The clinical significance of bone mineral density and testosterone levels in Korean men with non-mosaic Klinefelter's syndrome.

OBJECTIVE

To measure bone mineral density (BMD) and testosterone levels in patients with non-mosaic Klinefelter's syndrome (KS), as a low BMD is common in hypogonadal men, but little is known about the relationship between BMD and serum testosterone levels in men with KS.

PATIENTS, SUBJECTS AND

METHODS

The study included 40 patients with KS and 20 healthy fertile men recruited as controls. Serum testosterone, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels were measured by radioimmunoassay. The BMD was obtained at the lumbar spine (L2-4), femoral neck and Ward's triangle, by dual-energy X-ray absorptiometry.

RESULTS

The serum testosterone level was lower, while FSH and LH were higher, in patients with KS than in the control group (P < 0.001). Patients with KS had a significantly lower mean (sd) BMD at the lumbar spine, femoral neck and Ward's triangle, than the controls, at 0.88 (0.13) vs 1.09 (0.10) (P < 0.001), 0.78 (0.12) vs 0.87 (0.10) (P = 0.006) and 0.65 (0.12) vs 0.76 (0.11) g/cm(2) = 0.001), respectively. There was a linear correlation between all BMD values and serum testosterone levels in men with KS who had a low serum testosterone level.

CONCLUSIONS

There was a relationship between a lower BMD and testosterone levels in patients with KS. These findings suggest that low testosterone levels cause inadequate bone development and a low BMD in men with KS; therefore, testosterone replacement might be necessary to prevent bone mineral deficiency and future risk of fractures in men with KS who also have low serum testosterone levels.