Waist-to-Hip Ratio, Body Mass Index, and Subsequent Kidney Disease and Death
Received 31 December 2007; accepted 25 February 2008. published online 30 May 2008.
Background
Chronic kidney disease (CKD) and obesity are important public health concerns. We examined the association between anthropomorphic measures and incident CKD and mortality.
Study Design
Cohort study.
Setting & Participants
Individual patient data pooled from the Atherosclerosis Risk in Communities Study and the Cardiovascular Health Study.
Predictors
Waist-to-hip ratio (WHR), body mass index (BMI).
Outcomes & Measurements
Incident CKD defined as serum creatinine level increase greater than 0.4 mg/dL with baseline creatinine level of 1.4 mg/dL or less in men and 1.2 mg/dL or less in women and final creatinine level greater than these levels, and, in separate analyses, estimated glomerular filtration rate (eGFR) decrease of 15 mL/min/1.73 m2 or greater with baseline eGFR of 60 mL/min/1.73 m2 or greater and final eGFR less than 60 mL/min/1.73 m2. Multivariable logistic regression to determine the association between WHR, BMI, and outcomes. Cox models to evaluate a secondary composite outcome of all-cause mortality and incident CKD.
Results
Of 13,324 individuals, mean WHR was 0.96 in men and 0.89 in women and mean BMI was 27.2 kg/m2 in both men and women. During 9.3 years, 300 patients (2.3%) in creatinine-based models and 710 patients (5.5%) in eGFR-based models developed CKD. In creatinine-based models, each SD increase in WHR was associated with increased risk of incident CKD (odds ratio, 1.22; 95% confidence interval [CI], 1.05 to 1.43) and the composite outcome (hazard ratio, 1.12; 95% CI, 1.06 to 1.18), whereas each SD increase in BMI was not associated with CKD (odds ratio, 1.05; 95% CI, 0.93 to 1.20) and appeared protective for the composite outcome (hazard ratio, 0.94; 95% CI, 0.90 to 0.99). Results of eGFR-based models were similar.
Limitations
Single measures of creatinine, no albuminuria data.
Conclusions
WHR, but not BMI, is associated with incident CKD and mortality. Assessment of CKD risk should use WHR rather than BMI as an anthropomorphic measure of obesity.
1Nephrology Research Center, Tufts-New England Medical Center, Boston, MA
2Biostatistics Research Center, Tufts-New England Medical Center, Boston, MA
3Preventive Medicine, Brigham and Women's Hospital, Boston, MA
4Division of Cardiology, Tufts-New England Medical Center, Boston, MA.
Address correspondence to Daniel E. Weiner, MD, MS, Division of Nephrology, Box #391, Tufts Medical Center, Boston, MA 02111.
Because an author of this manuscript is an editor for AJKD, the peer-review and decision-making processes were handled entirely by an Associate Editor (Katherine Tuttle, MD, Sacred Heart Medical Center) who served as Acting Editor-in-Chief. Details of the journal's procedures for potential editor conflicts are given in the Editorial Policies section of the AJKD website.
ABSTRACT