Impact of exercise training on cardiac function among patients with type 2 diabetes: A systematic review and meta-analysis

Purpose: Type 2 diabetes (T2D) is associated with subclinical abnormalities in left ventricular function and an increased downstream risk for heart failure. Exercise training has been associated with significant improvement in cardiorespiratory fitness among these patients. However, its impact on cardiac function is not well established. Methods: We conducted a meta-analysis including all randomized and nonrandomized trials that evaluated effects of exercise training on cardiac function among patients with T2D. Primary outcomes were measures of left ventricular systolic (global longitudinal strain) and diastolic (early diastolic velocity [é]) function. The effects of exercise training on peak oxygen uptake; other markers of diastolic dysfunction: Mitral peak early-to-late diastolic filling velocity (E/A), mitral inflow to annular ratio (E/é), and deceleration time (DT); and systolic velocity were also assessed. Results: Our study included 441 patients enrolled in 6 trials. Exercise training significantly improved early diastolic velocity (standardized mean difference [SMD], 0.58; 95% CI, 0.09-1.07), global longitudinal strain (SMD, 0.62; 95% CI, 0.04-1.21), and peak oxygen uptake (SMD, 1.43; 95% CI, 0.51-2.35) as compared with control group. However, no significant changes were observed in other markers of diastolic function (E/A, E/é and DT) and systolic velocity. Conclusion: Exercise training in patients with T2D is associated with a significant improvement in some echocardiographic indicators of systolic and diastolic function and cardiorespiratory fitness. These findings suggest that exercise training may improve subclinical systolic and diastolic dysfunction in patients at risk for clinical heart failure.