M1354 Abdominal Obesity vs. Total Body Obesity: Specific Risk Factors

Abstract

Background: Abdominal obesity (characterized by increased waist to hip ratio, WHR) is associated with diabetes, cardiovascular disease, fatty liver disease, and various cancers. Increased WHR is associated with gender and race. Little is known about what behavioral factors may be associated with this body fat distribution. Methods: 283 men aged 50-79 years undergoing colonoscopy for colon cancer screening underwent body measurements and answered questionnaires regarding dietary habits and physical activity. We estimated Pearson and Spearman correlations between measures of obesity and various behaviors, and used linear regression models of the behaviors for body mass index (BMI per 1 kg/m2), waist circumference (per 1 cm), hip circumference (per 1 cm), and WHR (per 0.01), both unadjusted, and adjusted for each other. Results: Mean BMI was 30.4 kg/m2 (standard deviation, SD = 5.9), waist 109cm (SD = 15), hip 109cm (SD = 12), and WHR 1.00 (SD = 0.06). Waist was very closely correlated with BMI (rho = 0.93), as was hip (rho = 0.92), but WHR was only moderately correlated with BMI (rho = 0.45). Correlations with each measure of obesity are shown in Table 1. Linear regressions results for obesity, adjusted for each factor and for BMI or WHR, are shown in Table 2. Conclusions: WHR appears to measure a construct distinct from waist circumference or BMI. The association between the ratio of fat to carbohydrate intake and WHR may be due to the increased capacity of visceral fat for taking up fatty acids. The inverse association of frequent moderate exercise with WHR may be due to the increased sensitivity of visceral fat to catecholamines for lipolysis. Age is also associated with WHR. These findings may direct future research aimed at reducing the risk of sequelae from abdominal obesity. Table 1: Correlations (rho)