Prevalence of known diabetes in Chennai City.

AIM: To determine prevalence of known diabetes in those more than 20 years of age in Chennai city. METHODOLOGY: Urban population was selected for the survey. Assuming the prevalence of known diabetes as 5.0% in those aged > 20 years, the cluster sample size calculated to estimate it with 95% CI and +/- 10% precision, was 25800 individuals of all ages. This population obtained from 200 households in each of 30 randomly selected corporation divisions of the city, was surveyed by social workers by house to house enquiry. General information and health status of every member of the household were recorded on prescribed forms. This survey was conducted during January-July, 1998. RESULTS: Among 26,066 individuals of all ages 779 had known diabetes and 99.4% of them had type 2 diabetes. The prevalence of known diabetes was 2.9% for all ages and both sexes combined. Crude and age-standardized prevalence was 4.9% (95% CI 4.6-5.2) for those aged > 20 years. The standardized prevalence was 10.5% (95% CI 9.8 - 11.2) in those aged > or = 40 years. The prevalence was significantly high (P < 0.05) in females. CONCLUSION: The prevalence of known diabetes was low in total population but increased in those aged > 20 and further increased in those aged > or = 40 years. The causes for high prevalence in > or = 40 year age group needs to be explored in this population.

Prevalence and incidence of type-2 diabetes and impaired glucose tolerance in a selected Indian urban population.

AIM: To study the impact of diabetes mellitus on a selected Indian urban population. METHODS: The staff of Indian Institute of Technology in Chennai and their relatives were screened for diabetes by oral glucose tolerance test (OGTT) in 1992. But those on treatment for diabetes were not screened by OGTT. All those found to have diabetes during initial screening were excluded from further follow-up. Those without diabetes were followed with repeat OGTT one year later in 1993. RESULTS: A total of 1198 persons, 455 (38.0%) females and 743 (62.0%) males, participated in this study. While 116 (9.7%), 80 (69.0%) males and 36 (31.0%) females, suffering from diabetes were exempted from OGTT, the remaining 1082 (90.3%), 663 (61.3%) males and 419 (38.7%) females, were screened by OGTT. Among the 663 males, 450 (67.9%) were normal, 155 (23.4%) had impaired glucose tolerance (IGT) and 58 (8.7%) had diabetes. Among the 419 females, 275 (65.6%) were normal, 120 (28.6%) had IGT and 24 (5.7%) had diabetes. Out of 1000 persons without diabetes, 696 (69.6%), 444 (63.8%) with normal glucose tolerance and 252 (36.2%) with IGT had participated in the repeat screening by OGTT after one year. One (0.7%) normal person and 14 (5.5%) with IGT, progressed to diabetes in one year. All had type-2 diabetes and non type-1 diabetes. Of 444 normal persons 34 (7.7%) developed IGT during one year. CONCLUSIONS: The prevalence of 9.7% and 7.7% for known and newly detected type-2 diabetes respectively and the annual incidence of 2.2% indicate the magnitude of impact of diabetes mellitus on this population. Though IGT was found to be a risk factor, factors leading to its progression to diabetic state could not be identified in this study.

Prevalence of diabetes in the young in south India.

Students from nine schools and one college in Madras city, were screened for diabetes by oral glucose tolerance test. The criteria recommended by the World Health Organization was adopted to classify glucose tolerance. Among 3,515 students, between 5 and 19 years of age, participated in this survey, 1982 (56.4%) were males and 1.533 were (43.6%) females. Family history of diabetes was positive in 302 (8.6%) students. There was no overt case of diabetes of any type. Three (0.09%) males had renal glycosuria. It is therefore concluded that insulin-dependent diabetes, non-insulin dependent diabetes or any other type of diabetes in the young is rare in South India.