Factors Affecting Serum Albumin Level in Continuous Ambulatory Peritoneal Dialysis Patients

Ma, Kyoung Ai; Lee, Seoung Woo; Kang, Shin Wook; Choi, Kyu Hun; Lee, Ho Yung; Cho, Eun Young; Lee, Jong Ho; Han, Dae Suk

Abstract

OBJECTIVES
Protein-calorie malnutrition is a common problem in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). Serum albumin(SA) concentration has been used as a marker for assessing nutritional status. Hypoalbuminemia has been linked to an increased risk of morbidity and mortality and more numerous, prolonged hospitalization for peritoneal dialysis patients. The aim of this study was to determine factors affecting SA value in CAPD patients.
METHODS
We performed a cross-sectional study which included patients' demographics, anthropometric data, biochemical parameters, urea kinetic data and comorbidity in 106 stable CAPD patients.
RESULTS
1) There were 50 men and 56 women with a mean CAPD duration of 43 months and mean age of 49 years. The mean concentration of SA was 3.9+/-0.5 (range 2.5-5.3) g/dl and weekly Kt/Vurea 2.0+/-0.4 (range 1.32-3.79) 2) Twenty-one patients(20%) were classified as group I(SA<3.5g/dl)and the remaining patients(80%) as group II(SA 3.5g/dl) 3) Group I patients were significantly older(55+/-11 vs 47+/-11 years, p<0.05) and had significantly higher comorbidity score(1.5+/-0.8 vs 0.7+/-0.9, p<0.05), C-reactive protein (4.5+/-0.9 vs 0.5+/-0.1 mg/dl, p<0.05), 24-hr dialysate-toplasma creatinine(D/PCr) ratio(0.84+/-0.1 vs 0.76+/-0.1, p<0.05), 24-hr dialysate protein (7167+/-2031 vs 5471+/-1515 mg, p<0.05) and had significantly lower residual renal function(RRF)(0.2+/-0.3 vs 0.7+/-1.2 ml/min, p<0.05), BUN(48+/-14.8 vs 55.6+/-14.9 mg/dl, p<0.05), serum creatinine(10.4+/-2.8 vs 12.6+/-3.5 mg/dl, p<0.05), IGF-1(186+/-99 vs 260+/-131 ng/ml, p<0.05), serum phosphorus(4.1+/-1.2 vs 5.0+/-1.3 mg /dl, p<0.05) than group II.4) SA showed positive correlation with anion gap (r=0.43, p value=0.001), transferrin(r=0.41, p value= 0.001) phosphorus(r=0.31, p value=0.001) and negative correlation with 24-hr dialysate protein loss(r=-0.51, p value=0.001), 24-hr D/PCr ratio(r=-0.49, p value=0.001), comorbidity score(r=-0.36, p vluue=0.001). NPCR(r=0.22, p value=0.023), IGF-1(r=0.30, p value=0.002), BUN(r=0.23, p value=0.016) weakly correlated with SA.5) By stepwise multiple logistic regression analysis, age, CRP, 24-hr D/PCr ratio and RRF independently influenced SA level.
CONCLUSION
SA level seems to be affected by non-nutritional factors such as age, peritoneal membrane transport characteristics, residual renal function and presence of acute phase protein response manifested by CRP elevation, in addition to nutritional factors.