Familial aggregation of subcutaneous fat deposits and the peripheral fat distribution pattern.

The familial aggregation of fatness into subcutaneous fat distribution was studied in a sample of 122 nuclear families with adolescent children. Subcutaneous fat thickness was measured using ultrasound images. Other variables considered were anthropometric measurements, body composition, and indices of relative fat distribution. The measurements were adjusted for age and body mass index (BMI), and the residuals were transformed to normalized z-scores by sex and age group. The z-scores were used to calculated intraclass correlations between all family members. The results show significant familial correlations for the fat deposits on the upper abdomen, triceps, calf, and subscapula. They also show strong familial aggregation for the level of fatness and ponderosity. However, the subcutaneous fat on the lower abdomen and the corresponding indices were closely related to the level of fatness, and were significantly correlated between sisters, and between mothers and daughters. These lower abdominal fat deposits are more likely to be influenced by environmental components such as diet and level of physical activity.