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

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

AUTHORS: Natalie R. Daya, Annie Voskertchian, Andrea L.C. Schneider, Shoshana Ballew, Mara McAdams DeMarco, Josef Coresh, Lawrence J. Appel, Elizabeth Selvin, Morgan E. Grams

JOURNAL: Am J Kidney Dis. 2015 Aug 3. pii: S0272-6386(15)00946-4. doi: 10.1053/j.ajkd.2015.06.020. [Epub ahead of print]

Abstract

BACKGROUND: 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.

STUDY DESIGN: Prospective cohort study.

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

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

OUTCOMES: Fracture-related hospitalizations determined by diagnostic code.

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

RESULTS: 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 eGFR_cr and fracture risk was nonlinear: <60mL/min/1.73m², lower eGFR_cr was associated with higher fracture risk (adjusted HR per 10mL/min/1.73m² lower, 1.24; 95% CI, 1.05-1.47); there was no statistically significant association for ≥60mL/min/1.73m² 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).

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

CONCLUSIONS: 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.

For a link to the full article, click here: http://www.sciencedirect.com/science/article/pii/S0272638615009464

Link to abstract online: http://www.ncbi.nlm.nih.gov/pubmed/26250781