Do hormonal indices of maturation explain energy expenditure differences in African American and Caucasian prepubertal children?

OBJECTIVE: To examine the relationships between hormonal indices of maturat ion and total, resting and physical activity-related energy expenditure (TE E, REE and AEE) in African American and Caucasian prepubertal children. DESIGN: Cross-sectional study. SUBJECTS: Sixty-four African American and 48 Caucasian prepubertal children . MEASUREMENTS: TEE (by doubly labeled water), REE (by indirect calorimetry), fat mass and fat-free mass (by dual-energy X-ray absorptiometry), fasting serum dehydroepiandrosterone-sulfate (DHEAS), androstenedione, and estrone- sulfate (by radioimmunoassay). RESULTS: Serum concentrations of hormones correlated significantly with REE and TEE (r values range from 0.33 to 0.76, P < 0.001). Only androstenedion e correlated significantly with AEE (r = 0.23, P , 0.05). However, these co rrelations were no longer significant after adjusting energy expenditure co mponents for fat-free mass. In multiple regression models, ethnicity was no t a significant determinant of any energy expenditure component after adjus ting for body composition and hormone concentrations. CONCLUSION: Hormonla indices of maturation do not influence energy expendit ure in this group of African American and Caucasian prepubertal children.