Chronic kidney disease and hip fracture-related mortality in older people in the UK

Background. Dialysis patients have increased hip fracture rates when compared to the general population of the same age and sex. There have been few studies of the association of earlier stages of chronic kidney disease (CKD) with hip fractures amongst older people in the general population. The aim of this study was to examine whether CKD at older ages is associated with hip-fracture-related mortality. Methods. In a trial of health and social assessment of people aged 75 and over in the UK with baseline assessment between 1995 and 1998, there were 13 177 (87%) participants in 53 general practices who had a serum creatinine measured at baseline. Estimated glomerular filtration rate (eGFR) was derived from the modification of diet in renal disease formula (MDRD). Mortality follow-up using linkage to national mortality data was until the end of November 2005. We used propensity scores to adjust for potential confounders in Cox regression models. Results. There were 84 hip-fracture-related deaths over a median follow-up of 7.25 years (IQR 3.79-8.77). Compared to eGFR 60 ml/min/1.73 m(2) and above, the age- and sex-adjusted hazard ratio (HR) for hip-fracture-related death was 1.06 (95% confidence interval: 0.71, 1.58) for eGFR 45-59 and 1.98 (1.12, 3.50) for eGFR < 45. In adjusted models, the HR for eGFR < 45 ml/min/1.73 m(2) compared to above was 1.81 (1.11, 2.96). Conclusions. Amongst older people, an eGFR of < 45 ml/ min/1.73 m(2) is associated with an almost 2-fold increase in hip-fracture-related mortality.