*2.5. Renal Replacement Therapy*

The increasing prevalence of obesity produces a challenge for optimal care of patients in renal replacement therapy, in both hemo- and peritoneal dialysis [80]. In the case of hemodialysis, at 3 years, adiposity of the subcutaneous tissue produced problems with vascular access and a reduction in the catheter functionality. Moreover, in obese subjects, increased dialysis time or frequency is necessary, and it is more difficult to achieve the dry weight. Proximal calciphylaxis is more frequent in obese than in lean patients. In patients on peritoneal dialysis, catheter malfunction and exit site infections are more prevalent in obese subjects. In some patients with severe adiposity, a prophylactic omentectomy could be useful. In addition, patients with advanced CKD, especially those undergoing dialysis, tend to have severe nutritional disorders, protein-energy wasting, and the presence of obesity may be better in this population, an obesity paradox [81].
