MRI Assessment of Subclinical Cardiac Dysfunction and its Association With Ectopic Fat in Adults With Type 2 Diabetes

Background Visceral adipose tissue (VAT) is metabolically active and has been implicated in the development of Heart Failure with Preserved Ejection Fraction (HFpEF) through dysregulation of circulating adipokines in people with type 2 diabetes (T2D). Objective The purpose of this research was to determine whether VAT is independently related to subclinical cardiac dysfunction in a multi-ethnic cohort of obese people with T2D using magnetic resonance imaging (MRI). Methods Data was derived from two randomised controlled trials: the LYDIA study (NCT02043054) and the DIASTOLIC study (NCT02590822). Participants had T2D and obesity with no history or symptoms of cardiovascular disease. They underwent one of five interventions in open-label, blinded endpoint designs: 1) standard care, 2) supervised exercise training, 3) a meal replacement program, and 4) liraglutide or sitagliptin. Multiparametric cardiovascular MRI strain rate analysis using feature tracking and 2-point Dixon (fat-water) imaging for VAT quantification were performed at baseline and follow-up. Multivariable regression was used to identify the associations between VAT and liver fat with LV systolic strain/diastolic strain rates and LV mass:volume in subjects with T2D. Multivariable models were adjusted for age, sex, ethnicity, systolic BP, BMI, and WHR at baseline and for change in SBP and weight at follow-up, with leptin and adiponectin added to the final model. Results At baseline, 132 working-age adults, respectively, with T2D (mean age: 47.5±7.3, 54.5% male and 59.8% White European, VAT: 100/mL) showed a significant association with circumferential PEDSR (P = 0.046) independent of age, sex, ethnicity, systolic BP, BMI, and WHR. This association shows that for every 100 mL or VAT mL/cm increase in VAT volume is associated with a decrease in circumferential PEDSR (s-1) that is equivalent to the b coefficient (b = -3.225). A total of 103 working-age adults with T2D (mean age of 47.5±7.3 years, 54.5% male and 60% WE) completed the trials. A significant reduction in weight was reported (mean change 4.3 kg, (3.3, 5.4), p -1 of 0.022 (, (0.004,0.040)) for every 100 mL reduction in VAT volume. The association continued to do show significance when leptin and adiponectin were added to the model separately (p = 0.004, p =0.007) respectively. Conclusion VAT (100/mL) and a reduction in VAT (100/mL) are independently associated with diastolic strain rates. These findings support the putative role of VAT in the development and possible management of HFpEF in people living with obesity and T2D.