Risk factors for hip fractures in a middle-aged population: a study of 33,000 men and women

Abstract

Knowledge about subjects who sustain hip fractures in middle age is poor. This study prospectively investigated risk factors for hip fracture in middle age and compared risk factors for cervical and trochanteric hip fractures. The Malmö Preventive Project consists of 22,444 men, mean age 44 years, and 10,902 women, mean age 50 years at inclusion. Baseline assessment included multiple examinations and lifestyle information. Follow-up was up to 16 years with regard to occurrence of fracture. One hundred thirty-five women had one low-energy hip fracture each, 93 of which were cervical and 42 trochanteric. One hundred sixty-three men had 166 hip fractures, of which 81 were cervical and 85 trochanteric. In the final Cox regression model for women, the risk factors with the strongest associations with hip fracture were diabetes (risk ratio (RR) 3.89, 95% confidence interval (CI) 1.69-8.93, p=0.001) and poor self-rated health (RR 1.74, 95%CI 1.22-2.48, p=0.002). A history of previous fracture (RR 4.76, 95%CI 2.74-8.26, p=0.0001) was also a significant risk factor. In men, diabetes had the strongest association with hip fracture (RR 6.13, 95%CI 3.19-11.8, p=0.001). Smoking (RR 2.20, 95%CI 1.54-3.15, p=0.001), high serum gamma-glutamyl transferase (RR 1.84, 95%CI 1.50-2.26, p=0.001), poor self-rated health (RR 1.49, 95%CI 1.06-2.10, p=0.02) and reported sleep disturbances (RR 1.52, 95%CI 1.03-2.27, p=0.04) were other significant risk factors. The strongest risk factor for hip fracture for both women and men in middle age was diabetes. Many risk factors were similar for men and women, although the risk ratio differed. The risk factor pattern for cervical versus trochanteric fractures differed in both men and women. The findings indicate that those suffering a hip fracture before the age of 75 have a shorter life expectancy, suggesting that hip fractures affect the less healthy segment of the population.