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 > or = 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.