USING QUANTITATIVE CT TO ASSESS ADIPOSE DISTRIBUTION IN ADULT MEN WITH ACQUIRED HYPOGONADISM

OBJECTIVE. Quantitative CT is a powerful tool that may be used to asse ss distribution of adipose and lean mass and bone mineral density in s pecific anatomic compartments. Testosterone deficiency (hypogonadism) is increasingly recognized in adult men and is associated with osteopo rosis, diminished strength, and an increase in cardiovascular risk. We used quantitative CT to determine whether hypogonadism is associated with fat redistribution and altered bone density. SUBJECTS AND METHODS . Quantitative CT was performed at the level of the L4 vertebra in 26 men with adult onset testosterone deficiency and 17 eugonadal men of s imilar body mass index and age. Adipose area in the subcutaneous, visc eral, and skeletal muscle areas was determined and trabecular bone den sity was measured. Values between the groups were compared using t tes ts. RESULTS. The ages of the hypogonadal and eugonadal men were 52 +/- 14 years and 51 +/- 8 years (p value not significant), respectively. Subcutaneous fat area was higher in the testosterone-deficient men tha n in the control subjects (270 +/- 101 cm(2) versus 202 +/- 111 cm(2); p = .046). Muscle fat area was higher in the hypogonadal men (6 +/- 3 cm(2) versus 2 +/- 1 cm(2); p = .001). Measurements of visceral fat we re similar for both groups. Trabecular bone density was lower in the h ypogonadal than in the eugonadal men (112 +/- 38 mg K2HPO4/dl versus 1 48 +/- 34 mg K2HPO4/dl, respectively; p = .003). CONCLUSION. Our findi ngs indicate that testosterone deficiency is associated with a decreas e in bone density and a redistribution of fat. Quantitative CT is a se nsitive method that may be useful in determining alterations in region al adipose deposition in hypogonadal men and in evaluating the benefit of interventional therapy such as testosterone replacement.