Abstract :
There is an increasing body of evidence suggesting a relationship between central obesity, insulin resistance/hyperinsulinemia, type II diabetes mellitus and hypertension in women. CARDIA is an ongoing longitudinal study of a biracial cohort of over 5,000 young adults. Among the four race-sex groups, Black women had the highest insulin levels, perhaps related to increased central obesity in this gender. Central obesity also contributes to the higher prevalence of type II diabetes in African-American women. Although the mechanisms that link central obesity, dyslipidemia and hypertension are not thoroughly understood, a role for insulin resistance/hyperinsulinemia has emerged. Compared with adipocytes found in the gluteo-femoral area, abdominal adipocytes possess fewer insulin receptors, are less insulin-responsive, and have a greater sensitivity to lipolytic hormones. In this context, women with predominantly central obesity have significantly higher insulin and glucose concentrations after an oral glucose tolerance test than women with gluteo-femoral obesity. Further, weight reduction has been observed to lower blood pressure, improve insulin sensitivity, and leads to a fall in cholesterol and triglycerides and an elevation in HDL cholesterol. Although dietary cation intake difference (i.e. potassium, calcium, magnesium and sodium) likely contribute to racial differences in hypertension and other risk factors for atherosclerosis, current evidence of their etiological importance is not nearly as striking as obesity, particularly the central type of adiposity.
