Sexual dimorphism in fat patterning in a sample of 5 to 7-year-old children in Oxford.

It is now well recognised that, in addition to total body fat, fat distribution is a major risk factor for cardiovascular disease and insulin resistance/diabetes in both adults and children. Traditionally, sexual dimorphism in fat patterning has been regarded as occurring at puberty. The aim of this study was to investigate gender differences in fat patterning in a group of children in Oxford. Anthropometric data was collected for 95 girls and 93 boys aged 5-7 years. Body mass index, percentage body fat and fat patterning indices were calculated using skinfold thickness measurements. While girls at this age had significantly larger percentage body fat and skinfolds, the fat patterning indices showed no differences between genders and no indication of greater truncal adiposity. The boys had a larger mean waist-hip ratio (0.96+/-0.04) compared with the girls (0.93+/-0.04) (P<0.001). The larger ratio in boys was the outcome of the smaller hip circumference in the boys reflecting less gluteal adiposity. This suggests that even at this young age there is clear evidence of sexual dimorphism in fat patterning, with girls showing greater subcutaneous adiposity mainly contributed by gluteal fat. The present study confirms the findings of American and European workers that sexual dimorphism of fat patterning in children is present at 5-7 years of age. Second, that these differences in fat patterning can be detected using simple anthropometric measurements such as hip circumference and skinfold thicknesses. The significance and importance of hip circumference measurements in predicting health outcome is an area that merits further investigation.