VISCERAL ADIPOSITY, FASTING PLASMA-INSULIN, AND LIPID AND LIPOPROTEINLEVELS IN JAPANESE-AMERICANS

OBJECTIVE: To examine the associations among visceral and subcutaneous adiposity, body-mass-index (BMI), fasting plasma insulin, lipid, and lipoprotein levels. DESIGN: Cross-sectional observational study. SUBJE CTS: Non-diabetic second- (Nisei, n = 290) and third-generation (Sanse i, n = 229) Japanese Americans. MEASUREMENTS: Intra-abdominal (IAF) an d subcutaneous abdominal fat (SAF) area were measured using computed t omography. Easting plasma insulin, lipid, and lipoprotein levels were measured using standard methods. RESULTS: Higher fasting insulin was s ignificantly related to greater mean IAF and SAF area, plasma triglyce rides, total HDL and HDL(2) cholesterol in men and women of both gener ations. In a multiple linear regression analysis model among Nisei adj usted for gender, age, SAF, antihypertensive medication use, smoking, alcohol use, and exercise energy expenditure, IAF area and fasting ins ulin level were independently correlated with plasma triglycerides (IA F r = 0.22, fasting insulin r = 0.23), total HDL (IAF r = -0.29, fasti ng insulin r = -0.28), HDL(2) (IAF r = -0.30, fasting insulin r = -0.2 7), and HDL(3) cholesterol (IAF r = -0.19, fasting insulin r = -0.19). Among Sansei, similar associations were seen, except that fasting ins ulin was unrelated to total HDL or HDL(3) cholesterol. These effects d iffered by gender in several instances. CONCLUSIONS: Both visceral adi posity and fasting insulin level are significantly and independently r elated to adverse levels of lipids and lipoproteins in both generation s of nondiabetic Japanese Americans. The association between adverse l ipid profile and visceral obesity is not mediated solely through detri mental effects of intra-abdominal fat deposition on fasting insulin le vel.