Abstract

     Osteoporosis is underrecognized and undertreated in men, even though up to 25% of fractures in patients over the age of 50 years occur in men. Men develop osteoporosis with normal aging and accumulation of comorbidities that cause bone loss. Secondary causes of bone loss may be found in up to 60% of men with osteoporosis. Mortality in men who experience major fragility fracture is greater than in women. Diagnosis of osteoporosis in men is similar to women, based on low-trauma or fragility fractures, and/or bone mineral density dual-energy X-ray absorptiometry (DXA) T-scores at or below −۲٫۵٫ Because most clinical trials with osteoporosis drugs in men were based on bone density endpoints, not fracture reduction, the antifracture efficacy of approved treatments in men is not as well documented as that in women. Men at a high risk of fracture should be offered treatment to reduce future fractures.

Introduction

     Osteoporosis is a worldwide disease that causes more than nine million fragility fractures annually, one every 3 s [1].

     Men have a lower risk of osteoporosis and fragility fractures than women. This is because women have bones with smaller diameters, lower peak bone mass, a menopause-related bone resorption process, and a higher risk of falls than men [2]. Despite osteoporosis and fragility fractures being less common in men than women, 39% of osteoporotic fractures worldwide occur in men [1]. Data from 2005 indicate that of the 2 million osteoporotic fractures that occur annually in the US, 29% occur in men. This percentage corresponds to an associated cost of 17 billion US dollars [3]. In men and women, the incidence of hip fractures increases exponentially with age, although in men, the increase begins approximately 10 years later [4]. Data from the U.S. 2008 Nationwide Emergency Department Sample showed the incidence of hip fracture in men ranging from 0.56 per 1000 per year at the age of 60 years to 13 per 1000 per year at age 85 years [5]. Similar results were reported in a Norwegian study covering the years 2004–۲۰۰۵, with an incidence of 0.49 per 1000 person-years of hip fractures in men at age 60 and 12.3 per 1000 person-years at age 85 [6]. A 60-year-old man has an approximately 25% risk of having an osteoporotic fracture during his remaining lifetime [7]. Men are less likely than women to be evaluated and receive antiresorptive treatment after a hip fracture [8,9]. The mortality rate associated with hip fractures [10,11] and vertebral and other fractures [12] is higher in men than in women. In a prospective study in community dwelling women and men aged 60 years and older in Australia, mortality after a low trauma fracture was 48% in women and 57% in men within 10 years [13]. The reason for this difference in mortality is not clear, but higher risk of infection in men than in women after a low trauma fracture could be one explanation [14].

Conclusion

     Male osteoporosis occurs less frequently than osteoporosis in postmenopausal women but is still responsible for a substantial disease burden in the population. Approximately 25% of fractures in patients over 50 years occur in men. Osteoporosis in men increases with age as in women, and mortality after major fragility fractures is greater in men than women. Male osteoporosis is defined by the occurrence of fragility fractures, in some parts of the world, only hip and spine fractures or by DXA BMD T-scores of −۲٫۵ or lower at the hip, lumbar spine, and/or forearm. Men having T-scores of −۲٫۵ or lower and prior fragility fractures are at high risk of future fractures. Men with T-scores between −۱٫۰ and −۲٫۵ should be assessed by FRAX or similar tools to determine fracture risk. At least half of men with osteoporosis have secondary causes of bone loss, and identification and treatment of these causes may help prevent further bone loss and possibly improve bone density. Treatment trials of osteoporosis in men have led to the approval of multiple medications for use in men, although these trials were typically small, short in duration, and used bone density rather than fracture endpoints.