Obesity dominates early effects on cardiac structure and arterial stiffness in people with type 2 diabetes

Objective: Type 2 diabetes (T2D) and obesity are global epidemics leading to excess cardiovascular disease (CVD). This study investigates standard and novel cardiac MRI parameters to detect subclinical cardiac and central vascular dysfunction in inactive people with and without T2D. Methods: Physically inactive age and BMI-similar premenopausal women and men with ( n = 22) and without [ n = 34, controls with overweight/obesity (CWO)] uncomplicated T2D were compared to an age-similar and sex-similar reference control cohort ( n = 20). Left ventricular (LV) structure, function, and aortic stiffness were assessed by MRI. Global arterial pulse wave velocity (PWV) was assessed using carotid-to-femoral applanation tonometry. Regional PWV was measured via 2D phase-contrast MRI and 4D flow MRI. Results: Global arterial PWV did not differ between CWO and T2D. 2D PC-MRI PWV in the ascending aorta was higher in people with T2D compared with CWOs ( P < 0.01). 4D flow PWV in the thoracic aorta was higher in CWO ( P < 0.01), and T2D ( P < 0.001) compared with RC. End-diastolic volume, end-systolic volume, stroke volume, and cardiac output were lower in CWO and T2D groups compared with reference control. Conclusion: Subclinical changes in arterial stiffening and cardiac remodeling in inactive CWO and T2D compared with reference control support obesity and/or physical inactivity as determinants of incipient CVD complications in uncomplicated T2D. Future studies should determine the mechanistic causes of the CVD complications in greater detail in order to create therapeutic targets. Clinical Trial Registration: Cardiovascular Mechanisms of Exercise Intolerance in Diabetes and the Role of Sex (NCT03419195).