Abdominal obesity and all-cause and cardiovascular mortality in end-stage renal disease.

OBJECTIVE: The aim of this study was to investigate the predictive value for all-cause and cardiovascular (CV) death of anthropometric measurements of abdominal obesity in patients with end-stage renal disease (ESRD).
BACKGROUND: Surrogate measures of abdominal obesity and segmental fat distribution (waist circumference and waist/hip ratio [WHR]) are stronger predictors of all-cause and CV death than body mass index (BMI) in the general population, but the issue has never been investigated in patients with ESRD.
METHODS: We performed a prospective cohort study in 537 patients with ESRD (age 63 +/- 15 years).
RESULTS: In BMI-adjusted Cox models, waist circumference was a direct predictor of all-cause and CV mortality (p < 0.001), whereas BMI showed an inverse relationship (p < 0.001) with these outcomes. The incidence rates of overall and CV death were maximal in patients with relatively lower BMI scores (below the median) and higher waist circumferences (at least the median) and minimal in patients with higher BMI scores (at least the median) and small waist circumferences (below the median). The prognostic power of waist circumference for all-cause (hazard ratio [HR] [10-cm increase]: 1.23; 95% confidence interval [CI]: 1.02 to 1.47; p = 0.03) and CV mortality (HR: 1.37; 95% CI: 1.09 to 1.73; p = 0.006) remained significant after adjustment for CV comorbidities and traditional and emerging risk factors. WHR was found to be related to all-cause (p = 0.009) and CV mortality (p = 0.07).
CONCLUSIONS: Abdominal obesity underlies a high risk of all-cause and CV mortality in patients with ESRD. Redefinition of nutritional status by combining the metrics of abdominal obesity and BMI may refine prognosis in the ESRD population.