Clinical characteristics and causes of primary male osteoporosis in Korea

Lim, Sung Kil; Lee, Yong Ho; Lee, Hyun Chul; Song, Young Duk; Huh, Kap Bum; Kim, Mi Kyung; Jang, Jun Ho; Nam, Jae Hyun; Ahn, Chul Woo

Abstract

Osteoporosis in men has recently been recognized as an important public health problem. In women, pathophysiology, risk factors, etiology and treatment of osteoporosis have become well defined. However, less information has been availabe concerning men until now. Male osteoporosis has been known to be associated with drugs and diseases that threaten bone health. However, the causes of male osteoporosis are not apparent in some instances. This study was designed to evaluate the clinical characteristics and causes of primary osteoporosis in Korean men.
METHODS
The BMD was measured with DEXA in 327 healthy adult Korean men who were employed by the same company in Seoul. Among them, we studied 20 patients who visited the department of internal medicine at Yonsei University Medical Center for evaluation of osteoporosis. Osteoporosis was defined by WHO criteria for women. We performed history taking, physical examination, nutritional assessment and laboratory examination.
RESULTS
The mean age of patients was 52 years. None of them have taken corticosteroid or any other medicine. None of them had suffered from any other medical illness. The mean BMI was 22.1 kg/m2 and the values of 7 patients were less than the age-matched normal value of healthy Korean men. Six patients were current smokers and there were no heavy drinkers. Urinary calcium excretion was elevated in 5 patients and dietary calcium intake was less than 400mg/day in 4 patients. Vitamin D deficiency, as evidenced by serum 25(OH) D levels below 12 ng/mL, was detected in 2 patients, however, subclinical hypovitaminosis D (below 20 ng/mL) was observed in 8 patients. Serum free testosterone levels below normal value were observed in 5 patients. The mean serum IGF-I level was 183.7 ng/mL and that was lower than for normal Korean men. Lower IGF-I levels than age-matched normal values were observed in 5 patients. CONCLUSION: The clinical characteristics of Korean male osteroporosis were heterogenous in many aspects of its features. Several factors could be suggested as possible causes of idiopathic male osteoporosis. Men with osteoporosis in this study revealed low BMI(7 patients), family history of osteoporosis(1 patient), low calcium intake(4 patients), hypercalciuria(5 patients), Vitamin D deficiency(2 patients), subclinical hypovitaminosis D(8 patients), testosterone deficiency (5 patients) and low IGF-I level(5 patients). Multiple causes of osteoporosis were found in 6 patients.