Liver Fat Reduction and Cardiovascular Remodelling in Adults with Obesity and Type 2 Diabetes: A Secondary Analysis of the DIASTOLIC Randomised Controlled Trial

Background: Type 2 diabetes (T2D) increases cardiovascular disease (CVD) risk and predisposes individuals to heart failure with preserved ejection fraction. Metabolic dysfunction-associated steatotic liver disease (MASLD), prevalent in T2D, may worsen cardiac remodelling and haemodynamics. This secondary analysis of the DIASTOLIC trial examined the relationship of liver fat to cardiac remodelling in T2D at baseline and after a 12-week intervention or standard care. Methods: Adults with obesity and T2D and matched controls underwent hepatic MRI, cardiac MRI, echocardiography, and adipokine profiling as part of the DIASTOLIC study (NCT02590822). Participants with T2D were randomised to supervised exercise, a low-calorie meal-replacement plan (MRP), or routine care for 12 weeks. A baseline case–control and then pre- and post-analyses in those with T2D were performed. Associations between changes in liver fat and cardiovascular measures were assessed using correlation and adjusted generalised linear models. Results: At baseline, 81 T2D and 35 healthy controls were compared, and 76 subjects with T2D completed the trial. Participants with T2D had ~4× higher hepatic fat and adverse haemodynamics. The MRP arm achieved the greatest reductions in BMI, blood pressure, dysglycaemia, insulin resistance, and hepatic fat (−8.9%), with favourable adipokine changes. Overall, hepatic fat loss was associated with reductions in cardiac index and stroke volume and with additional reductions in end-diastolic volume in the MRP arm, independent of BMI. Conclusions: In T2D, hepatic fat is strongly linked to pathological haemodynamic profiles. Intensive caloric restriction achieves substantial hepatic fat loss and normalisation of hyperdynamic cardiovascular physiology independent of weight loss, identifying hepatic steatosis as a potential therapeutic target for early cardiovascular risk reduction.