Kidney Function and Fracture Risk: The Atherosclerosis Risk in Communities (ARIC) Study

People with end-stage renal disease are at high risk for bone fracture. Less is known about fracture risk in milder chronic kidney disease and whether chronic kidney disease-associated fracture risk varies by sex or assessment with alternative kidney markers.

Prospective cohort study.

10,955 participants from the Atherosclerosis Risk in Communities (ARIC) Study followed up from 1996 to 2011.

Kidney function as assessed by creatinine-based estimated glomerular filtration rate (eGFRcr), urine albumin-creatinine ratio, and alternative filtration markers.

Fracture-related hospitalizations determined by diagnostic code.

Baseline kidney markers; hospitalizations identified by self-report during annual telephone contact and active surveillance of local hospital discharge lists.

Mean age of participants was 63 years, 56% were women, and 22% were black. During a median follow-up of 13 years, there were 722 incident fracture-related hospitalizations. Older age, female sex, and white race were associated with higher risk for fracture (P<0.001). The relationship between eGFRcr and fracture risk was nonlinear: <60mL/min/1.73m(2), lower eGFRcr was associated with higher fracture risk (adjusted HR per 10mL/min/1.73m(2) lower, 1.24; 95% CI, 1.05-1.47); there was no statistically significant association for ≥60mL/min/1.73m(2) in the primary analysis. In contrast, there was a graded association between other markers of kidney function and subsequent fracture, including albumin-creatinine ratio (HR per doubling, 1.10; 95% CI, 1.06-1.14), cystatin C-based eGFR (HR per 1-SD decrease, 1.15; 95% CI, 1.06-1.25), and 1/β2-microglobulin (HR per 1-SD decrease, 1.26, 95% CI, 1.15-1.37).

No bone mineral density assessment; one-time measurement of kidney function.

Both low eGFR and higher albuminuria were significant risk factors for fracture in this community-based population. The shape of the association in the upper ranges of eGFR varied by the filtration marker used in estimation.