A low-protein diet does not necessarily lead to malnutrition in peritoneal dialysis patients

Background: The Dialysis Outcomes Quality Initiative (DOQI) group guideline recommends that the dietary protein intake (DPI) for peritoneal dialysis patients should be more than 1.2 g/kg/d. However, this target is not realistic for many Chinese peritoneal dialysis patients. In the present study, we investigated the impact of a low-protein diet on patients' nutritional status in a longitudinal cohort study in peritoneal dialysis patients. Methods: Forty-seven peritoneal dialysis patients who had been on peritoneal dialysis for at least 3 months by the end of 2002 were included in the present study. All of the patients were followed up for 1 year, The patients were asked to collect their 3-day dietary record once every 3 months, and dialysis adequacy was evaluated once every 6 months. Subjective global assessment was performed at the beginning and by the end of the study. Comorbidities occurring during the follow-up were recorded. Fluid status was assessed once every 3 months. Patients were divided into three groups, with patients having a consistent DPI >= 0.8 g/kg/d in group 1, patients with a variable DPI in group 2, and patients with a consistent DPI < 0.8 g/kg/d in group 3. Results: There were 12, 18, and 17 patients in groups 1, 2, and 3, respectively. At the beginning of the study, 53.2% of the patients were malnourished. During the follow-up, nutritional status had improved in 12 patients, did not change in 32 patients, and had worsened in 3 patients. By the end of the follow-up, 34% of the patients were malnourished with only one severely malnourished patient. Malnourished patients by the end of the study had a significantly higher incidence of new comorbidities, more inflammation, and a higher incidence of fluid overload. There were no significant differences in the dialysis adequacy index among the three groups, Conclusions: Our study suggests that (1) many Chinese peritoneal dialysis patients did not achieve a high protein intake as recommended by the DOQI, but the low-protein diet does not necessarily lead to malnutrition in these patients, and (2) comorbidities occurring during the follow-up and volume overload may be the important risk factors for malnutrition in peritoneal dialysis patients. (c) 2005 by the National Kidney Foundation, Inc.