Use of waist circumference and ultrasonographic assessment of abdominal fat distribution in predicting metabolic risk factors in healthy Japanese adults.

The purpose of this study is to evaluate the association of abdominal fat thickness with obesity-associated metabolic risk factors. A total of 186 men and 350 women aged 30-78, who were voluntary participants in a community-based health screening program, were examined for body mass index (BMI), waist circumference (WC), and WC-stature ratio (WCSR). Using the ultrasonographic method, the maximum thickness of the preperitoneal fat layer (Pmax) and the minimum and maximum thicknesses of the subcutaneous fat layer (Smin and Smax) in the abdominal region were measured and the abdominal wall fat index (AFI=Pmax/Smin) was calculated. Each measurement was used as a main predictor in the logistic model where the presence of a metabolic risk factor (high blood pressure, high triglyceride, low high-density lipoprotein cholesterol, high glucose, and high uric acid) was predicted. Common covariates in the models were age, smoking status, drinking habit, and overall physical activity. Both WC and WCSR, which behaved in the same manner as BMI, showed a significant association with the majority of metabolic risk factors, but these anthropometric indices were not independent of the confounding effect of BMI. In relationship with atherogenic dyslipidemia, Smax in women and Pmax in both men and women were significant predictors independent of BMI. AFI was also found to be a BMI-independent predictor of atherogenic dyslipidemia in both genders. In men, AFI and high glucose were not significantly associated; in women, they were inversely associated. No measurement showed a significant association with high uric acid. Results suggest that ultrasonographic evaluation of abdominal fat is useful for identifying those at atherogenic risk. A larger sample of subjects in terms of body composition may be required to confirm the usefulness of ultrasonographic evaluation of high glucose.