A 3-year, prospective, randomized, controlled study on amino acid dialysate in patients on CAPD

Malnutrition is prevalent in patients on continuous ambulatory peritoneal dialysis (CAPD) and confers a poor prognosis. Inadequate nutrient intake is an important contributing factor. Although short-term studies have shown mild to modest nutritional benefit with amino acid dialysate, its long-term effects and tolerability remain obscure.

The authors have performed a 3-year, randomized, prospective, controlled study of amino acid dialysate in malnourished Chinese patients on CAPD. Sixty patients were assigned randomly to either replace 1 exchange daily with amino acid dialysate (Nutrineal; DAA group, n = 30) or to continue with dextrose dialysate (Dianeal; DD group, n = 30).

The 2 groups had similar mortality, hospitalization duration, serial C-reactive protein levels, and drop-out rates during the study. Biochemical nutritional parameters including albumin and cholesterol decreased in the DD group but remained stable or increased in the DAA group. The composite nutritional index did not differ between the 2 groups throughout the study period. Triglyceride decreased only in DAA-treated patients. Normalized protein equivalent of nitrogen appearance and dietary protein intake showed a sustained increase only in DAA patients. The nutritional benefit of DAA appeared more prominent in women, whose lean body mass and body mass index was maintained with DAA but not with DD. Mass transfer area coefficient for creatinine increased in DAA-treated patients, whereas that for urea as well as macromolecular restriction coefficients remained stable. Total Kt/V(urea) and daily ultrafiltration volume were similarly maintained in the 2 groups throughout the study.

Long-term administration of amino acid dialysate is well tolerated and presents a means to improve the nutritional status in high-risk patients. The current study, however, has not shown a significant effect of amino acid dialysate on patient survival.