Effects of ultrapure dialysis fluid on nutritional status and inflammatory parameters.
BACKGROUND
Malnutrition and chronic systemic inflammatory response syndrome not only coexist in uraemia, but may also have a bi-directional cause-and-effect relationship. To evaluate the role of dialysate-related cytokine induction in inflammatory response and nutritional status, we conducted a prospective comparison of two dialysis fluids differing in their microbiological quality.


METHODS
Forty-eight early haemodialysis patients were assigned to either treatment with conventional (potentially microbiologically contaminated) or on-line produced ultrapure dialysis fluid. Study parameters were bacterial growth, markers of systemic inflammation (C-reactive protein (CRP) and interleukin 6), and parameters of nutritional status (estimated dry weight, upper mid-arm muscle circumference, serum albumin concentration, insulin-like growth factor 1, leptin, and protein catabolic rate). Patients were followed for 12 months.


RESULTS
There were no statistically significant differences in demographic and treatment characteristics, degree of bacterial contamination of the dialysate, markers of systemic inflammation, or parameters of nutritional status among the two treatment groups at recruitment. Changing from conventional to ultrapure dialysis fluid reduced significantly the levels of IL-6 (19+/-3 pg/ml to 13+/-3 pg/ml) and CRP (1.0+/- 0.4 mg/dl to 0.5+/-0.2 mg/dl), and resulted in significant increases in estimated dry body weight, mid-arm muscle circumference, serum albumin concentration, levels of the humoral factors, and in protein catabolic rate after 12 months. Continuous use of conventional dialysis fluid (median 40-60 c.f.u./ml) was not associated with significant alterations in markers of inflammation (IL-6 21+/-4 pg/ml vs 24+/-6 pg/ml, CRP 0.9+/-0.3 mg/dl vs 1.1+/-0.4 mg/dl) or of nutritional status at any time of the study. All differences in systemic inflammation and nutritional parameters observed during the study period (from recruitment to month 12) were significant between the two patient groups.


CONCLUSIONS
Cytokine induction by microbiologically contaminated dialysis fluid has a negative impact on nutritional parameters of early haemodialysis patients. The microbiological quality of the dialysis fluid represents an independent determinant of the nutritional status in addition to known factors, such as dose of dialysis and biocompatibility of the dialyser membrane. Ultrapure dialysis fluid adds to the cost of the dialytic treatment, but may improve the nutritional status in long-term haemodialysis patients.
Schiffl
H
H
Department of Nephrology, Medizinische Klinik and Medizinische Poliklinik Innenstadt, Universität München, Ziemssenstr. 1, D-80336 Münich, Germany.
Lang
S M
SM
Stratakis
D
D
Fischer
R
R
D000368:Aged; D001835:Body Weight; D002097:C-Reactive Protein / Q000032:analysis; D015314:Dialysis Solutions / Q000494:pharmacology*; D004340:Drug Contamination; D005260:Female; D006801:Humans; D007249:Inflammation / Q000503:physiopathology*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D015850:Interleukin-6 / Q000097:blood; D020738:Leptin / Q000097:blood; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology; D009752:Nutritional Status / Q000187:drug effects*; D011446:Prospective Studies; D012709:Serum Albumin / Q000032:analysis
D015314:Dialysis Solutions; D015850:Interleukin-6; D020738:Leptin; D012709:Serum Albumin; D007334:Insulin-Like Growth Factor I; D002097:C-Reactive Protein