Temporal Responses of a Low-Energy Meal Replacement Plan or Exercise Training on Cardiovascular Function and Fibro-Inflammatory Markers in People with Type 2 Diabetes—A Secondary Analysis of the 'Diabetes Interventional Assessment of Slimming or Training to Lessen Inconspicuous Cardiovascular Dysfunction' Study

Background: This study assesses the temporal responses of cardiovascular function, fibro-inflammation, and glucometabolic profiles in asymptomatic adults with type 2 diabetes, following a low-energy meal replacement plan (MRP) or exercise training. Methods: Secondary analysis of DIASTOLIC: a randomised, open-label, blinded-endpoint trial of 12 weeks MRP (~810 kcal/day) or exercise training. Cardiac magnetic resonance, plasma fibroinflammatory, and metabolic markers were undertaken at baseline, 4, and 12 weeks. Results: Out of 24 participants in the MRP group and 22 in exercise training, 18 and 11 completed all three visits. MRP resulted in early (0–4 weeks) improvement in insulin resistance (HOMA-IR: 10.82 to 4.32), decrease in FABP-4 (4.87 ± 0.19 to 5.15 ± 0.32 mg/L), and improvement in left ventricular remodelling LV mass: volume (0.86 ± 0.14 to 0.78 ± 0.11), all with large effect sizes. MMP8 levels increased moderately at 4–12 weeks. Peak early diastolic strain rate (cPEDSR) initially decreased, then improved. Exercise training led to minor improvements in insulin resistance and MMP-8 levels, with no significant changes in cPEDSR or LV remodelling. Conclusions: MRP resulted in early improvements in insulin resistance, cardiac remodelling, and inflammation, but with an initial decrease in diastolic function, improving by 12 weeks. Exercise training showed minor early benefits in insulin resistance and inflammation, but no significant cardiac changes.