The Anabolic Steroid Oxandrolone Increases Muscle Mass in Prepubertal Boys with Constitutional Delay of Growth

The aim of this study was to investigate the effect of oxandrolone on body composition in boys with constitutional delay of growth and puberty. In 14 prepubertal boys, height, weight, triceps and subscapular skinfolds and upper arm circumference were measured. Body mass index, the ratio of subscapular to triceps skinfolds and the upper muscle area were also determined. The difference of the various measurements and indices, 3 to 6 months before and after commencement of oxandrolone treatment, were calculated, while the boys remained prepubertal. We observed a marked increase in body mass index, a decrease of triceps and subscapular skinfolds, an increase in the ratio of subscapular to triceps skinfolds and also an increase in upper muscle area after the onset of oxandrolone treatment. These results suggest that low dose oxandrolone administration in prepubertal boys with constitutional growth delay causes a disproportionate increase of weight to height which is largely due to increased body muscle.