Association of waist circumference with ApoB to ApoAl ratio in black and white Americans

BACKGROUND: Although numerous studies have demonstrated obesity as an aspec t of the insulin resistance syndrome in cardiovascular disease (CVD), the m echanism is not clear. Central adiposity, acting through many CVD risk fact ors, including, plasma glucose, insulin, total cholesterol, low density lip oprotein-cholesterol (LDL-C) and lipoprotein moities-apolipoprotein B (ApoB ), apolipoprotein A-l (ApoAl), by atherogenic and thrombotic mechanisms has been proposed as a possible mechanism. In this study, we examined the rela tionship between central fat distribution (defined by waist circumference) and the ratio of these lipoproteins (ApoB/ApoAl). SUBJECTS AND METHODS: Association between ApoB/ApoAl ratio and waist circum ference was compared in Blacks (n = 854) and Whites (n = 2552) using the NH ANES III population-based samples. Correlation analyses and multiple regres sion analyses were used to determine the association between ApoB/ApoAl and waist circumference, controlling for age, body mass index (BMI), race, gen der, plasma glucose, insulin, serum triglyceride and total cholesterol. RESULTS: Adjusting for age, ApoB/ApoAl was significantly correlated with wa ist circumference (Black men: r = 0.38, White men: r = 0.26, Black women: r = 0.20, White women: r = 0.36) (all P < 0.01). Adjusting for age and trigl yceride or insulin, waist circumference was also positively correlated with CVD risk factors including, ApoB, LDL-C, plasma glucose and fasting insuli n, and inversely correlated with ApoAl and HDL-C in Blacks and Whites (P < 0.05). Overall, triglyceride and total cholesterol were the strongest predi ctors of ApoB/ApoAl in Blacks and Whites adjusting for age, BMI and insulin , than waist girth (P < 0.01). CONCLUSIONS: The result of this study suggests the need to investigate ApoB /ApoAl as another possible facet in the insulin resistant syndrome.