Effects of a Fasting-mimicking Diet on MRI-assessed Cardiac Structure and Function in Participants with Type 2 Diabetes.

Purpose To evaluate the effects of a monthly 5-day fasting-mimicking diet (FMD) for 1 year on left ventricular (LV) geometry and function in individuals with type 2 diabetes (T2D). Materials and Methods This secondary analysis of the prospective Fasting In diabetes Treatment trial (ClinicalTrials.gov identifier no. NCT03811587) included individuals with T2D randomized to monthly 5-day FMD or usual care for 12 months (November 2018-July 2020). MRI (3.0 T) was performed at baseline, 6 months, and 12 months. LV geometry and systolic function were assessed from two-dimensional cine images, and diastolic function was assessed from four-dimensional flow MRI. Intention-to-treat linear mixed models and linear regression were used to evaluate treatment effects and LV-metabolic associations. Results A total of 82 participants (mean age, 62.9 years ± 8.5 [SD]; 43 female) were included. FMD reduced LV mass at 6 months (mean difference, -5.47 g [95% CI: -9.19, -1.75]; P = .005) but not at 12 months (P = .83). End-diastolic volume remained stable in the FMD group versus controls (mean difference, 7.75 mL [95% CI: 0.19, 15.32]; P = .045). Both the early-to-late peak filling ratio (E/A) (mean difference, 0.27 [95% CI: 0.04, 0.50]; P = .02) and the mitral annular early peak velocity (Ea) (mean difference, 0.84 cm/sec [95% CI: -0.02, 1.67]; P = .04) increased at 12 months. No other treatment effects were observed (all P > .05). ∆E/A was positively associated with change in hemoglobin A1c (HbA1c) level (standardized β = 0.47, P = .01) and negatively associated with changes in high-density lipoprotein cholesterol levels (standardized β = -0.55, P = .01). Conclusion FMD positively influenced LV diastolic function by increasing E/A and Ea in participants with T2D; E/A improvements were associated with reduced HbA1c levels. Keywords: MR Imaging, Cardiac, Left Ventricle, Outcomes Analysis, Metabolic Disorders, Diet, Fasting-mimicking Diet, Left Ventricle Function, Type 2 Diabetes, Cardiac Magnetic Resonance ClinicalTrials.gov identifier number NCT03811587 Supplemental material is available for this article. © RSNA, 2026.