Relative contribution of obesity and body fat distribution to alterations in glucose insulin homeostasis: predictive values of selected indices in premenopausal women.

Obesity and fat topography are risk factors for hyperinsulinemia, insulin resistance, and diabetes mellitus. The relative contribution of obesity and body fat distribution indices to fasting and oral glucose-stimulated C peptide, insulin, and glucose concentrations were determined in 33 healthy premenopausal women. Obesity level was assessed by hydrostatic weighing and fat topography by computerized tomography-derived intraabdominal fat area, waist to hip ratio, subscapular skinfold thickness and the ratio of subscapular to triceps skinfold thickness. Both fat mass and regional fat distribution indices were associated closely with changes in insulin secretion. Fat topography indices were more closely correlated (p less than 0.001) to insulin response than were fat mass indices (p less than 0.01). The subscapular skinfold thickness had the greatest integrity for reflecting fat mass and fat distribution as they relate to the metabolic profile. The subscapular skinfold thickness may help identify individuals at risk for noninsulin dependent diabetes mellitus.