Depression and hip fracture risk: the NHANES I epidemiologic follow-up study

Since hip fracture is the most devastating consequence of osteoporosis from a public health standpoint, addressing whether depression is predictive of fracture risk is important. The purpose of this study is to determine whether individuals with high depressive symptomatology are more likely to suffer an osteoporotic hip fracture than subjects with intermediate or low depressive symptomatology.

Data from the first National Health and Nutrition Examination Survey (NHANES I) were obtained from a nationally representative sample of noninstitutionalized civilians. A cohort aged 25 through 74 at baseline (1971-1975) was observed through 1992. Subjects were followed-up for a maximum of 22 years. Included in the analyses were 6,195 white and black subjects. Ninety-five percent of the original cohort completed the study. Hospital records and death certificates were used to identify a total of 122 hip fracture cases.

In an unadjusted Cox proportional hazards regression model for all individuals, depression was predictive of hip fracture (hazard ratio [HR]=1.90; 95% confidence interval [CI]=1.13, 3.21; p=0.016). In a multivariate proportional hazards model controlling for (1) age at baseline, (2) gender, (3) race, (4) body mass index, (5) smoking status, (6) alcohol consumption, and (7) physical activity level, high depressive symptomatology remained predictive of hip fracture (HR=1.70; 95% CI=0.99, 2.91; p=0.055).

This study gives evidence of a prospective association between depression and hip fracture. Additional studies are needed to verify these findings and to elucidate the pathways for the effects of depression on hip fracture incidence.