Two cases of male hypogonadal osteoporosis

Two males with bone abnormalities associated with hypogonadotropic hypogonadism are reported. Case 1, 28 years old male, developed growth disturbance at the age of eight years, after suffering from tuberculous meningitis. No secondary sex characteristics appeared and fractures occurred at five times. Case 2, 29 years old male, also suffered from growth disturbance from around the age of 6 years, without appearance of secondary sex characteristics even after puberty. Bone X-ray studies and bone biopsy revealed marked osteoporosis in Case 1, while in Case 2, slipped capital femoral epiphysis was also noted with mild osteoporosis. In these two cases, osteoporosis is associated with eunuchoidism, in agreement of the concept of so-called “male hypogonadal osteoporosis”. Both patients showed insufficient secretion of somatomedin C, testosterone and growth hormone (GH) with insulin tolerance test and arginine tolerance test. The insufficient secretion of LH and FSH with LH-RH tolerance test was also revealed in both cases. The decrease of GH and somatomedin C was quite pronounced in Case 1, whereas the fall of testosterone was more conspicuous in Case 2. The imbalance between these hormone deficiencies might lead to different expression of bone abnormalities.