Intra-Abdominal Fat Is a Major Determinant of the National Cholesterol Education Program Adult Treatment Panel III Criteria for the Metabolic Syndrome

Intra-Abdominal Fat Is a Major Determinant of the National Cholesterol Education Program Adult Treatment Panel III Criteria for the Metabolic Syndrome Darcy B. Carr 1 , Kristina M. Utzschneider 2 , Rebecca L. Hull 2 , Keiichi Kodama 2 , Barbara M. Retzlaff 2 , John D. Brunzell 2 , Jane B. Shofer 3 , Brian E. Fish 2 , Robert H. Knopp 2 and Steven E. Kahn 2 1 Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Washington, Seattle, Washington 2 Division of Metabolism, Endocrinology, and Nutrition, Department of Medicine, Veterans Affairs Puget Sound Health Care System and Harborview Medical Center, University of Washington, Seattle, Washington 3 Department of Rehabilitation Research and Development, University of Washington, Seattle, Washington Address correspondence and reprint requests to Darcy B. Carr, MD, Assistant Professor, Box 356460, Dept. OB/GYN, University of Washington, Seattle, WA 98195-6460. E-mail: darcarr{at}u.washington.edu Abstract The underlying pathophysiology of the metabolic syndrome is the subject of debate, with both insulin resistance and obesity considered as important factors. We evaluated the differential effects of insulin resistance and central body fat distribution in determining the metabolic syndrome as defined by the National Cholesterol Education Program (NCEP) Adult Treatment Panel III. In addition, we determined which NCEP criteria were associated with insulin resistance and central adiposity. The subjects, 218 healthy men ( n = 89) and women ( n = 129) with a broad range of age (26–75 years) and BMI (18.4–46.8 kg/m 2 ), underwent quantification of the insulin sensitivity index ( S i ) and intra-abdominal fat (IAF) and subcutaneous fat (SCF) areas. The metabolic syndrome was present in 34 (15.6%) of subjects who had a lower S i [median: 3.13 vs. 6.09 × 10 −5 min −1 /(pmol/l)] and higher IAF (166.3 vs. 79.1 cm 2 ) and SCF (285.1 vs. 179.8 cm 2 ) areas compared with subjects without the syndrome ( P < 0.001). Multivariate models including S i , IAF, and SCF demonstrated that each parameter was associated with the syndrome. However, IAF was independently associated with all five of the metabolic syndrome criteria. In multivariable models containing the criteria as covariates, waist circumference and triglyceride levels were independently associated with S i and IAF and SCF areas ( P < 0.001). Although insulin resistance and central body fat are both associated with the metabolic syndrome