Cardiovascular determinants of aerobic exercise capacity in adults with type 2 diabetes

To assess the relationship between subclinical cardiac dysfunction and aerobic exercise capacity (peak VO₂) in adults with type 2 diabetes (T2D), a group at high risk of developing heart failure.

Research design and methods

Cross-sectional study. We prospectively enrolled a multi-ethnic cohort of asymptomatic adults with T2D and no history, signs or symptoms of cardiovascular disease. Age-, sex-, and ethnicity-matched controls were recruited for comparison. Participants underwent bio-anthropometric profiling, cardiopulmonary exercise testing and cardiovascular magnetic resonance with adenosine stress perfusion imaging. Multivariable linear regression analysis was undertaken to identify independent associations between measures of cardiovascular structure and function and peak VO₂.

Results

Two hundred and forty seven adults with T2D (age 51.8±11.9 years, 55% males, 37% black or south Asian ethnicity, HbA1c 7.4±1.1% (57±12 mmol/mol), duration of diabetes 61 (32 – 120) months and 78 controls were included. Subjects with T2D had increased concentric left ventricular (LV) remodelling, reduced myocardial perfusion reserve, and markedly lower aerobic exercise capacity (peak VO₂ 18.0±6.6 vs. 27.8±9.0mL/kg/min, p<0.001) compared with controls. In a multivariable linear regression model containing age, sex, ethnicity, smoking status and systolic blood pressure, only myocardial perfusion reserve (β=0.822, p=0.006) and E/e’ (β= -0.388, p=0.001) were independently associated with peak VO₂ in subjects with T2D.

Conclusions

In a multi-ethnic cohort of asymptomatic people with T2D, myocardial perfusion reserve and diastolic function are key determinants of aerobic exercise capacity, independent of age, sex, ethnicity, smoking status, or blood pressure.