Treatment of osteoporosis in men with bisphosphonates: rationale and latest evidence

Osteoporosis in men contributes to significant morbidity and mortality. Hip fractures in men are associated with greater mortality compared with women, with a mortality rate of up to 37.5% within a year following the fracture. Its timely diagnosis and treatment are therefore essential. However, despite one-third of all hip fractures worldwide occurring in men, osteoporosis in men remains an immensely under-recognized and undertreated public health problem. Bisphosphonates are well studied first-line treatments for postmenopausal women with osteoporosis and have been shown to reduce fragility fractures at all clinically important sites (vertebral, nonvertebral, hip and wrist). However, the majority of studies of oral or intravenous bisphosphonate therapy in men with osteoporosis report effects on surrogate markers, including bone mineral density (BMD) and biochemical bone turnover markers, rather than on fragility fractures. Oral or intravenous bisphosphonate therapy increases spinal, total hip and femoral neck BMD compared with placebo in men with osteoporosis. Both bone resorption and bone formation markers are decreased following bisphosphonate therapy, with the onset of the decrease in bone formation markers being delayed. In a study of intravenous zoledronic acid given to older men and women following a hip fracture, any clinical vertebral and nonvertebral fractures were all reduced compared with placebo infusions. In addition, mortality was reduced in patients who received zoledronic acid. Recent studies in men with osteoporosis have increasingly reported reductions in incident vertebral fractures with oral or intravenous bisphosphonate therapy, although all studies have been underpowered to detect effects on nonvertebral and hip fracture outcomes. Bisphosphonates have a role as monotherapy, as consolidative therapy after a course of teriparatide therapy, or in combination with testosterone replacement in men with hypogonadism and osteoporosis. Bisphosphonate therapy is validated and important in the treatment of osteoporosis in men.