Effects of a Short-Term Lifestyle Intervention on Myocardial Function in Patients with Type II Diabetes

Abstract

Long-term lifestyle interventions improve insulin sensitivity and cardiovascular disease risk factors in patients with type II diabetes. Furthermore, pharmaceutical interventions targeting insulin sensitivity have shown improvements in myocardial function in these patients. PURPOSE: To investigate the effects of a short-term (4-week) lifestyle intervention on myocardial function in patients with type II diabetes. METHODS: Patients with type II diabetes were randomised into a control group (n = 85) or a lifestyle intervention group (n = 84). The lifestyle intervention consisted of two one-hour supervised exercise training sessions/week and a session with a dietician. The training sessions contained cardiorespiratory and resistance exercises individualised for each patient. Insulin sensitivity (QUICKI), glycemic control (HbA1 c), VO2max and myocardial function (left ventricular tissue velocity, strain and strain rate) were assessed before and after the intervention. RESULTS: There was a significant (p < 0.05) improvement in VO2max from pre-post between intervention and control group. Myocardial strain and insulin sensitivity were preserved in the lifestyle intervention group (p < 0.05). Bivariate analyses showed that changes in myocardial strain negatively correlated with changes in HbA1c (r = − 0.225, p = 0.020), fasting plasma glucose (r = − 0.200, p = 0.034) and positively correlated with changes in QUICKI (r = 0.353, p = 0.015), diastolic ventricular tissue velocity (r = 0.228, p = 0.015) and treatment group (r = 0.188, p = 0.046). Changes in QUICKI positively correlated with changes in VO2max (r = 0.298, p = 0.011) and negatively with changes in BMI (r = − 0.482, p < 0.001). Multiple regression analysis showed lifestyle intervention was an independent predictor of myocardial strain (? = 0.455, p = 0.008) and accounts for 20% of improvement in this myocardial function measure. CONCLUSIONS: A four-week lifestyle intervention improved exercise capacity and preserved myocardial function and insulin sensitivity in patients with type 2 diabetes. Improvements in myocardial function were associated with improvements in glycemic control and treatment group. Improvements in insulin sensitivity were correlated with improvements in body composition and exercise capacity. Furthermore, the short-term improvements in myocardial function were independently predicted by lifestyle intervention.