Aerobic Interval Training and Cardiometabolic Health in Patients with Type 2 Diabetes: A Meta-Analysis

PRO-FIT-CARE study: the feasibility assessment of a pilot online exercise intervention for persons living with obesity and female infertility

Introduction

Moderate-to-high physical activity participation is associated with a reduced risk of infertility. Yet, exercise interventions that target cardiorespiratory fitness, independent of weight loss, are lacking in obesity and female fertility research.

Purpose

The primary objective of the PRO-FIT-CARE (PROmoting FITness for CArdiometabolic & REproductive Health) study was to assess the feasibility of a moderate-to-high-intensity online exercise program for persons with obesity and female infertility.

Methods

Feasibility, safety, acceptability, and efficacy were assessed by examining: (1) recruitment and consent rate, (2) study retention, (3) adverse events, (4) participant satisfaction, (5) adherence, and (6) cardiorespiratory fitness.

Results

Eleven of thirty-two women contacted agreed to participate in the program (34.4% consent rate). Eight participants (72.7%) completed the study. One musculoskeletal injury was reported. There was a 30% adherence rate based on prescribed exercise intensity (60%-80% of heart rate maximum). One of eleven participants attended 80% of the exercise intervention. Based on a weekly satisfaction survey, the program had an overall high level of satisfaction. Compared to sex and age normative data, post-intervention, two of eight participants improved their cardiorespiratory fitness percentile rank.

Conclusion

The study highlights challenges with adherence to an online exercise program. While the program was safe and participants reported high levels of program satisfaction, approaches to improve adherence must be incorporated.

Effects of high-intensity interval training and its different protocols on lipid profile and glycaemic control in type 2 diabetes: A meta-analysis

This meta-analysis of randomised clinical trials aimed to compare the effects of high-intensity interval training (HIIT) and its different protocols versus moderate-intensity continuous training (MICT) and/or control on total cholesterol, HDL, LDL, triglycerides, HbA1c levels, and fasting glucose in individuals with type 2 diabetes mellitus (T2DM). The search strategy was performed in PubMed/MEDLINE, Cochrane CENTRAL, EMBASE, Web of Science, Sport DISCUS, and PEDro, until January 2023. A total of 31 studies (1092 individuals) were included. When compared to control, HIIT decreased total cholesterol by -0.31 mmol/L (95% CI -0.49; -0.12), LDL by -0.31 mmol/L (95% CI -0.49; -0.12), triglycerides by -0.27 mmol/L (95% CI -0.33; -0.2), HbA1c by -0.75% (95% CI -0.97; -0.53), fasting glucose by -1.15 mmol/L (95% CI -1.44; -0.86), and increased HDL by 0.24 mmol/L (95% CI 0.06; 0.42). No difference was found in the comparison between HIIT versus MICT for any of the outcomes analysed, however subgroup analysis showed that a moderate-interval (>30s to < 2 min) and moderate-term (>4 to < 12 weeks) HIIT protocol reduced total cholesterol, when compared to MICT. HIIT is able to improve lipid profile and glycaemic control in T2DM individuals, and specific protocols can be recommended for improving total cholesterol levels.

Dose-Dependent Effect of Supervised Aerobic Exercise on HbA1c in Patients with Type 2 Diabetes: A Meta-analysis of Randomized Controlled Trials

BACKGROUND

Previous meta-analyses indicated that aerobic exercise can improve glycemic control. However, the optimum dose of exercise is still being discussed.

OBJECTIVE

The aim of this study was to examine the dose-dependent effect of supervised aerobic training (SAT) on glycated hemoglobin (HbA_1c).

METHODS

We searched PubMed, Scopus, and Web of Science to May 2021 for randomized trials with an intervention period of 12 weeks or longer evaluating the effect of SAT on HbA_1c in adults with type 2 diabetes mellitus. Secondary outcomes included quality of life, change in hypoglycemic medications, and adverse events. A random-effects dose-response meta-analysis was conducted.

RESULTS

The analysis of 26 trials with 1253 participants indicated that each 30-min/week SAT reduced HbA_1c by - 0.22 percentage point (95% CI - 0.29 to - 0.15; GRADE = strong). Levels of HbA_1c decreased proportionally with the increase in the duration of moderate to vigorous-intensity SAT to 100 min/week (mean difference_{100 min/week}: - 0.96 percentage point, 95% CI - 1.25 to - 0.67), with flattening of the curve at higher duration. Aerobic exercise decreased antidiabetic medications by 13 per 100 patients (risk difference 0.13, 95% CI 0.02-0.23; 7 trials, n = 375; GRADE = moderate), and increased hypoglycemic reactions by 10 per 100 patients (risk difference: 0.10, 95% CI 0.03-0.17; 4 trials, n = 263; GRADE = low) and adverse events by 4 per 100 patients (risk difference: 0.04, 95% CI - 0.02 to 0.11; 2 trials, n = 236; GRADE = low). Limited evidence is available for quality of life.

CONCLUSIONS

Every 30 min/week of moderate to vigorous aerobic exercise can exert a significant effect on HbA_1c, with the highest effect observed from 100 min/week and above. However, exercise durations above 100 min/week seem ineffective for further reductions.

PROTOCOL REGISTRATION

PROSPERO (CRD42021257251).

Physiological Responses to Low-Volume Interval Training in Women

Interval training is a form of exercise that involves intermittent bouts of relatively intense effort interspersed with periods of rest or lower-intensity exercise for recovery. Low-volume high-intensity interval training (HIIT) and sprint interval training (SIT) induce physiological and health-related adaptations comparable to traditional moderate-intensity continuous training (MICT) in healthy adults and those with chronic disease despite a lower time commitment. However, most studies within the field have been conducted in men, with a relatively limited number of studies conducted in women cohorts across the lifespan. This review summarizes our understanding of physiological responses to low-volume interval training in women, including those with overweight/obesity or type 2 diabetes, with a focus on cardiorespiratory fitness, glycemic control, and skeletal muscle mitochondrial content. We also describe emerging evidence demonstrating similarities and differences in the adaptive response between women and men. Collectively, HIIT and SIT have consistently been demonstrated to improve cardiorespiratory fitness in women, and most sex-based comparisons demonstrate similar improvements in men and women. However, research examining insulin sensitivity and skeletal muscle mitochondrial responses to HIIT and SIT in women is limited and conflicting, with some evidence of blunted improvements in women relative to men. There is a need for additional research that examines physiological adaptations to low-volume interval training in women across the lifespan, including studies that directly compare responses to MICT, evaluate potential mechanisms, and/or assess the influence of sex on the adaptive response. Future work in this area will strengthen the evidence-base for physical activity recommendations in women.

Effect of high-intensity interval training protocols on VO2max and HbA1c level in people with type 2 diabetes: A systematic review and meta-analysis

BACKGROUND

The effect of high-intensity interval training (HIIT) protocols according to different work intervals, session volumes and training periods has not been evaluated in patients with type 2 diabetes mellitus (T2DM).

OBJECTIVE

This was a systematic review and meta-analysis of the effect of HIIT and its different protocols compared to moderate-intensity continuous training (MICT) and the control group on VO₂max and glycated hemoglobin (HbA1c) level in patients with T2DM.

METHODS

The search strategy considered studies published up to September 2020 in the databases MEDLINE (PubMed), EMBASE, Cochrane CENTRAL, Web of Science and SPORTDiscus. Two authors independently searched the selected databases for randomized clinical trials that compared HIIT to MICT or the control in adults with T2DM. A random-effects meta-analysis was performed and the data are presented as the mean difference (95% confidence intervals [95% CIs]) between HIIT, MICT and control groups.

RESULTS

A total of 20 studies (738 participants) were included. Overall, HIIT increased VO₂max by 5.09 mL/kg/min (95% CI 2.99; 7.19, I² = 80.89) versus the control and by 1.9 mL/kg/min (95% CI 0.81; 2.98, I² = 25.62) versus MICT. HIIT promoted a significant reduction in HbA1c level of -0.8% (95% CI -1.06; -0.49, I² = 77.31) versus the control but with no difference versus MICT. Moderate-interval, high-volume and long-term training promoted a greater increase in VO₂max. A long interval and moderate volume and period conferred a greater increase in VO₂max versus MICT. A short interval and moderate volume and period conferred a greater reduction in HbA1c level versus the control. No publication bias was detected, as evaluated by a funnel chart and Egger's test (p > 0.05).

CONCLUSIONS

As compared with MICT, HIIT had better effect on VO₂max and a similar effect on HbA1C level. Interval protocols, moderate to long training period and moderate to high volume may maximize the HIIT effect in patients with T2DM.

Effects of Yoga Therapy and Walking Therapy in Reducing Blood Sugar Levels on Diabetes Mellitus Patients in the Community

BACKGROUND: The increasing of diabetes mellitus cases in Indonesia may be due to changes in people’s lifestyles, which is lack of exercise. Factors that may contribute to the high prevalence of diabetes mellitus sufferers other than genetics are exacerbated by environmental factors. Exercise interventions have been effective in counterbalancing diabetes complications. Yoga exerts a beneficial effect on insulin kinetics and the resulting lipid profile. Yoga helps redistribute body fat and reduces obesity which may lead to insulin resistance. In addition, other types of physical activity that can be done by diabetes mellitus patients are adequate morning walking while having scenery leisure for 30 min or more. AIM: This study was conducted to determine the effect of yoga therapy and walking therapy on diabetes mellitus patients in the community. METHODS: Quantitative research using randomized control trial, conducted in Gedongan Village, Baki Subdistrict, Sukoharjo Regency, involving 54 samples divided into three groups. Inclusion criteria: Patients with type 2 diabetes mellitus, fasting glucose levels of 126 mg/dl, no complication, and no insulin therapy or diabetes medication. The outcome measured was fasting blood sugar levels. The intervention group performed therapy for 12 weeks with a duration of 3 times a week. RESULTS: The average fasting sugar levels in the yoga group pre (217.00) post (187.72) p (0.001), the walking group averaged pre (209.89) post (193.83) p (0.001), and the control group averaged pre (221.50) post (225.17) p (0.067). CONCLUSION: There was an effect of yoga therapy and walking therapy on reducing fasting glucose levels.

Evidence-Based Effects of High-Intensity Interval Training on Exercise Capacity and Health: A Review with Historical Perspective

Engaging in regular exercise results in a range of physiological adaptations offering benefits for exercise capacity and health, independent of age, gender or the presence of chronic diseases. Accumulating evidence shows that lack of time is a major impediment to exercise, causing physical inactivity worldwide. This issue has resulted in momentum for interval training models known to elicit higher enjoyment and induce adaptations similar to or greater than moderate-intensity continuous training, despite a lower total exercise volume. Although there is no universal definition, high-intensity interval exercise is characterized by repeated short bursts of intense activity, performed with a "near maximal" or "all-out" effort corresponding to ≥90% of maximal oxygen uptake or >75% of maximal power, with periods of rest or low-intensity exercise. Research has indicated that high-intensity interval training induces numerous physiological adaptations that improve exercise capacity (maximal oxygen uptake, aerobic endurance, anaerobic capacity etc.) and metabolic health in both clinical and healthy (athletes, active and inactive individuals without any apparent disease or disorder) populations. In this paper, a brief history of high-intensity interval training is presented, based on the novel findings of some selected studies on exercise capacity and health, starting from the early 1920s to date. Further, an overview of the mechanisms underlying the physiological adaptations in response to high-intensity interval training is provided.

Effects of high-intensity interval training in patients with coronary artery disease after percutaneous coronary intervention: A systematic review and meta-analysis

AIM

To evaluate whether high-intensity interval training (HIIT) was superior to low-intensity training or usual care among patients after percutaneous coronary intervention. The hypothesis was that HIIT would help patients after percutaneous coronary intervention (PCI) improve cardiopulmonary function, lipid profiles and in-stent restenosis.

DESIGN

A systematic review and meta-analysis were conducted according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA)2009 Checklist.

METHODS

Randomized controlled trials (RCTs) focusing on HIIT programme in patients after PCI were searched in Cochrane Library, Web of Science Core Collection, EMbase, PubMed, China National Knowledge Infrastructure (CNKI) and SinoMed from the inception to 24 March 2020. Standard Mean difference (SMD) and 95% confidence intervals (CI) were performed to summarize the effect sizes.

RESULTS

Six RCTs (247 patients) met the criteria. HIIT programme had a statistically significant effect on raising left ventricular ejection function (LVEF) (SMD = 0.38, 95%CI [0.03, 0.73], I2  = 3%), VO2peak (SMD = 0.94, 95%CI [0.61, 1.28], I2  = 0%), as well as improving the serum level of high-density lipoprotein (SMD = 0.55, 95%CI [0.06, 1.03], I2  = 0%) and late luminal loss (SMD = -0.65, 95%CI [-1.07, -0.23], I2  = 0%). But HIIT had no prominent effect on improving heart rate (SMD = -0.04, 95%CI [-0.29, 0.21], I2  = 0%). Summarily, HIIT programme appears to be favourable for CAD patients after PCI by improving cardiopulmonary function, such as LVEF and VO2peak , as well as reducing late luminal loss in per stented arteries. Nevertheless, HIIT has no advantage for adjusting heart rate. More researches with rigorous methods are warranted to explore the controversy about lipid profiles.

The effects and acceptability of different exercise modes on glycemic control in type 2 diabetes mellitus: A protocol for systematic review and network meta-analysis

INTRODUCTION

Exercise has been believed to have positive effects on blood glucose control in patients with type 2 diabetes mellitus. However, few medical evidences have been found to ascertain which type of exercise has the best effect on blood glucose control in diabetes and which type of exercise is more acceptable. The purpose of this study is to compare the effects and acceptability of different exercise modes on glycemic control in type 2 diabetes patients by using systematic review and network meta-analysis.

METHODS AND ANALYSIS

Relevant randomized controlled trial studies will be searched from PubMed, EMbase, CochraneCENTRAL, CNKI, VIP, and Chinese medical paper libraries. Primary outcome indicators: glycosylated hemoglobin and dropout rate of the research (number of dropouts/numbers of initially enrolled subjects). Secondary outcome measures: fasting blood glucose, body weight, total cholesterol (TC), low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol, triglycerides (TG), diastolic pressure, systolic pressure (SBP). Two reviewers are arranged to screen Title, Abstract, and then review full text to further extract data. Standard meta-analysis and network meta-analysis of the data are performed afterward. Methodological quality assessment is planned to be conducted using Cochrane risk of bias tool. The outcome will be analyzed statistically according to Bayesian analysis methods. After that, subgroup analysis is conducted on the duration of intervention, whether there is supervision of intervention, frequency of intervention per week, age, gender, and medication use.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42020175181.

DISCUSSION

The systematic review and network meta-analysis include evidence of the impact of different exercise modes on blood glucose control in type 2 diabetes mellitus. There are 2 innovative points in this study. One is to conduct a classified study on exercise in as much detail as possible, and the other is to study the acceptability of different exercise modes. The network meta-analysis will reduce the uncertainty of intervention and enable clinicians, sports practitioners, and patients to choose more effective and suitable exercise methods.

ETHICS AND DISSEMINATION

The findings of the study will be disseminated through publications in peer-reviewed journals and scientific conferences and symposia. Further, no ethical approval is required in this study.

Global Public Health Guidelines on Physical Activity and Sedentary Behavior for People Living With Chronic Conditions: A Call to Action

Background: In 2020, the World Health Organization (WHO) released global guidelines on physical activity (PA) and sedentary behavior, for the first time providing population-based recommendations for people living with selected chronic conditions. This article briefly presents the guidelines, related processes and evidence, and, importantly, considers how they may be used to support research, practice, and policy. Methods: A brief overview of the scope, agreed methods, selected chronic conditions (adults living with cancer, hypertension, type 2 diabetes, and human immunodeficiency virus), and appraisal of systematic review evidence on PA/sedentary behavior is provided. Methods were consistent with World Health Organization protocols for developing guidelines. Results: Moderate to high certainty evidence (varying by chronic condition and outcome examined) supported that PA can reduce the risk of disease progression or premature mortality and improve physical function and quality of life in adults living with chronic conditions. Direct evidence on sedentary behavior was lacking; however, evidence extrapolated from adult populations was considered applicable, safe, and likely beneficial (low certainty due to indirectness). Conclusions: Clinical and public health professionals and policy makers should promote the World Health Organization 2020 global guidelines and develop and implement services and programs to increase PA and limit sedentary behavior in adults living with chronic conditions.

High-Intensity Interval Training Versus Moderate-Intensity Continuous Training in Middle-Aged and Older Patients with Type 2 Diabetes: A Randomized Controlled Crossover Trial of the Acute Effects of Treadmill Walking on Glycemic Control

Background: This study aimed to compare the acute effects of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) on glycemic control in middle-aged and older patients with type 2 diabetes (T2D), using treadmill walking as aerobic exercise mode. Methods: Fifteen patients with T2D (60.25 ± 3.14 years; glycated hemoglobin 7.03 ± 0.33%; medicated with metformin and/or gliptins), participated in a randomized controlled crossover trial. They underwent three experimental conditions (treadmill walking HIIT session (5 × (3 min at 70% of heart rate reserve (HRR) + 3 min at 30% HRR)); treadmill walking MICT session (30 min at 50% HRR); and a control session of rest (CON)) in random order and in the postprandial state. Measurements of capillary blood glucose (BG) were taken immediately before, during, and until 50 min after the experimental conditions. Results: Both HIIT and MICT treadmill walking sessions reduced BG levels during exercise and laboratory 50 min recovery period compared to CON (time*condition interaction effect; p < 0.001). The effect of HIIT was greater compared with MICT (p = 0.017). Conclusions: Treadmill walking HIIT seems a safe and more effective exercise strategy on immediate acute glycemic control compared with MICT in middle-aged and older patients with T2D under therapy with metformin and/or gliptins. Trial Registration Number: ISRCTN09240628.

Effectiveness of Exercise Intervention in Reducing Body Weight and Glycosylated Hemoglobin Levels in Patients with Type 2 Diabetes Mellitus in Korea: A Systematic Review and Meta-Analysis

BACKGROUND

This study aimed to assess the effectiveness of exercise intervention in reducing body weight and glycosylated hemoglobin (HbA1c) level in patients with type 2 diabetes mellitus (T2DM) in Korea.

METHODS

Cochrane, PubMed, Embase, KoreaMed, KMbase, NDSL, KCI, RISS, and DBpia databases were used to search randomized controlled trials and controlled clinical trials that compared exercise with non-exercise intervention among patients with non-insulin-treated T2DM in Korea. The effectiveness of exercise intervention was estimated by the mean difference in body weight changes and HbA1c level. Weighted mean difference (WMD) with its corresponding 95% confidence interval (CI) was used as the effect size. The pooled mean differences of outcomes were calculated using a random-effects model.

RESULTS

We identified 7,692 studies through literature search and selected 23 articles (723 participants). Compared with the control group, exercise intervention (17 studies) was associated with a significant decline in HbA1c level (WMD, -0.58%; 95% CI, -0.89 to -0.27; I²=73%). Although no significant effectiveness on body weight was observed, eight aerobic training studies showed a significant reduction in body weight (WMD, -2.25 kg; 95% CI, -4.36 to -0.13; I²=17%) in the subgroup analysis.

CONCLUSION

Exercise significantly improves glycemic control; however, it does not significantly reduce body weight. Aerobic training can be beneficial for patients with non-insulin-treated T2DM in Korea.

Association Between Cardiorespiratory Fitness and Risk of Type 2 Diabetes: A Meta-Analysis

OBJECTIVE

This meta-analysis aimed to (1) quantify the association of cardiorespiratory fitness (CRF) with type 2 diabetes risk in the general population and statin users and (2) investigate the joint effects of CRF and fatness with type 2 diabetes risk.

METHODS

Databases were searched for cohort studies reporting the association between CRF and type 2 diabetes risk. Summary hazard ratios (HRs) were obtained using random-effects models.

RESULTS

Fifteen studies were included. The HRs of type 2 diabetes for every 1-metabolic equivalent increase in CRF were 0.90 (95% CI: 0.86-0.94) for the general population and 0.92 (95% CI: 0.87-0.97) for statin users, and the HRs were linearly shaped (both P_nonlinearity  > 0.40). Compared with the nonstatin cohort, there was an increased risk of type 2 diabetes in statin users with the lowest and moderate CRF categories, but this was not present in the highest CRF category. The HR of type 2 diabetes for overweight/obesity-fit category versus normal weight-fit category was larger than that of the normal weight-unfit category versus the normal weight-fit category (P_interaction   = 0.004).

CONCLUSIONS

There was an inverse and dose-dependent association between CRF and type 2 diabetes risk. High CRF may eliminate the diabetogenic effect from statins, yet decreased body weight index seems superior in preventing type 2 diabetes.

Exercise training and endothelial function in patients with type 2 diabetes: a meta-analysis

BACKGROUND AND AIMS

Exercise training is considered a cornerstone in the management of type 2 diabetes, which is associated with impaired endothelial function. However, the association of exercise training with endothelial function in type 2 diabetes patients has not been fully understood. This meta-analysis aimed to investigate their associations with focus on exercise types.

METHODS

Databases were searched up to January 2018 for studies evaluating the influences of exercise training with durations ≥ 8 weeks on endothelial function assessed by flow-mediated dilation (FMD) among type 2 diabetes patients or between type 2 diabetics and non-diabetics. Data were pooled using random-effects models to obtain the weighted mean differences (WMDs) and 95% confidence intervals (CIs).

RESULTS

Sixteen databases were included. Exercise training resulted in an overall improvement in FMD by 1.77% (95% CI 0.94-2.59%) in type 2 diabetes patients. Specifically, both aerobic and combined aerobic and resistance exercise increased FMD by 1.21% (95% CI 0.23-2.19%) and 2.49% (95% CI 1.17-3.81%), respectively; but resistance exercise only showed a trend. High-intensity interval aerobic exercise did not significantly improve FMD over moderate-intensity continuous exercise. Notably, the improvement in FMD among type 2 diabetes patients was smaller compared with non-diabetics in response to exercise training (WMD - 0.72%, 95% CI - 1.36 to - 0.08%) or specifically to aerobic exercise (WMD - 0.65%, 95% CI - 1.31 to 0.01%).

CONCLUSIONS

Exercise training, in particular aerobic and combined exercise, improves endothelial function in type 2 diabetes patients, but such an improvement appears to be weakened compared with non-diabetics. Trial registration PROSPERO CRD42018087376.