Oral contraceptives and fat patterning in young adult women.

90 nulliparous white female college students, selected from 2 undergraduate introductory courses at Kansas University, participated in a cross-sectional study designed to compare the fat distribution of oral contraceptive (OC) users to that of nonusers matched for height and weight. The subjects ranged in age from 18-26 years. The 30 OC users had been using the same brand of OCs for an average of 17.7 months (range of 3-36 months) and had not used another brand previously. Each OC user was matched to 2 nonusers. Each subject's height was measured to the nearest cm. A Detecto sliding-weight balance was used to measure body weights of the women (in light clothing) to the nearest 0.1 kg. Circumference measurements also were taken to determine body shape and fat distribution. The waist girth to hip ratio (WHR) also was calculated. Fat distribution of the OC users was similar to that of nonusers matched for height and weight. Both groups were comparable in their circumference and skinfold measurements, except that the OC users had larger axilla skinfolds. Progestational activity of the combined OCs was not associated with any of the physical measurements. Estrogenic activity of the combined OCs was correlated positively with body mass index, arm and thigh circumference, and peripheral fat distribution. Estrogenic activity also was associated weakly with hip and low chest circumferences but no with any of the 7 skinfold thickness measurements. The women taking the higher estrogen OCs were more likely to have circumference measurements consistent with a more gynoid shape. Thigh skinfold thickness was consistent with those findings, though not statistically significant.