Pilot study of the effect of high-protein, renal-appropriate meals during hemodialysis on intradialytic hypotension in maintenance hemodialysis patients

Mun S Choi, Purdue University

Abstract

Background: In the United Sates (US), more than 400,000 people have end stage renal disease (ESRD) or chronic kidney disease (CKD) stage 5D requiring in-center hemodialysis (HD), and approximately $35 billion is spent annually in healthcare costs. Maintenance HD patients with ESRD have increased protein (1.2 g/kg/d) and energy (30-35 kcal/kg/d) requirements, but the average protein and energy intake in these patients is only 0.8-1.0 g/kg/d and 20-25 kcal/kg/d, respectively. Subsequently, protein-energy wasting (PEW) is common, affecting up to an estimated 75% of maintenance HD patients, and low protein and energy intake are one of the main contributors of PEW. Consequences of PEW range from diminished quality of life (QoL) to increased mortality rate, and high protein meals during HD may help prevent PEW. However, eating during HD is often discouraged in US dialysis centers due to possible adverse events, particularly postprandial hypotension. The aim of this pilot study was to determine the effects of high protein meals during HD on symptomatic intradialytic hypotension (SH). Methods: 19 HD patients were recruited from 2 shifts (∼10AM-2PM, MWF & TTS) at one dialysis center for a 9-week, non-randomized, parallel arm study. Patients in the intervention group (N = 10) received meals with 30 grams of protein and one-third of sodium, potassium, phosphorus, and fluid recommendations according to Kidney Disease Outcomes Quality Initiative (KDOQI) for 25 dialysis sessions. Patients in the control group (N = 9) received a control social interaction. Blood pressure data from 2 months prior to the initiation of study and during the study (25 sessions each) were collected. Secondary outcomes included serum/plasma biochemistries (monthly renal laboratories to assess nutritional status and electrolyte balance), dialysis compliance, fluid retention, sleep, and other QoL measures. The difference in the frequency of SH events within groups for 2-month pre-study and during study, was determined by Wilcoxon signed-rank test, and between group differences were determined by Wilcoxon rank-sum test. Other outcomes were assessed using repeated measures ANOVA with fixed effects for group, time, and group × time interaction, and random effect for subject nested within group. Results: One patient in the intervention arm withdrew from the study upon discontinuation of dialysis. Thus, N = 9 patients per group completed the study and are included in the analyses. Patients were 62 ± 16 years old, 55% female, and had been on dialysis for 3.4 ± 2.6 years. In the intervention group, there were 4 SH events in 3 patients over 25 dialysis sessions in the pre-study period and 12 SH events in 4 patients over 25 dialysis sessions during the study period. In the control group, there was 1 SH event in 1 patient pre-study and 5 SH in 4 patients during study. Change in the frequency of SH events from pre-study to during study was not different between groups (P = NS). The average lowest mean arterial pressure (MAP) was significantly higher in the control group compared with the intervention group, but difference between pre-study and during study was not significant for either group. Serum albumin and pre-albumin did not change throughout the study and when compared with values obtained during the pre-study period in either group. There were no significant improvements in QoL with the meal intervention, but results showed that HD patients had poorer quality of life and sleep quality compared with the general US population. When patients were asked “how interested would you be in receiving nutritious meals during dialysis?” at the end of study, 70% of patients responded ≥ 4 (5-point scale, 5 = very interested; P = NS between groups). Conclusions: These pilot data suggest that meals during HD do not increase the frequency of SH events. Additionally, patients generally have positive attitudes towards receiving meals. However, changes in nutritional status indicators, electrolyte balance, and QoL were not observed in either group. Larger, longer-term studies are needed to confirm these results along with effects on nutritional and clinical outcomes in HD patients.

Degree

M.S.

Advisors

Hill Gallant, Purdue University.

Subject Area

Nutrition

COinS