The Effect Of Exercise On Vascular Function In Type 2 Diabetes

Abstract

Individuals with type 2 diabetes (T2D) have a two to four-fold greater risk of cardiovascular disease (CVD). This is due to vascular maladaptations resulting from chronic hyperglycaemia and hyperinsulinaemia, along with comorbid hypertension, proinflammatory cytokines, and the presence of excess free fatty acids. To date, the primary treatment for vascular dysfunction is pharmacological interventions. Regular exercise has been shown to produce physiological changes in the cardiovascular system and reduce risk factors associated with CVD, leading to overall reductions in cardiovascular morbidity and mortality in T2D. Current studies assessing the effect of exercise on vascular function have used different techniques usually on vessel structure, or endothelial function, making it difficult to conclude on the efficacy of exercise in vascular function. PURPOSE: The aim of this study was to assess the effect of exercise on vascular function in T2D. METHODS: Electronic database searches were performed in AMED, MEDLINE, MEDLINE Daily Update, PREMEDLINE, SPORTDiscus, CINAHL, EMBASE and Web of Science. Studies that were eligible for this review performed controlled trials (CTs) and completed an exercise intervention of ≥ 4 weeks in individuals with T2D. The effect size (ES), and 95% confidence intervals (CIs) of eligible studies were calculated. RESULTS: Of the studies employing an aerobic exercise (AEx) intervention alone, three used pulse wave velocity (PWV), three used endothelial-independent dilation (EID), and three used flow-mediated dilation (FMD), and had sufficient data for calculation of ES and 95% CIs for the purpose of meta-analyses. Results found that AEx had a significant effect in vascular stiffness (PWV: ES = -0.402, 95% CI: -0.716 to -0.088; P = 0.012) and a non-significant benefit in endothelial function measures (EID: ES =-0.262, 95% CI: -0.615 to 0.091; FMD: ES =-0.029, 95% CI: -0.384 to 0.326; P= 0.873). There were limited studies using resistance training, or in combination with aerobic exercise, to assess a pooled effect. CONCLUSIONS: Exercise therapy may be considered as a primary intervention to treat vascular stiffness as it targets the pathology associated with vascular maladaptation. Future research is needed in controlled trials targeting aerobic, resistance or combined exercise to provide guidelines in exercise prescription to manage vascular health in T2D.