Kimberley L. Way

The Effect of Regular Exercise on Insulin Sensitivity in Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis

The purpose of this study was to examine the effect of regular exercise training on insulin sensitivity in adults with type 2 diabetes mellitus (T2DM) using the pooled data available from randomised controlled trials. In addition, we sought to determine whether short-term periods of physical inactivity diminish the exercise-induced improvement in insulin sensitivity. Eligible trials included exercise interventions that involved ≥3 exercise sessions, and reported a dynamic measurement of insulin sensitivity. There was a significant pooled effect size (ES) for the effect of exercise on insulin sensitivity (ES, –0.588; 95% confidence interval [CI], –0.816 to –0.359; P<0.001). Of the 14 studies included for meta-analyses, nine studies reported the time of data collection from the last exercise bout. There was a significant improvement in insulin sensitivity in favour of exercise versus control between 48 and 72 hours after exercise (ES, –0.702; 95% CI, –1.392 to –0.012; P=0.046); and this persisted when insulin sensitivity was measured more than 72 hours after the last exercise session (ES, –0.890; 95% CI, –1.675 to –0.105; P=0.026). Regular exercise has a significant benefit on insulin sensitivity in adults with T2DM and this may persist beyond 72 hours after the last exercise session.

The Effect of Exercise on Vascular Function and Stiffness in Type 2 Diabetes: A Systematic Review and Meta-analysis

Deterioration of the structure and function of the vascular system is the underlying feature in cardiovascular disease (CVD), which is the highest cause of mortality in type 2 diabetes (T2D). Studies assessing the effect of exercise on vascular function and stiffness have used different measurement techniques and small cohorts, making it difficult to conclude on the overall efficacy of exercise on these outcomes. The aim of this study was to assess the effect of exercise on vascular function and stiffness in T2D. Electronic database searches were performed in AMED, MEDLINE, MEDLINE Daily Update, PREMEDLINE, SPORTDiscus, CINAHL, EMBASE and Web of Science. The effect size (ES), and 95% confidence intervals (CIs) of eligible studies were calculated. Pooled estimates of the effect of aerobic exercise (AEx) on vascular function and stiffness, using ES, were obtained. Results show that AEx led to a near-significant reduction in PWV (ES = -0.472; 95% CI: -0.949 to 0.005; P = 0.052), a significant reduction in EID (ES = 0.416, 95% CI: 0.062 to 0.769; P= 0.021), and a non-significant benefit in FMD measures. There were limited studies using resistance training or in combination with aerobic exercise, to assess a pooled effect on vascular function or stiffness. These data suggest that aerobic exercise training should be used as a primary treatment strategy for improving vascular smooth muscle function as measured by EID in individuals with T2D. There is currently insufficient evidence concerning the efficacy of regular exercise for improving vascular function and stiffness as measured by FMD and PWV.

Effect of resistance training on liver fat and visceral adiposity in adults with obesity: A randomized controlled trial

Regular aerobic exercise reduces visceral adipose tissue (VAT) and liver fat, however, not all individuals are able to adopt and adhere to such programs. Progressive resistance training (PRT) may be an alternative therapy, but there is limited available evidence. We examined the efficacy of PRT as per current exercise guidelines, compared with sham exercise placebo on liver fat and VAT.

The effect of high Intensity interval training versus moderate intensity continuous training on arterial stiffness and 24 h blood pressure responses: A systematic review and meta-analysis

OBJECTIVES Greater arterial stiffness and poor 24h blood pressure (BP) are recognized as indicators of poor cardiovascular health. Evidence has shown that high intensity interval training (HIIT) may be a superior alternative to moderate intensity continuous training (MICT) for improving cardiovascular disease risk factors such as cardiorespiratory fitness and vascular function. However, there are limited data comparing the effect of HIIT to MICT on central arterial stiffness and/or 24h BP response. The purpose of this study was to compare HIIT versus MICT on central arterial stiffness and 24h BP outcomes by systematic review and meta-analysis. DESIGN A systematic review and meta-analysis was conducted. METHODS Eligible studies were exercise training interventions (≥4weeks) that included both HIIT and MICT and reported central arterial stiffness, as measured by pulse wave velocity and augmentation index and/or 24h BP outcome measures. RESULTS HIIT was found to be superior to MICT for reducing night-time diastolic BP (ES: -0.456, 95% CI: -0.826 to -0.086mmHg; P=0.016). A near-significant greater reduction in daytime systolic (ES: -0.349, 95% CI: -0.740 to 0.041mmHg; p=0.079) and diastolic BP was observed with HIIT compared to MICT (ES: -0.349, 95% CI: -0.717 to 0.020mmHg; p=0.063). No significant difference was found for other BP responses or arterial stiffness outcomes. CONCLUSIONS HIIT leads to a superior reduction in night-time diastolic BP compared to MICT. Furthermore, a near-significant greater reduction in daytime BP was found with HIIT compared to MICT. No significant difference was observed for changes to central arterial stiffness between HIIT and MICT.