The efficacy of denosumab in Korean male patients with osteoporosis

Background/Aims: Despite the prominence of denosumab as the number one prescribed anti-osteoporosis drug in Korea, the effects of denosumab in male osteoporosis patients were not researched sufficiently. Moreover, concerns on rebound vertebral fractures associated with poor denosumab adherence exist. Methods: We retrospectively evaluated 147 Korean male osteoporosis patients treated with denosumab. After 12 months of treatment, 60 patients were lost during follow-up, and eight were excluded due to missing data. Out of the initial 147 patients, 79 were considered eligible for the analysis of the efficacy of denosumab. 54 patients were initially drug-naive, and 25 had previously received bisphosphonate therapy. Results: In 54 drug-naive patients, significant increases in bone mineral density (BMD) were observed in all measurement sites: 5.2% +/- 3.7% in the lumbar spine, 2.3% +/- 2.8% in the femoral neck, and 1.9% +/- 2.8% in the total hip (p < 0.01, respectively). Trabecular bone score showed an increase of 0.5% +/- 5.8% in drug-naive patients. Likewise, in 25 patients with previous bisphosphonate treatment, increase in BMD were observed as well: 4.8% +/- 3.5% in the lumbar spine, 1.4% +/- 3.6% in the femoral neck, and 0.8% +/- 2.1% in the total hip (p < 0.01, p = 0.06, p = 0.06, respectively). Significant declines of -55.1% +/- 31.8% in C-terminal telopeptide of type 1 collagen (CTX), and -62.9% +/- 21.3% in total procollagen 1 N-terminal propeptide (P1NP), in drug-naive patients; and -37.7% +/- 41.5%, in CTX and -55.4% +/- 30.1%, in P1NP in patients with previous bisphosphonate treatment were exhibited after 12 months of treatment. The adherence rates of the second and third dosing schedules were 79.9% and 56.8%, respectively. Conclusions: Our study indicates that denosumab is effective in increasing BMD in Korean osteoporosis males regardless of prior bisphosphonate treatment.