Background: Obesity is increasing worldwide and has become a nontraditional risk factor in chronic kidney disease (CKD).
Summary: Obesity-related nephropathy may aggravate renal complications of the metabolic syndrome and progress to advanced CKD stages, while obesity in early stages of CKD is clearly related to the development of kidney disease. A high body mass index (BMI) in advanced CKD stages and dialysis is an advantage for survival (so called "obesity paradox"). A high lean body to fat mass index indicates a beneficial state of body composition. In contrast, loss of muscle mass with increasing fat mass causes "sarcopenia obesity," which is related to unfavorable outcomes in renal replacement therapy. Obesity (BMI > 30-35) in renal transplant recipients is associated with a higher risk of complications such as delayed graft function, increased rates of rejection, and graft loss. While conservative management of morbid obesity is failing in most cases, bariatric surgery seems to be an option in some cases to improve renal complications in the early stage of CKD or in transplant candidates.
Key message: In conclusion, obesity is increasingly prevalent among CKD patients. Adequate management with respect to the specific role of obesity in different stages of CKD should be integrated in routine renal care.
Keywords: Chronic kidney disease; Dialysis; Kidney transplantation; Nephropathy; Obesity.