Independent effects of residual renal function and dialysis adequacy on actual dietary protein, calorie, and other nutrient intake in patients on continuous ambulatory peritoneal dialysis.
Previous studies have suggested that the cross-sectional relationship observed between total solute clearance (Kt/V) and dietary protein intake (DPI) in patients undergoing dialysis is possibly mathematical in origin. A cross-sectional study on 242 patients undergoing continuous ambulatory peritoneal dialysis (CAPD) was performed to determine the differential effects of dialysis adequacy and residual renal function (RRF) on actual dietary intake. All patients underwent a 7-d food frequency questionnaire to quantify daily dietary protein, calorie (DCI), and other nutrient intake, subjective global assessment (SGA), and collection of 24-h dialysate and urine for total (PD and renal) Kt/V and RRF. Patients were categorized into three groups: I (n = 94), total Kt/V >/=1.7 and GFR >0.5 ml/min per 1.73 m(2); II (n = 58), total Kt/V >/=1.7 but GFR <0.5 ml/min per 1.73 m(2); and III (n = 90), total Kt/V <1.7. Sixty-nine percent versus 62% versus 42% of group I versus II versus III patients were well nourished according to SGA (P = 0.004). DPI (1.23 [0.47] versus 1.12 [0.49] versus 0.99 [0.40] g/kg per d; P = 0.002) and DCI (27.3 [8.9] versus 23.8 [8.6] versus 23.0 [8.2] kcal/kg per d; P = 0.002) showed significant decline across the three groups. Intake of other nutrients, including carbohydrate, fat, fatty acids, and cholesterol was higher for group I compared with groups II and III. Adjusting for age, gender, weight, and diabetes, every 1 ml/min per 1.73 m(2) increase in GFR was associated with a 0.838-fold increase in DCI (95% confidence interval to interval, 0.279 to 1.397; P = 0.003) and a 0.041-fold increase in DPI (95% confidence interval, 0.009 to 0.072; P = 0.012), whereas every 0.25-unit increase in total (PD and renal) Kt/V was associated with a 0.570-fold increase in DCI (95% confidence interval, 0.049 to 1.092; P = 0.032) and a 0.052-fold increase in DPI (95% confidence interval, 0.023 to 0.081; P = 0.001). Greater small-solute clearances are associated with better dietary intake and better nutrition. The study confirmed significant and independent effect of RRF, but not PD solute clearance, on actual DPI, DCI, and other nutrient intake in patients on CAPD.
Wang
Angela Yee-Moon
AY
Department of Medicine and Therapeutics, Center for Nutritional Studies, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, Hong Kong.
Sea
Mandy Man-Mei
MM
Department of Medicine and Therapeutics, Center for Nutritional Studies, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, Hong Kong.
Ip
Ricky
R
Department of Medicine and Therapeutics, Center for Nutritional Studies, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, Hong Kong.
Law
Man-Ching
MC
Department of Medicine and Therapeutics, Center for Nutritional Studies, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, Hong Kong.
Chow
Kai-Ming
KM
Department of Medicine and Therapeutics, Center for Nutritional Studies, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, Hong Kong.
Lui
Siu-Fai
SF
Department of Medicine and Therapeutics, Center for Nutritional Studies, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, Hong Kong.
Li
Philip Kam-Tao
PK
Department of Medicine and Therapeutics, Center for Nutritional Studies, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, Hong Kong.
Woo
Jean
J
Department of Medicine and Therapeutics, Center for Nutritional Studies, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, Hong Kong.
D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D004044:Dietary Proteins / Q000008:administration & dosage*; D002149:Energy Intake; D005260:Female; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009747:Nutritional Physiological Phenomena; D009752:Nutritional Status; D010531:Peritoneal Dialysis, Continuous Ambulatory / Q000592:standards*
D004044:Dietary Proteins