Effect of high amylose resistant starch (HAM-RS2) supplementation on biomarkers of inflammation and oxidative stress in hemodialysis patients: a randomized clinical trial

Introduction: Systemic inflammation and oxidative stress play a central role in the pathogenesis of cardiovascular disease and numerous other complications of CKD. Recent studies demonstrated that consumption of a diet enriched with amylose (HAM-RS2), attenuates oxidative stress and inflammation, and improves intestinal microbiome in CKD rats. The present study was designed to explore the effect of dietary amylose supplementation in hemodialysis patients. Methods: Forty-six stable hemodialysis patients were randomized to receive biscuits containing 20 g/day during the first four weeks and 25 g/day in the next four weeks of either HAM-RS2 or wheat-flour. Fasting predialysis blood samples obtained before, during and at the end of trial were processed for biomarkers of oxidative stress and inflammation. Findings: There was no significant difference in baseline clinical or biochemical parameters between the two groups. Serum levels of TNF-, IL-6, and malondialdehyde declined significantly (P<0.05) in the HAM-RS2-treated group but remained unchanged in the placebo-treated group. No significant difference was observed in serum Interleukin-1 (IL-1) and hs-CRP concentrations and total antioxidant activity between two groups. Serum urea and creatinine concentrations significantly declined and severity of constipation improved in HAM-RS2-treated patients (P<0.05). HAM-RS2 consumption was well tolerated and did not cause discernible side effects. Discussion: Administration of HAM-RS2 for eight weeks significantly reduced levels of inflammatory and oxidative markers in hemodialysis patients confirming the results observed in CKD animals. Long term trials are needed to explore the impact of HAM-RS2 supplementation on clinical outcomes in end stage renal disease population.