Effect of 5:2 Regimens: Energy-Restricted Diet or Low-Volume High-Intensity Interval Training Combined With Resistance Exercise on Glycemic Control and Cardiometabolic Health in Adults With Overweight/Obesity and Type 2 Diabetes: A Three-Arm Randomized Controlled Trial.

OBJECTIVE: We aimed to examine the effects of a 5:2 diet (2 days per week of energy restriction by formula diet) or an exercise (2 days per week of high-intensity interval training and resistance training) intervention compared with routine lifestyle education (control) on glycemic control and cardiometabolic health among adults with overweight/obesity and type 2 diabetes. RESEARCH DESIGN AND METHODS: This two-center, open-label, three-arm, parallel-group, randomized controlled trial recruited 326 participants with overweight/obesity and type 2 diabetes and randomized them into 12 weeks of diet intervention (n = 109), exercise intervention (n = 108), or lifestyle education (control) (n = 109). The primary outcome was the change of glycemic control measured as glycated hemoglobin (HbA1c) between the diet or exercise intervention groups and the control group after the 12-week intervention. RESULTS: The diet intervention significantly reduced HbA1c level (%) after the 12-week intervention (-0.72, 95% CI -0.95 to -0.48) compared with the control group (-0.37, 95% CI -0.60 to -0.15) (diet vs. control -0.34, 95% CI -0.58 to -0.11, P = 0.007). The reduction in HbA1c level in the exercise intervention group (-0.46, 95% CI -0.70 to -0.23) did not significantly differ from the control group (exercise vs. control -0.09, 95% CI -0.32 to 0.15, P = 0.47). The exercise intervention group was superior in maintaining lean body mass. Both diet and exercise interventions induced improvements in adiposity and hepatic steatosis. CONCLUSIONS: These findings suggest that the medically supervised 5:2 energy-restricted diet could provide an alternative strategy for improving glycemic control and that the exercise regimen could improve body composition, although it inadequately improved glycemic control.

Sex Differences in the Feasibility of Aerobic Exercise Training for Improving Cardiometabolic Health Outcomes in Adults with Type 2 Diabetes.

Females with type 2 diabetes (T2D) have a 25-50% greater risk of developing cardiovascular disease compared with males. While aerobic exercise training is effective for improving cardiometabolic health outcomes, there is limited sex-segregated evidence on the feasibility of aerobic training in adults with T2D. A secondary analysis of a 12-week randomized controlled trial examining aerobic training in inactive adults with T2D was conducted. Feasibility outcomes were recruitment, retention, treatment fidelity, and safety. Sex differences and intervention effects were assessed using two-way analyses of variances. Thirty-five participants (14 females) were recruited. The recruitment rate was significantly lower among females (9% versus 18%; p = 0.022). Females in the intervention were less adherent (50% versus 93%; p = 0.016), and experienced minor adverse events more frequently (0.08% versus 0.03%; p = 0.003). Aerobically trained females experienced clinically meaningful reductions in pulse wave velocity (-1.25 m/s, 95%CI [-2.54, 0.04]; p = 0.648), and significantly greater reductions in brachial systolic pressure (-9 mmHg, 95%CI (3, 15); p = 0.011) and waist circumference (-3.8 cm, 95%CI (1.6, 6.1); p < 0.001) than males. To enhance the feasibility of future trials, targeted strategies to improve female recruitment and adherence are needed. Females with T2D may experience greater cardiometabolic health improvements from aerobic training than males.

Effect of exercise on hepatic steatosis: Are benefits seen without dietary intervention? A systematic review and meta-analysis.

BACKGROUND: Interventions involving both exercise and dietary modification are effective in reducing steatosis in nonalcoholic fatty liver disease (NAFLD). However, exercise alone may reduce liver fat and is known to have other positive effects on health. The primary aim of this study was to systematically review the effect of exercise alone without dietary intervention on NAFLD and to examine correlations across changes in liver fat and metabolic markers during exercise. METHODS: Relevant online databases were searched from earliest records to May 2020 by two researchers. Studies were included where the trial was a randomized controlled trial, participants were adults, exercise intervention was longer than 4 weeks, no dietary intervention occurred, and the effect of the intervention on liver fat was quantified via magnetic resonance imaging/proton magnetic resonance spectroscopy. RESULTS: Of 21 597 studies retrieved, 16 were included involving 706 participants. Exercise was found to have a beneficial effect on liver fat without dietary modification (-2.4%, -3.13 to -1.66) (mean, 95% CI). Pearson correlation showed significant relationships between change in liver fat and change in weight (r = 0.67, P = .007), liver enzymes aspartate aminotransferase (r = 0.76, P = .002) and alanine aminotransferase (r = 0.91, P < .001), and cardiorespiratory fitness VO2 peak (peak volume oxygen consumption) (r = -0.88, P = .004). By multivariate regression, change in weight and change in VO2 peak significantly contributed to change in liver fat (R2 = 0.84, P = .01). CONCLUSIONS: This systematic review found that exercise without dietary intervention improves liver fat and that clinical markers may be useful proxies for quantifying liver fat changes.

Non-invasive lower limb small arterial measures co-segregate strongly with foot complications in people with diabetes.

AIMS: It is unclear how well non-invasive lower-limb vascular assessments can identify those at risk of foot complications in people with diabetes. We aimed to investigate the relationship between a history of foot complication (ulceration or amputation) and non-invasive vascular assessments in people with diabetes. METHODS: Bilateral ankle-brachial index (ABI), toe brachial index (TBI) and continuous wave Doppler (CWD) were performed in 127 adults with diabetes (97% type 2; age 66.08±11.4years; 55% men; diabetes duration 8.8±7.6years; 28% on insulin therapy; 31% with foot complication history. Correlations were performed between known risk factors for, and documented history of, foot complication. Regression analysis was used to determine the effect of TBI on the likelihood of a prior foot complication. RESULTS: By logistic regression, the likelihood of foot complication history was highest in those with TBI <0.6 (OR=7.74, p=0.001); then longer diabetes duration (OR=1.06, p=0.05). HbA1c did not independently predict history of foot complications (OR=1.10, p=0.356). CONCLUSIONS: Likelihood of previous foot complication in this population was ~8 times higher when TBI was <0.6. Such clinical risk profiling was not shown by other non-invasive measures. Prioritizing TBI as a measure of lower-limb vascular disease may be useful to prospectively identify those at risk of diabetic foot complications.

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.