SHBG levels are associated with bone loss and vertebral fractures in patients with prostate cancer

Abstract

Fractures are increased among prostate cancer patients. No data have been reported in patients with prostate cancer about the relation between serum sex hormone-binding globulin (SHBG) and bone metabolism. We found that SHBG levels were inversely related to bone mass and vertebral fractures in this population. Fractures are increased among prostate cancer patients, especially those on androgen deprivation therapy (ADT), but few data are available on the role of SHBG in their bone status. Our objective was to analyze the relation between serum SHBG and bone metabolism in prostate cancer patients. This is a cross-sectional study including 91 subjects with prostate cancer (54 % with ADT). We measured serum levels of SHBG and sex steroids, bone mineral density (BMD) by dual-energy X-ray absorptiometry, and prevalent radiographic vertebral fractures. SHBG levels were inversely related to BMD (femoral neck: r = -0.299, p = 0.00; total hip: r = -0.259, p = 0.019). Subjects with osteoporosis had higher SHBG concentrations than patients without osteoporosis (60.97 ± 39.56 vs 44.45 ± 23.32 nmol/l, p = 0.022). Patients with SHBG levels in the first quartile (>57.6 nmol/l) had an odds ratio (OR) for osteoporosis of 2.59 (95 % CI, 1.30-5.12; p = 0.009) compared with patients with lower SHBG levels. In patients with SHBG >57.6 nmol/l, the OR for vertebral fractures was 2.34 (95 % CI, 1.15-4.78; p = 0.034). The calculated OR was higher after adjustment for age (OR, 5.16; 95 % CI, 1.09-24.49; p = 0.039), estrogens (OR, 6.45; 95 % CI, 1.44-28.95; p = 0.023), and androgens (OR, 5.51; 95 % CI, 1.36-22.37; p = 0.017). In prostate cancer patients, SHBG levels were inversely related to bone mass and vertebral fractures. Determination of the serum SHBG level may constitute a useful and straightforward marker for predicting the severity of osteoporosis in these patients.