Risk factors for fractures in older men and women: The Leisure World Cohort Study

Abstract

Background: Osteoporosis results in >1.5 million fractures in the United States each year, leading to substantial health care costs and loss of quality of life. One major gap in our knowledge is how to effectively identify individuals at risk of developing a fracture.

Objective: We examined a population-based cohort for risk factors for fractures of the hip, wrist, and spine in men and women.

Methods: The Leisure World Cohort Study was established between 1981 and 1985 when residents of a southern California retirement community completed a postal health survey. Multiple lifestyle, medical, attitudinal, and anthropomorphic factors were self-reported. Fractures were identified from 4 follow-up surveys, hospital discharge records, and death certificates. Fracture rates were determined separately for men and women. Cox proportional hazards regression was used to identify predictors of fracture.

Results: Incident fractures of the hip (n = 1,227), wrist (n = 445), and spine (n = 729) incurred over the course of 2 decades were identified in the 13,978 residents surveyed. Mean (SD) age at entry was 74.9 (7.2) years for men and 73.7 (7.4) years for women. The most important risk factors for fracture were the same in men and women: age increased risk of hip and spine fractures (hazard ratio [HR] = 2.3-3.2 per 10 years) and history of fracture increased fracture risk at all 3 sites (HR = 1.4-3.2). In both men and women, glaucoma was a significant risk factor for hip fracture (HR = 1.9 and 1.3, respectively), and smoking was a risk factor for hip and spine fractures. Men and women with a positive mental attitude had fewer hip and spine fractures (HR = 0.7-0.9). High body mass index was protective at all 3 fracture sites in women (HR = 0.7-0.8), but those who used vitamin A supplements had increased rates of hip and wrist fracture (HR = 1.1 per 10,000 IU per day).

Conclusions: Attitude, lifestyle choices, and the presence of medical conditions may influence the rate of osteoporotic fracture in older women and men and may help identify individuals at high risk.