Type 2 diabetes and reduced exercise tolerance: a review of the literature through an integrated physiology approach

L-Arginine supplementation as mitochondrial therapy in diabetic cardiomyopathy

In patients with type II diabetes, the development of diabetic cardiomyopathy (DC) is associated with a high risk of mortality. Left ventricular hypertrophy, diastolic dysfunction, and exercise intolerance are the first signs of DC. The underlying mechanisms are not fully elucidated, and there is an urgent need for specific biomarkers and molecular targets for early diagnosis and treatment. Mitochondrial alterations play a key role in the development of DC, and microRNAs regulating mitochondrial function are emerging as potential biomarkers of metabolic stress in DC. L-Arginine (Arg) supplementation has been shown to be an effective strategy for improving mitochondrial function and energetics, with a significant impact on physical performance. The aim of the current study was to evaluate the effects of Arg supplementation on cardiac mitochondrial function, DC development, and relative phenotypes including exercise intolerance. We used db/db mice as a model of type II diabetes, chronically treated with Arg (1 mg/kg/day) for 12 weeks. Arg-treated db/db mice showed preserved diastolic function and left ventricular morphology compared with untreated diabetic mice. Arg supplementation also improved exercise tolerance and the propensity to physical activity. Mitochondrial respiration was significantly increased in cardiomyocytes isolated from treated db/db mice, as well as in diabetic cardiomyocytes treated with Arg in vitro. The improvement of cardiac mitochondrial function in db/db + Arg mice was associated with an increase in PGC-1-alpha levels, mitochondrial biogenesis, recycling, and antioxidant capacity. Arg treatment prevented the accumulation of circulating and cardiac miR-143 in db/db mice, which is an index of metabolic stress and activation of mitochondrial damage mechanisms. In conclusion, Arg supplementation is effective in preventing the development of DC, preserving diastolic function and exercise tolerance by improving mitochondrial fitness and homeostasis. Additionally, miR-143 could potentially be employed to monitor cardiac metabolic stress and the effects of Arg treatment in diabetes.

Acute and chronic effects of inspiratory muscle training in patients with type 2 diabetes mellitus: a systematic review of randomized controlled trials

Objectives

To conduct a systematic review to determine the acute and chronic effects of inspiratory muscle training (IMT) in type 2 diabetes mellitus (T2DM) patients on cardiac autonomic function, glucose variability, inspiratory muscle strength and endurance, hemodynamic variables, and exercise capacity.

Methods

A search was carried out according to a specific search strategy, following the PRISMA statement, and three independent reviewers have undertaken the article selection process. Searches were carried out in June 2023, on the following electronic databases: EMBASE, MEDLINE (PubMed), SCOPUS (Elsevier), and Web of Science. The methodological quality of the studies was assessed using the PEDro scale. The search was limited to English-language, randomized controlled trials (RCTs), involving T2DM patients (>18 years old, with or without autonomic neuropathy, and/or inspiratory muscle weakness) following an acute or chronic intervention protocol based on IMT. Exclusion criteria were reviews, clinical trials, case studies, theses, dissertations, scientific conference abstracts, subjects with other chronic respiratory/neurological/cardiovascular diseases, and studies addressing other breathing exercises.

Results

The search strategy identified 1,352 studies, of which eight (two involving acute and six involving chronic IMT effects) were included. A total of 214 adults aged 52-63 years (51/49 male/female ratio), with BMI ranging from 27 to 36.8 kg/m², were included. The results demonstrated that after IMT, acute effects were reported, such as reduced glucose levels and an increase in the parasympathetic pathway, but also chronic effects including improved inspiratory muscle strength, endurance, and exercise capacity.

Conclusion

Although some methodological differences among the studies were found, IMT may have beneficial effects on cardiac autonomic function, glucose level control, inspiratory muscle strength/endurance as well as exercise capacity. However, further studies are necessary to confirm these benefits.

Personal and Social-Built Environmental Factors of Glucose Variability Among Multiethnic Groups of Adults With Type 2 Diabetes: Research Protocol Using Ecological Momentary Assessment, Continuous Glucose Monitoring, and Actigraphy

Glucose variability (GV)-the degree of fluctuation in glucose levels over a certain period of time-is emerging as an important parameter of dynamic glycemic control. Repeated glycemic oscillations have been reported to be the link to diabetes complications. This prospective observational study aims to: (1) identify multilevel risk factors (personal and social-built environmental factors) associated with high GV; (2) identify "within-person predictors" of high GV leveraging the intra-person data to inform future personalized diabetes interventions; and (3) examine which lifestyle factors either mediate or moderate the relationship between emotional well-being and GV among diverse adults with type 2 diabetes (T2D). We will recruit 200 adults with T2D from the community. All participants will complete baseline surveys assessing demographics, lifestyle, social-built environmental, and clinical factors. Real-time dynamic glucose levels will be measured using continuous glucose monitoring (CGM). Sleep, physical activity, diet/eating, and emotional well-being will be measured with an actigraphy device and a real-time self-report tool (ecological momentary assessment [EMA]) across 14 days. Two 24-h dietary recall data will be collected by online video calls. Generalized linear models, multilevel models, and structural equation models will be developed to achieve the study aims. The findings from the study will identify high-risk groups of high GV who would benefit from CGM to improve diabetes outcomes and inform the future development of personalized just-in-time interventions targeting lifestyle behaviors with an increased understanding of GV and by supporting healthcare providers' clinical decisions.

The effect of repeated hot water immersion on vascular function, blood pressure and central haemodynamics in individuals with type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is characterised by endothelial dysfunction, leading to increased risk of cardiovascular disease. Emerging evidence suggest that HWI may favourably improve vascular function but data are limited in individual with T2DM. The aim was to investigate whether repeated hot water immersion (HWI) improved macrovascular, microvascular and central haemodynamic function in individuals with T2DM. Fourteen individuals completed a pre-post experimental study where participants were assessed pre- and post-8-10 × 1 h HWI sessions (40 °C water) undertaken within a 14-day period. During HWIs, body position was adjusted to clamp rectal temperature at 38.5-39.0 °C for the duration of the immersion. Stroke volume index (SVi), cardiac index (Q˙ i), resting heart rate (HR), systolic blood pressure (SBP), diastolic BP (DBP), brachial flow-mediated dilation (FMD) and cutaneous microvascular endothelial function (via transdermal iontophoresis) and plasma [nitrate] and [nitrite] (NOX; via ozone chemiluminescence) were assessed pre- and post HWI. Neither brachial FMD measures of macrovascular endothelial function (p = 0.43) or forearm microvascular function (ACh max, p = 0.63; ACh area under curve (AUC), p = 0.63; insulin max, p = 0.51; insulin AUC, p = 0.86) or NOX (p = 0.38) were changed. Q˙ i (p < 0.01), SVi (p < 0.02) and resting HR (p < 0.01) were all significantly reduced following the 10-days HWI intervention. SBP was reduced (p = 0.03), whereas DBP was unchanged (p = 0.56). HWI may represent an appropriate intervention to improve Q˙ I, SVi and BP in individuals with T2DM, but not macrovascular endothelial or cutaneous microvascular function.

Health-related fitness benefits following concurrent high-intensity interval training and resistance training in patients with type-1 diabetes or type-2 diabetes

Introduction

Cardiorespiratory fitness (CRF), as assessed by VO2peak, along with metabolic and cardiovascular health indices, represents the strongest predictors of survival. However, it remains unclear whether concurrent high-intensity interval training (HIIT) and resistance training (RT) can similarly enhance these health markers in patients with type-1 diabetes (T1D) or type-2 diabetes (T2D) compared to healthy individuals.

Methods

Adults with uncomplicated T1D or T2D and healthy normoglycemic controls matched for sex and age (HC1 and HC2) performed 3 training sessions/week of concurrent HIIT and RT for 12 weeks. Pre- and post-intervention assessments included: lipids and glycemic profile, body composition (dual-energy x-ray absorptiometry) and a cyclo-ergometric cardio-pulmonary exercise test.

Results

Training improved VO2peak, the ventilatory threshold (VT1), maximal workload, ventilation and O2pulse, similarly in T1D in HC1 without changes in body composition or glycemic profile. In patients with T2D, training improved insulin sensitivity (HOMA-IR), lean mass, VE/VCO2 slope, VT1 and maximal O2pulse, workload and VO2peak with reduction in fat mass and visceral adipose tissue (VAT) (all, p < 0.05). However, improvements in VO2peak and O2pulse were lower than in healthy controls (respectively, T2D: +9%, HC2: +18% and T2D: +6%, HC2: +19%, p < 0.05).

Conclusions

Both patients with T1D and T2D benefit from combined HIIT and RT by improving CRF with specific adaptations influenced by the presence and type of diabetes. While identical magnitude of achievements were observed in T1D and HC1, T2D patients exhibited lower VO2peak and maximal O2pulse improvements but associated with notable additional health benefits regarding insulin sensitivity, body composition, visceral adipose tissue and ventilatory efficiency.

Meta-analysis of the effects of different exercise modes on cardiac function and peak oxygen uptake in patients with type 2 diabetes mellitus

Background

The benefits of exercise for primary and secondary prevention of cardiovascular events have been reported in patients with type 2 diabetes mellitus (T2DM). However, the effects of exercise on cardiac structure and function require clarification.

Methods

A literature search for clinical studies reporting on the effects of exercise on cardiac structure, cardiac function, and VO2peak in T2DM patients was conducted. PubMed, Embase, EBSCO, Web of Science, and China National Knowledge Infrastructure were systematically searched for original articles published from January 2000 to July 2023. The effect size was expressed as the mean difference (MD) or standardized mean difference (SMD) and its 95% confidence interval (CI). Subgroup analyses were performed by exercise mode (high-intensity interval training [HIIT] or moderate-intensity continuous training [MICT]) and intervention duration (>6 or ≤6 months).

Results

Compared to usual care, both HIIT and MICT significantly affected left ventricular end-diastolic volume (MD: 19.44, 95% CI: 13.72 to 25.17, p < 0.00001; I2 = 42%; MD: 13.90, 95% CI: 7.64 to 20.16, p < 0.0001; I2 = 0%), but only HIIT significantly affected left ventricular mass (MD: 17.04 g, 95% CI: 5.45 to 28.62, p = 0.004; I2 = 0%). HIIT significantly improved left ventricular ejection fraction (MD: 5.52, 95% CI: 2.31 to 8.73, p = 0.0008; I2 = 0%), as did MICT in the ≤6 months subgroup (MD: 1.36, 95% CI: 0.61 to 2.10, p = 0.0004; I2 = 0%). Neither significantly affected systolic tissue velocity. HIIT significantly improved VO2peak (MD: 8.04, 95% CI: 6.26 to 9.83, p < 0.00001; I2 = 0%), as did MICT in the ≤6 months subgroup (MD: 3.33, 95% CI: 2.39 to 4.27, p < 0.00001; I2 = 0%).

Conclusion

Exercise significantly improved cardiac structure, systolic function, and VO2peak, but did not significantly affect diastolic function in T2DM patients. HIIT seemed to be superior to MICT at improving VO2peak and left ventricular ejection fraction in T2DM patients. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/, PROSPERO registration no.: CRD4242018087376.

Effect of Glycated Haemoglobin (HBA1c) on Cardiorespiratory Fitness (CRF) in a Population with Type 2 Diabetes Mellitus (T2DM): A Cross-Sectional Study

Background and Objective: The aim of this study was to evaluate cardiorespiratory fitness (CRF) measures, maximal oxygen consumption (VO2 max), and minute ventilation/carbon dioxide production (VE/VCO2 slope and others) among the T2DM population based on glycated haemoglobin (HBA1c). Material and Methods: The present study comprised a cross-sectional design, with two groups, based on HbA1c values (≤7 and ≥7.1). Laboratory samples were taken to evaluate glycated haemoglobin and fasting blood glucose (FBS). Cardiopulmonary exercise testing was performed to calculate various fitness-related parameters. Data analysis: An independent t-test was used to analyse the outcomes in the two groups. p < 0.05 was considered significant. Linear regression was used to examine the influence of predictor variables on dependent variables. Results: A total of 70 patients agreed to participate in the study, with 19 females and 51 males. The mean (standard deviation) BMI (body mass index) of all participants was 29.7(5.2), the mean (SD) weight was 84.4 (18.9) kg, and the mean height was 167.4 (23) cm. The average age of the individuals was 52 ± 8 years. The independent t-test revealed a significant difference between the two groups in terms of CRF measures. Conclusions: The current research identified the presence of poor glycaemic control and cardiorespiratory fitness measures among the Brazilian population with T2DM. HBA1c, duration of diabetes, age, and BMI can be employed to predict the ventilatory threshold (VT) and VO2 max.

Glucagon-Like Peptide-1 Receptor Agonists and Sodium Glucose Cotransporter-2 Inhibitors and Cardiorespiratory Fitness Interaction

INTRODUCTION

Cardiorespiratory fitness (CRF) is a stronger predictor of mortality than traditional risk factors and is a neglected vital sign of health. Enhanced fitness is a cornerstone in diabetes management and is most often delivered concurrently with pharmacological agents, which can have an opposing impact, as has been reported with metformin. Considering the rapid evolution of diabetes medications with improved cardiovascular outcomes, such as glucagon-like peptide-1 receptor agonists and sodium glucose cotransporter-2 inhibitors, it is of importance to consider the influence of these vis-a-vis effects on CRF.

MATERIALS AND METHODS

Combining the words glucagon-like peptide-1 receptor agonists and sodium glucose cotransporter-2 inhibitors with cardiorespiratory fitness, an online search was done using PubMed, Embase, Scopus, Web of Science, Scientific Electronic Library Online, and Cochrane.

RESULTS

There were only a few randomized controlled studies that included CRF, and the results were mostly neutral. A handful of smaller studies detected improved CRF using sodium glucose cotransporter-2 inhibitors in patients with congestive heart failure.

CONCLUSIONS

Since CRF is a superior prognosticator for cardiovascular outcomes and both medications can cause lean muscle mass loss, the current review highlights the paucity of relevant interactive analysis.

Diabetes mellitus is associated with low exercise capacity and impaired peripheral vasodilation in patients with heart failure - a propensity score-matched study

AIMS

Diabetes mellitus (DM) and heart failure (HF) share vascular, skeletal and metabolic abnormalities that can reduce exercise capacity. We investigated whether exercise capacity differ in patients with type 2 DM compared to those without DM with HF of similar severity.

METHODS AND RESULTS

The Studies Investigating Co-morbidities Aggravating HF (SICA-HF) prospectively enrolled 615 patients with chronic HF, 259 (42.1 %) of whom had DM. We assembled a propensity score-matched cohort of 231 pairs of patients with HF with or without DM who were balanced on age, sex and variables reflecting HF severity. Patients with DM had lower median peak VO2 (15.7 [13.0-19.1] vs. 17.3 [14.1-21.0] ml/min/kg; p = 0.005). Forearm blood flow reserve (per 1 ml/min/100 ml increase) was associated with lower exercise capacity (peak VO2 ≤ 16.6 ml/min/kg) in patients with DM (OR, 0.92; 95 % CI, (0.85-0.98; p = 0.014), but not in those without DM (OR, 0.98; 95 % CI, 0.93-1.02). A similar heterogeneity was also observed for HDL cholesterol.

CONCLUSIONS

Diabetes is associated with a reduced exercise capacity in patients with HF. Most predictors of lower exercise capacity in HF are similar regardless of DM except impaired vascular function and lower HDL cholesterol which predict lower exercise capacity only in those with DM.

Association between subclinical right ventricular alterations and aerobic exercise capacity in type 2 diabetes

BACKGROUND

Type 2 diabetes (T2D) leads to cardiovascular remodeling, and heart failure has emerged as a major complication of T2D. There is a limited understanding of the impact of T2D on the right heart. This study aimed to assess subclinical right heart alterations and their contribution to aerobic exercise capacity (peak oxygen consumption; peak VO2) in adults with T2D.

METHODS

Single center, prospective, case-control comparison of adults with and without T2D, and no prevalent cardiac disease. Comprehensive evaluation of the left and right heart was performed using transthoracic echocardiography and stress cardiovascular magnetic resonance. Cardiopulmonary exercise testing on a bicycle ergometer with expired gas analysis was performed to determine peak VO2. Between group comparison was adjusted for age, sex, race, and body mass index using analysis of covariance (ANCOVA). Multivariable linear regression, including key clinical and left heart variables, was undertaken in people with T2D to identify independent associations between measures of right ventricular (RV) structure and function with peak VO2.

RESULTS

Three hundred and forty people with T2D (median age 64years, 62% (211) male, mean glycated hemoglobin (HbA1c) 7.3%) and 66 controls (median age 58years, 58% (38) male, mean HbA1c 5.5%) were included. T2D participants had markedly lower peak VO2 (adjusted mean 20.3 (95% confidence interval (CI): 19.8-20.9) vs 23.3(22.2-24.5)mL/kg/min, P < 0.001) than controls and had smaller left ventricular (LV) volumes and LV concentric remodeling. Those with T2D had smaller RV volumes (indexed RV end-diastolic volume: 84 (82-86) vs 100 (96-104)mL/m, P < 0.001) with evidence of hyperdynamic RV systolic function (global longitudinal strain (GLS): 26.3 (25.8-26.8) vs 23.5 (22.5-24.5)%, P < 0.001) and impaired RV relaxation (longitudinal peak early diastolic strain rate (PEDSR): 0.77 (0.74-0.80) vs 0.92 (0.85-1.00) s-1, P < 0.001). Multivariable linear regression demonstrated that RV end-diastolic volume (β =-0.342, P = 0.004) and RV cardiac output (β = 0.296, P = 0.001), but not LV parameters, were independent determinants of peak VO2.

CONCLUSION

In T2D, markers of RV remodeling are associated with aerobic exercise capacity, independent of left heart alterations.

Blood pressure and ECG variables of healthy young males and females participating in moderate aerobic exercise

INTRODUCTION

Changes in blood pressure and electrocardiogram are important factors that determine exercise testing. This study investigated blood pressure and electrocardiogram (ECG) changes in healthy young adults after performing acute moderate aerobic exercise protocols.

METHODS

Forty young healthy untrained non-athletes, twenty males and twenty females (age, 25 ± 5.6 years; body weight, 65 ± 4.0 kg; body height, 176.9 ± 2.5 cm) were recruited for the study. The exercise regimen was acute moderate exercise for 20 min on a treadmill consistently for 14 days daily at the speed of 13 km/h. The body weight, blood pressure, and electrocardiograph were measured before and after exercise.

RESULTS

There was a significant reduction (P < 0.05) in body weight (59 ± 3.2 kg) of female participants after 14 days of aerobic exercise relative to their baseline mean value (63 ± 2.9 kg). The systolic blood pressure decreased (P < 0.05) in males (117 ± 1.1 mmHg) and females (117 ± 1.0 mmHg) when compared to the mean baseline values in males (127 ± 1.3 mmHg) and females (128 ±0 .3 mmHg). The diastolic blood pressure also decreased (P < 0.05) in male (71 ± 0.88 mmHg) participants after exercise when compared to the baseline mean values (79 ± 1.2 mmHg) while there was no change in diastolic blood pressure of females. The ECG parameters remained unchanged, while the heart rate (75 ± 1.3 beats/min) increased (P < 0.05) after exercise in all participants relative to the baseline (69 ± 2 beats/min).

CONCLUSION

The results suggest that moderate aerobic exercise normalized blood pressure and electrical activity of the heart while reducing heart rate after 14 days of consistent aerobic exercise in healthy individuals.

The effects of resistance training on cardiovascular factors and anti-inflammation in diabetic rats

Diabetes induces a range of macrovascular and microvascular changes, which lead to significant clinical complications. Although many studies have tried to solve the diabetic problem using drugs, it remains unclear. In this study, we investigated whether resistance exercise affects cardiovascular factors and inflammatory markers in diabetes. The study subjected Otsuka Long-Evans Tokushima Fatty (OLETF) rats, which have genetically induced diabetes mellitus, to a resistance exercise program for 12 weeks and assessed the levels of cardiovascular factors and inflammatory markers using western blotting analysis, ELISA, and immunohistochemistry. During the training period, OLETF + exercise (EX) group exhibited lower body weight and reduced glucose levels when compared with OLETF group. Western blotting analysis, ELISA, and immunohistochemistry revealed that the levels of PAI-1, VACM-1, ICAM-1, E-selectin, TGF-β, CRP, IL-6, and TNF-α were decreased in OLETF + EX group when compared with the OLETF group. Moreover, the anti-inflammatory markers, IL-4 and IL-10, were highly expressed after exercise. Therefore, these results indicate that exercise may influence the regulation of cardiovascular factors and inflammatory markers, as well as help patients with metabolic syndromes regulate inflammation and cardiovascular function.

Type 2 diabetes mellitus negatively affects the functional performance of 6-min step test in chronic heart failure: a 3-year follow-up study

BACKGROUND

Type 2 diabetes mellitus (T2DM) and chronic heart failure (CHF) present a decrease in functional capacity due to the intrinsic nature of both pathologies. It is not known about the potential impact of T2DM on functional capacity when assessed by 6-min step test (6MST) and its effect as a prognostic marker for fatal and non-fatal events in patients with CHF.

OBJECTIVE

to evaluate the coexistence of T2DM and CHF in functional capacity through 6MST when compared to CHF non-T2DM, as well as to investigate the different cardiovascular responses to 6MST and the risk of mortality, decompensation of CHF and acute myocardial infarction (AMI) over 36 months.

METHODS

This is a prospective cohort study with 36 months of follow-up in individuals with T2DM and CHF. All participants completed a clinical assessment, followed by pulmonary function testing, echocardiography, and 6MST. The 6MST was performed on a 20 cm high step and cardiovascular responses were collected: heart rate, systemic blood pressure, oxygen saturation, BORG dyspnea and fatigue. The risk of mortality, acute myocardial infarction and decompensation of CHF was evaluated.

RESULTS

Eighty-six participants were included. The CHF-T2DM group had a significantly lower functional capacity than the CHF non-T2DM group (p < 0.05). Forced Expiratory Volume in one second (L), ejection fraction (%), gender and T2DM influence and are predictors of functional capacity (p < 0.05; adjusted R squared: 0.419). CHF-T2DM group presented a higher risk of mortality and acute myocardial infarction over the 36 months of follow-up (p < 0.05), but not to the risk of decompensation (p > 0.05).

CONCLUSION

T2DM negatively affects the functional performance of 6MST in patients with CHF. Gender, ejection fraction (%), FEV1 (L) and T2DM itself negatively influence exercise performance.

Inspiratory muscle strength training to improve cardiometabolic health in patients with type 2 diabetes mellitus: protocol for the diabetes inspiratory training clinical trial

Type 2 diabetes mellitus (T2DM) is a complex, chronic metabolic disease that carries with it a high prevalence of comorbid conditions, making T2DM one of the leading causes of death in the U.S. Traditional lifestyle interventions (e.g., diet, exercise) can counter some adverse effects of T2DM, however, participation in these activities is low with reasons ranging from physical discomfort to lack of time. Thus, there is a critical need to develop novel management strategies that effectively reduce cardiometabolic disease risk and address barriers to adherence. High-resistance inspiratory muscle strength training (IMST) is a time-efficient and simple breathing exercise that significantly reduces systolic and diastolic BP and improves vascular endothelial function in adults with above-normal blood pressure. Herein we describe the study protocol for a randomized clinical trial to determine the effects of a 6-week IMST regimen on glycemic control and insulin sensitivity in adults with T2DM. Our primary outcome measures include fasting plasma glucose, fasting serum insulin, and insulin resistance utilizing homeostatic model assessment for insulin resistance (HOMA-IR). Secondary outcome measures include resting systolic BP and endothelium-dependent dilation. Further, we will collect plasma for exploratory proteomic analyses. This trial seeks to establish the cardiometabolic effects of 6 weeks of high-resistance IMST in patients with T2DM.

High-Intensity Interval Versus Moderate-Intensity Continuous Exercise Training on Glycemic Control, Beta Cell Function, and Aerobic Fitness in Women with Type 2 Diabetes

Objective: This study aimed to compare the effects of High-Intensity Interval Training (HIIT) and Moderate-Intensity Continuous Training (MICT) on glycemic control, beta-cell function, and aerobic fitness in women with Type 2 Diabetes Mellitus (T2DM). Methods: Thirty-six women with T2DM were assigned equally to HIIT, MICT, and control (CON) groups. Participants in the exercise cohorts underwent a 12-week training regimen (three sessions per week), while the CON group maintained an inactive lifestyle. Glycaemia variables, beta-cell function, maximal oxygen uptake (VO2max), lipid profiles, and body composition were assessed at baseline and post-intervention. Results: Both HIIT and MICT interventions led to significant improvements in glucose, insulin, HbA1c, and insulin resistance index. Moreover, visceral adiposity index (VAI), lipid accumulation product (LAP), total cholesterol (TC), and low-density lipoprotein (LDL) levels significantly decreased in the HIIT and MICT groups after 12 weeks. Triglyceride (TG) levels decreased only after MICT, while high-density lipoprotein (HDL) levels increased after both interventions. Maximal oxygen uptake (VO2max), body mass, body mass index (BMI), and waist circumference (WC) significantly improved in all exercise groups. Notably, the HIIT group showed greater reductions in body mass compared to MICT. Nevertheless, beta-cell function remained unaltered after these two exercise regimens. Conclusion: Both HIIT and MICT interventions effectively managed T2DM in women, regardless of exercise intensity. The HIIT regimen can be considered for time-efficient lifestyle interventions in people with T2DM.

Accelerometer-derived physical activity and mortality in individuals with type 2 diabetes

Physical activity (PA) has been shown to reduce diabetes mortality, but largely based on imprecise self-reported data, which may hinder the development of related recommendations. Here, we perform a prospective cohort study of 19,624 individuals with type 2 diabetes (T2D) from the UK Biobank with a median follow-up of 6.9 years. Duration and intensity of PA are measured by wrist-worn accelerometers over a 7-day period. We observe L-shaped associations of longer duration of PA, regardless of PA intensity, with risks of all-cause and cancer mortality, as well as a negatively linear association with cardiovascular disease mortality. 12.7%, 15.8%, and 22.3% of deaths are attributable to the lowest level of light-intensity, moderate-intensity PA, and vigorous-intensity PA, respectively. Collectively, our findings provide insights for clinical guidelines that should highlight the potential value of adherence to greater intensity and duration of PA for patients with T2D.

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.

Novel Techniques, Biomarkers and Molecular Targets to Address Cardiometabolic Diseases

Cardiometabolic diseases (CMDs) are interrelated and multifactorial conditions, including arterial hypertension, type 2 diabetes, heart failure, coronary artery disease, and stroke. Due to the burden of cardiovascular morbidity and mortality associated with CMDs' increasing prevalence, there is a critical need for novel diagnostic and therapeutic strategies in their management. In clinical practice, innovative methods such as epicardial adipose tissue evaluation, ventricular-arterial coupling, and exercise tolerance studies could help to elucidate the multifaceted mechanisms associated with CMDs. Similarly, epigenetic changes involving noncoding RNAs, chromatin modulation, and cellular senescence could represent both novel biomarkers and targets for CMDs. Despite the promising data available, significant challenges remain in translating basic research findings into clinical practice, highlighting the need for further investigation into the complex pathophysiology underlying CMDs.

Prevalence and clinical characteristics of diabetic cardiomyopathy in patients with acute heart failure

BACKGROUND AND AIMS

Diabetic cardiomyopathy refers to cases of diabetes mellitus (DM) complicated by cardiac dysfunction in the absence of cardiovascular disease and hypertension. Its epidemiology remains unclear due to the high rate of coexistence between DM and hypertension. Therefore, this study aimed to examine the prevalence and clinical characteristics of diabetic cardiomyopathy among patients with acute heart failure (HF).

METHODS AND RESULTS

This multicenter, retrospective study included 17,614 consecutive patients with acute HF. DM-related HF was defined as HF complicating DM without known manifestations of coronary artery disease, significant valvular heart disease, or congenital heart disease, while diabetic cardiomyopathy was defined as DM-related HF without hypertension. Univariable and multivariable logistic regression analyses were performed to identify factors associated with in-hospital mortality. Diabetic cardiomyopathy prevalence was 1.6 % in the entire cohort, 5.2 % in patients with acute HF complicating DM, and 10 % in patients with DM-related HF. Clinical characteristics, including the presence of comorbidities, laboratory data on admission, and factors associated with in-hospital mortality, significantly differed between the diabetic cardiomyopathy group and the DM-related HF with hypertension group. The in-hospital mortality rate was significantly higher in patients with diabetic cardiomyopathy than in patients with DM-related HF with hypertension (7.7 % vs. 2.8 %, respectively; P < 0.001).

CONCLUSION

The prevalence of diabetic cardiomyopathy was 1.6 % in patients with acute HF, and patients with diabetic cardiomyopathy were at high risk for in-hospital mortality. The clinical characteristics of patients with diabetic cardiomyopathy were significantly different than those of patients with DM-related HF with hypertension.

New Mechanisms to Prevent Heart Failure with Preserved Ejection Fraction Using Glucagon-like Peptide-1 Receptor Agonism (GLP-1 RA) in Metabolic Syndrome and in Type 2 Diabetes: A Review

This review examines the impact of obesity on the pathophysiology of heart failure with preserved ejection fraction (HFpEF) and focuses on novel mechanisms for HFpEF prevention using a glucagon-like peptide-1 receptor agonism (GLP-1 RA). Obesity can lead to HFpEF through various mechanisms, including low-grade systemic inflammation, adipocyte dysfunction, accumulation of visceral adipose tissue, and increased pericardial/epicardial adipose tissue (contributing to an increase in myocardial fat content and interstitial fibrosis). Glucagon-like peptide 1 (GLP-1) is an incretin hormone that is released from the enteroendocrine L-cells in the gut. GLP-1 reduces blood glucose levels by stimulating insulin synthesis, suppressing islet α-cell function, and promoting the proliferation and differentiation of β-cells. GLP-1 regulates gastric emptying and appetite, and GLP-1 RA is currently indicated for treating type 2 diabetes (T2D), obesity, and metabolic syndrome (MS). Recent evidence indicates that GLP-1 RA may play a significant role in preventing HFpEF in patients with obesity, MS, or obese T2D. This effect may be due to activating cardioprotective mechanisms (the endogenous counter-regulatory renin angiotensin system and the AMPK/mTOR pathway) and by inhibiting deleterious remodeling mechanisms (the PKA/RhoA/ROCK pathway, aldosterone levels, and microinflammation). However, there is still a need for further research to validate the impact of these mechanisms on humans.

Moderation of associations between weight discrimination and diabetes status by psychosocial factors

Weight discrimination has adverse effects on health that include increasing the risk factors for developing type 2 diabetes. Preliminary evidence suggests a positive association between weight discrimination and diagnosed diabetes; however, it is unknown whether psychosocial resources may buffer this association. In logistic regressions stratified by gender, we examined links between weight discrimination and diabetes among a nationally representative sample of U.S. adults (the National Social Life, Health, and Aging Project; N = 2,794 adults age 50 and older in 2015-16). We also tested the extent to which trait-resilience and social support from a spouse/partner, family, and friends buffered any observed association. We adjusted for known predictors of diabetes (age, race/ethnicity, Body Mass Index) and conducted sensitivity analyses restricted to men and women with obesity. Net of covariates, in the overall sample, weight discrimination was associated with significantly greater odds of having ever had diabetes among women (OR = 2.00, 95% CI [1.15, 3.47]), but not men. Among women with obesity, weight discrimination was only significantly associated with greater odds of diabetes for those with low resilience (OR = 1.84, 95% CI [1.01, 3.35]). Among men overall, weight discrimination was associated with lower odds of diabetes for those with high family support (OR = 0.03, 95% CI [0.003, 0.25]) as well as those with high friend support (OR = 0.34, 95% CI [0.13, 0.91]); similar effects were observed in men with obesity. These novel findings evince a role for psychosocial resources in buffering associations between weight discrimination and diabetes.

The cardiovascular changes underlying a low cardiac output with exercise in patients with type 2 diabetes mellitus

The significant morbidity and premature mortality of type 2 diabetes mellitus (T2DM) is largely associated with its cardiovascular consequences. Focus has long been on the arterial atheromatosis of DM giving rise to early stroke and myocardial infarctions, whereas less attention has been given to its non-ischemic cardiovascular consequences. Irrespective of ischemic changes, T2DM is associated with heart failure (HF) most commonly with preserved ejection fraction (HFpEF). Largely due to increasing population ages, hypertension, obesity and T2DM, HFpEF is becoming the most prevalent form of heart failure. Unfortunately, randomized controlled trials of HFpEF have largely been futile, and it now seems logical to address the important different phenotypes of HFpEF to understand their underlying pathophysiology. In the early phases, HFpEF is associated with a significantly impaired ability to increase cardiac output with exercise. The lowered cardiac output with exercise results from both cardiac and peripheral causes. T2DM is associated with left ventricular (LV) diastolic dysfunction based on LV hypertrophy with myocardial disperse fibrosis and significantly impaired ability for myocardial blood flow increments with exercise. T2DM is also associated with impaired ability for skeletal muscle vasodilation during exercise, and as is the case in the myocardium, such changes may be related to vascular rarefaction. The present review discusses the underlying phenotypical changes of the heart and peripheral vascular system and their importance for an adequate increase in cardiac output. Since many of the described cardiovascular changes with T2DM must be considered difficult to change if fully developed, it is suggested that patients with T2DM are early evaluated with respect to their cardiovascular compromise.

Characterizing diabetic cardiomyopathy: baseline results from the ARISE-HF trial

BACKGROUND

Diabetic cardiomyopathy (DbCM) is a form of Stage B heart failure (HF) at high risk for progression to overt disease. Using baseline characteristics of study participants from the Aldose Reductase Inhibition for Stabilization of Exercise Capacity in Heart Failure (ARISE-HF) Trial we sought to characterize clinical characteristics of individuals with findings consistent with DbCM.

METHODS

Among study participants meeting inclusion criteria, clinical characteristics, laboratory testing, imaging, Kansas City Cardiomyopathy Questionnaire (KCCQ), Physical Activity Scale of the Elderly (PASE) and cardiopulmonary exercise testing (CPET) results were tabulated. Cluster phenogroups were identified.

RESULTS

Among 691 study participants (mean age 67.4 years; 50% were female), mean duration of type 2 diabetes mellitus (T2DM) was 14.5 years. The median (Q1, Q3) N-terminal pro-B type natriuretic peptide and high sensitivity cardiac troponin T were 71 (35, 135) ng/L and 9 [6, 12] ng/L. The most common echocardiographic abnormalities were reduced global longitudinal strain in 25.3% and impaired diastolic relaxation in 17.7%. Despite rather well-preserved KCCQ scores the average PASE score was markedly impaired at 155 accompanied by an average maximal oxygen consumption of 15.7 mL/Kg/minute on CPET. In K-means clustering, 4 phenogroups were identified including a higher-risk group with more advanced age, greater elevation of cardiac biomarkers, and more prevalent evidence for diastolic dysfunction and left ventricular hypertrophy.

CONCLUSIONS

Baseline data from the ARISE-HF Trial provide clinical characterization of individuals with T2DM and features of stage B HF, and may help clarify the diagnosis of DbCM.

TRIAL REGISTRATION

ARISE-HF, NCT04083339.

Distinct effects of type 2 diabetes and obesity on cardiopulmonary performance

AIM

Effort intolerance is frequent in patients with overweight/obesity and/or type 2 diabetes (T2D) free from cardiac and respiratory disease. We sought to quantify the independent effects of T2D and body mass index (BMI) on cardiopulmonary capacity and gain insights on the possible pathophysiology by case-control and regression analyses.

METHODS

Patients at high/moderate cardiovascular risk, with or without T2D, underwent spirometry and combined echocardiography-cardiopulmonary exercise test as part of their clinical workup. Subjects with evidence of cardiopulmonary disease were excluded. The effects of T2D and obesity were estimated by multivariable models accounting for known/potential confounders and the major pathophysiological determinants of oxygen uptake at peak exercise (VO2peak ) normalized for fat-free mass (FFM).

RESULTS

In total, 109 patients with T2D and 97 controls were included in the analysis. The two groups had similar demographic and anthropometric characteristics except for higher BMI in T2D (28.6 ± 4.6 vs. 26.3 ± 4.4 kg/m2 , p = .0003) but comparable FFM. Patients with T2D achieved lower VO2peak than controls (18.5 ± 4.4 vs. 21.7 ± 8.3 ml/min/kg, p = .0006). Subclinical cardiovascular dysfunctions were observed in T2D: concentric left ventricular remodelling, autonomic dysfunction, systolic dysfunction and reduced systolic reserve. After accounting for confounders and major determinants of VO2peakFFM , T2D still displayed reduced VO2peak by 1.0 (-1.7/-0.3) ml/min/kgFFM , p = .0089, while the effect of BMI [-0.2 (-0.3/0.1) ml/min/kgFFM , p = .06 per unit increase], was largely explained by a combination of chronotropic incompetence, reduced peripheral oxygen extraction, impaired systolic reserve and ventilatory (in)efficiency.

CONCLUSIONS

T2D is an independent negative determinant of VO2peak whose effect is additive to other pathophysiological determinants of oxygen uptake, including BMI.

Intramyocellular Triglyceride Content During the Early Course of Type 1 and Type 2 Diabetes

Intramyocellular lipid content (IMCL) is elevated in insulin-resistant humans, but it changes over time, and relationships with comorbidities remain unclear. We examined IMCL during the initial course of diabetes and its associations with complications. Participants of the German Diabetes Study (GDS) with recent-onset type 1 (n = 132) or type 2 diabetes (n = 139) and glucose-tolerant control subjects (n = 128) underwent 1H-MRS to measure IMCL and muscle volume, whole-body insulin sensitivity (hyperinsulinemic-euglycemic clamps; M-value), and cycling spiroergometry (VO2max). Subgroups underwent the same measurements after 5 years. At baseline, IMCL was ∼30% higher in type 2 diabetes than in other groups independently of age, sex, BMI, and muscle volume. In type 2 diabetes, the M-value was ∼36% and ∼62% lower compared with type 1 diabetes and control subjects, respectively. After 5 years, the M-value decreased by ∼29% in type 1 and ∼13% in type 2 diabetes, whereas IMCL remained unchanged. The correlation between IMCL and M-value in type 2 diabetes at baseline was modulated by VO2max. IMCL also associated with microalbuminuria, the Framingham risk score for cardiovascular disease, and cardiac autonomic neuropathy. Changes in IMCL within 5 years after diagnosis do not mirror the progression of insulin resistance in type 2 diabetes but associate with early diabetes-related complications.

ARTICLE HIGHLIGHTS

Intramyocellular lipid content (IMCL) can be elevated in insulin-resistant humans, but its dynamics and association with comorbidities remain unclear. Independently of age, sex, body mass, and skeletal muscle volume, IMCL is higher in recent-onset type 2, but not type 1 diabetes, and remains unchanged within 5 years, despite worsening insulin resistance. A degree of physical fitness modulates the association between IMCL and insulin sensitivity in type 2 diabetes. Whereas higher IMCL associates with lower insulin sensitivity in people with lower physical fitness, there is no association between IMCL and insulin sensitivity in those with higher degree of physical fitness. IMCL associates with progression of microalbuminuria, cardiovascular disease risk, and cardiac autonomic neuropathy.

Physical Activity and Type 2 Diabetes: In Search of a Personalized Approach to Improving β-Cell Function

Type 2 diabetes mellitus (T2DM) is one of the most widespread diseases worldwide. Lifestyle interventions, including diet and physical activity (PA), are fundamental non-pharmacological components of T2DM therapy. Exercise interventions are strongly recommended for people with or at risk of developing or already with overt diabetes, but adherence to PA guidelines in this population is still challenging. Furthermore, the heterogeneity of T2DM patients, driven by differing residual β-cell functionality, as well as the possibility of practicing different types and intensities of PA, has led to the need to develop tailored exercise and training plans. Investigations on blood glucose variation in response to exercise could help to clarify why individuals do not respond in the same way to PA, and to guide the prescription of personalized treatments. The aim of this review is to offer an updated overview of the current evidence on the effects of different regimens and modalities of PA regarding glucose sensing and β-cell secretory dynamics in individuals with prediabetes or T2DM, with a special focus on β-cell function.

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).

Enhancing Muscle Intracellular Ca2+ Homeostasis and Glucose Uptake: Passive Pulsatile Shear Stress Treatment in Type 2 Diabetes

Type 2 diabetes mellitus (T2D) is a significant global public health problem that has seen a substantial increase in the number of affected individuals in recent decades. In a murine model of T2D (db/db), we found several abnormalities, including aberrant intracellular calcium concentration ([Ca2+]i), decreased glucose transport, increased production of reactive oxygen species (ROS), elevated levels of pro-inflammatory interleukins and creatine phosphokinase (CK), and muscle weakness. Previously, we demonstrated that passive pulsatile shear stress, generated by sinusoidal (headward-forward) motion, using a motion platform that provides periodic acceleration of the whole body in the Z plane (pGz), induces the synthesis of nitric oxide (NO) mediated by constitutive nitric oxide synthase (eNOS and nNOS). We investigated the effect of pGz on db/db a rodent model of T2D. The treatment of db/db mice with pGz resulted in several beneficial effects. It reduced [Ca2+]i overload; enhanced muscle glucose transport; and decreased ROS levels, interleukins, and CK. Furthermore, pGz treatment increased the expression of endothelial nitric oxide synthase (eNOS), phosphorylated eNOS (p-eNOS), and neuronal nitric oxide synthase (nNOS); reduced inducible nitric oxide synthase (iNOS); and improved muscle strength. The cytoprotective effects of pGz appear to be mediated by NO, since pretreatment with L-NAME, a nonspecific NOS inhibitor, abolished the effects of pGz on [Ca2+]i and ROS production. Our findings suggest that a non-pharmacological strategy such as pGz has therapeutic potential as an adjunct treatment to T2D.

Epstein-Barr virus-acquired immunodeficiency in myalgic encephalomyelitis-Is it present in long COVID?

Both myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS) and long COVID (LC) are characterized by similar immunological alterations, persistence of chronic viral infection, autoimmunity, chronic inflammatory state, viral reactivation, hypocortisolism, and microclot formation. They also present with similar symptoms such as asthenia, exercise intolerance, sleep disorders, cognitive dysfunction, and neurological and gastrointestinal complaints. In addition, both pathologies present Epstein-Barr virus (EBV) reactivation, indicating the possibility of this virus being the link between both pathologies. Therefore, we propose that latency and recurrent EBV reactivation could generate an acquired immunodeficiency syndrome in three steps: first, an acquired EBV immunodeficiency develops in individuals with "weak" EBV HLA-II haplotypes, which prevents the control of latency I cells. Second, ectopic lymphoid structures with EBV latency form in different tissues (including the CNS), promoting inflammatory responses and further impairment of cell-mediated immunity. Finally, immune exhaustion occurs due to chronic exposure to viral antigens, with consolidation of the disease. In the case of LC, prior to the first step, there is the possibility of previous SARS-CoV-2 infection in individuals with "weak" HLA-II haplotypes against this virus and/or EBV.

Impact of diabetes on remodelling, microvascular function and exercise capacity in aortic stenosis

OBJECTIVE

To characterise cardiac remodelling, exercise capacity and fibroinflammatory biomarkers in patients with aortic stenosis (AS) with and without diabetes, and assess the impact of diabetes on outcomes.

METHODS

Patients with moderate or severe AS with and without diabetes underwent echocardiography, stress cardiovascular magnetic resonance (CMR), cardiopulmonary exercise testing and plasma biomarker analysis. Primary endpoint for survival analysis was a composite of cardiovascular mortality, myocardial infarction, hospitalisation with heart failure, syncope or arrhythmia. Secondary endpoint was all-cause death.

RESULTS

Diabetes (n=56) and non-diabetes groups (n=198) were well matched for age, sex, ethnicity, blood pressure and severity of AS. The diabetes group had higher body mass index, lower estimated glomerular filtration rate and higher rates of hypertension, hyperlipidaemia and symptoms of AS. Biventricular volumes and systolic function were similar, but the diabetes group had higher extracellular volume fraction (25.9%±3.1% vs 24.8%±2.4%, p=0.020), lower myocardial perfusion reserve (2.02±0.75 vs 2.34±0.68, p=0.046) and lower percentage predicted peak oxygen consumption (68%±21% vs 77%±17%, p=0.002) compared with the non-diabetes group. Higher levels of renin (log10renin: 3.27±0.59 vs 2.82±0.69 pg/mL, p<0.001) were found in diabetes. Multivariable Cox regression analysis showed diabetes was not associated with cardiovascular outcomes, but was independently associated with all-cause mortality (HR 2.04, 95% CI 1.05 to 4.00; p=0.037).

CONCLUSIONS

In patients with moderate-to-severe AS, diabetes is associated with reduced exercise capacity, increased diffuse myocardial fibrosis and microvascular dysfunction, but not cardiovascular events despite a small increase in mortality.

Ventilation and perceived exertion are sensitive to changes in exercise tolerance: arm+leg cycling vs. leg cycling

Purpose: Growing evidence suggests that respiratory frequency (f R) is a marker of physical effort and a variable sensitive to changes in exercise tolerance. The comparison between arm+leg cycling (Arm+leg) and leg cycling (Leg) has the potential to further test this notion because a greater exercise tolerance is expected in the Arm+leg modality. We systematically compared Arm+leg vs. Leg using different performance tests. Methods: Twelve males underwent six performance tests in separate, randomized visits. Three tests were performed in each of the two exercise modalities, i.e. an incremental test and two time-to-exhaustion (TTE) tests performed at 90% or 75% of the peak power output reached in the Leg incremental test (PPOLeg). Exercise tolerance, perceived exertion, and cardiorespiratory variables were recorded during all the tests. Results: A greater exercise tolerance (p < 0.001) was found for Arm+leg in the incremental test (337 ± 32 W vs. 292 ± 28 W), in the TTE test at 90% of PPOLeg (638 ± 154 s vs. 307 ± 67 s), and in the TTE test at 75% of PPOLeg (1,675 ± 525 s vs. 880 ± 363 s). Unlike V ˙ O2 and heart rate, both f R and minute ventilation were lower (p < 0.003) at isotime in all the Arm+leg tests vs. Leg tests. Furthermore, a lower perceived exertion was observed in the Arm+leg tests, especially during the TTE tests (p < 0.001). Conclusion: Minute ventilation, f R and perceived exertion are sensitive to the improvements in exercise tolerance observed when comparing Arm+leg vs. Leg, unlike V ˙ O2 and heart rate.

Acute Effects of a Maximal Cardiopulmonary Exercise Test on Cardiac Hemodynamic and Cerebrovascular Response and Their Relationship with Cognitive Performance in Individuals with Type 2 Diabetes

Cardiovascular and cerebrovascular diseases are prevalent in individuals with type 2 diabetes (T2D). Among people with T2D aged over 70 years, up to 45% might have cognitive dysfunction. Cardiorespiratory fitness (V˙O₂max) correlates with cognitive performances in healthy younger and older adults, and individuals with cardiovascular diseases (CVD). The relationship between cognitive performances, V˙O₂max, cardiac output and cerebral oxygenation/perfusion responses during exercise has not been studied in patients with T2D. Studying cardiac hemodynamics and cerebrovascular responses during a maximal cardiopulmonary exercise test (CPET) and during the recovery phase, as well as studying their relationship with cognitive performances could be useful to detect patients at greater risk of future cognitive impairment. Purposes: (1) to compare cerebral oxygenation/perfusion during a CPET and during its post-exercise period (recovery); (2) to compare cognitive performances in patients with T2D to those in healthy controls; and (3) to examine if V˙O₂max, maximal cardiac output and cerebral oxygenation/perfusion are associated with cognitive function in individuals with T2D and healthy controls. Nineteen patients with T2D (61.9 ± 7 years old) and 22 healthy controls (HC) (61.8 ± 10 years old) were evaluated on the following: a CPET test with impedance cardiography and cerebral oxygenation/perfusion using a near-infrared spectroscopy. Prior to the CPET, the cognitive performance assessment was performed, targeting: short-term and working memory, processing speed, executive functions, and long-term verbal memory. Patients with T2D had lower V˙O₂max values compared to HC (34.5 ± 5.6 vs. 46.4 ± 7.6 mL/kg fat free mass/min; p < 0.001). Compared to HC, patients with T2D showed lower maximal cardiac index (6.27 ± 2.09 vs. 8.70 ± 1.09 L/min/m², p < 0.05) and higher values of systemic vascular resistance index (826.21 ± 308.21 vs. 583.35 ± 90.36 Dyn·s/cm⁵·m²) and systolic blood pressure at maximal exercise (204.94 ± 26.21 vs. 183.61 ± 19.09 mmHg, p = 0.005). Cerebral HHb during the 1st and 2nd min of recovery was significantly higher in HC compared to T2D (p < 0.05). Executive functions performance (Z score) was significantly lower in patients with T2D compared to HC (-0.18 ± 0.7 vs. -0.40 ± 0.60, p = 0.016). Processing speed, working and verbal memory performances were similar in both groups. Brain tHb during exercise and recovery (-0.50, -0.68, p < 0.05), and O₂Hb during recovery (-0.68, p < 0.05) only negatively correlated with executive functions performance in patients with T2D (lower tHb values associated with longer response times, indicating a lower performance). In addition to reduced V˙O₂max, cardiac index and elevated vascular resistance, patients with T2D showed reduced cerebral hemoglobin (O₂Hb and HHb) during early recovery (0-2 min) after the CPET, and lower performances in executive functions compared to healthy controls. Cerebrovascular responses to the CPET and during the recovery phase could be a biological marker of cognitive impairment in T2D.

Cardiometabolic Phenotyping in Heart Failure: Differences between Patients with Reduced vs. Preserved Ejection Fraction

AIMS

We explored multiple cardiometabolic patterns, including inflammatory and congestive pathways, in patients with heart failure (HF).

METHODS AND RESULTS

We enrolled 270 HF patients with reduced (<50%, HFrEF; n = 96) and preserved (≥50%, HFpEF; n = 174) ejection fraction. In HFpEF, glycated hemoglobin (Hb1Ac) seemed to be relevant in its relationship with inflammation as Hb1Ac positively correlated with high-sensitivity C-reactive protein (hs-CRP; Spearman's rank correlation coefficient ρ = 0.180, p < 0.05). In HFrEF, we found a correlation between Hb1Ac and norepinephrine (ρ = 0.207, p < 0.05). In HFpEF, we found a positive correlation between Hb1Ac and congestion expressed as pulmonary B lines (ρ = 0.187, p < 0.05); the inverse correlation, although not significant, was found in HFrEF between Hb1Ac and N-terminal pro-B-type natriuretic peptide (ρ = 0.079) and between Hb1Ac and B lines (ρ = -0.051). In HFrEF, we found a positive correlation between E/e' ratio and Hb1Ac (ρ = 0.203, p < 0.05) and a negative correlation between tricuspid annular systolic excursion (TAPSE)/echocardiographically measured systolic pulmonary artery pressure (sPAP) (TAPSE/sPAP ratio) (ρ = -0.205, p < 0.05) and Hb1Ac. In HFpEF, we found a negative correlation between TAPSE/sPAP ratio and uric acid (ρ = -0.216, p < 0.05).

CONCLUSION

In HF patients, HFpEF and HFrEF phenotypes are characterized by different cardiometabolic indices related to distinct inflammatory and congestive pathways. Patients with HFpEF showed an important relationship between inflammatory and cardiometabolic parameters. Conversely, in HFrEF, there is a significant relationship between congestion and inflammation, while cardiometabolism appears not to influence inflammation, instead affecting sympathetic hyperactivation.

Systemic proinflammatory-profibrotic response in aortic stenosis patients with diabetes and its relationship with myocardial remodeling and clinical outcome

BACKGROUND

Previous studies have mainly focused more on how diabetes affects the valve than the myocardium in aortic stenosis (AS). In the pressure-overloaded heart, myocardial fibrosis is an important driver of the progression from compensated hypertrophy to heart failure. Using comprehensive noninvasive imaging and plasma proteomics, we investigated whether and how diabetes aggravates the remodeling of the myocardium and its relation with prognosis in AS patients.

METHODS

Severe AS patients were enrolled in two prospective cohorts for imaging and biomarker analysis. The imaging cohort (n = 253) underwent echocardiography and cardiac magnetic resonance, and the biomarker cohort (n = 100) blood sampling with multiplex proximity extension assay for 92 proteomic biomarkers. The composite outcome of hospitalization for heart failure admissions and death was assessed in the imaging cohort.

RESULTS

Diabetic patients were older (70.4 ± 6.8 versus 66.7 ± 10.1 years) with more advanced ventricular diastolic dysfunction and increased replacement and diffuse interstitial fibrosis (late gadolinium enhancement % 0.3 [0.0-1.6] versus 0.0 [0.0-0.5], p = 0.009; extracellular volume fraction % 27.9 [25.7-30.1] versus 26.7 [24.9-28.5], p = 0.025) in the imaging cohort. Plasma proteomics analysis of the biomarker cohort revealed that 9 proteins (E-selectin, interleukin-1 receptor type 1, interleukin-1 receptor type 2, galectin-4, intercellular adhesion molecule 2, integrin beta-2, galectin-3, growth differentiation factor 15, and cathepsin D) were significantly elevated and that pathways related to inflammatory response and extracellular matrix components were enriched in diabetic AS patients. During follow-up (median 6.3 years), there were 53 unexpected heart failure admissions or death in the imaging cohort. Diabetes was a significant predictor of heart failure and death, independent of clinical covariates and aortic valve replacement (HR 1.88, 95% CI 1.06-3.31, p = 0.030).

CONCLUSIONS

Plasma proteomic analyses indicate that diabetes potentiates the systemic proinflammatory-profibrotic milieu in AS patients. These systemic biological changes underlie the increase of myocardial fibrosis, diastolic dysfunction, and worse clinical outcomes in severe AS patients with concomitant diabetes.

Effects of baduanjin exercise on blood glucose, depression and anxiety among patients with type II diabetes and emotional disorders: A meta-analysis

BACKGROUND

Diabetes mellitus (DM) is a group of metabolic disorders reflected by high blood glucose levels and lack of hormone insulin. Notably, T2DM patients are three times more likely to report depression than the general population. Conventional exercise training programs have been shown to be beneficial for T2DM, but less is known regarding the effects of Baduanjin exercise on hemoglobin A1c (HbA1c) and psychological measures among this unique group. Therefore, this systematic review and meta-analysis aimed to investigate the effects of Baduanjin exercise on HbA1c, depression, and anxiety among type 2 diabetes mellitus (T2DM) patients with emotional disorders.

METHODS

The potential literature was searched from six electronic databases (PubMed, MEDLINE, CINAHL, Scopus, Wanfang, and CNKI) from their inception to July 2022. The randomized controlled studies that investigated the effects of Baduanjin on HbA1c, depression , and anxiety in T2DM with emotional disorders were included. The effect sizes were calculated using the random-effect models with a 95% confidence interval (CI). The Physiotherapy Evidence Database (PEDro) scale was employed to assess the study quality.

RESULTS

Eleven studies involving 755 T2DM participants with emotional disorders were analyzed in this study. The pooled results showed that Baduanjin had significant improvements in HbA1c (SMD = 0.75, 95% CI 0.46 to 1.04, p < 0.001), depression (SMD = 0.69, 95% CI 0.30 to 1.08, p < 0.01) and anxiety (SMD = 0.98, 95% CI 0.44 to 1.53, p < 0.01) compared to the control group.

CONCLUSION

Findings suggest that Baduanjin exercise may effectively alleviate HbA1c, depression, and anxiety among T2DM patients with emotional disorders. However, more well-designed studies are required to further substantiate the promising findings.

Association of physical activity and trajectories of physical activity with cardiovascular disease

INTRODUCTION

Prolonged sedentary life existence is associated with increased incidence of cardiovascular disease (CVD), coronary heart disease (CHD), obesity, type 2 diabetes mellitus (T2DM), hypertension, heart failure (HF), and all-cause mortality. On the contrary, regular exercise is known from antiquity to be associated with beneficial cardiovascular (CV) effects and decreased mortality.

AREAS COVERED

The cardiovascular (CV) benefits of exercise have been confirmed by many studies, but the trajectories of the different modes of PA are not well recognized. In order to examine the different modalities of exercise and its long-term trajectories, a Medline search of the English literature was conducted between 2015 and 2022 and 60 pertinent papers were selected for review.

EXPERT OPINION

Careful review of the selected papers showed that the beneficial CV effects of PA are mediated through several favorable modifications of molecular and clinical factors. Also, any type of physical activity in conjunction with lifestyle adjustments is associated with decreased incidence of CVD, CHD, obesity, T2DM, hypertension, HF, and all-cause mortality. In addition, the long-term trajectories regarding the duration and the level of exercise are associated with greater beneficial CV effects, with even the resumption of discontinued exercise can lead to beneficial CV effects.

Risk of heart failure in elderly patients with atrial fibrillation and diabetes taking different oral anticoagulants: a nationwide cohort study

BACKGROUND

Heart failure (HF) is a critical complication in elderly patients with atrial fibrillation (AF) and diabetes mellitus (DM). Recent preclinical studies suggested that non-vitamin K antagonist oral anticoagulants (NOACs) can potentially suppress the progression of cardiac fibrosis and ischemic cardiomyopathy. Whether different oral anticoagulants influence the risk of HF in older adults with AF and DM is unknown. This study aimed to evaluate the risk of HF in elderly patients with AF and DM who were administered NOACs or warfarin.

METHODS

A nationwide retrospective cohort study was conducted based on claims data from the entire Taiwanese population. Target trial emulation design was applied to strengthen causal inference using observational data. Patients aged  ≥ 65 years with AF and DM on NOAC or warfarin treatment between 2012 and 2019 were included and followed up until 2020. The primary outcome was newly diagnosed HF. Propensity score-based fine stratification weightings were used to balance patient characteristics between NOAC and warfarin groups. Hazard ratios (HRs) were estimated using Cox proportional hazard models.

RESULTS

The study included a total of 24,835 individuals (19,710 NOAC and 5,125 warfarin users). Patients taking NOACs had a significantly lower risk of HF than those taking warfarin (HR = 0.80, 95% CI 0.74-0.86, p < 0.001). Subgroup analyses for individual NOACs suggested that dabigatran (HR = 0.86, 95% CI 0.80-0.93, p < 0.001), rivaroxaban (HR = 0.80, 95% CI 0.74-0.86, p < 0.001), apixaban (HR = 0.78, 95% CI 0.68-0.90, p < 0.001), and edoxaban (HR = 0.72, 95% CI 0.60-0.86, p < 0.001) were associated with lower risks of HF than warfarin. The findings were consistent regardless of age and sex subgroups and were more prominent in those with high medication possession ratios. Several sensitivity analyses further supported the robustness of our findings.

CONCLUSIONS

This nationwide cohort study demonstrated that elderly patients with AF and DM taking NOACs had a lower risk of incident HF than those taking warfarin. Our findings suggested that NOACs may be the preferred oral anticoagulant treatment when considering the prevention of heart failure in this vulnerable population. Future research is warranted to elucidate causation and investigate the underlying mechanisms.

Epicardial adipose tissue thickness is associated with reduced peak oxygen consumption and systolic reserve in patients with type 2 diabetes and normal heart function

AIM

To investigate the impact of epicardial adipose tissue (EAT) thickness on cardiopulmonary performance in patients with type 2 diabetes (T2D) and normal heart function.

MATERIALS AND METHODS

We analysed EAT thickness in subjects with T2D and normal biventricular systo-diastolic functions undergoing a maximal cardiopulmonary exercise test combined with stress echocardiography, speckle tracking and pulmonary function assessment, as well as serum N-terminal pro B-type natriuretic peptide (NT-proBNP).

RESULTS

In the 72 subjects enrolled, those with EAT thickness above the median (> 5 mm) showed higher body fat mass, smaller indexed left ventricular dimensions and marginally reduced diastolic function variables at rest. Higher EAT thickness was associated with lower peak oxygen uptake (VO_2peak 17.1 ± 3.6 vs. 21.0 ± 5.7 ml/min/kg, P = .001), reduced systolic reserve (ΔS' 4.6 ± 1.6 vs. 5.8 ± 2.5 m/s, P = .02) and higher natriuretic peptides (NT-proBNP 64 [29-165] vs. 31 [26-139] pg/ml, P = .04), as well as chronotropic insufficiency and impaired heart rate recovery. Ventilatory variables and peripheral oxygen extraction were not different between groups. EAT was independently associated with VO_2peak and linearly and negatively correlated with peak heart rate, heart rate recovery, workload, VO₂ at the anaerobic threshold and at peak, and cardiac power output, and was directly correlated with natriuretic peptides.

CONCLUSION

Higher EAT thickness in T2D is associated with worse cardiopulmonary performance and multiple traits of subclinical cardiac systolic dysfunction.

Eight weeks of inorganic nitrate/nitrite supplementation improves aerobic exercise capacity and the gas exchange threshold in patients with type 2 diabetes

Patients with type 2 diabetes mellitus (T2DM) have reduced exercise capacity, indexed by lower maximal oxygen consumption (V̇o2max) and achievement of the gas exchange threshold (GET) at a lower % V̇o2max. The ubiquitous signaling molecule nitric oxide (NO) plays a multifaceted role during exercise and, as patients with T2DM have poor endogenous NO production, we investigated if inorganic nitrate/nitrite supplementation (an exogenous source of NO) improves exercise capacity in patients with T2DM. Thirty-six patients with T2DM (10F, 59 ± 9 yr, 32.0 ± 5.1 kg/m2, HbA1c = 7.4 ± 1.4%) consumed beetroot juice containing either inorganic nitrate/nitrite (4.03 mmol/0.29 mmol) or a placebo (0.8 mmol/0.00 mmol) for 8 wk. A maximal exercise test was completed before and after both interventions. V̇o2max was determined by averaging 15-s data, whereas the GET was identified using the V-slope method and breath-by-breath data. Inorganic nitrate/nitrite increased both absolute (1.96 ± 0.67 to 2.07 ± 0.75 L/min) and relative (20.7 ± 7.0 to 21.9 ± 7.4 mL/kg/min, P < 0.05 for both) V̇o2max, whereas no changes were observed following placebo (1.94 ± 0.40 to 1.90 ± 0.39 L/min, P = 0.33; 20.0 ± 4.2 to 19.7 ± 4.6 mL/kg/min, P = 0.39). Maximal workload was also increased following inorganic nitrate/nitrite supplementation (134 ± 47 to 140 ± 51 W, P < 0.05) but not placebo (138 ± 32 to 138 ± 32 W, P = 0.98). V̇o2 at the GET (1.11 ± 0.27 to 1.27 ± 0.38L/min) and the %V̇o2max in which GET occurred (56 ± 8 to 61 ± 7%, P < 0.05 for both) increased following inorganic nitrate/nitrite supplementation but not placebo (1.10 ± 0.23 to 1.08 ± 0.21 L/min, P = 0.60; 57 ± 9 to 57 ± 8%, P = 0.90) although the workload at GET did not achieve statistical significance (group-by-time P = 0.06). Combined inorganic nitrate/nitrite consumption improves exercise capacity, maximal workload, and promotes a rightward shift in the GET in patients with T2DM. This manuscript reports data from a registered Clinical Trial at ClinicalTrials.gov ID: NCT02804932.NEW & NOTEWORTHY We report that increasing nitric oxide bioavailability via 8 wk of inorganic nitrate/nitrite supplementation improves maximal aerobic exercise capacity in patients with type 2 diabetes mellitus. Similarly, we observed a rightward shift in the gas exchange threshold. Taken together, these data indicate inorganic nitrate/nitrite may serve as a means to improve fitness in patients with type 2 diabetes mellitus.

Combined evaluation of arterial stiffness, glycemic control and hypertension for macrovascular complications in type 2 diabetes

BACKGROUND

Arterial stiffness, glycemic control and blood pressure are risk factors of macrovascular complications in type 2 diabetes. This study aimed to investigate the combined association of arterial stiffness, glycemic control and hypertension status with the occurrence of diabetic macrovascular complication.

METHODS

A total of 1870 patients of diabetes were enrolled from Beijing Health Management Cohort between 2008 and 2018 as baseline, and then followed for macrovascular complication onset. We proposed a composite risk score (0-4) by arterial stiffness severity, pool glycemic control and hypertension status. Cox model was used to estimate the hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

The mean age (SD) of this population was 59.90 (12.29) years. During a median follow-up of 4.0 years, 359 (19.2%) patients developed macrovascular complication. Compared to the normal arterial stiffness and good glycemic control group, patients with severe arterial stiffness and pool glycemic control had the highest risk of macrovascular complications (HR: 2.73; 95% CI: 1.42-5.25). Similarly, those of severe arterial stiffness and hypertension had the highest risk (HR: 2.69; 95% CI: 1.61-4.50). Patients of the composite score > 2 had a significantly increased risk of macrovascular complication.

CONCLUSION

This study suggested the clinical importance of combined evaluation of arterial stiffness, glycemic control and hypertension status for the risk stratification and management of macrovascular complication of type 2 diabetes.

Treating equivalent cases differently: A comparative analysis of substance use disorder and type 2 diabetes in Norwegian treatment guidelines

BACKGROUND

Substance use disorder (SUD) is often understood as a chronic illness.

AIMS

This paper investigates whether SUD is treated as a chronic illness.

METHOD

To this aim, we have used World Health Organizations (WHO's) definition of chronic illness to conduct a comparative analysis of SUD and type 2 diabetes (T2D), which is another chronic illness.

RESULTS

When analysing Norwegian treatment guidelines, we found that only the T2D guideline reflects the WHO's conceptualization of chronic illnesses. We argue that this discrepancy implies that SUD is understood as a moral and legal problem, while T2D is conceptualized as a somatic illness. We discuss how social, political and historical conditions of the possibility for understanding SUD are interwoven with normative presumptions about the clinician, patient, treatment guidelines and drug policies in a way that may impede the development of continuing care.

CONCLUSION

The paper concludes that the delivery of treatment services is inequitable as SUD is not treated as a chronic illness.

Effect of empagliflozin on left ventricular contractility and peak oxygen uptake in subjects with type 2 diabetes without heart disease: results of the EMPA-HEART trial

Background

The mechanism through which sodium-glucose cotransporter 2 inhibitors (SGLT2i) prevent the incidence of heart failure and/or affect cardiac structure and function remains unclear.

Methods

The EMPA-HEART trial is aimed at verifying whether empagliflozin improves myocardial contractility (left ventricle global longitudinal strain, LV-GLS) and/or cardiopulmonary fitness (peak oxygen uptake, VO2peak) in subjects with type 2 diabetes (T2D) without heart disease. Patients with T2D, normal LV systolic function (2D-Echo EF > 50%), and no heart disease were randomized to either empagliflozin 10 mg or sitagliptin 100 mg for 6 months and underwent repeated cardiopulmonary exercise tests with echocardiography and determination of plasma biomarkers.

Results

Forty-four patients completed the study, 22 per arm. Despite comparable glycaemic control, modest reductions in body weight (− 1.6; [− 2.7/− 0.5] kg, p = 0.03) and plasma uric acid (− 1.5; [− 2.3/− 0.6], p = 0.002), as well as an increase in haemoglobin (+ 0.7; [+ 0.2/+ 1.1] g/dL, p = 0.0003) were evident with empagliflozin. No difference was detectable in either LV-GLS at 1 month (empagliflozin vs sitagliptin: + 0.44; [− 0.10/+ 0.98]%, p = 0.11) and 6 months of therapy (+ 0.53; [− 0.56/+ 1.62]%), or in VO_2peak (+ 0.43; [− 1.4/+ 2.3] mL/min/kg, p = 0.65). With empagliflozin, the subgroup with baseline LV-GLS below the median experienced a greater increase (time*drug p < 0.05) in LV-GLS at 1 month (+ 1.22; [+ 0.31/+ 2.13]%) and 6 months (+ 2.05; [+ 1.14/+ 2.96]%), while sitagliptin induced a modest improvement in LV-GLS only at 6 months (+ 0.92; [+ 0.21/+ 0.62]%).

Conclusions

Empagliflozin has neutral impact on both LV-GLS and exercise tolerance in subjects with T2D and normal left ventricular function. However, in patients with subclinical dysfunction (LV-GLS < 16.5%) it produces a rapid and sustained amelioration of LV contractility.

Trial registration EUDRACT Code 2016-002225-10

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01618-1.

Distinctive exercise-induced inflammatory response and exerkine induction in skeletal muscle of people with type 2 diabetes

Mechanistic insights into the molecular events by which exercise enhances the skeletal muscle phenotype are lacking, particularly in the context of type 2 diabetes. Here, we unravel a fundamental role for exercise-responsive cytokines (exerkines) on skeletal muscle development and growth in individuals with normal glucose tolerance or type 2 diabetes. Acute exercise triggered an inflammatory response in skeletal muscle, concomitant with an infiltration of immune cells. These exercise effects were potentiated in type 2 diabetes. In response to contraction or hypoxia, cytokines were mainly produced by endothelial cells and macrophages. The chemokine CXCL12 was induced by hypoxia in endothelial cells, as well as by conditioned medium from contracted myotubes in macrophages. We found that CXCL12 was associated with skeletal muscle remodeling after exercise and differentiation of cultured muscle. Collectively, acute aerobic exercise mounts a noncanonical inflammatory response, with an atypical production of exerkines, which is potentiated in type 2 diabetes.

Impaired fatigue resistance, sarcoplasmic reticulum function, and mitochondrial activity in soleus muscle of db/db mice

Type 2 diabetes mellitus (T2DM) is characterized by reduced exercise tolerance due to increased fatigability in skeletal muscle. In this study, we investigated muscle fatigue resistance of soleus (SOL) muscle in obese type 2 diabetic model mice (db/db). No differences in muscle volume, absolute force, or specific force in SOL muscle were observed between db/db mice and control mice (db/+), while fatigue resistance evaluated by repeated tetanic contractions was significantly lower in db/db mice (30th tetani, db/+: 63.7 ± 4.7%, db/db: 51.3 ± 4.8%). The protein abundance related to Ca2+ release from the sarcoplasmic reticulum (SR) in SOL muscle was not different between db/db mice and db/+ mice, while SR Ca2+ -ATPase (Ca2+ reuptake to SR) protein was decreased in db/db mice compared to db/+ mice (db/+: 1.00 ± 0.17, db/db: 0.60 ± 0.04, relative units). In addition, mitochondrial oxidative enzyme activity (succinate dehydrogenase) was decreased in the SOL muscle of db/db mice (p < 0.05). These data suggest that fatigue resistance in slow-twitch dominant muscle is impaired in mice with T2DM. Decreased mitochondrial oxidative enzyme activity and impairment of Ca2+ uptake to SR, or both might be involved in the mechanisms.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

PROTOCOL REGISTRATION

PROSPERO (CRD42021257251).

Cardiovascular risk factors, exercise capacity and health literacy in patients with chronic ischaemic heart disease and type 2 diabetes mellitus in Germany: Baseline characteristics of the Lifestyle Intervention in Chronic Ischaemic Heart Disease and Type 2 Diabetes study

BACKGROUND

Lifestyle interventions are a cornerstone in the treatment of chronic ischaemic heart disease (CIHD) and type 2 diabetes mellitus (T2DM). This study aimed at identifying differences in clinical characteristics between categories of the common lifestyle intervention targets BMI, exercise capacity (peak V̇O₂) and health literacy (HL).

METHODS

Cross-sectional baseline characteristics of patients enrolled in the LeIKD trial (Clinicaltrials.gov NCT03835923) are presented in total, grouped by BMI, %-predicted peak V̇O₂ and HL (HLS-EU-Q16), and compared to other clinical trials with similar populations.

RESULTS

Among 499 patients (68.3±7.7 years; 16.2% female; HbA1c, 6.9±0.9%), baseline characteristics were similar to other trials and revealed insufficient treatment of several risk factors (LDL-C 92±34 mg/dl; BMI, 30.1±4.8 kg/m²; 69.6% with peak V̇O₂<90% predicted). Patients with lower peak V̇O₂ showed significantly higher (p < 0.05) CIHD and T2DM disease severity (HbA1c, CIHD symptoms, coronary artery bypass graft). Obese patients had a significantly higher prevalence of hypertension and higher triglyceride levels, whereas in patients with low HL both quality of life components (physical, mental) were significantly reduced.

CONCLUSIONS

In patients with CIHD and T2DM, peak V̇O2, BMI and HL are important indicators of disease severity, risk factor burden and quality of life, which reinforces the relevance of lifestyle interventions.

Peripheral Cytopenia and Its Associated Factors in Type 2 Diabetes Mellitus Patients, Northwest Ethiopia

Background

Hematological abnormalities are linked with diabetes mellitus (DM) and play a major role in diabetes-related micro- and macro-vascular complications. Therefore, this study aimed to investigate the magnitude of peripheral cytopenia and associated factors in type 2 diabetes (T2DM) patients.

Methods

A cross-sectional study was conducted from March to May 2021 at the University of Gondar Comprehensive Specialized Hospital. A total of 357 T2DM participants were selected using a simple random sampling technique. A total of 3 mL of venous blood samples were collected using the vacutainer method for the complete blood count (CBC). A univariate and multivariate regression analysis were used to investigate the association between dependent and independent variables. P-value ˂0.05 was considered statistically significant.

Results

The magnitude of cytopenia, bicytopenia, and pancytopenia were 21% (95% CI: 17.1, 25.53), 1.1% (95% CI: 0.44, 2.85), and 0.56% (95% CI: 0.01, 1.12), respectively. Furthermore, the magnitudes of anemia, leucopenia, and thrombocytopenia were 8.7% (95% CI: 6.18, 12.06), 10.9% (95% CI: 8.09, 14.59), and 5.3% (95% CI: 3.43, 8.16), respectively. Being male (AOR: 3.23; 95% CI: 1.43, 7.56), lack of exercise (AOR: 2.70; 95% CI: 1.137, 6.43), and never married (AOR: 3.90; 95% CI: 1.248, 12.18) were all associated with anemia.

Conclusion

This study showed that T2DM causes disturbances in the hematological parameters and leads to a mild level of cytopenia. It is, therefore, suggested that hematological abnormalities, especially cytopenia, should be monitored and controlled on a regular basis in T2DM patients for better prognosis and quality of life.