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.

HLA, ESD, GLOI, C3 and HP polymorphisms and juvenile insulin dependent diabetes mellitus in Tamil Nadu (south India).

Fifty juvenile insulin dependent diabetes mellitus (JIDDM) patients of Tamil Nadu (South India) were typed for HLA-A, -B, -C, -DR, and -DQ, ESD, GLOI, C3 and HP polymorphisms. The frequencies of B8, DR3, DR4, DR53 and DQ2 antigens of the HLA system were significantly higher in the patients than in controls (relative risk, RR = 4.81; 5.14; 3.98; 3.36 and 2.53, respectively). However HLA-DR2, -DR5 and -DQ1, observed less frequently in the patient group, appear to play a role of protection against the disease (RR = 0.32; 0.30 and 0.20 respectively). HLA haplotype analysis demonstrated very high relative risk associated with two hitherto unreported haplotypes namely A3,DR1 and Cw3,DR4 (RR = 27.30 and 20.00, respectively) and also scanty distribution of the haplotypes A1,B17 and DR2,DQ1 (RR = 0.39 and 0.36, respectively) in the patient group. Among other genetic markers tested, GLOI is informative with its phenotype GLOI 2-1 showing positive association with JIDDM (RR = 4.06).

Glycosuria and diabetes mellitus in children and adolescents in south India.

In Madras city (India) 10,513 school students between 3 and 20 yr of age were investigated for glycosuria and its causes. While no previously known cases of diabetes mellitus of any type were encountered, four students (0.038%) in the survey population were found to have glycosuria. One (0.009%) had renal glycosuria, two (0.019%) were possibly NIDDY (MODY) and one (0.009%) had transient glycosuria while receiving anti-tuberculous chemotherapy. It is therefore concluded that neither diabetes mellitus nor glycosuria of non-diabetic causes is a crucial health problem in Indian children and adolescents. While the reasons for this are not known, further research in this field could be of global interest.

The significance of certain epidemiological variants in the genesis of juvenile insulin-dependent diabetes mellitus--the need for a global program of co-operation.

Published data from literature show a two-to four-fold increase in the incidence of JIDDM, in the Western hemisphere over the past decade (5% to 10-20%). WHO Expert Committee Technical Report Series No. 646 (1980) gives the risk of development of diabetes in the first two decades of life, in the sub-populations of Europe and North America, as 0.1% to 0.3%. In Japan, it is stated to be less than 0.02%; in Tamil Nadu, India, we have calculated the risk to be less than 0.01%. The incidence of JIDDM amongst diabetics in urban Southern India has remained low and static in the last decade; 0.8% and 0.84% in 1973 and 1981 respectively. This is so, despite the fact that infant and perinatal mortality rates over the past two decades have registered a sharp decline in our area. Childhood diabetes and its complications have not shown an uptrend in hospital admissions or infant mortality analysis. It is speculative that our ethnic group is lacks the genetic factor, Bf F1 (which is strongly linked with HLA B18 and IDDM) and the increased association of S1. It remains to be elucidated whether the increased susceptibility to JIDDM of Caucasian children may be associated with a genetic factor or some other exogenous factor, Such as a nutritional factor or virus infection. A plea is made to exchange groups of diabetic children and study the "behavior" of their diabetes under different environments.