Relationship among salivary androstenedione, body composition and physical activity in young girls

Abstract

High androgenic activity in young girls may be associated with adiposity and the development of metabolic disturbances. This study examined the relationship between salivary androstenedione, body composition and physical activity (PA) levels in young girls. Twenty-three prepubescent girls (8.4±0.9 years), 9 normal and 14 overweight, according to Centres for Disease Control and Prevention body mass index (BMI) percentile ranking, wore an ActiGraph accelerometer for 5 days. Skinfolds were measured for per cent body fat and fat free mass calculation. Saliva samples were collected three times at home over 1 day (waking, 30-min postwaking and evening). Previously published cut points estimated the minutes of moderate, moderate-to-vigorous (MVPA), vigorous and very vigorous PA. Meeting PA recommendations was defined as accumulating 60 min/day of MVPA. t Tests, correlation and regression analysis examined relationships between the variables. Only 35% of the girls met current PA recommendations. Evening androstenedione levels were significantly higher among girls who did not meet the PA recommendations. Evening androstenedione levels were negatively related to time spent performing very vigorous PA and positively related to the per cent change in androstenedione from waking to evening. There were no correlations between androstenedione and BMI or per cent body fat. Salivary androstenedione is related to PA, but not either BMI or per cent body fat in young girls. This suggests an important role for PA in determining androgenic activity independently from the proposed mechanism linking adiposity with elevated androgenic activity.