Background: Case-mix comorbidities and malnutrition influence outcome in continuous ambulatory peritoneal dialysis (CAPD) patients. In the present study, we analyzed the influence of stratified comorbidities on nutrition indices and survival in CAPD patients.
Patients and methods: We categorized 373 CAPD patients (197 with and 176 without diabetes) into three risk groups: low-age under 70 years and no comorbid illness; medium- age 70 - 80 years, or any age with 1 comorbid illness, or age under 70 years with diabetes; high-age over 80 years, or any age with 2 comorbid illnesses. We then compared nutrition indices and malnutrition by subjective global assessment (SGA) between the three groups. Survival was compared using Kaplan-Meier survival analysis.
Results: Mean daily calorie and protein intakes in the low-risk group (21 +/- 6.7 Kcal/kg, 0.85 +/- 0.28 g/kg) were significantly higher than in the medium- (17.6 +/- 5.2 Kcal/kg, 0.79 +/- 0.25 g/kg) and high-risk (17.5 +/- 6.1 Kcal/kg, 0.78 +/- 0.26 g/kg) groups (p = 0.001 and p = 0.04 respectively). Relative risk (RR) of malnutrition was less in the low-risk group (103/147, 70.06%) than in the medium-risk group [135/162, 83.3%; RR: 2.0; 95% confidence interval (CI): 2.1 to 3.4; p = 0.01] or the high-risk group (54/64, 84.4%; RR: 2.3; 95% CI: 2.1 to 4.9; p = 0.03). Mean survivals of patients in the low-, medium-, and high-risk groups were 51 patient-months (95% CI: 45.6 to 56.4 patient-months), 43.3 patient-months (95% CI: 37.8 to 48.7 patient-months), and 29.7 patient-months (95% CI: 23 to 36.4 patient-months) respectively (log-rank: 35.9 patient-months; p = 0.001). The 1-, 2-, 3-, 4-, and 5-year patient survivals in the low-, medium-, and high-risk groups were 96%, 87%, 79%, 65%, and 56%; 89%, 67%, 54%, 43%, and 34%; and 76%, 48%, 31%, 30%, and 30% respectively.
Conclusions: Intake of calories and protein was significantly lower in the medium-risk and high-risk groups than in the low-risk group. Survival was significantly better in low-risk patients than in medium- and high-risk patients.