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Hyposalivation is Associated with High BMI Among Young Adults and is Associated with Medication in Older Adults in Sweden
ETIOLOGY/OTHER
ARTICLE ANALYSIS & EVALUATION ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION Prevalence of hyposalivation in relation to general health, body mass index and remaining teeth in different age groups of adults. Flink H, Bergdahl M, Tegelber A, Rosenblad A, Lagerlo¨f F. Community Dent Oral Epidemiol 2008;36(6):523-31.
REVIEWER Toshiyuki Saito, DDS, PhD
PURPOSE/QUESTION Do very low and low unstimulated (UWSFR) and stimulated (SWSFR) whole salivary flow rates vary in different sex and age groups between adults aged 20 and 69 years; and what is the relationship between hyposalivation and self-perceived dryness, and other factors such as prescribed medicine use, tooth loss, BMI, and tobacco use?
SOURCE OF FUNDING Government, university, and nonprofit foundations.
TYPE OF STUDY/DESIGN Cross-sectional study
LEVEL OF EVIDENCE Level 3: Other evidence
STRENGTH OF RECOMMENDATION GRADE Not applicable
Hyposalivation is Associated with High BMI Among Young Adults and is Associated with Medication in Older Adults in Sweden SUMMARY Subjects A total of 1000 men and 1000 women, aged 20 to 69 years, were randomly selected from a population of 48,500 patients attending 14 dental clinics in 2 counties in northern Sweden. The selection was stratified into 10 groups, each spanning 5 years and containing 100 men and 100 women. In the subsequent statistical analyses these groups were merged into 5 age groups (with 10-year intervals). Of the invited individuals, 1427 (70%) volunteered to participate in the study.
Key Risk/Study Factor Systemic condition including, age, gender, diagnosed diseases, BMI greater than 25, medication, and low number of teeth.
Main Outcome Measure Low unstimulated (UWSFR) and stimulated (SWSFR) whole salivary flow rates.
Main Results The prevalence of very low (<0.1 mL min) and low (0.10–0.19 mL min) UWSFR was similar for different age groups up to 50 years, ranging between 10.9% and 17.8% and between 17.3% and 22.7%, respectively. The prevalence of very low UWSFR was significantly higher for women aged 50 to 69 years than for younger women. For men, prevalence of very low UWSFR was higher at 60 to 69 years. The prevalence of very low (<0.7 mL min) and low (0.70–0.99 mL min) SWSFR was between 0.0% and 5.5% and between 0.8% and 8.2%, respectively, for the different age groups 20 to 69 years. Multiple logistic regression revealed that age older than 50 years, female gender, having fewer than 20 teeth, and taking xerogenic drugs significantly increased the risk of very low UWSFR. For very low SWSFR, only having fewer than 20 teeth and taking more than 2 drugs were significant. In the younger individuals (<50 years) only BMI greater than 25 for very low UWSFR and diagnosed disease for very low SWSFR were found significant. In this younger subset, female gender combined with having fewer than 27 teeth was significant for low UWSFR.
Conclusions Hyposalivation is prevalent in younger adults, among whom it is associated with diagnosed disease and high BMI, whereas after age 50 years it is associated with prescribed medication. It is also associated with gender and with fewer remaining teeth.
J Evid Base Dent Pract 2009;9:242-243
COMMENTARY AND ANALYSIS
1532-3382/$34.00 Ó 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.jebdp.2009.05.011
For many years we have believed that salivary flow rate decreases with age and medicine use. Given the findings from this study, we may need to
JOURNAL OF EVIDENCE-BASED DENTAL PRACTICE
TABLE 3. Prevalence of very low (<0.1 mL/min) and low (0.10-0.19 mL/min) unstimulated whole salivary flow rates, very low (<0.7 mL/min) and low (0.70-0.99 mL/min) stimulated whole salivary flow rates and xerostomia in different age groups according to sex Unstimulated whole saliva
Sex
Age
N
<0.1 mL/min, n (%)
Males
20-29 30-39 40-49 50-59 60-69 All 20-29 30-39 40-49 50-59 60-69 All
90 120 137 153 163 663 110 157 161 157 172 757 1420
13 (14.4) 14 (11.7)†† 15 (10.9)†† 18 (11.8)†† 39 (23.9) 99 (14.9) 12 (10.9)††† 28 (17.8)†† 21 (13.0)††† 44 (28.0)*** 58 (33.7)** 163 (21.5)*** 262 (18.5)
Females
Total
0.10-0.19 mL/min, n (%) 16 (17.8) 22 (18.3) 24 (17.5) 32 (20.9) 35 (21.5) 129 (19.5) 25 (22.7) 30 (19.1) 36 (22.4) 43 (27.4)* 48 (27.9)* 182 (24.0)** 311 (21.9)
Stimulated whole saliva
Xerostomia
N
<0.7 mL/min, n (%)
0.70-0.99 mL/min, n (%)
N
n (%)
88 119 135 154 162 658 109 154 160 156 169 748 1406
0 (0)† 2 (1.7) 4 (3.0) 0 (0)†† 9 (5.6) 15 (2.3) 1 (0.9) 7 (4.5) 3 (1.9) 4 (2.6)* 9 (5.3) 24 (3.2) 39 (2.8)
2 (2.3) 1 (0.8) 4 (3.0) 4 (2.6) 7 (4.3) 18 (2.7) 4 (3.7) 9 (5.8)* 12 (7.5) 13 (8.3)* 12 (7.1) 50 (6.7)*** 68 (4.8)
90 120 139 155 165 669 108 157 161 157 172 755 1424
11 (12.2)† 10 (8.3)††† 16 (11.5)†† 22 (14.2)† 42 (25.5) 101 (15.1) 15 (13.9)††† 40 (25.5)***†† 42 (26.1)***† 52 (33.1)*** 67 (39.0)** 216 (28.6)*** 317 (22.3)
*P < 0.05. **P < 0.01. ***P < 0.001 difference between sexes. †P < 0.05. ††P < 0.01. †††P < 0.001 compared with ages 60-69 years.
reconsider some of our current understanding of hyposalivation. An important finding from this study is that the prevalence of low and very low salivary flow rates did not differ much between age groups as many of us would have expected (Table 3). However, lower participation rates (approximately 50%) among younger adults may have biased the results. As expected, diagnosed disease, prescribed medications, and a decreased number of teeth, which may be caused by dental caries, did have an association with low salivary flow rate. Although age and gender differences existed, there were high percentages of young adults secreting very low amounts of unstimulated whole saliva. In subjects younger than 50 years, BMI greater than 25 was significantly associated with very low flow rates. Because obesity is the most significant risk factor for type 2 diabetes, and dry mouth is a prevalent symptom of diabetes, obesity and diabetes may be related to reduced secretion of saliva. A recent cohort study indicated that dry tongue in hospitalized elderly patients leads to pyrexia, suggesting a development of pneumonia.1 An appropriately moist oral cavity may be important in preventing the inhalation of oral pathogens into the lungs. Because saliva is very important not only for oral health but also for general health, additional research in hyposalivation is needed, Volume 9, Number 4
including prospective studies. The current study would have benefited from assessing the relationship between low salivary flow and dental diseases, such as periodontitis and dental caries, not just tooth loss. If young adults continue to experience low salivary flow rates as they age, this may impact dental treatment considerations. Although findings from the present study do not support changing treatment considerations for individuals with low salivary flow, dentists could consider measuring salivary flow rates in younger adults when they experience extensive oral disease that cannot be explained by known risk factors.
REFERENCE 1. Saito T, Oobayashi K, Shimazaki Y, Yamashita Y, Iwasa Y, Nabeshima F, et al. Association of dry tongue to pyrexia in long-term hospitalized patients. Gerontology 2008;54(2):87-91.
REVIEWER Professor Toshiyuki Saito, DDS, PhD Department of Oral Health, Unit of Social Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan. Phone: þ81.95.819.7662 [email protected] 243
ARTICLE ANALYSIS & EVALUATION ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION Prevalence of hyposalivation in relation to general health, body mass index and remaining teeth in different age groups of adults. Flink H, Bergdahl M, Tegelber A, Rosenblad A, Lagerlo¨f F. Community Dent Oral Epidemiol 2008;36(6):523-31.
REVIEWER Toshiyuki Saito, DDS, PhD
PURPOSE/QUESTION Do very low and low unstimulated (UWSFR) and stimulated (SWSFR) whole salivary flow rates vary in different sex and age groups between adults aged 20 and 69 years; and what is the relationship between hyposalivation and self-perceived dryness, and other factors such as prescribed medicine use, tooth loss, BMI, and tobacco use?
SOURCE OF FUNDING Government, university, and nonprofit foundations.
TYPE OF STUDY/DESIGN Cross-sectional study
LEVEL OF EVIDENCE Level 3: Other evidence
STRENGTH OF RECOMMENDATION GRADE Not applicable
Hyposalivation is Associated with High BMI Among Young Adults and is Associated with Medication in Older Adults in Sweden SUMMARY Subjects A total of 1000 men and 1000 women, aged 20 to 69 years, were randomly selected from a population of 48,500 patients attending 14 dental clinics in 2 counties in northern Sweden. The selection was stratified into 10 groups, each spanning 5 years and containing 100 men and 100 women. In the subsequent statistical analyses these groups were merged into 5 age groups (with 10-year intervals). Of the invited individuals, 1427 (70%) volunteered to participate in the study.
Key Risk/Study Factor Systemic condition including, age, gender, diagnosed diseases, BMI greater than 25, medication, and low number of teeth.
Main Outcome Measure Low unstimulated (UWSFR) and stimulated (SWSFR) whole salivary flow rates.
Main Results The prevalence of very low (<0.1 mL min) and low (0.10–0.19 mL min) UWSFR was similar for different age groups up to 50 years, ranging between 10.9% and 17.8% and between 17.3% and 22.7%, respectively. The prevalence of very low UWSFR was significantly higher for women aged 50 to 69 years than for younger women. For men, prevalence of very low UWSFR was higher at 60 to 69 years. The prevalence of very low (<0.7 mL min) and low (0.70–0.99 mL min) SWSFR was between 0.0% and 5.5% and between 0.8% and 8.2%, respectively, for the different age groups 20 to 69 years. Multiple logistic regression revealed that age older than 50 years, female gender, having fewer than 20 teeth, and taking xerogenic drugs significantly increased the risk of very low UWSFR. For very low SWSFR, only having fewer than 20 teeth and taking more than 2 drugs were significant. In the younger individuals (<50 years) only BMI greater than 25 for very low UWSFR and diagnosed disease for very low SWSFR were found significant. In this younger subset, female gender combined with having fewer than 27 teeth was significant for low UWSFR.
Conclusions Hyposalivation is prevalent in younger adults, among whom it is associated with diagnosed disease and high BMI, whereas after age 50 years it is associated with prescribed medication. It is also associated with gender and with fewer remaining teeth.
J Evid Base Dent Pract 2009;9:242-243
COMMENTARY AND ANALYSIS
1532-3382/$34.00 Ó 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.jebdp.2009.05.011
For many years we have believed that salivary flow rate decreases with age and medicine use. Given the findings from this study, we may need to
JOURNAL OF EVIDENCE-BASED DENTAL PRACTICE
TABLE 3. Prevalence of very low (<0.1 mL/min) and low (0.10-0.19 mL/min) unstimulated whole salivary flow rates, very low (<0.7 mL/min) and low (0.70-0.99 mL/min) stimulated whole salivary flow rates and xerostomia in different age groups according to sex Unstimulated whole saliva
Sex
Age
N
<0.1 mL/min, n (%)
Males
20-29 30-39 40-49 50-59 60-69 All 20-29 30-39 40-49 50-59 60-69 All
90 120 137 153 163 663 110 157 161 157 172 757 1420
13 (14.4) 14 (11.7)†† 15 (10.9)†† 18 (11.8)†† 39 (23.9) 99 (14.9) 12 (10.9)††† 28 (17.8)†† 21 (13.0)††† 44 (28.0)*** 58 (33.7)** 163 (21.5)*** 262 (18.5)
Females
Total
0.10-0.19 mL/min, n (%) 16 (17.8) 22 (18.3) 24 (17.5) 32 (20.9) 35 (21.5) 129 (19.5) 25 (22.7) 30 (19.1) 36 (22.4) 43 (27.4)* 48 (27.9)* 182 (24.0)** 311 (21.9)
Stimulated whole saliva
Xerostomia
N
<0.7 mL/min, n (%)
0.70-0.99 mL/min, n (%)
N
n (%)
88 119 135 154 162 658 109 154 160 156 169 748 1406
0 (0)† 2 (1.7) 4 (3.0) 0 (0)†† 9 (5.6) 15 (2.3) 1 (0.9) 7 (4.5) 3 (1.9) 4 (2.6)* 9 (5.3) 24 (3.2) 39 (2.8)
2 (2.3) 1 (0.8) 4 (3.0) 4 (2.6) 7 (4.3) 18 (2.7) 4 (3.7) 9 (5.8)* 12 (7.5) 13 (8.3)* 12 (7.1) 50 (6.7)*** 68 (4.8)
90 120 139 155 165 669 108 157 161 157 172 755 1424
11 (12.2)† 10 (8.3)††† 16 (11.5)†† 22 (14.2)† 42 (25.5) 101 (15.1) 15 (13.9)††† 40 (25.5)***†† 42 (26.1)***† 52 (33.1)*** 67 (39.0)** 216 (28.6)*** 317 (22.3)
*P < 0.05. **P < 0.01. ***P < 0.001 difference between sexes. †P < 0.05. ††P < 0.01. †††P < 0.001 compared with ages 60-69 years.
reconsider some of our current understanding of hyposalivation. An important finding from this study is that the prevalence of low and very low salivary flow rates did not differ much between age groups as many of us would have expected (Table 3). However, lower participation rates (approximately 50%) among younger adults may have biased the results. As expected, diagnosed disease, prescribed medications, and a decreased number of teeth, which may be caused by dental caries, did have an association with low salivary flow rate. Although age and gender differences existed, there were high percentages of young adults secreting very low amounts of unstimulated whole saliva. In subjects younger than 50 years, BMI greater than 25 was significantly associated with very low flow rates. Because obesity is the most significant risk factor for type 2 diabetes, and dry mouth is a prevalent symptom of diabetes, obesity and diabetes may be related to reduced secretion of saliva. A recent cohort study indicated that dry tongue in hospitalized elderly patients leads to pyrexia, suggesting a development of pneumonia.1 An appropriately moist oral cavity may be important in preventing the inhalation of oral pathogens into the lungs. Because saliva is very important not only for oral health but also for general health, additional research in hyposalivation is needed, Volume 9, Number 4
including prospective studies. The current study would have benefited from assessing the relationship between low salivary flow and dental diseases, such as periodontitis and dental caries, not just tooth loss. If young adults continue to experience low salivary flow rates as they age, this may impact dental treatment considerations. Although findings from the present study do not support changing treatment considerations for individuals with low salivary flow, dentists could consider measuring salivary flow rates in younger adults when they experience extensive oral disease that cannot be explained by known risk factors.
REFERENCE 1. Saito T, Oobayashi K, Shimazaki Y, Yamashita Y, Iwasa Y, Nabeshima F, et al. Association of dry tongue to pyrexia in long-term hospitalized patients. Gerontology 2008;54(2):87-91.
REVIEWER Professor Toshiyuki Saito, DDS, PhD Department of Oral Health, Unit of Social Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan. Phone: þ81.95.819.7662 [email protected] 243