Dose-Response Effects of Exercise on Glucose-Lowering Medications for Type 2 Diabetes: A Secondary Analysis of a Randomized Clinical Trial

Does type 2 diabetes duration influence the effectiveness of an aerobic exercise intervention: Results from the INTENSITY study

BACKGROUND

Studies suggest that longer durations of T2DM increase the risk of T2DM complications and premature mortality. However, whether T2DM duration impacts the efficacy of an aerobic exercise intervention is unclear.

OBJECTIVE

The purpose of this study was: 1) to compare changes in body composition, cardiorespiratory fitness, and glycemia between individuals with short- and long-duration T2DM after aerobic exercise and 2) to determine whether these changes were associated with changes in glycemia by T2DM duration.

METHODS

A secondary analysis of the INTENSITY study (NCT03787836), including thirty-four adults (≥19 years) with T2DM who participated in 28 weeks of aerobic exercise training for 150 minutes per week at a moderate-to-vigorous intensity (4.5 to 6.0 metabolic equivalents (METs)). Using pre-established cut-points, participants were categorized into two groups 1) short-duration T2DM (<5 years) or 2) long-duration T2DM (≥5 years). Glycemia was measured by glycated hemoglobin (HbA1c), body composition by BodPod, and cardiorespiratory fitness by a measure of peak oxygen consumption (VO2peak). All measurements were performed at baseline, 16 weeks, and 28 weeks.

RESULTS

Participants in the short-duration T2DM group experienced decreases in fat mass (kg) (p = 0.03), HbA1c (p = 0.05), and an increased relative VO2peak (p = 0.01). Those with long-duration T2DM experienced decreases in fat mass (kg) (p = 0.02) and HbA1c (p <0.001) and increased fat-free mass (p = 0.02). No significant differences were observed between groups in any outcomes. Changes in fat mass (r = 0.54, p = 0.02), and body fat percentage (r = 0.50, p = 0.02) were significantly associated with the change in HbA1c in those with a long-duration T2DM only.

CONCLUSION

Our results suggest T2DM duration did not differently impact the efficacy of a 28-week aerobic exercise intervention. However, changes in body composition were associated with better glycemia in individuals with longer T2DM duration only.

Physical exercise as treatment for adults with type 2 diabetes: a rapid review

Background

Type 2 diabetes mellitus (T2DM) is a leading cause of disability-adjusted life years (DALY). Physical exercise is an effective non-pharmacological intervention to promote glycaemic control in T2DM. However, the optimal exercise parameters for glycemic control in individuals with T2DM remain unclear.

Objective

This study aimed to analyze the relationship between physical training variables - frequency, intensity, type, duration, volume, and progression - and glycemic control in individuals with T2DM.

Methods

A rapid systematic literature review was conducted on PubMed and LILACS databases. The PICOT strategy was employed to define the inclusion criteria. Eligible studies had to assess the impact of exercise parameters (frequency, intensity, type, duration, volume, and progression) on glycemic control indicators, primarily glycosylated hemoglobin (HbA1c). Randomized and non-randomized clinical trials were included in the review. The methodological quality of each study was assessed using the PEDro scale (PROSPERO - CRD 42021262614).

Results

Out of 1188 papers initially identified, 18 reports met the inclusion criteria and were included in the analysis. A total of 1,228 participants with T2DM (1086 in exercise groups) were included in the selected studies. Among these studies, 16 (88.9%) were RCTs and 2 (11.1%) were nRCTs. The age of participants ranged from 43.1 and 68.9 years, and the average intervention duration was 16.8 weeks. Data on adherence to the intervention, adverse events, detailed intervention protocol, and its impacts on glycaemic control, lipid profile, blood pressure, anthropometric measures, medication, body composition, and physical fitness are reported.

Conclusion

The evidence supports the safety and effectiveness of physical exercises as non-pharmacological interventions for glycemic control. Aerobic, resistance and combined training interventions were associated with reductions in HbA1c and fasting glucose. The diversity of the physical exercise intervention protocols investigated in the studies included in this review is an important limitation to generalizing evidence-based practice. The call for action is mandatory to implement large-scale education programs on the prevention of diabetes and public health policies aimed to include well-planned and supervised exercise programs as an essential part of the primary prevention of type 2 diabetes.

Systematic Review Registration

PROSPERO, identifier (CRD42021262614).

Effects of an exercise-based lifestyle intervention on systemic markers of oxidative stress and advanced glycation endproducts in persons with type 2 diabetes: Secondary analysis of a randomised clinical trial

AIMS/HYPOTHESIS

This secondary analysis aimed to investigate the effects of a 12 months intensive exercise-based lifestyle intervention on systemic markers of oxidative stress in persons with type 2 diabetes. We hypothesized lifestyle intervention to be superior to standard care in decreasing levels of oxidative stress.

METHODS

The study was based on the single-centre, assessor-blinded, randomised, controlled U-turn trial (ClinicalTrial.gov NCT02417012). Persons with type 2 diabetes ˂ 10 years, ˂ 3 glucose lowering medications, no use of insulin, BMI 25-40 kg/m² and no severe diabetic complications were included. Participants were randomised (2:1) to either intensive exercise-based lifestyle intervention and standard (n = 64) or standard care alone (n = 34). Standard care included individual education in diabetes management, advice on a healthy lifestyle and regulation of medication by a blinded endocrinologist. The lifestyle intervention included five to six aerobic exercise sessions per week, combined with resistance training two to three times per week and an adjunct dietary intervention aiming at reduction of ∼500 kcal/day (month 0-4). The diet was isocaloric from months 5-12. The primary outcome of this secondary analysis was change in oxidative stress measured by 8-oxo-7,8-dihydroguanosine (8-oxoGuo) and secondarily in 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), as markers of RNA and DNA oxidation, respectively, from baseline to 12-months follow-up.

RESULTS

A total of 77 participants, 21 participants receiving standard care and 56 participants receiving the lifestyle intervention, were included in the analysis. Mean age at baseline was 54.1 years (SD 9.1), 41% were women and mean duration of type 2 diabetes was 5.0 years (SD 2.8). From baseline to follow-up the lifestyle group experienced a 7% decrease in 8-oxoGuo (-0.15 nmol/mmol creatinine [95% CI -0.27, -0.03]), whereas standard care conversely was associated with a 8.5% increase in 8-oxoGuo (0.19 nmol/mmol creatinine [95% CI 0.00, 0.40]). The between group difference in 8-oxoGuo was -0.35 nmol/mmol creatinine [95% CI -0.58, -0.12,], p = 0.003. No between group difference was observed in 8-oxodG.

CONCLUSION/INTERPRETATION

A 12 months intensive exercise-based lifestyle intervention was associated with a decrease in RNA, but not DNA, oxidation in persons with type 2 diabetes.

Women Have Lower Mortality Than Men After Attending a Long-Term Medically Supervised Exercise Program

PURPOSE

Medically supervised exercise programs (MSEPs) are equally recommended for men and women with cardiovascular disease (CVD). Aware of the lower CVD mortality in women, we hypothesized that among patients attending a MSEP, women would also have better survival.

METHODS

Data from men and women, who were enrolled in a MSEP between 1994 and 2018, were retrospectively analyzed. Sessions included aerobic, resistance, flexibility and balance exercises, and cardiopulmonary exercise test was performed. Date and underlying cause of death were obtained. Kaplan-Meier methods and Cox proportional hazards regression were used for survival analysis.

RESULTS

A total of 2236 participants (66% men, age range 33-85 yr) attended a median of 52 (18, 172) exercise sessions, and 23% died during 11 (6, 16) yr of follow-up. In both sexes, CVD was the leading cause of death (39%). Overall, women had a more favorable clinical profile and a longer survival compared to men (HR = 0.71: 95% CI, 0.58-0.85; P < .01). When considering those with coronary artery disease and similar clinical profile, although women had a lower percentage of sex- and age-predicted maximal oxygen uptake at baseline than men (58 vs 78%; P < .01), after adjusting for age, women still had a better long-term survival (HR = 0.68: 95% CI, 0.49-0.93; P = .02).

CONCLUSION

Survival after attendance to a long-term MSEP was better among women, despite lower baseline cardiorespiratory fitness. Future studies should address whether men and women would similarly benefit when participating in an MSEP.

Impact of intensive lifestyle intervention on gut microbiota composition in type 2 diabetes: a post-hoc analysis of a randomized clinical trial

Type 2 diabetes (T2D) management is based on combined pharmacological and lifestyle intervention approaches. While their clinical benefits are well studied, less is known about their effects on the gut microbiota. We aimed to investigate if an intensive lifestyle intervention combined with conventional standard care leads to a different gut microbiota composition compared to standard care alone treatment in individuals with T2D, and if gut microbiota is associated with the clinical benefits of the treatments. Ninety-eight individuals with T2D were randomized to either an intensive lifestyle intervention combined with standard care group (N = 64), or standard care alone group (N = 34) for 12 months. All individuals received standardized, blinded, target-driven medical therapy, and individual counseling. The lifestyle intervention group moreover received intensified physical training and dietary plans. Clinical characteristics and fecal samples were collected at baseline, 3-, 6-, 9-, and 12-month follow-up. The gut microbiota was profiled with 16S rRNA gene amplicon sequencing. There were no statistical differences in the change of gut microbiota composition between treatments after 12 months, except minor and transient differences at month 3. The shift in gut microbiota alpha diversity at all time windows did not correlate with the change in clinical characteristics, and the gut microbiota did not mediate the treatment effect on clinical characteristics. The clinical benefits of intensive lifestyle and/or pharmacological interventions in T2D are unlikely to be explained by, or causally related to, changes in the gut microbiota composition.

Effects of a Lifestyle Intervention on Bone Turnover in Persons with Type 2 Diabetes: A Post Hoc Analysis of the U-TURN Trial

INTRODUCTION/PURPOSE

The increased risk of fractures with type 2 diabetes (T2D) is suggested to be caused by decreased bone turnover. Current international guidelines recommend lifestyle modifications, including exercise, as first-line treatment for T2D. The aim of this study was to investigate the effects of an exercise-based lifestyle intervention on bone turnover and bone mineral density (BMD) in persons with T2D.

METHODS

Persons with T2D were randomized to either a 12-month lifestyle intervention (n = 64) or standard care (n = 34). The lifestyle intervention included five to six weekly aerobic training sessions, half of them combined with resistance training. Serum markers of bone turnover (osteocalcin, N-terminal propeptide of type-I procollagen, reflecting bone formation, and carboxyterminal collagen I crosslinks, reflecting bone resorption) and BMD (by DXA) were measured before the intervention and at follow-up.

RESULTS

From baseline to follow-up, s-propeptide of type-I procollagen increased by 34% (95% confidence interval [CI], 17%-50%), serum-carboxyterminal collagen I crosslink by 36% (95% CI, 1%-71%), and s-osteocalcin by 31% (95% CI, 11-51%) more in the lifestyle intervention group compared with standard care. Loss of weight and fat mass were the strongest mediators of the increased bone turnover. Bone mineral density was unaffected by the intervention (ΔBMD, 0.1%; 95% CI, -1.1% to 1.2%).

CONCLUSIONS

A 12-month intensive exercise-based lifestyle intervention led to a substantial but balanced increase in bone turnover in persons with T2D. The increased bone turnover combined with a preserved BMD, despite a considerable weight loss, is likely to reflect improved bone health and warrants further studies addressing the impact of exercise on risk of fractures in persons with T2D.

A systematic review of adherence to physical activity interventions in individuals with type 2 diabetes

Lifestyle interventions are pivotal for successful management of type 2 diabetes (T2D), however, the proportion of people with T2D adhering to physical activity advice has not been thoroughly studied. The purpose of this systematic review was to summarise the evidence on adherence to exercise or physical activity components in lifestyle interventions in those with T2D. We searched MEDLINE EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and Scopus on 12 November 2019. Eligible studies enrolled adults with T2D and reported the proportion of adherence to lifestyle interventions as a primary or secondary outcome. We included 11 studies (nine randomised controlled trials (RCTs) enrolling 1717 patients and two nonrandomised studies enrolling 62 patients). Only one of the studies had low risk of bias. The proportion of participants adhering to physical activity varied from 32% to 100% with a median of 58%. Adherence was higher in interventions using supervised training and lowest in interventions using remote coaching and the adherence rate in observational studies was higher compared to RCTs (92% vs. 55%; p < 0.01). Study duration, risk of bias, or participants' sex, were not associated with adherence to physical activity. The proportion of those with T2D adhering to physical activity interventions for T2D varies widely and most of the included studies had a high risk of bias. These findings have important implications for planning and power analysis of future trials and when counselling patients about lifestyle interventions including physical activity or exercise components.

Non-alcoholic fatty liver disease: A patient guideline

This patient guideline is intended for all patients at risk of or living with non-alcoholic fatty liver disease (NAFLD). NAFLD is the most frequent chronic liver disease worldwide and comes with a high disease burden. Yet, there is a lot of unawareness. Furthermore, many aspects of the disease are still to be unravelled, which has an important impact on the information that is given (or not) to patients. Its management requires a close interaction between patients and their many healthcare providers. It is important for patients to develop a full understanding of NAFLD in order to enable them to take an active role in their disease management. This guide summarises the current knowledge relevant to NAFLD and its management. It has been developed by patients, patient representatives, clinicians and scientists and is based on current scientific recommendations, intended to support patients in making informed decisions.

Chronic musculoskeletal pain, catastrophizing, and physical function in adult women were improved after 3-month aerobic-resistance circuit training

Although exercise is beneficial for chronic musculoskeletal pain (CMP), the optimal type and amount of exercise are unclear. This study aimed to determine the impact of circuit training that combines aerobic and resistance exercises on adult women with CMP. A total of 139 women with CMP underwent circuit training for 3 months and were asked to complete the following questionnaires at baseline and 3 months later: Numeric Rating Scale (NRS), Pain Catastrophizing Scale (PCS), Roland-Morris Disability Questionnaire (RDQ), Shoulder36, and Knee injury and Osteoarthritis Outcome Score (KOOS). Significant improvements were observed in NRS, PCS, RDQ, and KOOS activities of daily living (ADL) scores after the intervention relative to baseline (p < 0.0001, p = 0.0013, 0.0004, and 0.0295, respectively), whereas shoulder function did not improve. When considering the impact of exercise frequency, NRS scores improved regardless of exercise frequency. Furthermore, PCS, RDQ, and KOOS scores improved in participants who exercised at least twice a week (24 sessions over the course of 3 months). In conclusion, CMP, pain catastrophizing, and physical function in adult female fitness club participants with CMP of NRS 4 or higher improved after 3 months of aerobic-resistance circuit training.

Exercise Reduces Medication for Metabolic Syndrome Management: A 5-Year Follow-up Study

PURPOSE

This study aimed to determine the effects of a 5-yr exercise intervention on metabolic syndrome (MetS) and health-related variables and medication use for MetS management.

METHODS

Participants were randomly assigned to an exercise intervention (n = 25, 54 ± 2 yr, 20% women) or control group (n = 26, 54 ± 2 yr, 38% women). The intervention lasted 4 months per year and consisted of high-intensity interval training on a cycloergometer thrice a week. Outcomes were MetS z-score and medication use score, MetS-related variables (including blood pressure, blood glucose homeostasis, and lipid profile), and cardiorespiratory fitness (CRF, as determined by maximal oxygen uptake).

RESULTS

MetS z-score was similarly reduced over time in both groups (P = 0.244 for group-time interaction). A quasi-significant and significant group-time interaction was found for MetS number of factors (P = 0.004) and CRF (P < 0.001), respectively. Thus, MetS factors tended to decrease over time only in the exercise group with no change in the control group, whereas CRF increased from baseline to 5-yr assessment in the exercise group (by 1.1 MET, P < 0.001) but decreased in the control group (-0.5 MET, P = 0.025). Medicine use score increased twofold from baseline to 5-yr follow-up in the control group (P < 0.001) but did not significantly change (10%, P = 0.52) in the exercise group (P < 0.001 for group-time interaction). The proportion of medicated patients who had to increase antihypertensive (P < 0.001), glucose-lowering (P = 0.036), or total medication (P < 0.0001) over the 5-yr period was lower in the exercise than that in the control group.

CONCLUSIONS

Exercise training can attenuate the increase in medication that would be otherwise required to manage MetS over a 5-yr period.

Association of Weight Loss With Type 2 Diabetes Remission Among Adults in Medically Underserved Areas: A Retrospective Cohort Study

PURPOSE

To examine the association between weight loss and type 2 diabetes remission among vulnerable populations living in medically underserved areas of the Mid-Southern United States.

DESIGN

Quantitative, retrospective cohort study.

SETTING

114 ambulatory sites and 5 adults' hospitals in the Mid-South participating in a regional diabetes registry.

PARTICIPANTS

9,900 adult patients with type 2 diabetes, stratified by remission status, with 1 year of baseline electronic medical record data, and 1 year of follow-up data for the 2015-2018 study period.

MEASURES

The outcomes were diabetes remissions, categorized as any remission, partial remission, and complete remission based on the guidelines of the American Diabetes Association. The exposure was weight loss, calculated by the change in the Body Mass Index (BMI) as a proxy measure.

ANALYSIS

χ² tests, Fisher's exact tests, and the Mann-Whitney U-test were used to examine the differences in patient characteristics by remission status across the 3 remission categories, as appropriate. Multiple multivariable logistic regressions adjusting for confounders were performed to estimate the adjusted odds ratios (aORs) for the associations between weight loss and diabetes remission.

RESULTS

Among 9,900 patients identified, a reduction of 0.3 kg/m² (standard deviation: 2.5) in the average BMI from the baseline to the follow-up was observed. 10.8% achieved any type of remission, with 9.8% for partial and 1.0% for complete remissions. Greater weight loss was significantly associated with an increased likelihood of any (aOR = 1.07, 95% confidence interval (CI), 1.06-1.08), partial (aOR 1.06, 95% CI, 1.04-1.07), and complete diabetes remission (aOR 1.10, 95% CI, 1.07-1.13).

CONCLUSIONS

Weight loss is significantly associated with diabetes remission among patients living in medically underserved areas, but complete remission is rare.

Mediterranean Diet and Physical Activity Decrease the Initiation of Cardiovascular Drug Use in High Cardiovascular Risk Individuals: A Cohort Study

Our aim was to assess whether long-term adherence to a Mediterranean diet (MedDiet) and leisure-time physical activity (LTPA) were associated with a lower initiation of cardiovascular drug use. We studied the association between cumulative average of MedDiet adherence and LTPA and the risk of cardiovascular drug initiation in older adults at high cardiovascular risk (PREvención con DIeta MEDiterránea trial participants) non-medicated at baseline: glucose-lowering drugs (n = 4437), antihypertensives (n = 2145), statins (n = 3977), fibrates (n = 6391), antiplatelets (n = 5760), vitamin K antagonists (n = 6877), antianginal drugs (n = 6837), and cardiac glycosides (n = 6954). One-point increases in MedDiet adherence were linearly associated with a decreased initiation of glucose-lowering (HR: 0.76 [0.71-0.80]), antihypertensive (HR: 0.79 [0.75-0.82]), statin (HR: 0.82 [0.78-0.85]), fibrate (HR: 0.78 [0.68-0.89]), antiplatelet (HR: 0.79 [0.75-0.83]), vitamin K antagonist (HR: 0.83 [0.74; 0.93]), antianginal (HR: 0.84 [0.74-0.96]), and cardiac glycoside therapy (HR: 0.69 [0.56-0.84]). LTPA was non-linearly related to a delayed initiation of glucose-lowering, antihypertensive, statin, fibrate, antiplatelet, antianginal, and cardiac glycoside therapy (minimum risk: 180-360 metabolic equivalents of task-min/day). Both combined were synergistically associated with a decreased onset of glucose-lowering drugs (p-interaction = 0.04), antihypertensive drugs (p-interaction < 0.001), vitamin K antagonists (p-interaction = 0.04), and cardiac glycosides (p-interaction = 0.01). Summarizing, sustained adherence to a MedDiet and LTPA were associated with lower risk of initiating cardiovascular-related medications.

One-year intensive lifestyle intervention and improvements in health-related quality of life and mental health in persons with type 2 diabetes: a secondary analysis of the U-TURN randomized controlled trial

INTRODUCTION

The effects of lifestyle interventions in persons with type 2 diabetes (T2D) on health-related quality of life (HRQoL) and subjective well-being are ambiguous, and no studies have explored the effect of exercise interventions that meet or exceed current recommended exercise levels. We investigated whether a 1-year intensive lifestyle intervention is superior in improving HRQoL compared with standard care in T2D persons.

RESEARCH DESIGN AND METHODS

We performed secondary analyses of a previously conducted randomized controlled trial (April 2015 to August 2016). Persons with non-insulin-dependent T2D (duration ≤10 years) were randomized to 1-year supervised exercise and individualized dietary counseling (ie, 'U-TURN'), or standard care. The primary HRQoL outcome was change in the 36-item Short Form Health Survey (SF-36) physical component score (PCS) from baseline to 12 months of follow-up, and a key secondary outcome was changes in the SF-36 mental component score (MCS).

RESULTS

We included 98 participants (U-TURN group=64, standard care group=34) with a mean age of 54.6 years (SD 8.9). Between-group analyses at 12-month follow-up showed SF-36 PCS change of 0.8 (95% CI -0.7 to 2.3) in the U-TURN group and deterioration of 2.4 (95% CI -4.6 to -0.1) in the standard care group (difference of 3.2, 95% CI 0.5 to 5.9, p=0.02) while no changes were detected in SF-36 MCS. At 12 months, 19 participants (30%) in the U-TURN group and 6 participants (18%) in the standard care group achieved clinically significant improvement in SF-36 PCS score (adjusted risk ratio 2.6, 95% CI 1.0 to 4.5 corresponding to number needed to treat of 4, 95% CI 1.6 to infinite).

CONCLUSION

In persons with T2D diagnosed for less than 10 years, intensive lifestyle intervention improved the physical component of HRQoL, but not the mental component of HRQoL after 1 year, compared with standard care.

TRIAL REGISTRATION NUMBER

NCT02417012.

Effects of an intensive lifestyle intervention on the underlying mechanisms of improved glycaemic control in individuals with type 2 diabetes: a secondary analysis of a randomised clinical trial

AIMS/HYPOTHESIS

The aim was to investigate whether an intensive lifestyle intervention, with high volumes of exercise, improves beta cell function and to explore the role of low-grade inflammation and body weight.

METHODS

This was a randomised, assessor-blinded, controlled trial. Ninety-eight individuals with type 2 diabetes (duration <10 years), BMI of 25-40 kg/m², no use of insulin and taking fewer than three glucose-lowering medications were randomised (2:1) to either the standard care plus intensive lifestyle group or the standard care alone group. Standard care consisted of individual guidance on disease management, lifestyle advice and blinded regulation of medication following a pre-specified algorithm. The intensive lifestyle intervention consisted of aerobic exercise sessions that took place 5-6 times per week, combined with resistance exercise sessions 2-3 times per week, with a concomitant dietary intervention aiming for a BMI of 25 kg/m². In this secondary analysis beta cell function was assessed from the 2 h OGTT-derived disposition index, which is defined as the product of the Matsuda and the insulinogenic indices.

RESULTS

At baseline, individuals were 54.8 years (SD 8.9), 47% women, type 2 diabetes duration 5 years (IQR 3-8) and HbA_1c was 49.3 mmol/mol (SD 9.2); 6.7% (SD 0.8). The intensive lifestyle group showed 40% greater improvement in the disposition index compared with the standard care group (ratio of geometric mean change [RGM] 1.40 [95% CI 1.01, 1.94]) from baseline to 12 months' follow-up. Plasma concentration of IL-1 receptor antagonist (IL-1ra) decreased 30% more in the intensive lifestyle group compared with the standard care group (RGM 0.70 [95% CI 0.58, 0.85]). Statistical single mediation analysis estimated that the intervention effect on the change in IL-1ra and the change in body weight explained to a similar extent (59%) the variance in the intervention effect on the disposition index.

CONCLUSIONS/INTERPRETATION

Our findings show that incorporating an intensive lifestyle intervention, with high volumes of exercise, in individuals with type 2 diabetes has the potential to improve beta cell function, associated with a decrease in low-grade inflammation and/or body weight.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02417012 Graphical abstract.