Change in nutritional status of patients on peritoneal dialysis

Objective: To document the prevalence of undernutrition/overnutrition in patients on peritoneal dialysis (PD) and to examine whether nutritional status (NS) changes with time on this form of dialysis. Design: Retrospective observational study. Patients had been on PD >2 years. Data included age, gender, diagnosis, peritonitis rate, anthropometry and biochemistry. A classification system for NS was devised using BMI, TSF, MAMC and serum albumin. Setting: Regional Peritoneal Dialysis Programme, University Teaching Hospital. Patients: 82 patients were on PD on March 1994. A cohort of 28 patients remained on PD after 2 years and complete nutritional data was available for 23 of these patients (9 male, 14 female: mean age 58yrs). Results: 65% of patients were classified as having an acceptable NS at the start of PD and 56% were classified as acceptable at the latest assessment. The prevalence of mild/moderate undernutrition both at the start of PD and at the latest assessment was 26% (different patients at each assessment). No patients were classified as severely undernourished. The prevalence of overnutrition at the start of PD was 9% and at the latest assessment was 17%. There was no statistically significant difference in NS between diabetics and non-diabetics nor between male and female patients although undernutrition was more frequently observed in males. Overnutrition increased with time in both genders but this did not reach statistical significance. There was no difference in initial NS between those who remained on PD and those who died. Change in NS was not related to peritonitis rate. Conclusion: Whereas this study has insufficient statistical power to avoid a Type II error it supports our clinical observation that NS does not substantially change with time in this population. There are, however, a small number of individuals who exhibit changes in NS. Given the difficulty in predicting change in NS with time, regular nutritional assessment is important to identify those who require more intensive dietetic intervention.