Effects of different modes of exercise training on glucose control and risk factors for complications in type 2 diabetic patients: a meta-analysis

Physical activity and change in fasting glucose and HbA1c: a quantitative meta-analysis of randomized trials

AIMS

A systematic review was conducted of randomized trials which evaluated the impact of physical activity on the change in fasting glucose and HbA1c.

METHODS

A literature search was conducted in PubMed until December 2015. Studies reporting glucose or HbA1c at baseline and at the end of study were included, and the change and its variance were estimated from studies with complete data. Mixed-effect random models were used to estimate the change of fasting glucose (mg/dl) and HbA1c (%) per additional minutes of physical activity per week.

RESULTS

A total of 125 studies were included in the meta-analysis. Based on 105 studies, an increase of 100 min in physical activity per week was associated with an average change of -2.75 mg/dl of fasting glucose (95% CI -3.96; -1.55), although there was a high degree of heterogeneity (83.5%). When restricting the analysis on type 2 diabetes and prediabetes subjects (56 studies), the average change in fasting glucose was -4.71 mg/dl (95% CI -7.42; -2.01). For HbA1c, among 76 studies included, an increase of 100 min in physical activity per week was associated with an average change of -0.14% of HbA1c (95% CI -0.18; -0.09) with heterogeneity (73%). A large degree of publication bias was identified (Egger test p < 0.001). When restricting the analysis on type 2 diabetes and prediabetes subjects (60 studies), the average change in HbA1c was -0.16% (95% CI -0.21; -0.11).

CONCLUSIONS

This analysis demonstrates that moderate increases in physical activity are associated with significant reductions in both fasting glucose and HbA1c.

Aerobic Exercise Training Modalities and Prediabetes Risk Reduction

PURPOSE

Prediabetes is linked to several modifiable risk factors, in particular, physical activity participation. The optimal prescription for physical activity remains uncertain. This pilot study aimed to investigate the effectiveness of continuous moderate intensity (CON) versus high-intensity interval training (HIIT) in persons with prediabetes. Outcome measures included glycated hemoglobin (A1C), body composition, musculoskeletal and aerobic fitness.

METHODS

Participants (n = 35) were recruited and screened using a questionnaire plus capillary blood point-of-care A1C analysis. After baseline screening/exclusions, 21 participants were randomly assigned to either HIIT or CON training three times per week for 12 wk. All participants also undertook resistance training two times per week. A1C, an oral glucose tolerance test, select measures of physical and physiological fitness were assessed at baseline and follow-up.

RESULTS

There were no significant differences in improvements in select metabolic indicators to training between CON and HIT groups. Pooled participant data showed a mean reduction in A1C of 0.5% (95% confidence interval [CI] = 0.3%-0.7%), whereas β-cell function (%β) improved by 28.9% (95% CI = 16.5%-39.2%) and insulin sensitivity (%S) decreased by 34.8 (95% CI = 57.8%-11.8), as assessed by the Homeostatic Model Assessment. Significant reductions in waist circumference of 4.5 cm (P < 0.001) and a 20% (P < 0.001) improvement in aerobic fitness were also observed in both training groups.

CONCLUSION

The completion of a 12-wk exercise program involving both resistance training and either HIIT or CON training results in improved glycemic control, visceral adiposity, and aerobic fitness in persons with prediabetes.

Carbohydrate-Restriction with High-Intensity Interval Training: An Optimal Combination for Treating Metabolic Diseases?

Lifestyle interventions incorporating both diet and exercise strategies remain cornerstone therapies for treating metabolic disease. Carbohydrate-restriction and high-intensity interval training (HIIT) have independently been shown to improve cardiovascular and metabolic health. Carbohydrate-restriction reduces postprandial hyperglycemia, thereby limiting potential deleterious metabolic and cardiovascular consequences of excessive glucose excursions. Additionally, carbohydrate-restriction has been shown to improve body composition and blood lipids. The benefits of exercise for improving insulin sensitivity are well known. In this regard, HIIT has been shown to rapidly improve glucose control, endothelial function, and cardiorespiratory fitness. Here, we report the available evidence for each strategy and speculate that the combination of carbohydrate-restriction and HIIT will synergistically maximize the benefits of both approaches. We hypothesize that this lifestyle strategy represents an optimal intervention to treat metabolic disease; however, further research is warranted in order to harness the potential benefits of carbohydrate-restriction and HIIT for improving cardiometabolic health.

Aquatic exercise for adults with type 2 diabetes: a meta-analysis

AIMS

The purpose of this systematic review and meta-analysis was to examine the effects of aquatic exercise (AquaEx) on indicators of glycemic control (i.e., glycated hemoglobin [A1c] and fasting plasma glucose) in adults with type 2 diabetes mellitus (T2DM). It was hypothesized that AquaEx would improve glycemic control to a similar extent as land-based exercise (LandEx), but to a greater extent than non-exercise control (Ctrl).

METHODS

A literature search was completed in February 2017 for studies examining AquaEx training in adults with T2DM. Assessment of glycemic control was necessary for inclusion, while secondary outcomes such as quality of life and cardiometabolic risk factors (i.e., blood pressure, triglycerides and total cholesterol) were considered, but not required for inclusion. Outcomes were measured before and after at least 8 weeks of AquaEx, and data were analyzed using weighted mean differences (WMDs) and fixed effect models, when appropriate.

RESULTS

Nine trials including 222 participants were identified. Three trials compared AquaEx to LandEx, two compared AquaEx to Crtl, and four had a pre-/post-design without a comparison group. Results indicate no difference in A1c between LandEx and AquaEx (WMD = -0.02%, 95% confidence interval = [-0.71, 0.66]). Post-intervention A1c was lower in AquaEx when compared to Crtl (WMD = -0.96%, [-1.87, -0.05]). Post-AquaEx A1c was lower compared to baseline (WMD = -0.48%, [-0.66, -0.30]).

CONCLUSIONS

A1c can be reduced after eight-twelve weeks of AquaEx. However, at this time few studies have examined whether changes in A1c are different from LandEx or Crtl.

Treatment of NAFLD with diet, physical activity and exercise

Lifestyle intervention can be effective when treating non-alcoholic fatty liver diseases (NAFLD) patients. Weight loss decreases cardiovascular and diabetes risk and can also regress liver disease. Weight reductions of ⩾10% can induce a near universal non-alcoholic steatohepatitis resolution and fibrosis improvement by at least one stage. However, modest weight loss (>5%) can also produce important benefits on the components of the NAFLD activity score (NAS). Additionally, we need to explore the role of total calories and type of weight loss diet, micro- and macronutrients, evidence-based benefits of physical activity and exercise and finally support these modifications through established behavioural change models and techniques for long-term maintenance of lifestyle modifications. Following a Mediterranean diet can reduce liver fat even without weight loss and is the most recommended dietary pattern for NAFLD. The Mediterranean diet is characterised by reduced carbohydrate intake, especially sugars and refined carbohydrates (40% of the calories vs. 50-60% in a typical low fat diet), and increased monounsaturated and omega-3 fatty acid intake (40% of the calories as fat vs. up-to 30% in a typical low fat diet). Both TV sitting (a reliable marker of overall sedentary behaviour) and physical activity are associated with cardio-metabolic health, NAFLD and overall mortality. A 'triple hit behavioural phenotype' of: i) sedentary behaviour, ii) low physical activity, and iii) poor diet have been defined. Clinical evidence strongly supports the role of lifestyle modification as a primary therapy for the management of NAFLD and NASH. This should be accompanied by the implementation of strategies to avoid relapse and weight regain.

Qigong Exercises for the Management of Type 2 Diabetes Mellitus

Background: The purpose of this article is to clarify and define medical qigong and to identify an appropriate study design and methodology for a large-scale study looking at the effects of qigong in patients with type 2 diabetes mellitus (T2DM), specifically subject enrollment criteria, selection of the control group and study duration. Methods: A comprehensive literature review of English databases was used to locate articles from 1980-May 2017 involving qigong and T2DM. Control groups, subject criteria and the results of major diabetic markers were reviewed and compared within each study. Definitions of qigong and its differentiation from physical exercise were also considered. Results: After a thorough review, it was found that qigong shows positive effects on T2DM; however, there were inconsistencies in control groups, research subjects and diabetic markers analyzed. It was also discovered that there is a large variation in styles and definitions of qigong. Conclusions: Qigong exercise has shown promising results in clinical experience and in randomized, controlled pilot studies for affecting aspects of T2DM including blood glucose, triglycerides, total cholesterol, weight, BMI and insulin resistance. Due to the inconsistencies in study design and methods and the lack of large-scale studies, further well-designed randomized control trials (RCT) are needed to evaluate the 'vital energy' or qi aspect of internal medical qigong in people who have been diagnosed with T2DM.

Finding the Optimal volume and intensity of Resistance Training Exercise for Type 2 Diabetes: The FORTE Study, a Randomized Trial

AIM

To compare different volumes and intensities of resistance training (RT) combined with aerobic training (AT) for improvements in glycemic control and cardiovascular health for persons with type 2 diabetes (T2DM).

METHODS

Participants with T2DM were stratified by HbA1c and randomized: "usual care" (RT1), which consisted of moderate intensity (50% 1-repetition maximum [1-RM]), low volumeRT (initiated half-way through program); higher intensity (75% 1-RM) and higher volume (initiated at program onset) RT (RT2); or moderate intensity but higher volume RT (RT3). RT sets and repetitions were adjusted to maintain similar work and volume between RT2 and RT3. Walking or cycling (60-80% aerobic capacity)was prescribed 5 times/week, and RT was prescribed 2 times/week. An ANCOVA, adjusted for baseline and gender, assessed changes post-6months in glycemic control (HbA1c- primary outcome), aerobic capacity and anthropometrics.

RESULTS

Sixty-two participants (52.3±1.2years, 48% female) were randomized (RT1, n=20; RT2, n=20; RT3, n=22). Only post-training fasting glucose, without significant HbA1c change, was different between groups (RT1-RT3=-1.7mmol/L, p=0.046). Pre-post differences were found in pooled HbA1c (7.4±0.2%[57±2.2mmol/mol] vs. 6.7±0.2%[50±2.2mmol/mol], p<0.001), aerobic capacity (21.5±0.8vs. 25.2±0.8ml/kg/min, p<0.001), body mass (84.0±2.7vs. 83.0±2.7kg, p=0.022[DXA]), body mass index (30.8±0.9vs. 30.3±0.8kg/m², p=0.02) and body fat (32.3±1.1vs. 31.3±1.2%, p<0.001). The trial was discontinued early; no HbA1c advantage was found with either RT2 or RT3 over RT1.

CONCLUSIONS

Combined AT+RT exercise improved glycemic control, cardiovascular risk factors and body composition after 6months for participants with T2DM, but differential effects between the prescribed intensities and volumes of RT were not found to effect HbA1c.

Effectiveness of resistance exercise compared to aerobic exercise without insulin therapy in patients with type 2 diabetes mellitus: a meta-analysis

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Resistance exercise (> 12 weeks) appears to increase in VO_2max in diabetic patients.

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Resistance exercise didn’t decrease the glycemic level compared to aerobic exercises.

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The lipid profile of DM patients was the same in both types of exercise.

Background

Physical exercise has been used to mitigate the metabolic effects of diabetes mellitus.

Objective

To evaluate the effect of resistance exercise when compared to aerobic exercise without insulin therapy on metabolic and clinical outcomes in patients with type 2 diabetes mellitus.

Methods

Papers were searched on the databases MEDLINE/PubMed, CINAHL, SPORTDiscus, LILACS, and SCIELO, without language or date of publication limits. Clinical trials that compared resistance exercise to aerobic exercise in adults with type 2 diabetes mellitus who did not use insulin therapy were included. The quality of evidence and risk of bias were assessed using the GRADE system and the Cochrane Risk of Bias tool, respectively. Meta-analysis was also used, whenever possible. Two reviewers extracted the data independently. Eight eligible articles were included in this study, with a total of 336 individuals, with a mean age of 48–58 years. The protocols of aerobic and resistance exercise varied in duration from eight to 22 weeks, 30–60 min/day, three to five times/week.

Results

Overall the available evidence came from a very low quality of evidence and there was an increase in Maximal oxygen consumption (mean difference: −2.86; 95% CI: −3.90 to −1.81; random effect) for the resistance exercise and no difference was found in Glycated hemoglobin, Body mass index, High-density lipoprotein cholesterol, Low-density lipoprotein cholesterol, triglycerides, and total cholesterol.

Conclusions

Resistance exercise appears to be more effective in promoting an increase in Maximal oxygen consumption in protocols longer than 12 weeks and there is no difference in the control of glycemic and lipid levels between the two types of exercise.

The essential role of exercise in the management of type 2 diabetes

Exercise is typically one of the first management strategies advised for patients newly diagnosed with type 2 diabetes. Together with diet and behavior modification, exercise is an essential component of all diabetes and obesity prevention and lifestyle intervention programs. Exercise training, whether aerobic or resistance training or a combination, facilitates improved glucose regulation. High-intensity interval training is also effective and has the added benefit of being very time-efficient. While the efficacy, scalability, and affordability of exercise for the prevention and management of type 2 diabetes are well established, sustainability of exercise recommendations for patients remains elusive.

Concurrent Aerobic and Resistance Training Has Anti-Inflammatory Effects and Increases Both Plasma and Leukocyte Levels of IGF-1 in Late Middle-Aged Type 2 Diabetic Patients

Type 2 diabetes (T2D) is an age-related chronic disease associated with metabolic dysregulation, chronic inflammation, and activation of peripheral blood mononuclear cells (PBMC). The aim of this study was to assess the effects of a concurrent exercise training program on inflammatory status and metabolic parameters of T2D patients. Sixteen male patients (age range 55–70) were randomly assigned to an intervention group (n = 8), which underwent a concurrent aerobic and resistance training program (3 times a week; 16 weeks), or to a control group, which followed physicians' usual diabetes care advices. Training intervention significantly improved patients' body composition, blood pressure, total cholesterol, and overall fitness level. After training, plasma levels of adipokines leptin (−33.9%) and RBP4 (−21.3%), and proinflammatory markers IL-6 (−25.3%), TNF-α (−19.8%) and MCP-1 (−15.3%) decreased, whereas anabolic hormone IGF-1 level increased (+16.4%). All improvements were significantly greater than those of control patients. Plasma proteomic profile of exercised patients showed a reduction of immunoglobulin K light chain and fibrinogen as well. Training also induced a modulation of IL-6, IGF-1, and IGFBP-3 mRNAs in the PBMCs. These findings confirm that concurrent aerobic and resistance training improves T2D-related metabolic abnormalities and has the potential to reduce the deleterious health effects of diabetes-related inflammation.

Resistance Training for Glycemic Control, Muscular Strength, and Lean Body Mass in Old Type 2 Diabetic Patients: A Meta-Analysis

INTRODUCTION

Type 2 diabetes (T2D) in elderly patients is associated with accelerated loss of skeletal muscle mass and strength. However, there are few meta-analysis reviews which investigate the effects of resistance training (RT) on glycemic control and skeletal muscle in the patients.

METHODS

Three electronic databases were searched (from the earliest date available to November 2016). Studies were included according to the inclusion criteria: T2D patients at least 60 years old, fasting plasma glucose of at least 7.0, and at least 8 weeks of RT.

RESULTS

Fifteen cohorts of eight studies (360 patients, average age 66 years) met the inclusion criteria. RT groups lowered glycosylated hemoglobin (HbA1c) (mean ES = -0.37, 95% CI = -0.55 to -0.20, P < 0.01) but did not result in a significant effect on lean body mass (LBM) (mean ES = 0.08, 95% CI = -0.15 to 0.30, P = 0.50). Homogeneity was shown between studies regarding HbA1c and LBM (Q = 15.70, df = 9, P = 0.07 and Q = 0.12, df = 4, P = 0.998, respectively). High-intensity subgroups showed a slight tendency to improve (rather than duration, frequency, and weekly volume) and to decrease HbA1c levels more than low-intensity subgroups (P = 0.37). RT increased muscular strength (mean ES = 1.05, 95% CI = 0.26-1.84, P = 0.01). No training components explained the heterogeneity between studies with changes in muscle strength.

CONCLUSION

RT improves glycemic control and muscle strength in elderly patients with T2D. RT with high intensity can be a strategy to treat patients with T2D and sarcopenia associated with aging.

Discovering successful strategies for diabetic self-management: a qualitative comparative study

OBJECTIVE

This project explored lifestyles of patients in good and poor control to identify naturally occurring practices and strategies that result in successful diabetes management.

RESEARCH DESIGN AND METHODS

Semistructured interviews with adult patients with type 2 diabetes explored diet, food preparation, physical activity, medication use and glucose monitoring. Patients (n=56) were classified into good (A1C <7.0%), fair (7.0%8.0%) control groups and matched across groups on diabetes duration (±5 years) and medication modality (none, oral, insulin±oral) to control for non-lifestyle factors. A qualitative comparative analysis identified practices that distinguished glycemic groups.

RESULTS

Good control patients were more likely to test their glucose two or more times a day and reduce their sodium intake, as well as increase fruits and vegetables and limit portion sizes, some attaining good control without exercise. Fair control patients discussed several dietary strategies including limiting sweets, drinking non-caloric beverages, reducing carbs, 'cheating' (eating only a few sweets/limiting carbs in one meal to have more in another meal) and tested their glucose once a day. Poor control patients were more likely to skip antidiabetic medications and not test their glucose.

CONCLUSIONS

Although clinical trials indicate most self-management practices have limited effectiveness over time, increased glucose monitoring is a valuable component in daily management. Research is needed on effectiveness of dietary strategies that emphasize sodium monitoring and allow some degree of cheating. Reoffering diabetes education classes and providing pill boxes as memory aids may help improve poor control.

The Limits of Exercise Physiology: From Performance to Health

Many of the established positive health benefits of exercise have been documented by historical discoveries in the field of exercise physiology. These investigations often assess limits: the limits of performance, or the limits of exercise-induced health benefits. Indeed, several key findings have been informed by studying highly trained athletes, in addition to healthy or unhealthy people. Recent progress has been made in regard to skeletal muscle metabolism and personalized exercise regimes. In this perspective, we review some of the historical milestones of exercise physiology, discuss how these inform contemporary knowledge, and speculate on future questions.

Physician step prescription and monitoring to improve ARTERial health (SMARTER): A randomized controlled trial in patients with type 2 diabetes and hypertension

AIMS

There are few proven strategies to enhance physical activity and cardiometabolic profiles in patients with type 2 diabetes and hypertension. We examined the effects of physician-delivered step count prescriptions and monitoring.

METHODS

Participants randomized to the active arm were provided with pedometers and they recorded step counts. Over a 1-year period, their physicians reviewed their records and provided a written step count prescription at each clinic visit. The overall goal was a 3000 steps/day increase over 1 year (individualized rate of increase). Control arm participants were advised to engage in physical activity 30 to 60 min/day. We evaluated effects on step counts, carotid femoral pulse wave velocity (cfPWV, primary) and other cardiometabolic indicators including haemoglobin A1c in diabetes (henceforth abbreviated as A1c) and Homeostasis Model Assessment-Insulin Resistance (HOMA-IR) in participants not receiving insulin therapy.

RESULTS

A total of 79% completed final evaluations (275/347; mean age, 60 years; SD, 11). Over 66% of participants had type 2 diabetes and over 90% had hypertension. There was a net 20% increase in steps/day in active vs control arm participants (1190; 95% CI, 550-1840). Changes in cfPWV were inconclusive; active vs control arm participants with type 2 diabetes experienced a decrease in A1c (-0.38%; 95% CI, -0.69 to -0.06). HOMA-IR also declined in the active arm vs the control arm (ie, assessed in all participants not treated with insulin; -0.96; 95% CI, -1.72 to -0.21).

CONCLUSIONS

A simple physician-delivered step count prescription strategy incorporated into routine clinical practice led to a net 20% increase in step counts; however, this was below the 3000 steps/day targeted increment. While conclusive effects on cfPWV were not observed, there were improvements in both A1c and insulin sensitivity. Future studies will evaluate an amplified intervention to increase impact.

Long-term effect of smartphone-delivered Interval Walking Training on physical activity in patients with type 2 diabetes: protocol for a parallel group single-blinded randomised controlled trial

INTRODUCTION

Physical activity is a cornerstone in type 2 diabetes (T2D) rehabilitation. Effective long-term and low-cost strategies to keep these patients' physically active are needed. However, maintaining physical activity behaviour is difficult once formalised interventions end. Structured exercise training supported by mobile technology and remote feedback is potentially an effective strategy. The objective of the trial is to investigate whether mobile health support using the InterWalk application for smartphones is effective in increasing physical activity levels in persons with T2D over time compared with standard care. We investigate whether Interval Walking Training using the InterWalk application is superior to Danish municipality-based rehabilitation in increasing moderate-and-vigorous physical activity levels in patients with T2D across 52 weeks. Secondary, we hypothesise that a motivational programme added from end of intervention to 52 weeks further increases level of physical activity in everyday life in patients with T2D.

METHODS AND ANALYSIS

The trial is a parallel-group, open-labelled, randomised controlled trial with long-term follow-up at 52 week including patients with T2D. The primary outcome is change in moderate-and-vigorous physical activity. The key secondary outcome includes motivation for physical activity behaviour change. Other secondary outcomes are VO2-peak, strength in the lower extremities. Exclusion criterion is medical contraindication to exercise. We include up to 246 patients and randomly allocate them into a control (standard group) or an experimental group (8-12 weeks of IWT supported by the smartphone-based InterWalk application) in a 1:2 fashion. After intervention, the experimental group is randomly allocated into two follow-up conditions with unsupervised IWT with or without motivational support until 52-week follow-up. The intention-to-treat principle is applied.

ETHICS AND DISSEMINATION

The local regional Research Ethics Committee in Denmark (H-1-2014-074) and the Danish Data Protection Agency (j.nr. 2014-54-0897) have approved the trial. Positive, negative or inconclusive results will be disseminated in scientific journals and conferences.

TRIAL REGISTRATION NUMBER

NCT02341690.

Objectively-Measured Free-Living Physical Activity and Heart Rate Recovery

The purpose of this study was to examine the association of free-living, objectively-measured physical activity on treadmill-based heart rate recovery (HRR), a parameter known to associate with morbidity and mortality. Data was used from 2003 to 2004 NHANES. Physical activity was assessed via accelerometry, with HRR recovery assessed from a treadmill-based test. Heart rate recovery minute 1 (HRR₁) and minute 2 (HRR₂) were calculated. After adjustment, light and vigorous-intensity free-living physical activity, respectively, were associated with HRR₁ (β_adjusted = 0.69, 95% CI 0.22-1.14; β_adjusted 1.94, 95% CI 0.01-3.9) and HRR₂ (β_adjusted = 0.99, 95% CI 0.35-1.62; β_adjusted = 5.88, 95% CI 2.63-9.12). Moderate physical activity was not associated with HRR₁ (β_adjusted = 0.60, 95% CI -0.41 to 1.62), but was with HRR₂ (β_adjusted = 2.28, 95% CI 1.27-3.28). As free-living physical activity intensity increased, there was a greater association with HRR. This finding may provide mechanistic insight of previous research observations demonstrating intensity-specific effects of physical activity on various health outcomes.

Effects of long-term multicomponent exercise on health-related quality of life in older adults with type 2 diabetes: evidence from a cohort study

PURPOSE

To establish the effect of a long-term multicomponent exercise (LTMEX) intervention (24 months) on health-related quality of life (HRQoL), in older adults with type 2 diabetes (T2D).

METHODS

This longitudinal retrospective cohort study analyzes the effects of a supervised LTMEX program on HRQoL in older adults with T2D (n = 279). Participants underwent one of two conditions: LTMEX (n = 241) trained three times per week; and unchanged lifestyle-the control group (CO; n = 38). Participants completed baseline, and 2-year follow-up evaluations including the Short Form Health Survey 36 (SF-36), anthropometric, hemodynamic components, and cardiorespiratory fitness (VO₂ peak).

RESULTS

LTMEX improves HRQoL, specifically physical functioning (P < 0.001), general health (P < 0.05), vitality (P < 0.001), mental health (MH; P < 0.05), physical component score (P < 0.001), mental component score (P < 0.001), and total SF-36 (P < 0.001). LTMEX group also decreased body weight (BW; P < 0.005), waist circumference (WC; P < 0.001), waist-to-hip ratio (WHR; P < 0.001), and systolic blood pressure (SBP; P < 0.001), and increased VO₂ peak (P < 0.001). CO group increased WC (P = 0.012), BMI (P = 0.024), waist-to-hip ratio (WHR; P = 0.003) and SBP (P < 0.001), and decreased vitality (P < 0.001) and MH (P < 0.05).

CONCLUSIONS

A LTMEX intervention improves physical and mental HRQoL in older adults with T2D, and also anthropometric, hemodynamic profile, and cardiorespiratory fitness.

Clinical outcomes and glycaemic responses to different aerobic exercise training intensities in type II diabetes: a systematic review and meta-analysis

Aims

To establish if aerobic exercise training is associated with beneficial effects on clinical outcomes and glycaemic profile in people with type II diabetes.

Methods

A systematic search was conducted to identify studies through a search of MEDLINE (1985 to Sept 1, 2016, Cochrane Controlled Trials Registry (1966 to Sept 1, 2016), CINAHL, SPORTDiscus and Science Citation Index. The search strategy included a mix of MeSH and free text terms for related key concepts. Searches were limited to prospective randomized or controlled trials of aerobic exercise training in humans with type II diabetes, aged >18 years, lasting >2 weeks.

Results

Our analysis included 27 studies (38 intervention groups) totalling 1372 participants, 737 exercise and 635 from control groups. The studies contain data from 39,435 patient-hours of exercise training. Our analyses showed improvements with exercise in glycosylated haemoglobin (HbA1C%) MD: −0.71%, 95% CI −1.11, −0.31; p value = 0.0005. There were significant moderator effects; for every additional week of exercise HbA1C% reduces between 0.009 and 0.04%, p = 0.002. For those exercising at vigorous intensity peak oxygen consumption (peak VO₂) increased a further 0.64 and 5.98 ml/kg/min compared to those doing low or moderate intensity activity. Homeostatic model assessment of insulin resistance (HOMA-IR) was also improved with exercise MD: −1.02, 95% CI −1.77, −0.28; p value = 0.007; as was fasting serum glucose MD: −12.53 mmol/l, 95% CI −18.94, −6.23; p value <0.0001; and serum MD: −10.39 IU, 95% CI −17.25, −3.53; p value = 0.003.

Conclusions

Our analysis support existing guidelines that for those who can tolerate it, exercise at higher intensity may offer superior fitness benefits and longer program duration will optimize reductions in HbA1C%.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-017-0518-6) contains supplementary material, which is available to authorized users.

Physical Activity Throughout Adolescence and Hba1c in Early Adulthood: Birth Cohort Study

BACKGROUND

Physical inactivity is responsible for 7% of diabetes deaths worldwide, but little is known whether low levels of physical activity (PA) during adolescence increase the risk of diabetes in early adulthood. We evaluated the cross-sectional and longitudinal associations between PA throughout adolescence and HbA1c concentration in early adulthood.

METHODS

HbA1c was measured by high performance liquid chromatography. PA was assessed by self-report at the ages of 11, 15, and 18 years and by accelerometry at the ages of 13 (subsample) and 18 years. The loss percentages of follow up were 12.5% at 11 years, 14.4% at 15 years, and 18.7% at 18 years.

RESULTS

At 18 years, boys showed higher HbA1c than girls. At age 18 years, accelerometrybased PA at 18 years was inversely related to HbA1c levels in boys. Self-reported leisure-time PA at ages 11, 15, and 18 were unrelated to HbA1c in both genders. PA at 13 years of age was unrelated to HbA1c among both genders. In trajectory analysis, PA and accelerometer PA trajectories were not associated with later HbA1c.

CONCLUSIONS

Objectively measured PA at 18 years was cross-sectionally inversely associated with HbA1c in boys only. No prospective associations were identified.

Long-term effects of daily postprandial physical activity on blood glucose: a randomized controlled trial

Previous studies have shown that a bout of moderate or light postprandial physical activity effectively blunts the postprandial increase in blood glucose. The objective of this study was to test whether regular light postprandial physical activity can improve glycemia in persons with hyperglycemia or with a high risk of hyperglycemia. We randomized 56 participants to an intervention or a control group. They were diagnosed as hyperglycemic, not using antidiabetics, or were categorized as high-risk individuals for type 2 diabetes. The intervention group was instructed to undertake a minimum 30 min of daily light physical activity, starting a maximum of 30 min after a meal in addition to their usual physical activity for 12 weeks. The control group maintained their usual lifestyle. Blood samples were taken pre- and post-test. Forty participants completed the study and are included in the results. The self-reported increase in daily physical activity from before to within the study period was higher in the intervention group compared with control (41 ± 25 vs. 2 ± 16 min, p < 0.001). Activity diaries and accelerometer recordings supported this observation. The activity in the intervention group started earlier after the last meal compared with control (30 ± 13 vs. 100 ± 57 min, p = 0.001). There were no within- or between-group differences in any glycemic variable from pre- to post-test. In conclusion, the present study does not seem to support the notion that regular light postprandial physical activity improves blood glucose in the long term in persons with hyperglycemia or with high risk of hyperglycemia.

Reduced Inspiratory Muscle Strength in Patients with Type 2 Diabetes Mellitus and Obstructive Sleep Apnoea

BACKGROUND

Obstructive sleep apnoea (OSA) is related to type 2 diabetes (T2DM), and it may be associated with reduced inspiratory muscle strength (IMS). The aim of this study was to investigate the IMS in patients with T2DM, with or without OSA.

METHODS

Patients with T2DM with OSA (n = 33) and without OSA (n = 28) were included. The maximum IMS was tested using the POWERbreathe KH2 device. Reference IMS values were data calculated using an algorithm based on general populations and adjusted for age and gender.

RESULTS

There was no difference in IMS between the OSA group (median (range) 77 (35-124) cmH₂O) and the non-OSA group (84 (33-122) cmH₂O) (p = 0.97). The IMS values were reduced in the OSA group compared with the reference values (92.9 (62.3-100.0) cmH₂O) (p = 0.030), whereas the non-OSA group did not have reduced IMS. When the IMS values of all T2DM patients were compared with reference values, the IMS values were 79 (33-124) cmH₂O and 93.8 (62.3-102.4) cmH₂O, respectively (p = 0.017).

CONCLUSION

No difference in IMS between patients with T2DM with or without OSA was found. However, patients with T2DM and OSA had reduced IMS compared with age- and gender-matched references whereas the non-OSA group did not have reduced IMS.

Glycemic and Metabolic Effects of Two Long Bouts of Moderate-Intensity Exercise in Men with Normal Glucose Tolerance or Type 2 Diabetes

BACKGROUND

The glycemic and insulinemic responses following 30-60 min of exercise have been extensively studied, and a dose-response has been proposed between exercise duration, or volume, and improvements in glucose tolerance or insulin sensitivity. However, few studies have examined the effects of longer bouts of exercise in type 2 diabetes (T2D). Longer bouts may have a greater potential to affect glucagon, interleukin-6 (IL-6) and incretin hormones [i.e., glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP)].

AIM

To examine the effect of two bouts of long-duration, moderate-intensity exercise on incretins, glucagon, and IL-6 responses before and after exercise, as well as in response to an oral glucose tolerance test (OGTT) conducted the following day.

METHODS

Twelve men, six with and six without T2D, participated in two separate conditions (i.e., exercise vs. rest) according to a randomized crossover design. On day 1, participants either rested or performed two 90 min bouts of treadmill exercise (separated by 3.5 h) at 80% of their ventilatory threshold. All participants received standardized meals on day 1. On day 2 of each condition, glucose and hormonal responses were measured during a 4-h OGTT.

RESULTS

On day 1, exercise increased IL-6 at the end of the first bout of exercise (exercise by time interaction p = 0.03) and GIP overall (main effect of exercise p = 0.004). Glucose was reduced to a greater extent in T2D following exercise (exercise by T2D interaction p = 0.03). On day 2, GIP and active GLP-1 were increased in the fasting state (p = 0.05 and p = 0.03, respectively), while plasma insulin and glucagon concentrations were reduced during the OGTT (p = 0.01 and p = 0.02, respectively) in the exercise compared to the rest condition for both healthy controls and T2D. Postprandial glucose was elevated in T2D compared to healthy control (p < 0.05) but was not affected by exercise.

CONCLUSION

Long-duration, moderate-intensity aerobic exercise can increase IL-6. On the day following exercise, fasting incretins remained increased but postprandial insulin and glucagon were decreased without affecting postprandial glucose. This long duration of exercise may not be appropriate for some people, and further research should investigate why next day glucose tolerance was unchanged.

Osteoarthritis-related difficulty walking and risk for diabetes complications

OBJECTIVES

To examine the effect of Osteoarthritis (OA)-related difficulty walking on risk for diabetes complications in persons with diabetes and OA.

DESIGN

A population cohort aged 55+ years with symptomatic hip and knee OA was recruited 1996-98 and followed through provincial administrative data to 2015 (n = 2,225). In those with confirmed OA (examination and radiographs) and self-reported diabetes at baseline (n = 359), multivariate Cox regression modeling was used to examine the relationship between baseline difficulty walking (Health Assessment Questionnaire (HAQ) difficulty walking score; use of walking aid) and time to first diabetes-specific complication (hospitalization for hypo- or hyperglycemia, infection, amputation, retinopathy, or initiation of chronic renal dialysis) and cardiovascular (CV) events.

RESULTS

Participants' mean baseline age was 71.4 years; 66.9% were female, 77.7% had hypertension, 54.0% had pre-existing CV disease, 42.9% were obese and 15.3% were smokers. Median HAQ difficulty walking score was 2/3 indicating moderate to severe walking disability; 54.9% used a walking aid. Over a median 6.1 years, 184 (51.3%) experienced one or more diabetes-specific complications; 191 (53.2%) experienced a CV event over a median 5.7 years. Greater baseline difficulty walking was associated with shorter time to the first diabetes-specific complication (adjusted HR per unit increase in HAQ walking 1.24, 95% CI 1.04-1.47, P = 0.02) and CV event (adjusted HR for those using a walking aid 1.35, 95% CI 1.00-1.83, P = 0.04).

CONCLUSIONS

In a population cohort with OA and diabetes, OA-related difficulty walking was a significant - and potentially modifiable - risk factor for diabetes complications.

Benefits of a Paleolithic diet with and without supervised exercise on fat mass, insulin sensitivity, and glycemic control: a randomized controlled trial in individuals with type 2 diabetes

BACKGROUND

Means to reduce future risk for cardiovascular disease in subjects with type 2 diabetes are urgently needed.

METHODS

Thirty-two patients with type 2 diabetes (age 59 ± 8 years) followed a Paleolithic diet for 12 weeks. Participants were randomized to either standard care exercise recommendations (PD) or 1-h supervised exercise sessions (aerobic exercise and resistance training) three times per week (PD-EX).

RESULTS

For the within group analyses, fat mass decreased by 5.7 kg (IQR: -6.6, -4.1; p < 0.001) in the PD group and by 6.7 kg (-8.2, -5.3; p < 0.001) in the PD-EX group. Insulin sensitivity (HOMA-IR) improved by 45% in the PD (p < 0.001) and PD-EX (p < 0.001) groups. HbA_1c decreased by 0.9% (-1.2, -0.6; p < 0.001) in the PD group and 1.1% (-1.7, -0.7; p < 0.01) in the PD-EX group. Leptin decreased by 62% (p < 0.001) in the PD group and 42% (p < 0.001) in the PD-EX group. Maximum oxygen uptake increased by 0.2 L/min (0.0, 0.3) in the PD-EX group, and remained unchanged in the PD group (p < 0.01 for the difference between intervention groups). Male participants decreased lean mass by 2.6 kg (-3.6, -1.3) in the PD group and by 1.2 kg (-1.3, 1.0) in the PD-EX group (p < 0.05 for the difference between intervention groups).

CONCLUSIONS

A Paleolithic diet improves fat mass and metabolic balance including insulin sensitivity, glycemic control, and leptin in subjects with type 2 diabetes. Supervised exercise training may not enhance the effects on these outcomes, but preserves lean mass in men and increases cardiovascular fitness. Copyright © 2016 John Wiley & Sons, Ltd.

Effect of exercise on the quality of life in type 2 diabetes mellitus: a systematic review

PURPOSE

Diabetic patients tend to have a poor quality of life. A sedentary lifestyle is considered to be a modifiable risk factor for type 2 diabetes and an independent predictor of poor quality of life. Exercise is a key treatment for people living with diabetes. The purpose of this study was to conduct a systematic review to assess the effect of exercise on the quality of life of people with type 2 diabetes.

METHODS

We conducted a systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, Web of Science, Embase, Cochrane Library, CINAHL and three Chinese databases were searched for studies published until January 2016. The review included all clinical trials that evaluated the effect of exercise on quality of life compared with that of usual care for people with type 2 diabetes. Two reviewers independently assessed the quality of all the included studies, by using the Downs and Black Quality Index (QI).

RESULTS

Thirty studies met inclusion criteria, with 2785 participants. We divided the exercise into four modes: aerobic, resistance, a combination of aerobic and resistance and yoga. Aerobic exercise showed a significant effect between groups. Resistance and combined exercise showed mixed results. Yoga also showed good intervention effects on quality of life.

CONCLUSIONS

The effect of aerobic exercise on the quality of life in people with type 2 diabetes was safe and effective. Then, most of the studies on aerobic exercise were of good methodological quality. The effects of resistance exercise and combined exercise on the quality of life in people with type 2 diabetes were mixed, and the effect of yoga on quality of life still need more research.

Age and gender differential relationship between employment status and body mass index among middle-aged and elderly adults: a cross-sectional study

OBJECTIVE

To determine the influence of age and gender, respectively, on the association between employment status and body mass index (BMI) in Korean adults using a large, nationally representative sample.

DESIGN

Cross-sectional study.

SETTING

South Korea.

PARTICIPANTS

7228 from fourth wave of the Korean Longitudinal Study of Aging (KLoSA), the survey's short form and year: 'KLoSA 2012'.

MAIN OUTCOME MEASURES

BMI.

RESULTS

BMI among the employed was higher than among the unemployed for those under 60. In terms of gender, employed men reported higher BMI than their unemployed counterparts, whereas employed women reported lower BMI than did unemployed women.

CONCLUSIONS

Employment status showed varying impacts on obesity by age and gender. Both unemployment at or after 60, as well as unemployment among women, is associated with increased BMI compared with unemployment among younger individuals or men, respectively.

Physical Activity: The Role of Physical Activity and Fitness in the Prevention and Management of Type 2 Diabetes Mellitus

More than 18 million people in the United States are estimated to have type 2 diabetes mellitus (T2DM). The prevalence of coronary heart disease has been estimated to be as high as 55% in adult diabetics, and cardiovascular disease (CVD) is responsible for at least two thirds of deaths in persons with T2DM. The metabolic syndrome, a clustering of interrelated risk factors, is predictive of T2DM and CVD and prevalent in the T2DM population. Increased aerobic fitness and/or physical activity (3 hours per week moderate activity and/or 1 hour per week vigorous activity) have been demonstrated to be protective of metabolic syndrome. Regular moderate to vigorous physical activity (150 minutes per week moderate activity and/or 90 minutes per week vigorous activity) has been shown to reduce the risk of developing T2DM, even in high-risk individuals. Sedentary behaviors such as television watching are associated with increased risk for T2DM independent of diet and physical activity levels. Glycemic control is related more to exercise intensity than volume. Exercise should be performed at least 3 days per week, with no more than 2 days between exercise bouts. Long-term weight loss may require 7 hours per week of moderate to vigorous exercise. Strength training, alone or in combination with regular aerobic exercise, has been shown to improve glycemic control, hypertension, and other T2DM-related risk factors. Unless specifically contraindicated, strength training is safe for persons with T2DM. The American Diabetes Association now recommends 150 minutes per week of moderate activity and/or 90 minutes per week of vigorous aerobic activity and strength training 3 days per week as part of a program to prevent or manage T2DM. Guidelines for preparticipation screening and consideration for specific conditions are also presented.

The Acute Effects of Interval-Type Exercise on Glycemic Control in Type 2 Diabetes Subjects: Importance of Interval Length. A Controlled, Counterbalanced, Crossover Study

Interval-type exercise is effective for improving glycemic control, but the optimal approach is unknown. The purpose of this study was to determine the importance of the interval length on changes in postprandial glycemic control following a single exercise bout. Twelve subjects with type 2 diabetes completed a cross-over study with three 1-hour interventions performed in a non-randomized but counter-balanced order: 1) Interval walking consisting of repeated cycles of 3 min slow (aiming for 54% of Peak oxygen consumption rate [VO2peak]) and 3 min fast (aiming for 89% of VO2peak) walking (IW3); 2) Interval walking consisting of repeated cycles of 1 min slow and 1 min fast walking (IW1) and 3) No walking (CON). The exercise interventions were matched with regards to walking speed, and VO2 and heart rate was assessed throughout all interventions. A 4-hour liquid mixed meal tolerance test commenced 30 min after each intervention, with blood samples taken regularly. IW3 and IW1 resulted in comparable mean VO2 and heart rates. Overall mean postprandial blood glucose levels were lower after IW3 compared to CON (10.3±3.0 vs. 11.1±3.3 mmol/L; P < 0.05), with no significant differences between IW1 (10.5±2.8 mmol/L) and CON or IW3 and IW1 (P > 0.05 for both). Conversely blood glucose levels at specific time points during the MMTT differed significantly following both IW3 and IW1 as compared to CON. Our findings support the previously found blood glucose lowering effect of IW3 and suggest that reducing the interval length, while keeping the walking speed and time spend on fast and slow walking constant, does not result in additional improvements.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02257190.

Effect of aerobic exercise intensity on glycemic control in type 2 diabetes: a meta-analysis of head-to-head randomized trials

AIMS

To conduct a meta-analysis of head-to-head trials comparing aerobic exercise training of different intensities on glycemic control in type 2 diabetes.

METHODS

Databases, including MEDLINE and EMBASE, were searched up to January 2016. Randomized trials of at least 12 weeks in duration that compared two exercise interventions of different intensities were identified. Two reviewers independently extracted data from eligible trials. Using fixed effect model, weighted mean differences (WMD) between different exercise intensities were calculated for changes in glycated hemoglobin (HbA1c) and secondary outcomes, such as fasting glucose and fasting insulin.

RESULTS

Eight studies with a total of 235 participants were eligible. The exercise interventions lasted from 12 weeks to 6 months. The prescribed exercise intensities varied among studies. Four studies utilized vigorous exercise intensities for short durations by performing interval training. Overall, higher-intensity exercise resulted in a greater reduction in HbA1c compared to lower-intensity exercise (WMD = -0.22 %; 95 % confidence interval [-0.38, -0.06]; or -2.4 mmol/mol [-4.15, -0.66], I (2) = 0). Adherence to exercise and proportion of dropouts did not differ within trials. No adverse events were reported in these small trials with selected inclusion criteria.

CONCLUSIONS

Although our meta-analysis had a limited sample size, increasing exercise intensity safely accentuated reductions in HbA1c in some people with type 2 diabetes. Different approaches have been used to increase exercise intensity (i.e., some used interval training, whereas others used higher-intensity continuous exercise). However, at this time, it is unclear which form, if any, leads to the most favorable results.

Exercise as medicine - evidence for prescribing exercise as therapy in 26 different chronic diseases

This review provides the reader with the up-to-date evidence-based basis for prescribing exercise as medicine in the treatment of 26 different diseases: psychiatric diseases (depression, anxiety, stress, schizophrenia); neurological diseases (dementia, Parkinson's disease, multiple sclerosis); metabolic diseases (obesity, hyperlipidemia, metabolic syndrome, polycystic ovarian syndrome, type 2 diabetes, type 1 diabetes); cardiovascular diseases (hypertension, coronary heart disease, heart failure, cerebral apoplexy, and claudication intermittent); pulmonary diseases (chronic obstructive pulmonary disease, asthma, cystic fibrosis); musculo-skeletal disorders (osteoarthritis, osteoporosis, back pain, rheumatoid arthritis); and cancer. The effect of exercise therapy on disease pathogenesis and symptoms are given and the possible mechanisms of action are discussed. We have interpreted the scientific literature and for each disease, we provide the reader with our best advice regarding the optimal type and dose for prescription of exercise.

Community-Based Culturally Preferred Physical Activity Intervention Targeting Populations at High Risk for Type 2 Diabetes: Results and Implications

OBJECTIVES

In Canada, an ageing population, obesity rates and high risk among certain ethnocultural populations are driving diabetes prevalence. Given the burden associated with type 2 diabetes and its link to modifiable risk factors, this study aimed to implement culturally preferred physical activities at the community level, targeting individuals at high risk for type 2 diabetes. Glycated hemoglobin (A1C) levels were used to detect potential improvements in glycemic control.

METHODS

Participants were screened for diabetes risk using a questionnaire and capillary point-of-care A1C blood testing. Participants were offered community-based physical activity classes 2 to 3 times per week for 6 months. A subset of participants (n=84) provided additional measurements.

RESULTS

In total, 718 subjects were reached during recruitment. Substantial participant dropout took place, and 487 participants were exposed to the intervention. Among those who participated in the physical activity and provided follow up, mean A1C levels were reduced by 0.17 (p=0.002) after 3 months (n=84) and by 0.06 (p=0.35; n=49) after 6 months. The homeostatic model assessment (HOMA-beta) showed a significant improvement of 23.6% after 3 months (n=20; p=0.03) and 45.2% after 6 months (n=12; p=0.02). Resting systolic blood pressure and diastolic blood pressure plus combined hand-grip strength improved after 6 months (n=12).

CONCLUSIONS

Implementation of this community-based, culturally preferred physical activity program presented several challenges and was associated with significant participant dropout. After considering participant dropout, the relatively small group who participated and provided follow-up measures showed improvements various physiologic measures. Despite efforts to enhance accessibility, it appears that several barriers to physical activity participation remain and need to be explored to enhance the success of future programs.

Systematic development of a theory-informed multifaceted behavioural intervention to increase physical activity of adults with type 2 diabetes in routine primary care: Movement as Medicine for Type 2 Diabetes

BACKGROUND

Despite substantial evidence for physical activity (PA) as a management option for type 2 diabetes, there remains a lack of PA behavioural interventions suitable for delivery in primary care. This paper describes the systematic development of an evidence-informed PA behavioural intervention for use during routine primary care consultations.

METHODS

In accordance with the Medical Research Council Framework for the Development and Evaluation of Complex Interventions, a four-stage systematic development process was undertaken: (1) exploratory work involving interviews and workshop discussions identified training needs of healthcare professionals and support needs of adults with type 2 diabetes; (2) a systematic review with meta- and moderator analyses identified behaviour change techniques and optimal intervention intensity and duration; (3) usability testing identified strategies to increase implementation of the intervention in primary care and (4) an open pilot study in two primary care practices facilitated intervention optimisation.

RESULTS

Healthcare professional training needs included knowledge about type, intensity and duration of PA sufficient to improve glycaemic control and acquisition of skills to promote PA behaviour change. Patients lacked knowledge about type 2 diabetes and skills to enable them to make sustainable changes to their level of PA. An accredited online training programme for healthcare professionals and a professional-delivered behavioural intervention for adults with type 2 diabetes were subsequently developed. This multifaceted intervention was informed by the theory of planned behaviour and social cognitive theory and consisted of 15 behaviour change techniques. Intervention intensity and duration were informed by a systematic review. Usability testing resolved technical problems with the online training intervention that facilitated use on practice IT systems. An open pilot study of the intervention with fidelity of delivery assessment informed optimisation and identified mechanisms to enhance implementation of the intervention during routine diabetes consultations.

CONCLUSIONS

Movement as Medicine for Type 2 diabetes represents an evidence-informed multifaceted behavioural intervention targeting PA for management of type 2 diabetes developed for delivery in primary care. The structured development process undertaken enhances transparency of intervention content, replicability and scalability. Movement as Medicine for Type 2 diabetes is currently undergoing evaluation in a pilot RCT.

TRIAL REGISTRATION

ISRCTN67997502.

[Factors Influencing Physical Activity among Community-dwelling Older Adults with Type 2 Diabetes: A Path Analysis]

PURPOSE

The purpose of the study was to identify factors influencing physical activity among community-dwelling older adults with type 2 diabetes. The study design was based on the Theory of Triadic Influence.

METHODS

A total of 242 older adults with type 2 diabetes participated in this study. Six variables related to physical activity in older adults, including self-efficacy, social normative belief, attitudes, intention, experience, and level of physical activity, were measured using reliable instruments. Data were analyzed using descriptive statistics, Pearson's correlation analyses, and a path analysis.

RESULTS

The mean physical activity score was 104.2, range from zero to 381.21. The path analysis showed that self-efficacy had the greatest total effect on physical activity. Also, experience had direct and total effects on physical activity as well as mediated the paths of social normative beliefs to attitudes and intention to physical activity. These factors accounted for 10% of the total variance, and the fit indices of the model satisfied the criteria of fitness.

CONCLUSION

The findings of the study reveal the important role of self-efficacy and past experience in physical activity in older adults with type 2 diabetes.

Dose-response association of physical activity with HbA1c: Intensity and bout length

OBJECTIVE

The aims of this study were to characterize the dose-response relationship between moderate-to-vigorous intensity physical activity (MVPA), and light-intensity activity with HbA1c in adults at low, moderate, and high risks of type 2 diabetes, and to compare the relationship of short (1 to 9min) versus long (10+min) bouts of MVPA with HbA1c.

METHODS

Data from 2707 participants from the 2003-2006 National Health And Nutrition Examination Survey were analyzed in 2014-2015. Type 2 diabetes risk was classified into three groups based upon age (<40years; ≥40years) and BMI (<30; ≥30). The relationship between HbA1c and accelerometer-based physical activity variables was assessed using multiple regression models.

RESULTS

There was a curvilinear dose-response relationship between HbA1c with total activity and MVPA in adults at moderate or high risk for type 2 diabetes: higher amounts of physical activity were associated with lower HbA1c. The association of physical activity on HbA1c was stronger at lower levels of physical activity. There was no dose-response relationship in adults at low risk for type 2 diabetes. The relationship between short bouts with HbA1c was stronger than for bouts≥10min.

CONCLUSIONS

In adults at risk for type 2 diabetes, there is a dose-response relationship between physical activity and HbA1c levels such that the relationship: (1) is curvilinear; (2) is stronger when a higher percent of total activity comes from MVPA; and (3) is more potent with short bouts of MVPA. Fractionalized physical activity of at least moderate-intensity may contribute to long-term glucose control.

Motives for Participation in Physical Activity and Observance of Physical Activity Recommendations among Adults with Type 2 Diabetes

OBJECTIVES

Drawing on self-determination theory, this study examined how motivation to engage in physical activity (PA) influences the observance of PA recommendations by adults with type 2 diabetes.

METHODS

This study used a cross-sectional design. In total, 365 adults with type 2 diabetes (181 men and 184 women, mean age = 60.39 years; SD=6.47) completed a questionnaire assessing their motivations and behaviours regarding PA. PA behaviour was assessed by means of the weekly practice of moderate-to-vigorous PA (MVPA) during leisure time. A symptom checklist was also used to assess diabetes-related symptoms experienced over the past month.

RESULTS

Results of a hierarchic binary logistic regression revealed that participants accumulating at least 150 minutes per week of MVPA during their leisure time were more likely to display higher scores on intrinsic and identified motives, whereas participants not accumulating 150 minutes per week of MVPA during their leisure time were more likely to present higher scores on external regulation and amotivation. In addition, results of a multivariate analysis of covariance (MANCOVA) showed that participants accumulating at least 150 minutes per week of MVPA during their leisure time experienced less fatigue and fewer hyperglycemic symptoms.

CONCLUSIONS

These findings suggest that adults who observe PA recommendations for type 2 diabetes possess higher levels of autonomous motives to practise PA. Results further highlight the importance of motives for engaging in PA by adults with type 2 diabetes in terms of the positive relationship between observing PA recommendations and experiencing less fatigue and fewer hyperglycemic symptoms.

Exercising Tactically for Taming Postmeal Glucose Surges

This review seeks to synthesize data on the timing, intensity, and duration of exercise found scattered over some 39 studies spanning 3+ decades into optimal exercise conditions for controlling postmeal glucose surges. The results show that a light aerobic exercise for 60 min or moderate activity for 20-30 min starting 30 min after meal can efficiently blunt the glucose surge, with minimal risk of hypoglycemia. Exercising at other times could lead to glucose elevation caused by counterregulation. Adding a short bout of resistance exercise of moderate intensity (60%-80%  VO2max) to the aerobic activity, 2 or 3 times a week as recommended by the current guidelines, may also help with the lowering of glucose surges. On the other hand, high-intensity exercise (>80%  VO2max) causes wide glucose fluctuations and its feasibility and efficacy for glucose regulation remain to be ascertained. Promoting the kind of physical activity that best counters postmeal hyperglycemia is crucial because hundreds of millions of diabetes patients living in developing countries and in the pockets of poverty in the West must do without medicines, supplies, and special diets. Physical activity is the one tool they may readily utilize to tame postmeal glucose surges. Exercising in this manner does not violate any of the current guidelines, which encourage exercise any time.

The functional and clinical outcomes of exercise training following a very low energy diet for severely obese women: study protocol for a randomised controlled trial

Background

Clinical practice guidelines globally recommend lifestyle modification including diet and exercise training as first-line treatment for obesity. The clinical benefits of exercise training in adults with obesity is well-documented; however, there is no strong evidence for the effectiveness of exercise training for weight loss in class II and class III obesity. The purpose of the randomised controlled trial described in this protocol article is to examine the effect of exercise training, in addition to a very low energy diet (VLED), in clinically severe obese women for changes in body composition, physical function, quality of life, and markers of cardiometabolic risk.

Methods/Design

Sixty women, aged 18–50 years with a body mass index (BMI) greater than 34.9 kg.m² and at least one obesity-related co-morbidity, will be recruited for this 12-month study. Participants will be randomised to either exercise plus energy restriction (n = 30), or energy restriction alone (n = 30). All participants will follow an energy-restricted individualised diet incorporating a VLED component. The exercise intervention group will also receive exercise by supervised aerobic and resistance training and a home-based exercise programme totalling 300 minutes per week. Primary outcome measures include body composition and aerobic fitness. Secondary outcome measures include: physical function, cardiometabolic risk factors, quality of life, physical activity, and mental health. All outcome measures will be conducted at baseline, 3, 6 and 12 months.

Discussion

Previous research demonstrates various health benefits of including exercise training as part of a healthy lifestyle at all BMI ranges. Although clinical practice guidelines recommend exercise training as part of first-line treatment for overweight and obesity, there are few studies that demonstrate the effectiveness of exercise in class II and class III obesity. The study aims to determine whether the addition of exercise training to a VLED provides more favourable improvements in body composition, physical function, quality of life, and markers of cardiometabolic risk for women with clinically severe obesity, compared to VLED alone.

Trial registration

Australian New Zealand Clinical Trials Registry (ACTRN12611000694910). Date registered: 4 July 2011

Dietary and physical activity of adult patients with type 2 diabetes in Zhejiang province of eastern China: Data from a cross-sectional study

AIMS/INTRODUCTION

Lifestyle management helps improve the clinical outcome of patients with type 2 diabetes. The present study aimed to obtain lifestyle data on the dietary and physical activity of adult type 2 diabetes patients in Zhejiang province of eastern China for better patient education and improvement of clinical management.

MATERIALS AND METHODS

A cross-sectional survey of 607 adult type 2 diabetes patients was carried out in 12 hospitals within eight cities of Zhejiang province. Data were collected for sex, age, basic physical measurement (blood pressure, height, weight, waist circumference and hip circumference), dietary favor and habit (vegetarian diets vs meat diets, preference of salty or light flavors), detailed dietary intake (24-h recall method), as well as the weekly physical activity.

RESULTS

The mean age of the patients in the analysis was 56.39 ± 12.29 years, and 38.71% of the patients had higher levels of body mass index than recommended. The average daily total energy intake was 1887.71 ± 575.10 kcal. The percentage of calories from carbohydrate, protein and fat were 61.36 ± 11.59%, 13.29 ± 3.37% and 25.35 ± 11.16%, respectively. For physical activity, the patients generally spent most of their daily time sitting and sleeping, and the time for moderate vigorous activity was limited.

CONCLUSIONS

Adult patients with type 2 diabetes in Zhejiang province have a relatively high carbohydrate and low protein diet, with very limited physical activity. Patient education to achieve a better lifestyle intervention needs to improve in this region.