Abstract 10330: Intermittent Fasting Interacts with Red Cell Distribution Width to Differentially Improve Cardiometabolic Health

Abstract

Introduction: Intermittent fasting reduces weight and cardiometabolic risk factors. In the WONDERFUL Trial (NCT02770313), intermittent fasting reduced homeostatic model assessment of insulin resistance (HOMA-IR) and the Metabolic Syndrome Score (MSS), with insulin having the largest decline. The red cell distribution width (RDW) measures the dispersion of red blood cell size, is strongly predictive of mortality and major adverse events, and may be a biomarker of general health. This post hoc study of subjects from the WONDERFUL Trial examined the interactive effect of intermittent fasting and baseline RDW on changes in insulin, glucose, HOMA-IR, and MSS. Methods: Subjects aged 21-70 years who had pre-diabetes, diabetes, or ≥1 other metabolic syndrome factor and modestly elevated LDL-C were enrolled if they were not taking anti-diabetic or statin medications and were free of chronic diseases (N=71; n=38 intermittent fasting, n=33 controls). Subjects were randomized to 24-hour water-only fasting (twice-weekly for 4 weeks followed by once-weekly for 22 weeks) or ad libitum eating (control) for 26 weeks. Results: Age averaged 49.1±11.1 years and 64.8% were female. Change scores stratified by RDW size distribution (RDW-SD) are shown in the Table. Results were similar when the RDW coefficient of variation (RDW-CV) was used. Intermittent fasting did not change RDW-SD (1.27±9.6 fL vs. control: -0.37±1.76 fL, p=0.34) or RDW-CV (-0.15%±0.55% vs. control: -0.11%±0.45%, p=0.76) over the 26-week trial. Conclusions: Compared to controls, intermittent fasting significantly decreased insulin more in subjects with higher baseline RDW than those with RDW ≤median. This differential effect may also apply to changes in HOMA-IR, glucose, and MSS. These findings should be validated and expanded in larger studies since RDW may identify people who would derive the most cardiometabolic benefit from engaging in intermittent fasting.