Some studies reveal that obesity is associated with a decrease in mortality in hemodialysis (HD) patients. However, few studies have addressed the association between body mass index (BMI) and peritoneal dialysis (PD) patients.
There was a longitudinal, retrospective study to evaluate the impact of obesity on peritoneal dialysis patients, using data from the Catalan Registry of Renal Patients from 2002 to 2015 (n = 1573). Obesity was defined as BMI ≥30; low weight: BMI <18.5; normal range: BMI = 18.5-24.99; and pre-obesity: BMI = 25-29.99 kg/m2. Variations in BMI were calculated during follow-up. The main outcomes evaluated were the technique and patient survival.
Obesity was observed in 20% of patients starting peritoneal dialysis. There were no differences in sex or peritoneal dialysis modality, with the obesity group being older and presenting more diabetes mellitus and cardiovascular disease . Scientists did not observe differences in blood parameters, such as hemoglobin, albumin and Kt/V in obese patients. Regarding peritonitis rate, we did not find any difference between groups, presenting more peritonitis patients on continuous ambulatory peritoneal dialysis and aged ≥65 years. In relation to technique survival, we found higher transfer to hemodialysis in the obese group of patients in the univariate analysis, which was not confirmed in the multivariate analysis , and we did not find differences in mortality rate. In relation to being transplanted, the underweight group, elderly and patients with cardiovascular conditions or diabetic nephropathy presented less probability to undergo kidney transplantation. Obese patients did not present differences in survival with weight changes but in normal-weight patients, a gain of 7% of the basal weight during the first year had a protective effect on death risk.
Conclusions: Obese and non-obese patients starting on hemodialysis had similar outcomes. Obesity did not influence survival rate during hemodialysis,but can lead to some comorbidities, such as cardiovascular conditions.