BACKGROUND: Positive correlations between bone mass and androgen levels have been observed in premenopausal and postmenopausal women as well as in men. Androgen production was decreased in women with osteoporosis compared to that in age-matched controls. We hypothesized that androgen metabolism might be also deranged in osteoporosis. To clarify our hypothesis, we investigated the relationship between urinary metabolites of androgen and bone mineral density (BMD) in Korean postmenopausal osteoporotics. METHODS: We examined the anthropometry and bone turnover marker in 67 postmenopausal women. BMD was measured by dual energy X-ray absorptiometry (DEXA). Serurn levels of estrone, estradiol, free testosterone were measured by radioirnmunoassay and serum level of sex hormone binding globulin (SHBG) was measured by two site immunoradiometric assay. The urinary metabolites of androgen were determined by gas chromatography-mass spectrometry (GC-MS) at Korean Institute of Science and Technology Doping Control Center. RESULTS: 1. Spinal BMD had a positive correlation with height (r 0.3049, p<0.05), weight (r=0.4114, p<0.001) and body mass index (BMI, r=0.2638, p<0,05). 2. Spinal and femoral neck BMD had no correlation with serum levels of estrone, estradiol and ten major urinary metabolites of androgen, but serum free testosterone had positive correlation with spinal BMD (r=0.3622, p<0.01) and SHBG had negative correlation with femoral neck BMD (r=-0.2625, p< (0.05). 3. Serum free testosterone in osteoporotics was lower than non-osteoporotics with spinal BMD (p<0.05) and SHBG in patients with osteopenia was higher than non-osteopenic subjects with femoral neck BMD (p <0.05). 4. In multiple stepwise regression analysis, weight and serum free testosterone were statistically significant for spinal BMD (R =0.3072). As for femoral neck BMD, weight was the independent determinant (R 0.1307). 5. Serum level of osteo#ealcin and urinary deoxypyridinoline/creatinine had a positive correlation with urinary 11-ketoandrosterone (p<0.05). SHBG was positive correlation with osteocalcin (r=0.3190, p<0.05). 6. Serum free testosterone (r=-0.2740, p<0.05) decreased with aging. CONCLUSION: Our data suggest that androgen metabolism is not deranged in osteoporotics, but serum free testosterone is important than estrogen on postmenopausal osteoporosis after 5-10 years menopause.