Dietary Intake of ESTEEM (Exercise Study Testing Enhanced Energetics of Muscle Mitochondria in CKD) Participants

Background: Diet intake in people with CKD impacts metabolic acidosis and may have downstream effects on physical performance. Potential renal acid load (PRAL) is the acid or base forming potential from food, with greater acid production from protein foods, grains and diary and alkali production from fruits and vegetables. Protein amount and source are of interest for physical performance and plays a role in metabolic acidosis. The following is an analysis of dietary intake in people with CKD enrolled in a randomized exercise control trial. Methods: Participants were randomized to receive supervised exercise for 12 weeks or to participate in a control group consisting of education on healthy lifestyle. All participants were provided a brochure containing diet recommendations by the NKDEP. No other dietary information was provided to participants. Three 24-hour diet recalls were performed pre and post invention using ASA24 software. Physical performance was measured via 6-minute walk test (6MW). Healthy Eating Index 2020 (HEI), PRAL, and protein intake were calculated. Differences between treatment groups and amongst intervention group were determined, and linear mixed effects models were performed on dietary intake variables and performance on 6MW. Results: The average age of participants (n=30) was 64 years old, 60% were male, 46.6% had diabetes, and the mean eGFR was 34 mL/min. There were no significant differences in PRAL, HEI score, or protein intake between groups pre and post intervention. HEI and PRAL did not significantly affect changes in 6MW, however protein intake was inversely associated with 6MW in all participants (-60.50, 95%CI: -111.95 – -9.04, p= 0.021) as well as among exercisers (-64.59, 95%CI: -124.36 – -4.82, p=0.034). Conclusion: PRAL and HEI did not affect 6MW performance. Average protein intake was adherent to KIDGO guidelines (0.6-0.8 g/kg). Further investigation is needed to determine if increased protein intake beyond recommended guidelines in CKD adversely impacts exercise adaptation. Funding: NIDDK Support, Clinical Revenue Support - Control (n=9) Intervention (n=21) Baseline Post Baseline Post Protein (g/kg) 0.77 (0.21) 0.76 (0.26) 0.68 (0.24) 0.68 (0.29) HEI 58.7 (10.6) 59.7 (12.3) 57.1 (13.5) 55.7 (8.2) PRAL (mEq/day) 3.4 (15.3) 0.3 (11.2) 9.7 (15.1) 14.3 (15.4) 6MW (meters) 483 (77) 465 (62) 454 (92) 482 (75) Values mean (SD)