Bone Histomorphometry in Hypogonadal and Eugonadal Men with Spinal Osteoporosis*

Abstract

We present iliac bone histomorphometric data after in vivo double tetracycline labeling and related biochemical data from 14 nonalcoholic men referred for evaluation of symptomatic spinal osteoporosis. Six patients had previously undiagnosed hypogonadism, and 8 had normal gonadal function and no evident etiology for osteoporosis. Bone histomorphometry revealed no differences in structural measurements or resorption indices between the 2 groups. However, compared to reference values for normal postmenopausal women, osteoblast surface, mineralizing surface, and formation rate were normal or modestly increased in the hypogonadal men and significantly reduced in the idiopathic group. There were significant corresponding differences between the 2 groups in the fasting urinary hydroxyproline to creatinine ratio, an index of bone resorption, and serum total alkaline phosphatase, an index of bone formation. Plasma 25-hydroxyvitamin D levels did not differ between the 2 groups and were above 10 ng/mL in all patients. Plasma 1,25-dihydroxyvitamin D [1,25-(OH)2D] levels were normal in the hypogonadal group and significantly reduced in the idiopathic group, but did not correlate with any histological measurements. The formation indices fell substantially in 3 of 4 hypogonadal men after 7-14 months of therapy with testosterone and a calcium supplement. We conclude the following. In vitamin D-replete hypogonadal men with osteoporosis, 1,25-(OH)2D synthesis is normal, and bone remodeling is modestly increased and correctable by hormone replacement therapy, as in normal postmenopausal women. In middle-aged men with idiopathic osteoporosis, there is impairment of 1,25-(OH)2D synthesis and of the recruitment and activity of teams of osteoblasts, as in postmenopausal osteoporosis.

Bone mineral density, serum insulin-like growth factor I, and bone turnover markers in viral cirrhosis

“…27 In this study, viral cirrhotic patients had lower serum FTI concentrations than control subjects, but we found no correlation between FTI and BMD.…”

Osteoporosis in men with prostate carcinoma receiving androgen‐deprivation therapy

“…40 In hypogonadal men, the classic bone histomor- phometric findings include osteoclast activation associated with trabecular plate perforation and loss of trabecular connectivity. 41 Markers of bone turnover clearly are elevated in men after either undergoing orchidectomy or receiving ADT for prostate carcinoma. In recent studies, increases in urinary deoxypyridinoline excretion rates and telopeptide concentrations of between 150% and 200% above baseline values have been reported after the commencement of ADT, suggesting that these men lose bone at a much higher rate compared with others their age.…”

Androgen effects on bone metabolism: recent progress and controversies

“…The endpoints of these studies were BMD (5, 7, 8, 11-13, 59, 64-66, 68-80), static or dynamic histomorphometry (7, 59-62, 64, 65, 67, 68, 87, 88), measurement of biochemical markers of bone formation and bone resorption (5,12,65,66,69,(81)(82)(83)(84)(85)(86)(87)(88), or biomechanical properties of bone (63). The majority of studies were performed either in spontaneous or orchiectomy-induced hypogonadism with or without subsequent androgen replacement therapy, or androgen treatment of eugonadal male or female subjects.…”

“…Profound hypogonadism is associated with increased bone resorption (81,82). Tenover (83) showed that 3 months of testosterone treatment of 13 healthy men (aged 57 to 76 years) with borderline serum testosterone levels (<400 ng/dl) resulted in a 28% reduction in urinary hydroxyproline excretion.…”