Current zinc intake and risk of diabetes and coronary artery disease and factors associated with insulin resistance in rural and urban populations of North India.

OBJECTIVE: To determine the association between current zinc intake and prevalence of coronary artery disease (CAD) and diabetes as well as factors associated with insulin resistance. DESIGN, SUBJECTS AND METHODS: In this cross sectional survey, 3575 subjects, aged 25 to 64 years, including 1769 rural (894 men. 875 women) and 1806 urban (904 men, 902 women) subjects were studied. The survey methods included questionnaires for 7-day food intake record, physical examination, and electrocardiography using World Health Organization criteria. RESULTS: The prevalence of CAD, diabetes and glucose intolerance was significantly higher among subjects consuming lower intakes of dietary zinc. There was a higher prevalence of hypertension, hypertriglyceridemia and low high-density lipoprotein cholesterol levels which showed significant upward trend with lower zinc intakes. Serum lipoprotein (a) and 2-hour plasma insulin levels also were associated with low zinc intake. Multivariate logistic regression analysis after adjustment for age showed that zinc intake and CAD were inversely associated. Serum zinc (odds ratio:men 0.77, women 0.57), serum triglycerides (men 0.86, women 0.81), blood pressure (0.83 men, women 0.76), diabetes mellitus (men 0.90, women 0.85), central obesity (men 0.88, women 0.87), glucose intolerance (men 0.66, women 0.57) and low high-density lipoprotein cholesterol (men 0.72, women 0.70) were significant risk factors for CAD (explained by tertiles of zinc status) in urban subjects. These associations were not observed in rural subjects. CONCLUSION: Lower consumption of dietary zinc and low serum zinc levels were associated with an increased prevalence of CAD and diabetes and several of their associated risk factors including hypertension, hypertriglyceridemia and other factors suggestive of mild insulin resistance in urban subjects.

Association of low plasma concentrations of antioxidant vitamins, magnesium and zinc with high body fat per cent measured by bioelectrical impedance analysis in Indian men.

This cross-sectional study was conducted to determine the association of high body fat per cent measured by bioelectric impedance analysis with known risk factors of obesity as well as with serum levels of vitamins, trace elements and magnesium and oxidative stress in an urban population in India. There were 850 men aged 25-64 years, randomly selected from the city of Moradabad. Subjects were divided into high body fat per cent (n = 357), over fat per cent (n = 230), desirable fat (n = 200) and low fat (n = 63) based on criteria of body fat per cent analysis. The prevalence of central obesity, sedentary lifestyle, family history and higher visible fat intake showed significant association with higher over fat per cent. Postprandial plasma insulin and glucose and serum iron and oxidative stress were significantly higher and plasma levels of vitamin C and E and serum zinc/insulin ratio as well as serum magnesium/insulin ratio showed inverse association with high body fat per cent. Multivariate logistic regression analysis after adjustment of age showed a significant positive association of body mass index (odds ratio 0.97), sedentary lifestyle (odds ratio 1.12) and serum iron (OR 1.00) with higher body fat per cent. Zinc (OR 1.03), magnesium (OR 1.02), vitamins C (OR 1.08 and E (OR 1.09) deficiency were risk factors of higher body per cent and central obesity. It is possible that some Indian men can benefit by increased intake of zinc, magnesium, vitamin C and vitamin E in conjunction with lifestyle changes.