Effects Of Oral Whey Protein Supplementation On Nutritional Status, Quality Of Life And Physical Function In Malnourished Haemodialysis Patients

Abstract

Protein-energy malnutrition is prevalent in 65% of Malaysian haemodialysis patients based on serum albumin concentrations of less than 40 g/L and body mass index (BMI) of less than 25 kg/m². Malnutrition leads to increased risk of morbidity and mortality in dialysis patients. This study tested the effects of oral whey protein supplementation on nutritional status, Dialysis Malnutrition Score (DMS), quality of life (QOL) scores using the SF36 questionnaire, and physical function (assessed via handgrip dynamometer, back-leg-chest dynamometer, tandem walk and step test) in chronic haemodialysis patients. A total of 82 malnourished haemodialysis patients with mean age of 50 ± 14 years were recruited from two haemodialysis centers in Hospital Kuala Lumpur and Hospital Serdang and were randomized into intervention (n=41) and control (n=41) group. The intervention group was given dietary counselling plus whey protein supplement consisting of 30 g of protein and 129 kcal of energy while the control group received only dietary counselling over the 6 months period. In the intervention group, serum albumin increased significantly after 3 months (7 ± 2%; p=0.010), but it was not sustained after 6 months of supplementation (4 ± 2%, p=0.560). Dietary protein intake improved significantly after 6 months (0.5 ± 0.1 g/day, p<0.001) with lesser increase in energy intake (0.1 ± 0.0 kcal/day, p=1.000). The intervention patients also showed significant improvement of SF36 scores, which increased by 16 ± 7%; p=0.050 at the first 3 months of supplementation and continued to increase by 22 ± 7%; p=0.003 after the 6 months of supplementation. The weight and BMI in the intervention group decreased significantly by 1.4 ± 0.5%; p=0.008 and 1.3 ± 0.5%; p=0.027 respectively after 6 months of supplementation. This was probably influenced by increased levels of extracellular fluid over the 6 months (7.3 ± 3%, p=0.041), resulting in higher fluid extraction in these patients. There were no significant changes in body composition and DMS scores after supplementation. The control group had a similar increase of serum albumin at 3 months of the study (8 ± 2%; p<0.001), but the increase was also not sustained over the 6 months (5 ± 2%, p=0.031). Weight and BMI increased in the control group by 0.7 ± 0.5%; p=0.982 and 1.4 ± 0.6%; p=0.027 respectively but this was probably due to fluid changes as there were no significant changes in body composition. The controls had a slight improvement of dietary energy intake (0.1 ± 0.1 kcal/day; p=1.000) and dietary protein intake (0.1 ± 0.1 kcal/day; p=1.000) but these improvements were not significant over the 6 months. The control patients had a decline (-3 ± 3%, p=0.567) in the SF36 scores after the 3 months but after the 6 months of the study, these patients significantly improved their SF 36 scores (12 ± 4%; p=0.011). Measurements of physical functions in both intervention and control groups did not change significantly over the 3 and 6 months period. No significant difference was seen between groups for serum albumin, body composition, DMS, SF36 and physical function measurements over the 6 months. Dietary protein intake however, was significantly higher in the intervention group (70.7 ± 16.6 g) comparing to control group (53.4 ± 14.6 g); p<0.001 over the 6 months. In conclusion, whey protein supplementation conferred benefits to improve nutritional status of haemodialysis patients but was not sustained after 3 months compared to dietary counselling.