Older men have a higher risk than women of sustaining secondary fractures within a few years of their first fracture, but moderate physical activity may improve bone strength, potentially reducing their risk of fractures, according to two studies presented at the annual meeting of the American Society for Bone and Mineral Research in Montreal.

Dr. Suzanne N. Morin, associate professor of medicine at McGill University in Montreal

Dr. Suzanne N. Morin

The first study, a matched historical cohort of 57,783 people aged 50 or older (40,062 women and 17,721 men) in Manitoba, Canada, found that men had a threefold higher risk of sustaining a secondary major osteoporotic fracture (MOF) within 1 year of a first fracture, compared with healthy controls. The risk for women, by comparison, was 1.8 times higher than in age-matched controls who did not experience a fracture. These risks declined over time but remained elevated even as much as 15-25 years after the index fracture, according to primary investigator Suzanne N. Morin, MD, of the department of medicine at McGill University in Montreal.

“Often, men and clinicians don’t think men have skeletal fragility – everybody thinks it’s a women’s disease,” Dr. Morin said. “It’s true that it’s more frequent in women, but men do have osteoporosis, and often when they have it, they tend to have more serious complications following the fractures.” This includes higher risk of subsequent fractures and higher mortality, she said. “If you see an older gentleman with a fracture, it really should be some kind of an alarm signal.”

Using administrative health care databases, Dr. Morin and her colleagues reviewed records of patients who had an index MOF between 1989 and 2006. They compared rates of subsequent MOFs until 2016 with those of age- and sex-matched controls (n = 165,965), allowing for between 10 and 25 years of follow-up.

Researchers identified 29,694 index MOF cases (11,028 to the wrist, 9,313 to the hip, 5,799 to the humerus, and 3,554 to the spine). The annual crude rate of subsequent MOFs per 1,000 person-years was 18.5 in men (95% confidence interval, 17.3-19.8) and 29.6 in women (95% CI, 28.8-30.4). The cumulative incidence of subsequent MOFs up to 25 years later was higher in cases versus controls for both sexes and across all ages except those over 80.

Hazard ratios for subsequent MOFs were higher in men than women, particularly in the first year following the index fracture and remained very high for men during the first 3 years of follow-up. Across all follow-up years, men who had fractures were 2.5 times more likely to experience a secondary MOF (95% CI, 2.3-2.7) and women who had fractures were 1.6 times more likely to experience a secondary MOF (95% CI, 1.6-1.7), compared with controls.

To prevent fractures, clinicians should consider gait or balance training for older men and women, especially those who already have experienced a fracture, Dr. Morin said. Physicians also should note any medications such as sedatives that put patients at higher risk for falls and consider medications like bisphosphonates to reduce fracture risk. Additionally, they should ensure there are no underlying causes for skeletal fragility, such as severe vitamin D deficiency or a hormonal imbalance, she said.

Physical activity could reduce risk

In a second, unrelated study, researchers found that moderate physical activity may have a modest effect on bone strength in older men, accounting for up to a 20% lower fracture risk, according to Lisa Langsetmo, PhD, primary investigator and a senior research associate at the University of Minnesota, Minneapolis. She and her colleagues studied physical activity and bone strength in 994 older men (mean age 83.9) participating in the Osteoporotic Fractures in Men (MrOS) Study, a longitudinal, observational study of musculoskeletal health in older American men that initially enrolled about 6,000 participants.

Dr. Lisa Langsetmo, senior research associate at the University of Minnesota, Minneapolis

Dr. Lisa Langsetmo

Participants wore armband activity monitors for 5 days during their year-7 and year-14 assessments; investigators averaged their physical activity over the two time points and used armband data along with factors like height, weight, and smoking status to estimate total energy expenditure (TEE), total steps per day, and level of activity, from sedentary to at least moderate. The men also underwent bone microarchitecture assessments of the distal radius and tibia using high-resolution peripheral quantitative computed tomography (HR-pQCT), a technique that produces detailed pictures of the bones. Investigators used mathematical models to predict failure load, or the force required to break a bone – a predictor of osteoporotic fractures in men. They also computed total, cortical, and trabecular volumetric bone mineral density (BMD).

Overall, researchers found that time spent doing at least moderate activity versus time spent in sedentary activity was related to better bone strength at both sites, whereas time spent in light activity was not. The results suggest that at least moderate physical activity such as vigorous walking averaged over a period of time may have a modest effect on bone strength among older men, Dr. Langsetmo said.

“This is important for older men,” she said. “They may not be able to jog any more but they may be able to do more moderate activity.” Physicians should ask older male patients about their activity levels and any barriers to activity, or consider a referral to a physical therapist to keep them active, she said.

Higher TEE, step count, and peak 30-minute cadence (P30MC), a measure of vigorous activity, were each associated with higher failure load of the distal radius (effect size 0.08-0.13) but not higher volumetric or compartment-specific BMD. These measures also were associated with higher failure load of the distal tibia (effect size 0.19-0.21), higher volumetric BMD (effect size 0.08-0.15), higher trabecular BMD (effect size 0.07-0.11), and higher cortical BMD (0.09-0.13).

The first study was funded internally; Manitoba Health provided the data. The second study was funded by the National Institutes of Health. Dr. Morin and Dr. Langsetmo reported no relevant financial disclosures.