Body fat measurement in chronic kidney disease: implications in research and clinical practice

The paradoxical and inverse association between body mass index and mortality risk in patients with end-stage renal disease has raised a question of whether an increased fat mass is good or bad for patients with chronic kidney disease. The purpose of this review is to update the concept on body fat in patients with chronic kidney disease.

A greater fat mass is an independent predictor of better survival in patients on maintenance hemodialysis. Following the initiation of dialysis, chronic kidney disease patients gain body weight due mainly to increased fat mass. Fat mass gain over time predicts better survival in hemodialysis patients. In predialysis chronic kidney disease, there is also an inverse association between body mass index and mortality risk. The metabolic syndrome and a high body mass index are independent predictors for development of chronic kidney disease and end-stage renal disease, respectively. In diabetic patients with chronic kidney disease, however, a high initial body mass index is associated with a slower decline in glomerular filtration rate.

The impacts of fat mass on survival and renal function appear to vary depending upon the absence or presence, and stages of chronic kidney disease. Further research is required for optimal nutritional management and improved outcomes of patients with chronic kidney disease.