[Gonadal function in primary apparent male osteoporosis. 12 cases].

The testicular endocrine function was studied in 12 patients aged from 33 to 76 years (mean: 56.3 +/- 11.5 years) presenting with an apparently primary vertebral osteoporosis and in 14 age-matched controls (mean: 52.6 +/- 12.8 years). The mean bone mineral content, measured in the vertebral column by biphoton absorptiometry, was lower in patients than in control (P +/- 0.01). Plasma levels of testosterone, oestradiol, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were the same in both groups. In two patients of each group, a rise of LH with normal testosteronaemia was suggestive of compensated Leydig's cell deficiency. There was no correlation between bone mineral content, plasma testosterone, LH, FSH level and the subjects' weight and height. However, a positive correlation was found between plasma oestradiol level and bone mineral contents in patients with osteoporosis (P +/- 0.01) ans in all subjects under study (P +/- 0.05). This study shows that primary osteoporosis is not due to testicular deficiency and suggests a possible action of oestradiol on male bone.