A randomised controlled clinical trial of protein supplementation on the nutritional status in patients receiving continuous ambulatory peritoneal dialysis (CAPD) in Frere Hospital, East London

[摘要] English: CKD includes a variety of heterogeneous disorders which cause progressive structural or functional deterioration of the kidney (KDIGO, 2013). Renal replacement therapy (RRT), becomes necessary when accumulating waste products interfere with normal body functions, and physiologic changes can no longer be controlled by diet and medication alone (KDOQI, 2006; Schrier, 2009). Continuous ambulatory peritoneal dialysis (CAPD), uses the semi-permeable membrane of the peritoneum for dialysis, making it possible for patients to dialyse away from a dialysis unit (Wilkens, Juneja & Shanaman, 2012). No trial to date, has described the nutritional status of the CAPD population in the Eastern Cape, and the effect of protein supplementation in a South African CAPD population has not been investigated.A randomised controlled, open-label trial, was approved by the Ethics Committee of the Faculty of Health Sciences at the University of the Free State. Of the 28 patients receiving CAPD at Frere Hospital in 2012, 26 gave informed consent and were randomised into an experimental (n=13) and a control (n=13) group according to median age, gender, median serum albumin levels and median duration on CAPD. The intervention group were supplemented with a protein powder (Protifar) at 0.65g/kg actual body weight. Socio-demographics, medical histories, and CAPD regiments were recorded at baseline. Nutritional status assessed in terms of anthropometry, Subjective global assessment (SGA) nutrition assessment tool and biochemistry, was followed up monthly over the four month duration of the trial. Adequacy of dialysis was also assessed. Data was analysed with SAS statistical software and compared by 95% confidence intervals for median or percentage differences.The trial population were 76% female, 80% Black, 84% unemployed/receiving a grant; and 84% lived farther than 50 km away for Frere Hospital. Hypertension was the main cause of renal failure in 80%, and the main co-morbidity, in 92%. Most had been using CAPD for five to eight months, as four exchanges per day, and 69% also had a HD line. At baseline none were underweight based on body mass index (BMI) (calculated from dry weight); rather 35% were overweight/obese. Based on upper arm muscle area (AMA.) none were wasted. SGA nutrition assessment tool identified 23% as mildly to moderately malnourished, and only one participant as severely malnourished. Yet, most participants had inadequate intakes of energy (72%), protein (56%), HBV protein (64%), carbohydrate (52%) and fat (60%); and 92% had below normal serum albumin levels. Serum phosphate, urea and creatinine levels were elevated above normal in 44%, 96% and 100% of participants. Based on Kt/V and creatinine clearance, 90% and 100%, respectively, were inadequately dialysed.Protein supplementation did not statistically significantly impact on any parameter of nutritional status, although slight increases in the median dry weight, AMA and serum albumin levels, which may indicate some clinical benefit, was recorded. Compliance was generally good at above 82.% throughout the trial.As the first trial to describe the socio-demographic and nutritional status profile of patients receiving CAPD in the EC, a similar socio-demographic profile as described in other studies for the South African CAPD population in Johannesburg, Durban and Polokwane was found (Isla et al., 2014; Abdu et al., 2011; Naicker, 2002). The anthropometric profile was however found to be very different to that described for CAPD patients in developed countries, with a high prevalence of overweight/obesity. The causes of the overall inadequate dialysis reflected in highly elevated serum levels of waste products in this study population, needs to be investigate further. Although protein supplementation did not have a statistically significant impact on the nutritional status of CAPD patients in this trial, some non-significant improvements in anthropometry and biochemical indicators, suggest that studies of larger size with supplementation over a longer period of time are needed.

[发布机构] University of the Free State