Physical activity and hip fracture: a population-based case-control study

Background A growing body of literature suggests that physical activity may be a protective factor against hip fracture. Methods To study the association between hip fracture risk and recreational physical activity at various ages, changes in activity during adult life, occupational physical activity and how risks vary by adult weight change, w e performed a population-based case-control study among postmenopausal wome n aged 50-81 years residing in six counties in Sweden in 1993-1995. The ana lysis consisted of 1327 women with hip fracture and 3262 randomly selected controls. Information on leisure physical activity before age 18, at 18-30 years and during recent years was based on a questionnaire. Data on occupat ional physical activity were collected through an independent classificatio n of job titles obtained from record linkage with census data from 1960, 19 70 and 1980. Results There was a protective effect of recent leisure physical activity. Compared to women who reported no leisure activity, the odds ratios (OR) we re 0.79 (95% CI:0.62-1.00), 0.67 (95% CI:0.54-0.84) and 0.48 (95% CI:0.39-0 .60) for women who exercised <1 h per week, 1-2 h per week, and 3+ h per we ek, respectively. These decreased OR were more pronounced in women who had lost weight after 18 years of age than in those who had gained weight. Wome n with high physical activity at both 18-30 years and during recent years d id not have a stronger protection than those with isolated high activity la te in life, after accounting for recent activity. Occupational physical act ivity was not associated with hip fracture risk in this study. Conclusions Recent physical activity is protective against hip fracture. Th e protective effect is most pronounced in women who had lost weight after a ge 18.