci 2012;3(3):23–30. [8] Census of India. Register General and Census Commissioner, Government of India; 2001. http:// censusindia.gov.in/Census_And_You/scheduled_castes_ and_ sceduled_tribes.aspx [accessed 13.08.12]. [9] Balgir RS. Tribal health problems, disease burden and ameliorative challenges in tribal communities with special emphasis on tribes of Orissa. In: Proceeding of national symposium on tribal health; 2013, http://www.rmrct.org/ files_rmrc_web/centre’s_publications/NSTH_06/ NSTH06_22.RS. Balgir.pdf [accessed 15.08.12]. [10] New Delhi, India: Govt of India, Ministry of Home Affairs, Office of the Register General and Census Commissioner; 2001. Census of India 2001: Table A10 – State Primary Census Abstract for Individual Scheduled Caste and State Primary Census Abstract for Individual Scheduled Tribe. [11] Luxmi Y, Sachdeva MP. Prevalence of malnutrition among the Chiru children of Manipur, India. Int J Hum Sci 2012;2(9):405–16. [12] Rao KS. Heath care services in tribal areas of Andhra Pradesh: a public policy perspective. Econ Polit Week 1998;33(9):481–6. [13] Planning Commission of India. Eleventh five year plan, vol. 1(6). Oxford University Press; 2008. p. 113. [14] Bala SM, Thiruselvakumar D. Overcoming problems in the practice of public health among tribals of India. Indian J Commun Med 2009;34(4):283–7. [15] Khongsdier R. Increasing urbanisation in tribal states of Northeast India: implications for the prevalence of chronic diseases. Tribes Tribals 2008;2:25–33. [16] Greenlund KJ, Valde`z R, Casper ML, Rith-Najarian S, Croft JB. Prevalence and correlates of the insulin resistance syndrome among Native Americans: the Inter-Tribal Heart Project. Diabetes Care 1999;22(3):441–7. [17] Elbagir MN, Eltom MA, Elmahadi EM, Kadam IM, Berne C. A high prevalence of diabetes mellitus and impaired glucose tolerance in the Danagla community in northern Sudan. Diabet Med 1998;15:164–9. [18] Chen HD, Shaw CK, Tseng WP, Chen HI, Lee ML. Prevalence of diabetes mellitus and impaired glucose tolerance in
[19]
[20]
[21] [22]
[23] [24]
[25]
[26]
[27]
[28]
[29]
[30]
[31]
[32]
[33]
[34]
[35]
Aborigines and Chinese in eastern Taiwan. Diabetes Res Clin Pract 1997;38:199–205. Rowley KG, Iser DM, Best JD, O’Dea K, Leonard D, McDermott R. Albuminuria in Australian Aboriginal people: prevalence and associations with components of the metabolic syndrome. Diabetologia 2000;43:1397–403. Misra P, Upadhyay RP, Misra A, Anand K. A review of the epidemiology of diabetes in rural India. Diabetes Res Clin Pract 2011;92(3):303–11. Gupta R, Misra A. Type 2 diabetes in India: regional disparities. Br J Diabetes Vasc Dis 2007;7:12–6. STROBE Statement. Strengthening the reporting of observational studies in epidemiology; 2013 Available from:http://www.strobe-statement.org/ index.php?id=available-checklists [accessed 25.08.12]. StatsDirect Ltd. StatsDirect statistical software. England: StatsDirect Ltd.; 2008, http://www.statsdirect.com. Agrawal RP, Singh G, Nayak KC, Kochar DK, Sharma RC, Beniwal R, et al. Prevalence of diabetes in camel milk consuming ‘Raica’ rural community of north-west Rajasthan. Int J Diab Dev Ctries 2004;24:109–14. Sarkar S, Das M, Mukhopadhyay B, Chakrabarti CS, Majumder PP. High prevalence of metabolic syndrome and its correlates in two tribal populations of India and the impact of urbanization. Indian J Med Res 2006;123(5):679–86. Lau SL, Debarm R, Thomas N, Asha HS, Vasan KS, Alex RG, et al. Healthcare planning in north-east India: a survey on diabetes awareness, risk factors and health attitudes in a rural community. J Assoc Physicians India 2009;57:305–9. Sachdev B. Community based study on incidence of type 2 diabetes and hypertension among nomad tribal population of Rajasthan, India. Int J Sci Nat 2011;2(2):296–301. Kapoor S, Tyagi R, Saluja K, Chaturvedi A, Kapoor AK. Emerging health threats among a primitive tribal group of Central India. J Public Health Epidemiol 2010;2(2):13–9. Singh A, Milton PE, Nanaiah A, Samuel P, Thomas N. Awareness and attitude toward diabetes in the rural population of Arunachal Pradesh, Northeast India. Indian J Endocrinol Metab 2012;16(Suppl. 1):S83–6. Sachdev B. Screening of type 2 diabetes mellitus and its associated risk factors among select tribes of Rajasthan. Int J Health Sci Res 2012;2(1):33–44. Kulkarni P, Das KC, Pardeshi V. Understanding mobility among tribal population: a study in Andhra Pradesh, India; 2013 Available from:http://epc2010.princeton.edu/papers/ 100159 [accessed 10.09.12]. Migration of tribal women: its socioeconomic effects – an in-depth study of Chhatisgarh, Jharkhand, M.P. and Orissa. Society for Regional Research and Analysis; 2010, Available from: http://planningcommission.nic.in/reports/sereport/ ser/ser_mig.pdf [accessed 21.09.12]. Statistical profile of scheduled tribes in India. Ministry of Tribal Affairs, Statistics Division, Government of India; 2010, Available from: http://tribal.nic.in/writereaddata/ mainlinkfile/File1386.pdf [accessed 22.09.12].. Prabhakar H, Manoharan R. The Tribal Health Initiative model for healthcare delivery: a clinical and epidemiological approach. Natl Med J India 2005;18(4):197–204. URL: http://go.worldbank.org/81QRIZ0QG0 [accessed 28.09.12].
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