Assessment of obesity in chronic kidney disease: what is the best measure?

Purpose of review Obesity is a major driver of the current epidemic of chronic kidney disease (CKD), but metrics of obesity in the CKD population have been studied sparsely. This review updates knowledge on this issue. Recent findings Measures of abdominal obesity, waist circumference and waist-to-hip ratio (WHR), are better predictors than BMI of the high risk of mortality in predialysis and dialysis patients and waist circumference reliably reflects visceral fat in CKD patients. Skinfold thickness and WHR are superior to BMI for the classification of obesity in CKD patients. Multifrequency body impedance analysis (BIA) provides valid estimates of fat mass in hemodialysis patients. Summary Skinfold thickness, WHR and multifrequency BIA are superior to BMI for measuring body fat in CKD patients and measures of abdominal obesity are stronger predictors of adverse clinical outcomes than the BMI. These metrics should be preferentially applied for the assessment of obesity in CKD, but it remains unproven that these techniques offer real advantages over the BMI in clinical practice in CKD patients.