Osteoporosis affects approximately 200 million individuals worldwide. With aging as a top risk factor for the disease, its prevalence is growing as the elderly population expands.1 Osteoporosis is 4 times more common in women than men, and there are numerous other disparities between the sexes in the pathogenesis, management, and outcomes of osteoporosis.2
“While it is certainly more common in women, men with osteoporosis may actually have more associated complications,” Christine Peoples, MD, a rheumatologist and clinical assistant professor of medicine at the University of Pittsburgh Medical Center in Pennsylvania, told Endocrinology Advisor.
Additionally, men are generally screened for osteoporosis less often than women are, and they tend to be undertreated when they are diagnosed with the disease.
Although the growth of bone mineral density and content is delayed in boys compared with girls, they are often higher in males by adulthood. For example, a 2009 study used dual energy x-ray absorptiometry (DXA) to compare young male and female students aged 19 to 25 years on measures of bone density in the spine, total femur, and distal third of the radius and found that bone density was higher at all 3 sites in young men.3
Boys were also found to achieve peak bone density later than girls, particularly in the spine. The observed difference in density was not accounted for by diet or physical activity level. Other findings suggest that it is not explained by lean mass, which tends to be higher in males, although it may be due to increased bone size in males.4,5
Bone loss occurs at younger ages and higher rates in women vs men. A longitudinal study observed that rapid bone loss occurred in men aged 74 to 79 years vs aged 65 to 69 years in women, and the Framingham Osteoporosis Study showed that the average 4-year bone loss at a mean age of 74 was 0.2% to 3.6% in men vs 3.4% to 4.8% in women.6,7 Weight loss in both men and women and smoking in men were noted as modifiable risk factors for bone loss.
Estrogen deficiency contributes to osteoporosis in both sexes, and it is more significant in women and begins at a younger age.8,9 In addition, men lost more endosteal bone than women, but this is offset by more substantial gains in periosteal bone, resulting in greater bone strength compared with women.10
Fracture Risk and Related Mortality
The estimated lifetime fracture risk is 53.2% in women vs 20.7% in men, and the rate of vertebral and hip fractures increases sharply for women starting roughly 10 years earlier — at ages 55 and 65 vs 65 and 75 in men.11,12
“The increased fractures that are observed in women may be explained by their smaller bone size, early onset increased bone resorption and fall risk,” according to a recent review.2 “Larger bones in men are somewhat protective and increase [the] bone strength compared with women.”
Although women have a higher risk for fractures, men have increased mortality rates after osteoporosis-related fractures. In 2 large studies of mortality rates following hip fracture, for instance, men had mortality rates of 31% and 37.1% in the first year, compared with 17% and 26.4% in women.13,14 When controlling for age, comorbidities, fracture site, and medications, the mortality risk was 70% higher in men vs women. Infection may be one reason for the elevated risk, as indicated by findings of a similar mortality risk in men and women when controlling for infection.15
Men generally receive osteoporosis treatment less often than women even after sustaining a fracture. Men are less commonly prescribed bisphosphonate, which has been found to reduce mortality risk following hip fracture. In 2 separate studies investigating treatment after hip fracture, 8% and 9% of men received appropriate treatment vs 23.3% and 48% of women.16,17