Risk Factors for Hip Fracture in Older Men: The Osteoporotic Fractures in Men Study (MrOS)

Almost 30% of hip fractures occur in men; the mortality, morbidity, and loss of independence after hip fractures are greater in men than in women. To comprehensively evaluate risk factors for hip fracture in older men, we performed a prospective study of 5994 men, primarily white, age 65+ years recruited at six US clinical centers. During a mean of 8.6 years of 97% complete follow-up, 178 men experienced incident hip fractures. Information on risk factors including femoral neck bone mineral density (FNBMD) was obtained at the baseline visit. Cox proportional hazards models were used to calculate the hazard ratio (HR) with 95% confidence intervals; Fine and Gray models adjusted for competing mortality risk. Older age (≥75 years), low FNBMD, currently smoking, greater height and height loss since age 25 years, history of fracture, use of tricyclic antidepressants, history of myocardial infarction or angina, hyperthyroidism or Parkinson's disease, lower protein intake, and lower executive function were all associated with an increased hip fracture risk. Further adjustment for competing mortality attenuated HR for smoking, hyperthyroidism, and Parkinson's disease. The incidence rate of hip fracture per 1000 person-years (PY) was greatest in men with FNBMD T-scores <–2.5 (white women reference database) who also had 4+ risk factors, 33.4. Men age ≥80 years with 3+ major comorbidities experienced hip fracture at rates of 14.52 versus 0.88 per 1000 PY in men age <70 years with zero comorbidities. Older men with low FNBMD, multiple risk factors, and multimorbidity have a high risk of hip fracture. Many of these assessments can easily be incorporated into routine clinical practice and may lead to improved risk stratification.