Significant differences exist in the prevalence of various components of the metabolic syndrome even within an urban environment and this appears to be influenced by socioeconomic status.

OBJECTIVE -The epidemiology of peripheral vascular disease has rarely been studied in non-European populations. The purpose of this study was to determine the prevalence and risk factors of peripheral vascular disease (PVD) among South Indians. RESEARCH DESIGN AND METHODS -The Chennai Urban PopulationStudy is an epidemiological study involving 2 residential areas in Chennai in South India. Of the 1,399 eligible subjects (Ն20 years of age), 1,262 (90.2%) participated in the study. All of the study subjects underwent an oral glucose tolerance test and were categorized as having normal glucose tolerance (NGT), impaired glucose tolerance (IGT), or diabetes. Peripheral Doppler studies were performed on 50% of the study subjects, and PVD was defined as an ankle-brachial index (ABI) Ͻ0.9.RESULTS -The prevalence rates of PVD were 2.7, 2.9, and 6.3% in individuals with NGT, IGT, and diabetes, respectively. The overall prevalence rate was 3.2%. Known diabetic subjects had a higher prevalence of PVD (7.8%) compared with newly diagnosed diabetic subjects (3.5%). PVD was uncommon until middle-age and then the prevalence rate increased dramatically. Univariate regression analysis showed age Ͼ50 years (odds ratio [OR] 6.3, 95% CI 2.1-20.6, P Ͻ 0.001) and hypertension (OR 2.7, 0.9-7.3, P = 0.08) to be associated with PVD, whereas smoking and serum lipid levels showed no association. Multivariate regression analysis identified age as the most significant risk factor for PVD. Of the 90 subjects who had coronary artery disease (CAD), only 6 had PVD, and the positive predictive value of the ABI for CAD was only 30%.CONCLUSIONS -The prevalence of PVD in this urban South Indian population is considerably lower than that reported in European and U.S. studies and is in marked contrast to the high prevalence rate of CAD reported in this population.

The Chennai Urban Population Study investigates a South Indian population with a high prevalence of cardiovascular disease associated with the metabolic syndrome (MS). The Ala54Thr polymorphism in the fatty acid-binding protein 2 (FABP2) gene as well as the T-455C and C-482T polymorphisms in the apolipoprotein C-III (APOC3) gene promoter have been associated with features of the MS in specific populations. This study evaluates in Asian-Indians the association between these polymorphisms with MS and dyslipidemia, defined according to National Cholesterol Education Program Adult Treatment Panel III. Allelic frequencies in 70 controls and 110 patients with diabetes from the Chennai Urban Population Study were 52.9% for FABP2 Thr54, 73.0% for APOC3 -482T, and 80.2% for APOC3 -455C. The polymorphisms were in agreement with Hardy-Weinberg equilibrium. Controls carrying FABP2 Thr54 were more likely to have MS than noncarriers (Fisher's exact test P = 0.031; odds ratio = 6.9 with a 95% confidence interval of 1.1, 43.9). Those carrying at least one polymorphic allele in both genes had a higher likelihood of having MS than wild type (Fisher's exact test P = 0.003; odds ratio = 12.1 with a 95% confidence interval of 1.88, 77.6). Dyslipidemia was associated with the polymorphism as well. The polymorphisms were not associated with MS in patients with diabetes. The association of the polymorphisms with MS and dyslipidemia could contribute to the high cardiovascular disease prevalence in this population.

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