Cardiovascular and systemic determinants of exercise capacity in people with type 2 diabetes mellitus

Abstract

The global burden of heart failure (HF) is on the rise owing to an increasing incidence of lifestyle related diseases, predominantly type 2 diabetes mellitus (T2D). Diabetes is an independent risk factor for cardiovascular disease, and up to 75% of those with T2D develop HF in their lifetime. T2D leads to pathological alterations within the cardiovascular system, which can progress insidiously and asymptomatically in the absence of conventional risk factors. Reduced exercise tolerance is consistently reported, even in otherwise asymptomatic individuals with T2D, and is the first sign of a failing heart. Because aggressive modification of cardiovascular risk factors does not eliminate the risk of HF in T2D, it is likely that other factors play a role in the pathogenesis of HF. Early identification of individuals at risk of HF is advantageous, as it allows for modification of the reversible risk factors and early initiation of treatment with the aim of improving clinical outcomes. In this review, cardiac and extra-cardiac contributors to reduced exercise tolerance in people with T2D are explored.

Keywords: diabetic cardiomyopathy; exercise capacity; heart failure.

Figure 1.

Contributors to reduced exercise capacity in T2D. Reduced exercise capacity in T2D is a net result of complex interactions between the biomechanics of obesity and frailty and the systemic and cardiovascular factors. Molecular mechanisms involved in the interactions between excess nutrients, adiposity, and chronic inflammation result in insulin resistance, which further propels the vicious cycle of metabolic dysregulation. Adapted from Del Buono MG, et al. J Am Coll Cardiol 2019;73(17):2209-25 BMI, body mass index; LA, left atrium; LV, left ventricular; T2D, type 2 diabetes mellitus.

Figure 2.

Pathological alterations leading to diabetic cardiomyopathy in relation to stages of progression of heart failure. ACC/AHA, American College of Cardiology/American Heart Association; HF, heart failure; LA, left atrium; LV, left ventricular; NYHA, New York Heart Association; T2D, type 2 diabetes mellitus.