Growth hormone is essential in normal bone growth and maintenance of bone metabolism. In the setting of childhood onset growth hormone deficiency, osteoporosi s is inevitable without replacement therapy. Growth hormone demonstrates its function over bone in direct and indirect ways. Osteoporosis is usually overlooked in men, and many cases are defined as idiopathic after clinical examinations and laboratory tests. We aimed to demonstrate whether some cases of idiopathic male osteoporosis might actually be the result of adult onset growth hormone deficiency and we used L-dopa stimulation for growth hormone as this test is a safe and simple one to perform.
Age matched (51.2 ± 5.64 vs 54.71 ± 6.55) 17 osteoporotic and 25 healthy control subjects were enrolled in the study. Bone mineral density measurements were done at both lumbar vertebrae and femoral hip. Each subject passed through a series of clinical examinations and full laboratory study. Those subjects having no metabolic bone disease or diseases known to affect bone metabolism were included in the study.
After the basal growth hormone measurements, stimulation test with L-dopa was performed for each subject and patient. Although basal levels were not different, the difference between stimulated hormone levels was statistically significant (2.85 ± 0.5 vs 5.68 ± 1.1, p<0.05).
Our results imply that some cases of idiopathic male osteoporosis could actually be a result of adult onset growth hormone deficiency and L-dopa stimulatio n of growth hormone is a safe alternative to insulin stimulatıon test for this purpose.
Keywords: Male osteoporosis, growth hormone deficiency, L-dopa stimulation