Both romosozumab and calcium help fracture prevention, and most young adults have fractures at nonosteoporotic sites.
Romosozumab Helps Fracture Prevention in Women with Osteoporosis
Kenneth Saag and colleagues investigated romosozumab, a monoclonal antibody that binds to and inhibits sclerostin, increases bone formation, and decreases bone resorption, for fracture prevention in women with osteoporosis.
They enrolled 4093 postmenopausal women with osteoporosis and a fragility fracture and randomly assigned them in a 1:1 ratio to receive monthly subcutaneous romosozumab (210 mg) or weekly oral alendronate (70 mg) for 12 months, followed by open-label alendronate in both groups.
The cumulative incidence of new vertebral fracture at 24 months and the cumulative incidence of clinical fracture at the time of the primary analysis were the primary end points. The incidences of nonvertebral and hip fracture at the time of the primary analysis were secondary end points.
Serious cardiovascular adverse events, osteonecrosis of the jaw, and atypical femoral fractures were adjudicated.
• Over 24 months, a 48% lower risk of new vertebral fractures was observed in the romosozumab-to-alendronate group than in the alendronate-to-alendronate group.
• Clinical fractures occurred in 9.7% of patients in the romosozumab-to-alendronate group compared with 13.0% of patients in the alendronate-to-alendronate group, representing a 27% lower risk with romosozumab.
• The risk of nonvertebral fractures and the risk of hip fracture was lower by 19% and by 38%, respectively, in the romosozumab-to-alendronate group than in the alendronate-to-alendronate group.
• Overall adverse events and serious adverse events were balanced between the groups.
• During year 1, positively adjudicated serious cardiovascular adverse events were observed more often with romosozumab than with alendronate.
• During the open-label alendronate period, adjudicated events of osteonecrosis of the jaw and atypical femoral fracture were observed.
The authors concluded that romosozumab treatment for 12 months followed by alendronate resulted in a significantly lower risk of fracture than alendronate alone in postmenopausal women with osteoporosis who were at high risk for fracture.
Clinical Guide Cites Calcium in Postmenopausal Osteoporosis Prevention
A new clinical guide designed to raise awareness of the importance of calcium in lowering the risk of osteoporosis was issued by the European Menopause and Andropause Society.
Even with guidance provided by scientific societies and governmental bodies, many issues remain unresolved, it was noted.
A literature review and consensus of expert opinion were used to provide evidence on the impact of calcium intake on postmenopausal osteoporosis prevention and to critically appraise current guidelines.
Some of the results:
• The recommended daily intake of calcium varies between 700 and 1200 mg of elemental calcium, depending on the endorsing source.
• Calcium can be derived from the diet or from supplements, but diet is the preferred source.
• Intake below the recommended amount may increase fragility fracture risk, but there is no consistent evidence that calcium supplementation at or above recommended levels reduces risk.
• The addition of vitamin D may minimally reduce fractures, mainly among institutionalized persons.
• Excessive intake of calcium, defined as more than 2000 mg/d, can be harmful.
• Some studies demonstrated harm even at lower dosages.
• An increased risk of cardiovascular events, urolithiasis, and fractures has been found in association with excessive calcium intake.
The clinical guide recommended an adequate intake of calcium for general bone health and concluded that excessive calcium intake seems of no benefit and could be harmful.
Most Fractures in Young Adults Occur at Nonosteoporotic Sites
Because investigations of fractures generally focus on pediatric and older populations, Mayo Clinic researchers conducted a population-based study to look at the age group in between, young adults.
They used the comprehensive data resources of the Rochester Epidemiology Project to determine incidence rates for all fractures among young adults aged 18 to 49 years who were residents of Olmsted County, Minnesota, in 2009 to 2011. They compared the distribution of fracture sites and causes in this cohort with those for residents aged 50 years and older.
• During the 3-year study period, 2482 residents aged 18 to 49 years experienced 1 or more fractures.
• There were 1730 fractures among 1447 men compared with 1164 among 1035 women. The age-adjusted incidence of all fractures was 66% greater among the men.
• Of all fractures, 80% resulted from severe trauma compared with 33% in residents aged 50 years and older who sustained a fracture.
• Younger residents (aged 18 to 49 years), when compared with older residents (aged ≥50 years), had
A greater proportion of fractures occurred in the hands and feet in younger residents than in older residents (40% vs 18%). Relatively few fractures were observed at traditional osteoporotic fracture sites (14% vs 43%).
• Vertebral fractures were more likely to be the result of moderate trauma than fractures at other sites, especially in younger women.
The authors concluded that pediatric and older populations often fracture from no more than moderate trauma, but young adults, and more frequently men, experience fractures primarily at nonosteoporotic sites because of more significant trauma.