Achieving the standards for protein and calorie intake in haemodialysis – can our patients do it and does it matter?

L Wells, R Wolfenden, S Jorgensen, C Jones

York Hospital

Problem: Malnutrition is common in patients on haemodialysis. Consequently KDOQI and other organisations have set a number of standards for recommended nutritional intake. These include a protein intake (DPI) of 1.2 g/kg/day and a calorie intake (DCI) of 35 kcal/kg/day. However we know from routine nutritional assessment that these standards are rarely met. Whether this has clinical consequence was less certain.

Purpose: To examine the nutrient intake of our haemodialysis patients and to compare this to recommended standards. Secondly, to examine the nutritional status of these patients.

Design: All patients on our haemodialysis unit have a nutritional assessment annually. Data was collected on weight, BMI, 3‑ and 7‑point subjective global assessment (SGA), triceps skinfold thickness (TSF), mid arm muscle circumference (MAMC), a composite nutritional score (comprising both subjective and objective measures), protein catabolic rate, dialysis adequacy results and biochemistry, including CRP, haemoglobin, sodium, potassium, phosphate, albumin, urea and creatinine. All patients were asked to complete a 3 day food diary.

Findings: Of 104 patients assessed, 41 returned their food diary. In this subgroup of patients mean DPI was 1.00 ± 0.23 g/kg ideal body weight and mean DCI 26.6 ± 6.2 g/kg ideal body weight. Only 5 and 4 patients achieved the recommended DPI and DCI respectively. Despite this mean BMI was 25.5 ± 5.6, %IBW 109 ± 24.3 and 7‑point SGA score 5.8 ± 1.3. 20 patients had a %IBW of =100%, 37 a BMI =20 kg/m², 24 patients a 7‑point SGA of =5. Using a 3‑point SGA, patients with a normal score A (n=26) had a greater weight, %IBW, BMI, and MAMC than those with an abnormal score. There was no difference in protein and calorie intake. Calorie and protein intake were strongly correlated with each other but not with any of the other nutritional parameters. Conclusion: Despite the finding that most haemodialysis patients fail to achieve recommended nutrient intakes, most markers of malnutrition were in the normal range. There was no difference in calorie and protein intake between groups scored as having normal and abnormal nutrition.

Relevance: Meeting standards for nutritional intake is difficult in the haemodialysis population. However these standards should not be used to assess delivery of care as they have little relation to nutritional outcomes in a cross‑sectional assessment of patients.