- Email: [email protected]
Assessment of biomarkers in type 2 diabetic subjects without any complications
G Model
DSX-495; No. of Pages 3 Diabetes & Metabolic Syndrome: Clinical Research & Reviews xxx (2015) xxx–xxx
Contents lists available at ScienceDirect
Diabetes & Metabolic Syndrome: Clinical Research & Reviews journal homepage: www.elsevier.com/locate/dsx
Original article
Assessment of biomarkers in type 2 diabetic subjects without any complications Geetha Bhaktha a, Shivananda Nayak b,*, Manjula Shantaram c,d a
Department of Biochemistry, Shimoga Institute of Medical Sciences, Karnataka, India Department of Preclinical Sciences, Faculty of Medical Sciences, The University of the West Indies, Trinidad, Trinidad and Tobago c Department of Biochemistry, PG Centre, ChikkaAluvara, Somwarpet Taluk, Kodagu District, 571232, Karnataka, India d Department of Biochemistry, Yenepoya Medical College, Yenepoya University, Mangalore, Karnataka, 575 018, India b
A R T I C L E I N F O
S U M M A R Y
Keywords: Adiponectin Leptin TNF-a hs-CRP Type 2 diabetes
Background: Type 2-diabetes (T2D), is a public health problem which has reached epidemic proportions due to the rapidly increasing rates of this disease worldwide. It is known that adipose tissue can synthesize and release pro-inflammatory cytokines, tumor necrosis factor-alpha, interleukin-1, adiponectin and leptin that are associated with body fat mass. Hence comparing the biomarkers with individuals without hyperglycemia would help us to understand the level of increase in their values though the vascular complications have not begun. Materials and methods: This was a cross sectional study comprising 229 diabetic persons and 205 healthy individuals. High sensitivity reactive protein (hs-CRP) was estimated using nephelometry technique. Inflammatory markers and adiponectin were measured using ELISA instrument. Results: Tumor necrosis factor a (TNF-a) (40.56%) and Leptin (45.43%) were significantly increased in the diabetic group when compared with normal study population. Adiponectin was significantly decreased in diabetic study population (11.94%). This was supported by a significant correlation between the glycemic index HbA1c and TNF-a (r = 0.376, p = 0.01), adiponectin (r = 0.381, p = 0.01) and leptin (r = 0.269, p = 0.01) in diabetic population, but the significance was lost among the normal healthy individuals. Conclusions: The most promising biomarkers of diabetes such as TNF-a, adiponectin, leptin has shown a marked difference in this diabetic population. This study proves the assessment of these biomarkers as future predictors of type 2 diabetes. ß 2015 Published by Elsevier Ltd on behalf of Diabetes India.
1. Introduction Type 2 diabetes (T2D) and its complications have developed into an important public health problem even in Western countries. In U.S. population it is estimated that 12.9% of the aged greater than 20 years had diabetes in 2005–2006 and a rapid rise in the proportion was increased to 31.6% in persons aged greater than 65 years [1]. Diabetic complications are becoming a significant global health problem and a concern for health system in the present scenario. Different diabetic complications like retinopathy, neuropathy and nephropathy have significantly higher prevalence
Abbreviations: TNF, tumor necrosis factor; ELISA, enzyme linked immunosorbant assay; BMI, body mass index; T2D, type 2 daibetes. * Corresponding author. E-mail address: edu">[email protected].?edu (S. Nayak).
in developing countries like India. It is well known that diabetes increases the risk of coronary heart disease by 2–3 folds in men and by 3–4 folds in women [2,3]. It also increases the risk of stroke by 1.5–4 folds and accounts for 35–45% of cases of end-stage renal failure [4,5]. Stratification of individuals at risk for T2D and its risk within the general population is based on typical risk factors such as smoking, age, anthropometric variables such as body mass index (BMI), waist circumference (WC), hip circumference (HC), and biochemical parameters like fasting glucose, lipid profile etc. In addition to these several parameters, novel biomarkers have been proposed to improve clinical anticipation and to gain better insight into the pathogenesis of T2D [6,7]. These have produced promising results but the inferences have been limited by modest sample sizes, testing of one biomarker at a time and the lack of independent validation. After accounting for the classical risk factors of developing vascular complication, biomarkers would also act as predictors for identifying individuals who are more
http://dx.doi.org/10.1016/j.dsx.2015.08.014 1871-4021/ß 2015 Published by Elsevier Ltd on behalf of Diabetes India.
Please cite this article in press as: Bhaktha G, et al. Assessment of biomarkers in type 2 diabetic subjects without any complications. Diab Met Syndr: Clin Res Rev (2015), http://dx.doi.org/10.1016/j.dsx.2015.08.014
G Model
DSX-495; No. of Pages 3 G. Bhaktha et al. / Diabetes & Metabolic Syndrome: Clinical Research & Reviews xxx (2015) xxx–xxx
2
prone to develop the risk strategy of vascular complication. Hence comparing the biomarker levels between the normal healthy individuals and in individuals with hyperglycemia, without any systemic inflammation would help us to understand the improvement of preventive measures for the disease at the early stages and also the level that has risen due to hyperglycemia alone. Thus, the scenario of the level of the biomarkers would help in marginally discriminating the individual at the risk of developing the vascular complications in diabetes. 2. Methods
Table 1 Diverse parameters in study groups showing mean difference and statistical significance. Parameters
Mean difference between the groups (n = 229 and n = 205)
Difference in percent
P value
WC in cms HC in cms BMI hs-CRP[mg/dl) TNF-a (pg/ml) Adiponectin (mg/l) Leptin (ng/ml)
5.40 5.30 0.57 0.28 4.64 2.17 3.78
5.97 5.71 2.12 218.13 40.56 11.94 45.43
0.0001*** 0.0001*** 0.24 0.15 0.0014** 0.0021** 0.0001***
**
This was a cross sectional study comprising 229 diabetic persons and 205 healthy individuals of Dakshina Kannada district of Karnataka state, India. The study population was aged between 30 and 70 years. Persons with a history of T2D for at least 1 year, without any micro and macro vascular complication and on oral or on diet control were selected as the study group. Criteria for inclusion were – persons should have been recognized as diabetic for at least 1 year, should be on oral hypoglycemic drugs or diet control, free from diabetic neuropathy, nephropathy and retinopathy, free from any preexisting cardio vascular disease, nonpregnant in case of females and free from usage of oral contraceptives. Relevant examination was done to establish the inclusion and exclusion criteria. These were matched with 205 health individuals and were considered as controls. Anthropometric measurements were assessed which included record of weight, height, WC and HC. WC and HC were measured in duplicate with a flexible but inelastic measuring tape while the subject was standing relaxed. The electronic scale used to measure the weight was reset before every weighing procedure. Both systolic and diastolic blood pressures were measured with a gap of 5 min.
***
" " " " " # "
p < 0.05 level of significance. p < 0.0005 level of significance.
Table 2 Correlation of various biochemical markers within the diabetic study population.
hs-CRP HBA1C TNF-a Adiponectin Leptin **
hs-CRP
HBA1C
TNF-a
Adiponectin
Leptin
1 0.074 0.027 0.118 0.070
1 0.376** 0.381** 0.269**
1 0.366** 0.256**
1 0.244**
1
p = 0.01.
Table 3 Correlation of various biochemical markers within the normal study population.
hs-CRP HBA1C TNF-a Adiponectin Leptin
hs-CRP
HBA1C
TNF-a
Adiponectin
Leptin
1 0.059 0.079 0.111 0.037
1 0.137 0.087 0.028
1 0.233** 0.145*
1 0.170*
1
*
Correlation is significant at the 0.05 level. ** Correlation is significant at the 0.01 level.
2.1. Assessment of biochemical parameters Ten milliliter of blood sample in fasting state was drawn and used for the analysis. High sensitivity reactive protein (hs-CRP) was estimated using nephelometry technique. Adiponectin, leptin and tumor necrosis factor a (TNF-a) were measured with Ray biotech kit using ELISA instrument. Ethical clearance for the study was obtained from Yenepoya University Ethics Committee, Mangalore. 2.2. Statistical analysis The results were analyzed using SPSS 10.0. Student’s unpaired ‘t’ test was used to compare between the two groups and Pearson’s correlation was used to find the correlation between the subjects. p value <0.01 was taken as the level of significance. 3. Results This study involved 229 diabetic subjects matched with 205 normal individuals. The study population was free from any preexisting micro and macro vascular disorders. Table 1 shows the mean difference between the diabetic and the normal subjects of the study population. It was seen that the anthropometric variables and inflammatory markers were increased. The adiponectin was decreased by 11.94% and this was statistically significant (p < 0.0021). Table 2 shows the correlation of various biochemical markers within the diabetic study population. It is observed that the correlation with Glycemic index (HbA1c) was statistically significant when compared with other parameters.
Table 3 also shows the correlation of biochemical markers within the normal study population. It is observed that the correlation with glycemic index (HbA1c) was not statistically significant when compared with other parameters. 4. Discussion In this study we made an attempt to understand the difference in the levels of the most promising biomarkers of diabetes with regard to their glycemic levels. Comparing with the normal subjects has helped us to identify the rise in the marker level at this stage of clinical risk. Adiponectina potentanti-diabetic hormone [8], secreted by adipocytesis seen to be inversely correlated with obesity mostly due to the action of TNF-a [9]. It increases the sensitivity to insulin, inhibits inflammation and improves glucose tolerance. However, the influences of adiponectin with cardiovascular and total mortality are controversial; the majority of studies seem to support increased, rather than decreased risk [6,10]. Human studies were able to show an inverse correlation between CRP and adiponectin mRNA levels in subcutaneous adipose tissue who had angiographically demonstrated coronary atherosclerosis [11]. The same negative correlation was even extended with plasma hs-CRP [12] and adiponectin levels. This was also true in both normal and diabetic group of our study population. This reciprocal association between adiponectin and CRP levels in both human adipose tissue and plasma is supportive of a role for adiponectin against the development of atherosclerosis and vascular inflammation. Research studies by Yamagishi et al. [13] have shown that leptin induces oxidative stress in the endothelial cells and hence
Please cite this article in press as: Bhaktha G, et al. Assessment of biomarkers in type 2 diabetic subjects without any complications. Diab Met Syndr: Clin Res Rev (2015), http://dx.doi.org/10.1016/j.dsx.2015.08.014
G Model
DSX-495; No. of Pages 3 G. Bhaktha et al. / Diabetes & Metabolic Syndrome: Clinical Research & Reviews xxx (2015) xxx–xxx
participates in the atherogenesis [14] which includes monocyte chemotactic protein formation. Hence this study states an increase in the leptin concentration in a study population of diabetics, who may be expected to cause a surge in CVD in this generation. TNF-a, a pro-inflammatory cytokine, has shown to be linked with obesity. Our study has shown a higher mean value of TNF-a in diabetic group when compared with non-diabetic group which is also true in other studies, suggesting a link between obesity [15], diabetes and atherosclerosis [16,17]. TNF-a is known to provoke insulin resistance, thus facilitating hyperglycemic state. In our study TNF-a has shown positive significant correlation with HbA1c, proving its action in inducing insulin resistance but this correlation was lost in healthy individuals. Since adiponectin is known for anti-diabetic action, it indirectly decreases the activity and hence shows a significant negative correlation with adiponectin, which is also true in our study. Our results have shown a significant positive correlation between TNF and leptin which may suggest that TNF regulates leptin production [18]. The positive correlation in both the groups may be because there was no much difference in their BMI values. TNF mediated release of leptin from adipose tissue may be part of the adipo-stat mechanism. In conclusion, after accounting for classic risk factors, our study identified some of the known markers and made an attempt to evaluate their levels in diabetic subjects who have still not developed any clinical signs of vascular complications by comparing with the normal healthy individuals. This information may help for identifying individuals who are at an elevated risk of developing the diabetes and its complications. Perhaps more importantly, it may indicate directions towards which further research on the prevention of diabetes and pathogenesis should take place. Conflict of interest None. Acknowledgments We would like to express our gratitude to Dr. G.S. Chandrashekar, Senior Physician and Cardio Diabetologist of Adarsha Hospital and Institute of Cardio Diabetes, Trauma & Joint Replacement, Udupi, Karnataka for his support in conducting this study.
3
References [1] Cowie CC, Rust KF, Ford ES, Eberhardt MS, Byrd-Holt DD. Full accounting of diabetes and pre-diabetes in the US. Population in 1988-1994 and 2005-2006. Diabetes Care 2009;32:287–94. [2] Beckman JA, Creager MA, Libby P. Diabetes and atherosclerosis: epidemiology, pathophysiology, and management. JAMA 2002;287:2570–81. [3] Huxley R, Barzi F, Woodward M. Excess risk of fatal coronary heart disease associated with diabetes in men and women: meta-analysis of 37 prospective cohort studies. BMJ 2006;332:73–8. [4] Rossing P. Diabetic nephropathy: worldwide epidemic and effects of current treatment on natural history. Curr Diab Rep 2006;6:479–83. [5] Caramori ML, Mauer M. Diabetes and nephropathy. Curr Opin Nephrol Hypertens 2003;12:273–82. [6] Sattar N, Wannamethee SG, Forouhi NG. Novel biochemical risk factors for type 2 diabetes: pathogenic insights or prediction possibilities? Diabetologia 2008;51:926–40. [7] Kolberg JA, Jorgensen T, Gerwien RW, Hamren S, McKenna MP. Development of a type 2 diabetes risk model from a panel of serum biomarkers from the inter99 cohort. Diabetes Care 2009;32:1207–12. [8] Yamauchi T, Kamon J, Minokoshi Y, Ito Y, Waki H, Uchida S, et al. Adiponectin stimulates glucose utilization and fatty-acid oxidation by activating AMPactivated protein kinase. Nat Med 2002;8:1288–95. [9] Maeda N, Takahashi M, Funahashi T, Kihara S, Nishizawa H, Kishida K, et al. PPAR gamma ligands increase expression and plasma concentrations of adiponectin, an adipose-derived protein. Diabetes 2001;50:2094–9. [10] Wannamethee SG. Adiponectin and cardiovascular risk prediction: can the ambiguities be resolved? Nutr Metab Cardiovasc Dis 2008;18:581–4. [11] Matsuda M, Shimomura I, Sata M, Arita Y, Nishida M, Maeda N, et al. Role of adiponectin in preventing vascular stenosis: the missing link of adipo-vascular axis. J Biol Chem 2002;277:37487–91. [12] Ouchi N, Kihara S, Funahashi T, Nakamura T, Nishida M, Kumada M, et al. Reciprocal association of C-reactive protein with adiponectin in blood stream and adipose tissue. Circulation 2003;107:671–4. [13] Yamagishi SI, Edelstein D, Du XL. Leptin induces mitochondrial superoxide production and monocyte chemoattractant protein-1 expression in aortic endothelial cells by increasing fatty acid oxidation via protein kinase A. J Biol Chem 2001;276:25096–111. [14] Cao R, Brakenhielm E, Wahlestedt C, Thyberg J, Cao Y. Leptin induces vascular permeability and synergistically stimulates angiogenesis with FGF-2 and VEGF. Proc Natl Acad Sci USA 2001;98:6390–5. [15] Nayak BS, Soon SQ, Kunjal R, Ramadoo R, Baptiste O, Persad J, et al. Relationship between adiponectin, inflammatory markers and obesity in type 2 diabetic and non-diabetic Trinidadians. Arch Physiol Biochem 2009;115:28–30. [16] Scherer PE. Adipose tissue: from lipid storage compartment to endocrine organ. Diabetes 2006;55:1537–45. [17] Hotamisligil GS, Arner P, Caro JF, Atkinson RL, Spiegelman BM. Increased adipose tissue expression of tumor necrosis factor-alpha in human obesity and insulin resistance. J Clin Invest 1995;95:2409–15. [18] Mantzoros CS, Moschos S, Avramopoulos I, Kaklamani V, Liolios A, Doulgerakis DE, et al. Leptin concentrations in relation to body mass index and the tumor necrosis factor-alpha system in humans. J Clin Endocrinol Metab 1997;82: 3408–13.
Please cite this article in press as: Bhaktha G, et al. Assessment of biomarkers in type 2 diabetic subjects without any complications. Diab Met Syndr: Clin Res Rev (2015), http://dx.doi.org/10.1016/j.dsx.2015.08.014
DSX-495; No. of Pages 3 Diabetes & Metabolic Syndrome: Clinical Research & Reviews xxx (2015) xxx–xxx
Contents lists available at ScienceDirect
Diabetes & Metabolic Syndrome: Clinical Research & Reviews journal homepage: www.elsevier.com/locate/dsx
Original article
Assessment of biomarkers in type 2 diabetic subjects without any complications Geetha Bhaktha a, Shivananda Nayak b,*, Manjula Shantaram c,d a
Department of Biochemistry, Shimoga Institute of Medical Sciences, Karnataka, India Department of Preclinical Sciences, Faculty of Medical Sciences, The University of the West Indies, Trinidad, Trinidad and Tobago c Department of Biochemistry, PG Centre, ChikkaAluvara, Somwarpet Taluk, Kodagu District, 571232, Karnataka, India d Department of Biochemistry, Yenepoya Medical College, Yenepoya University, Mangalore, Karnataka, 575 018, India b
A R T I C L E I N F O
S U M M A R Y
Keywords: Adiponectin Leptin TNF-a hs-CRP Type 2 diabetes
Background: Type 2-diabetes (T2D), is a public health problem which has reached epidemic proportions due to the rapidly increasing rates of this disease worldwide. It is known that adipose tissue can synthesize and release pro-inflammatory cytokines, tumor necrosis factor-alpha, interleukin-1, adiponectin and leptin that are associated with body fat mass. Hence comparing the biomarkers with individuals without hyperglycemia would help us to understand the level of increase in their values though the vascular complications have not begun. Materials and methods: This was a cross sectional study comprising 229 diabetic persons and 205 healthy individuals. High sensitivity reactive protein (hs-CRP) was estimated using nephelometry technique. Inflammatory markers and adiponectin were measured using ELISA instrument. Results: Tumor necrosis factor a (TNF-a) (40.56%) and Leptin (45.43%) were significantly increased in the diabetic group when compared with normal study population. Adiponectin was significantly decreased in diabetic study population (11.94%). This was supported by a significant correlation between the glycemic index HbA1c and TNF-a (r = 0.376, p = 0.01), adiponectin (r = 0.381, p = 0.01) and leptin (r = 0.269, p = 0.01) in diabetic population, but the significance was lost among the normal healthy individuals. Conclusions: The most promising biomarkers of diabetes such as TNF-a, adiponectin, leptin has shown a marked difference in this diabetic population. This study proves the assessment of these biomarkers as future predictors of type 2 diabetes. ß 2015 Published by Elsevier Ltd on behalf of Diabetes India.
1. Introduction Type 2 diabetes (T2D) and its complications have developed into an important public health problem even in Western countries. In U.S. population it is estimated that 12.9% of the aged greater than 20 years had diabetes in 2005–2006 and a rapid rise in the proportion was increased to 31.6% in persons aged greater than 65 years [1]. Diabetic complications are becoming a significant global health problem and a concern for health system in the present scenario. Different diabetic complications like retinopathy, neuropathy and nephropathy have significantly higher prevalence
Abbreviations: TNF, tumor necrosis factor; ELISA, enzyme linked immunosorbant assay; BMI, body mass index; T2D, type 2 daibetes. * Corresponding author. E-mail address: edu">[email protected].?edu (S. Nayak).
in developing countries like India. It is well known that diabetes increases the risk of coronary heart disease by 2–3 folds in men and by 3–4 folds in women [2,3]. It also increases the risk of stroke by 1.5–4 folds and accounts for 35–45% of cases of end-stage renal failure [4,5]. Stratification of individuals at risk for T2D and its risk within the general population is based on typical risk factors such as smoking, age, anthropometric variables such as body mass index (BMI), waist circumference (WC), hip circumference (HC), and biochemical parameters like fasting glucose, lipid profile etc. In addition to these several parameters, novel biomarkers have been proposed to improve clinical anticipation and to gain better insight into the pathogenesis of T2D [6,7]. These have produced promising results but the inferences have been limited by modest sample sizes, testing of one biomarker at a time and the lack of independent validation. After accounting for the classical risk factors of developing vascular complication, biomarkers would also act as predictors for identifying individuals who are more
http://dx.doi.org/10.1016/j.dsx.2015.08.014 1871-4021/ß 2015 Published by Elsevier Ltd on behalf of Diabetes India.
Please cite this article in press as: Bhaktha G, et al. Assessment of biomarkers in type 2 diabetic subjects without any complications. Diab Met Syndr: Clin Res Rev (2015), http://dx.doi.org/10.1016/j.dsx.2015.08.014
G Model
DSX-495; No. of Pages 3 G. Bhaktha et al. / Diabetes & Metabolic Syndrome: Clinical Research & Reviews xxx (2015) xxx–xxx
2
prone to develop the risk strategy of vascular complication. Hence comparing the biomarker levels between the normal healthy individuals and in individuals with hyperglycemia, without any systemic inflammation would help us to understand the improvement of preventive measures for the disease at the early stages and also the level that has risen due to hyperglycemia alone. Thus, the scenario of the level of the biomarkers would help in marginally discriminating the individual at the risk of developing the vascular complications in diabetes. 2. Methods
Table 1 Diverse parameters in study groups showing mean difference and statistical significance. Parameters
Mean difference between the groups (n = 229 and n = 205)
Difference in percent
P value
WC in cms HC in cms BMI hs-CRP[mg/dl) TNF-a (pg/ml) Adiponectin (mg/l) Leptin (ng/ml)
5.40 5.30 0.57 0.28 4.64 2.17 3.78
5.97 5.71 2.12 218.13 40.56 11.94 45.43
0.0001*** 0.0001*** 0.24 0.15 0.0014** 0.0021** 0.0001***
**
This was a cross sectional study comprising 229 diabetic persons and 205 healthy individuals of Dakshina Kannada district of Karnataka state, India. The study population was aged between 30 and 70 years. Persons with a history of T2D for at least 1 year, without any micro and macro vascular complication and on oral or on diet control were selected as the study group. Criteria for inclusion were – persons should have been recognized as diabetic for at least 1 year, should be on oral hypoglycemic drugs or diet control, free from diabetic neuropathy, nephropathy and retinopathy, free from any preexisting cardio vascular disease, nonpregnant in case of females and free from usage of oral contraceptives. Relevant examination was done to establish the inclusion and exclusion criteria. These were matched with 205 health individuals and were considered as controls. Anthropometric measurements were assessed which included record of weight, height, WC and HC. WC and HC were measured in duplicate with a flexible but inelastic measuring tape while the subject was standing relaxed. The electronic scale used to measure the weight was reset before every weighing procedure. Both systolic and diastolic blood pressures were measured with a gap of 5 min.
***
" " " " " # "
p < 0.05 level of significance. p < 0.0005 level of significance.
Table 2 Correlation of various biochemical markers within the diabetic study population.
hs-CRP HBA1C TNF-a Adiponectin Leptin **
hs-CRP
HBA1C
TNF-a
Adiponectin
Leptin
1 0.074 0.027 0.118 0.070
1 0.376** 0.381** 0.269**
1 0.366** 0.256**
1 0.244**
1
p = 0.01.
Table 3 Correlation of various biochemical markers within the normal study population.
hs-CRP HBA1C TNF-a Adiponectin Leptin
hs-CRP
HBA1C
TNF-a
Adiponectin
Leptin
1 0.059 0.079 0.111 0.037
1 0.137 0.087 0.028
1 0.233** 0.145*
1 0.170*
1
*
Correlation is significant at the 0.05 level. ** Correlation is significant at the 0.01 level.
2.1. Assessment of biochemical parameters Ten milliliter of blood sample in fasting state was drawn and used for the analysis. High sensitivity reactive protein (hs-CRP) was estimated using nephelometry technique. Adiponectin, leptin and tumor necrosis factor a (TNF-a) were measured with Ray biotech kit using ELISA instrument. Ethical clearance for the study was obtained from Yenepoya University Ethics Committee, Mangalore. 2.2. Statistical analysis The results were analyzed using SPSS 10.0. Student’s unpaired ‘t’ test was used to compare between the two groups and Pearson’s correlation was used to find the correlation between the subjects. p value <0.01 was taken as the level of significance. 3. Results This study involved 229 diabetic subjects matched with 205 normal individuals. The study population was free from any preexisting micro and macro vascular disorders. Table 1 shows the mean difference between the diabetic and the normal subjects of the study population. It was seen that the anthropometric variables and inflammatory markers were increased. The adiponectin was decreased by 11.94% and this was statistically significant (p < 0.0021). Table 2 shows the correlation of various biochemical markers within the diabetic study population. It is observed that the correlation with Glycemic index (HbA1c) was statistically significant when compared with other parameters.
Table 3 also shows the correlation of biochemical markers within the normal study population. It is observed that the correlation with glycemic index (HbA1c) was not statistically significant when compared with other parameters. 4. Discussion In this study we made an attempt to understand the difference in the levels of the most promising biomarkers of diabetes with regard to their glycemic levels. Comparing with the normal subjects has helped us to identify the rise in the marker level at this stage of clinical risk. Adiponectina potentanti-diabetic hormone [8], secreted by adipocytesis seen to be inversely correlated with obesity mostly due to the action of TNF-a [9]. It increases the sensitivity to insulin, inhibits inflammation and improves glucose tolerance. However, the influences of adiponectin with cardiovascular and total mortality are controversial; the majority of studies seem to support increased, rather than decreased risk [6,10]. Human studies were able to show an inverse correlation between CRP and adiponectin mRNA levels in subcutaneous adipose tissue who had angiographically demonstrated coronary atherosclerosis [11]. The same negative correlation was even extended with plasma hs-CRP [12] and adiponectin levels. This was also true in both normal and diabetic group of our study population. This reciprocal association between adiponectin and CRP levels in both human adipose tissue and plasma is supportive of a role for adiponectin against the development of atherosclerosis and vascular inflammation. Research studies by Yamagishi et al. [13] have shown that leptin induces oxidative stress in the endothelial cells and hence
Please cite this article in press as: Bhaktha G, et al. Assessment of biomarkers in type 2 diabetic subjects without any complications. Diab Met Syndr: Clin Res Rev (2015), http://dx.doi.org/10.1016/j.dsx.2015.08.014
G Model
DSX-495; No. of Pages 3 G. Bhaktha et al. / Diabetes & Metabolic Syndrome: Clinical Research & Reviews xxx (2015) xxx–xxx
participates in the atherogenesis [14] which includes monocyte chemotactic protein formation. Hence this study states an increase in the leptin concentration in a study population of diabetics, who may be expected to cause a surge in CVD in this generation. TNF-a, a pro-inflammatory cytokine, has shown to be linked with obesity. Our study has shown a higher mean value of TNF-a in diabetic group when compared with non-diabetic group which is also true in other studies, suggesting a link between obesity [15], diabetes and atherosclerosis [16,17]. TNF-a is known to provoke insulin resistance, thus facilitating hyperglycemic state. In our study TNF-a has shown positive significant correlation with HbA1c, proving its action in inducing insulin resistance but this correlation was lost in healthy individuals. Since adiponectin is known for anti-diabetic action, it indirectly decreases the activity and hence shows a significant negative correlation with adiponectin, which is also true in our study. Our results have shown a significant positive correlation between TNF and leptin which may suggest that TNF regulates leptin production [18]. The positive correlation in both the groups may be because there was no much difference in their BMI values. TNF mediated release of leptin from adipose tissue may be part of the adipo-stat mechanism. In conclusion, after accounting for classic risk factors, our study identified some of the known markers and made an attempt to evaluate their levels in diabetic subjects who have still not developed any clinical signs of vascular complications by comparing with the normal healthy individuals. This information may help for identifying individuals who are at an elevated risk of developing the diabetes and its complications. Perhaps more importantly, it may indicate directions towards which further research on the prevention of diabetes and pathogenesis should take place. Conflict of interest None. Acknowledgments We would like to express our gratitude to Dr. G.S. Chandrashekar, Senior Physician and Cardio Diabetologist of Adarsha Hospital and Institute of Cardio Diabetes, Trauma & Joint Replacement, Udupi, Karnataka for his support in conducting this study.
3
References [1] Cowie CC, Rust KF, Ford ES, Eberhardt MS, Byrd-Holt DD. Full accounting of diabetes and pre-diabetes in the US. Population in 1988-1994 and 2005-2006. Diabetes Care 2009;32:287–94. [2] Beckman JA, Creager MA, Libby P. Diabetes and atherosclerosis: epidemiology, pathophysiology, and management. JAMA 2002;287:2570–81. [3] Huxley R, Barzi F, Woodward M. Excess risk of fatal coronary heart disease associated with diabetes in men and women: meta-analysis of 37 prospective cohort studies. BMJ 2006;332:73–8. [4] Rossing P. Diabetic nephropathy: worldwide epidemic and effects of current treatment on natural history. Curr Diab Rep 2006;6:479–83. [5] Caramori ML, Mauer M. Diabetes and nephropathy. Curr Opin Nephrol Hypertens 2003;12:273–82. [6] Sattar N, Wannamethee SG, Forouhi NG. Novel biochemical risk factors for type 2 diabetes: pathogenic insights or prediction possibilities? Diabetologia 2008;51:926–40. [7] Kolberg JA, Jorgensen T, Gerwien RW, Hamren S, McKenna MP. Development of a type 2 diabetes risk model from a panel of serum biomarkers from the inter99 cohort. Diabetes Care 2009;32:1207–12. [8] Yamauchi T, Kamon J, Minokoshi Y, Ito Y, Waki H, Uchida S, et al. Adiponectin stimulates glucose utilization and fatty-acid oxidation by activating AMPactivated protein kinase. Nat Med 2002;8:1288–95. [9] Maeda N, Takahashi M, Funahashi T, Kihara S, Nishizawa H, Kishida K, et al. PPAR gamma ligands increase expression and plasma concentrations of adiponectin, an adipose-derived protein. Diabetes 2001;50:2094–9. [10] Wannamethee SG. Adiponectin and cardiovascular risk prediction: can the ambiguities be resolved? Nutr Metab Cardiovasc Dis 2008;18:581–4. [11] Matsuda M, Shimomura I, Sata M, Arita Y, Nishida M, Maeda N, et al. Role of adiponectin in preventing vascular stenosis: the missing link of adipo-vascular axis. J Biol Chem 2002;277:37487–91. [12] Ouchi N, Kihara S, Funahashi T, Nakamura T, Nishida M, Kumada M, et al. Reciprocal association of C-reactive protein with adiponectin in blood stream and adipose tissue. Circulation 2003;107:671–4. [13] Yamagishi SI, Edelstein D, Du XL. Leptin induces mitochondrial superoxide production and monocyte chemoattractant protein-1 expression in aortic endothelial cells by increasing fatty acid oxidation via protein kinase A. J Biol Chem 2001;276:25096–111. [14] Cao R, Brakenhielm E, Wahlestedt C, Thyberg J, Cao Y. Leptin induces vascular permeability and synergistically stimulates angiogenesis with FGF-2 and VEGF. Proc Natl Acad Sci USA 2001;98:6390–5. [15] Nayak BS, Soon SQ, Kunjal R, Ramadoo R, Baptiste O, Persad J, et al. Relationship between adiponectin, inflammatory markers and obesity in type 2 diabetic and non-diabetic Trinidadians. Arch Physiol Biochem 2009;115:28–30. [16] Scherer PE. Adipose tissue: from lipid storage compartment to endocrine organ. Diabetes 2006;55:1537–45. [17] Hotamisligil GS, Arner P, Caro JF, Atkinson RL, Spiegelman BM. Increased adipose tissue expression of tumor necrosis factor-alpha in human obesity and insulin resistance. J Clin Invest 1995;95:2409–15. [18] Mantzoros CS, Moschos S, Avramopoulos I, Kaklamani V, Liolios A, Doulgerakis DE, et al. Leptin concentrations in relation to body mass index and the tumor necrosis factor-alpha system in humans. J Clin Endocrinol Metab 1997;82: 3408–13.
Please cite this article in press as: Bhaktha G, et al. Assessment of biomarkers in type 2 diabetic subjects without any complications. Diab Met Syndr: Clin Res Rev (2015), http://dx.doi.org/10.1016/j.dsx.2015.08.014