Cardiovascular Determinants of Aerobic Exercise Capacity in Adults With Type 2 Diabetes

Association Between Microvascular Disease and Cardiorespiratory Fitness Among Adults With Type 2 Diabetes

OBJECTIVE

Little is known about the extent to which microvascular disease is associated with cardiorespiratory fitness (CRF) among individuals with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A total of 4,766 participants with type 2 diabetes underwent maximal exercise testing in the Look AHEAD (Action for Health in Diabetes) study at baseline. Low CRF was defined based on the Aerobics Center Longitudinal Study reference standards. Microvascular disease was defined as having one or more of diabetes-related kidney disease (DKD), retinopathy, and neuropathy. The burden of microvascular disease was defined as the number of microvascular beds affected.

RESULTS

Of the 4,766 participants (mean age 58.9 ± 6.7 years, 58.5% women, 66.1% White individuals), 1,761 (37%) had microvascular disease. Participants with microvascular complications in three vascular territories had a lower CFR than those without any microvascular disease (mean adjusted metabolic equivalent of task [MET] 6.58 vs. 7.26, P = 0.001). Participants with any microvascular disease had higher odds of low CRF than those without microvascular disease (adjusted odds ratio [OR] 1.45, 95% CI 1.24-1.71). An increasing burden of microvascular disease was associated with higher odds of low CRF (for microvascular disease in three vascular territories, adjusted OR 2.82, 95% CI 1.36-5.85). Adjusted ORs for low CRF were 1.24 (95% CI 0.99-1.55), 1.34 (95% CI 1.02-1.76), and 1.44 (95% CI 1.20-1.73) for neuropathy, retinopathy, and DKD associations, respectively.

CONCLUSIONS

In a large cohort of adults with type 2 diabetes, the presence of microvascular disease and its burden were independently associated with lower CRF.

Is atrial fibrillation in HFpEF a distinct phenotype? Insights from multiparametric MRI and circulating biomarkers

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF) frequently co-exist. There is a limited understanding on whether this coexistence is associated with distinct alterations in myocardial remodelling and mechanics. We aimed to determine if patients with atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF) represent a distinct phenotype.

METHODS

In this secondary analysis of adults with HFpEF (NCT03050593), participants were comprehensively phenotyped with stress cardiac MRI, echocardiography and plasma fibroinflammatory biomarkers, and were followed for the composite endpoint (HF hospitalisation or death) at a median of 8.5 years. Those with AF were compared to sinus rhythm (SR) and unsupervised cluster analysis was performed to explore possible phenotypes.

RESULTS

136 subjects were included (SR = 75, AF = 61). The AF group was older (76 ± 8 vs. 70 ± 10 years) with less diabetes (36% vs. 61%) compared to the SR group and had higher left atrial (LA) volumes (61 ± 30 vs. 39 ± 15 mL/m2, p < 0.001), lower LA ejection fraction (EF) (31 ± 15 vs. 51 ± 12%, p < 0.001), worse left ventricular (LV) systolic function (LVEF 63 ± 8 vs. 68 ± 8%, p = 0.002; global longitudinal strain 13.6 ± 2.9 vs. 14.7 ± 2.4%, p = 0.003) but higher LV peak early diastolic strain rates (0.73 ± 0.28 vs. 0.53 ± 0.17 1/s, p < 0.001). The AF group had higher levels of syndecan-1, matrix metalloproteinase-2, proBNP, angiopoietin-2 and pentraxin-3, but lower level of interleukin-8. No difference in clinical outcomes was observed between the groups. Three distinct clusters were identified with the poorest outcomes (Log-rank p = 0.029) in cluster 2 (hypertensive and fibroinflammatory) which had equal representation of SR and AF.

CONCLUSIONS

Presence of AF in HFpEF is associated with cardiac structural and functional changes together with altered expression of several fibro-inflammatory biomarkers. Distinct phenotypes exist in HFpEF which may have differing clinical outcomes.

Research trends and hotspots in exercise rehabilitation for coronary heart disease: A bibliometric analysis

Exercise rehabilitation can improve the prognosis of patients with coronary heart disease. However, a bibliometric analysis of the global exercise rehabilitation for coronary heart disease (CHD) research topic is lacking. This study investigated the development trends and research hotspots in the field of coronary heart disease and exercise rehabilitation. CiteSpace software was used to analyze the literature on exercise therapy for CHD in the Web of Science Core Collection database. We analyzed the data of countries/institutions, journals, authors, keywords, and cited references. A total of 3485 peer-reviewed papers were found, and the number of publications on the topic has steadily increased. The most productive country is the USA (1125), followed by China (477) and England (399). The top 3 active academic institutions are Research Libraries UK (RLUK) (236), Harvard University (152), and the University of California System (118). The most commonly cited journals are Circulation (2596), The most commonly cited references are "Exercise-based cardiac rehabilitation for coronary heart disease" (75), Lavie CJ had published the most papers (48). World Health Organization was the most influential author (334 citations). The research frontier trends in this field are body composition, participation, and function. Research on the effects of physical activity or exercise on patients with CHD is a focus of continuous exploration in this field. This study provides a new scientific perspective for exercise rehabilitation and CHD research and gives researchers valuable information for detecting the current research status, hotspots, and emerging trends for further research.

The evolving role of cardiopulmonary exercise testing in ischemic heart disease - state of the art review

PURPOSE OF REVIEW

Cardiopulmonary exercise testing (CPET) is the gold standard for directly assessing cardiorespiratory fitness (CRF) and has a relatively new and evolving role in evaluating atherosclerotic heart disease, particularly in detecting cardiac dysfunction caused by ischemic heart disease. The purpose of this review is to assess the current literature on the link between cardiovascular (CV) risk factors, cardiac dysfunction and CRF assessed by CPET.

RECENT FINDINGS

We summarize the basics of exercise physiology and the key determinants of CRF. Prognostically, several studies have been published relating directly measured CRF by CPET and outcomes allowing for more precise risk assessment. Diagnostically, this review describes in detail what is considered healthy and abnormal cardiac function assessed by CPET. New studies demonstrate that cardiac dysfunction on CPET is a common finding in asymptomatic individuals and is associated with CV risk factors and lower CRF. This review covers how key CPET parameters change as individuals transition from the asymptomatic to the symptomatic stage with progressively decreasing CRF. Finally, a supplement with case studies with long-term longitudinal data demonstrating how CPET can be used in daily clinical decision making is presented.

SUMMARY

In summary, CPET is a powerful tool to provide individualized CV risk assessment, monitor the effectiveness of therapeutic interventions, and provide meaningful feedback to help patients guide their path to improve CRF when routinely used in the outpatient setting.

Subclinical left ventricular deformation and microvascular dysfunction in T2DM patients with and without peripheral neuropathy: assessed by 3.0 T cardiac magnetic resonance imaging

BACKGROUND

Diabetic peripheral neuropathy (DPN) has been shown to be independently associated with cardiovascular events and mortality. This study aimed to evaluate changes in left ventricular (LV) microvascular perfusion and myocardial deformation in type 2 diabetes mellitus (T2DM) patients with and without DPN, as well as to investigate the association between myocardial perfusion and LV deformation.

METHODS

Between October 2015 and July 2022, one hundred and twenty-three T2DM patients without DPN, fifty-four patients with DPN and sixty age‑ and sex‑matched controls who underwent cardiovascular magnetic resonance imaging were retrospectively analyzed. LV myocardial perfusion parameters at rest, including upslope, time to maximum signal intensity (TTM), max signal intensity (max SI), and myocardial strains, including global radial, circumferential and longitudinal strain (GRS, GCS and GLS, respectively), were calculated and compared among the groups with One‑way analysis of variance. Univariable and multivariable linear regression analyses were performed to explore the independent factors influencing LV myocardial perfusion indices and LV strains in diabetes.

RESULTS

The LV GLS, upslope and max SI were significantly deteriorated from controls, through patients without DPN, to patients with DPN (all P < 0.001). Compared with controls, TTM was increased and LV GRS and GCS were decreased in both patient groups (all P < 0.05). Multivariable regression analyses considering covariates showed that DPN was independently associated with reduced upslope, max SI and LV GLS (β = - 0.360, - 2.503 and 1.113, p = 0.021, 0.031 and 0.010, respectively). When the perfusion indices upslope and max SI were included in the multivariable analysis for LV deformation, DPN and upslope (β = 1.057 and - 0.870, p = 0.020 and 0.018, respectively) were significantly associated with LV GLS.

CONCLUSION

In patients with T2DM, there was more severe LV microvascular and myocardial dysfunction in patients with complicated DPN, and deteriorated subclinical LV systolic dysfunction was associated with impaired myocardial circulation.

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.

Impact of the Remission of Type 2 Diabetes on Cardiovascular Structure and Function, Exercise Capacity and Risk Profile: A Propensity Matched Analysis

Type 2 diabetes (T2D) confers a high risk of heart failure frequently with evidence of cardiovascular structural and functional abnormalities before symptom onset. The effects of remission of T2D on cardiovascular structure and function are unknown. The impact of the remission of T2D, beyond weight loss and glycaemia, on cardiovascular structure and function and exercise capacity is described. Adults with T2D without cardiovascular disease underwent multimodality cardiovascular imaging, cardiopulmonary exercise testing and cardiometabolic profiling. T2D remission cases (Glycated hemoglobin (HbA1c) < 6.5% without glucose-lowering therapy, ≥3 months) were propensity score matched 1:4 based on age, sex, ethnicity and time of exposure to those with active T2D (n = 100) with the nearest-neighbour method and 1:1 with non-T2D controls (n = 25). T2D remission was associated with a lower leptin-adiponectin ratio, hepatic steatosis and triglycerides, a trend towards greater exercise capacity and significantly lower minute ventilation/carbon dioxide production (VE/VCO2 slope) vs. active T2D (27.74 ± 3.95 vs. 30.52 ± 5.46, p < 0.0025). Evidence of concentric remodeling remained in T2D remission vs. controls (left ventricular mass/volume ratio 0.88 ± 0.10 vs. 0.80 ± 0.10, p < 0.025). T2D remission is associated with an improved metabolic risk profile and ventilatory response to exercise without concomitant improvements in cardiovascular structure or function. There is a requirement for continued attention to risk factor control for this important patient population.

The Interfield Strength Agreement of Left Ventricular Strain Measurements at 1.5 T and 3 T Using Cardiac MRI Feature Tracking

BACKGROUND

Left ventricular (LV) strain measurements can be derived using cardiac MRI from routinely acquired balanced steady-state free precession (bSSFP) cine images.

PURPOSE

To compare the interfield strength agreement of global systolic strain, peak strain rates and artificial intelligence (AI) landmark-based global longitudinal shortening at 1.5 T and 3 T.

STUDY TYPE

Prospective.

SUBJECTS

A total of 22 healthy individuals (mean age 36 ± 12 years; 45% male) completed two cardiac MRI scans at 1.5 T and 3 T in a randomized order within 30 minutes. FIELD STRENGTH/SEQUENCE: bSSFP cine images at 1.5 T and 3 T.

ASSESSMENT

Two software packages, Tissue Tracking (cvi42, Circle Cardiovascular Imaging) and QStrain (Medis Suite, Medis Medical Imaging Systems), were used to derive LV global systolic strain in the longitudinal, circumferential and radial directions and peak (systolic, early diastolic, and late diastolic) strain rates. Global longitudinal shortening and mitral annular plane systolic excursion (MAPSE) were measured using an AI deep neural network model.

STATISTICAL TESTS

Comparisons between field strengths were performed using Wilcoxon signed-rank test (P value < 0.05 considered statistically significant). Agreement was determined using intraclass correlation coefficients (ICCs) and Bland-Altman plots.

RESULTS

Minimal bias was seen in all strain and strain rate measurements between field strengths. Using Tissue Tracking, strain and strain rate values derived from long-axis images showed poor to fair agreement (ICC range 0.39-0.71), whereas global longitudinal shortening and MAPSE showed good agreement (ICC = 0.81 and 0.80, respectively). Measures derived from short-axis images showed good to excellent agreement (ICC range 0.78-0.91). Similar results for the agreement of strain and strain rate measurements were observed with QStrain.

CONCLUSION

The interfield strength agreement of short-axis derived LV strain and strain rate measurements at 1.5 T and 3 T was better than those derived from long-axis images; however, the agreement of global longitudinal shortening and MAPSE was good.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 2.

Type 2 Diabetes Related Mitochondrial Defects in Peripheral Mononucleated Blood Cells from Overweight Postmenopausal Women

Type 2 diabetes (T2D) is a multisystem disease that is the subject of many studies, but the earliest cause of the disease has yet to be elucidated. Mitochondrial impairment has been associated with diabetes in several tissues. To extend the association between T2D and mitochondrial impairment to blood cells, we investigated T2D-related changes in peripheral mononucleated blood cells’ (PBMCs) mitochondrial function in two groups of women (CTRL vs. T2D; mean age: 54.1 ± 3.8 vs. 60.9 ± 4.8; mean BMI 25.6 ± 5.2 vs. 30.0 ± 5), together with a panel of blood biomarkers, anthropometric measurements and physiological parameters (VO2max and strength tests). Dual-energy X-ray absorptiometry (DXA) scan analysis, cardio-pulmonary exercise test and blood biomarkers confirmed hallmarks of diabetes in the T2D group. Mitochondrial function assays performed with high resolution respirometry highlighted a significant reduction of mitochondrial respiration in the ADP-stimulated state (OXPHOS; −30%, p = 0.006) and maximal non-coupled respiration (ET; −30%, p = 0.004) in PBMCs samples from the T2D group. The total glutathione antioxidant pool (GSHt) was significantly reduced (−38%: p = 0.04) in plasma samples from the T2D group. The fraction of glycated hemoglobin (Hb1Ac) was positively associated with markers of inflammation (C-reactive protein-CRP r = 0.618; p = 0.006) and of dyslipidemia (triglycerides-TG r = 0.815; p < 0.0001). The same marker (Hb1Ac) was negatively associated with mitochondrial activity levels (OXPHOS r = −0.502; p = 0.034; ET r = −0.529; p = 0.024). The results obtained in overweight postmenopausal women from analysis of PBMCs mitochondrial respiration and their association with anthropometric and physiological parameters indicate that PBMC could represent a reliable model for studying T2D-related metabolic impairment and could be useful for testing the effectiveness of interventions targeting mitochondria.

Molecular mechanisms of exercise contributing to tissue regeneration

Physical activity has been known as an essential element to promote human health for centuries. Thus, exercise intervention is encouraged to battle against sedentary lifestyle. Recent rapid advances in molecular biotechnology have demonstrated that both endurance and resistance exercise training, two traditional types of exercise, trigger a series of physiological responses, unraveling the mechanisms of exercise regulating on the human body. Therefore, exercise has been expected as a candidate approach of alleviating a wide range of diseases, such as metabolic diseases, neurodegenerative disorders, tumors, and cardiovascular diseases. In particular, the capacity of exercise to promote tissue regeneration has attracted the attention of many researchers in recent decades. Since most adult human organs have a weak regenerative capacity, it is currently a key challenge in regenerative medicine to improve the efficiency of tissue regeneration. As research progresses, exercise-induced tissue regeneration seems to provide a novel approach for fighting against injury or senescence, establishing strong theoretical basis for more and more "exercise mimetics." These drugs are acting as the pharmaceutical alternatives of those individuals who cannot experience the benefits of exercise. Here, we comprehensively provide a description of the benefits of exercise on tissue regeneration in diverse organs, mainly focusing on musculoskeletal system, cardiovascular system, and nervous system. We also discuss the underlying molecular mechanisms associated with the regenerative effects of exercise and emerging therapeutic exercise mimetics for regeneration, as well as the associated opportunities and challenges. We aim to describe an integrated perspective on the current advances of distinct physiological mechanisms associated with exercise-induced tissue regeneration on various organs and facilitate the development of drugs that mimics the benefits of exercise.

Prognostic value of exercise capacity in incident diabetes: a country with high prevalence of diabetes

BACKGROUND

Diabetes Mellitus (DM) is a fast-growing health problem that imposes an enormous economic burden. Several studies demonstrated the association between physical inactivity and predicting the incidence of diabetes. However, these prediction models have limited validation locally. Therefore, we aim to explore the predictive value of exercise capacity in the incidence of diabetes within a high diabetes prevalence population.

METHODOLOGY

A retrospective cohort study including consecutive patients free of diabetes who underwent clinically indicated treadmill stress testing. Diabetic patients at baseline or patients younger than 18 years of age were excluded. Incident diabetes was defined as an established clinical diagnosis post-exercise testing date. The predictive value of exercise capacity was examined using Harrell's c-index, net reclassification index (NRI), and integrated discrimination index (IDI).

RESULTS

A total of 8,722 participants (mean age 46 ± 12 years, 66.3% were men) were free of diabetes at baseline. Over a median follow-up period of 5.24 (2.17-8.78) years, there were 2,280 (≈ 26%) new cases of diabetes. In a multivariate model adjusted for conventional risk factors, we found a 12% reduction in the risk of incident diabetes for each METs achieved (HR, 0.9; 95% CI, 0.88-0.92; P < 0.001). Using Cox regression, exercise capacity improved the prediction ability beyond the conventional risk factors (AUC = 0.62 to 0.66 and c-index = 0.62 to 0.68).

CONCLUSION

Exercise capacity improved the overall predictability of diabetes. Patients with reduced exercise capacity are at high risk for developing incidence diabetes. Improvement of both physical activity and functional capacity represents a preventive measure for the general population.

Multi index evaluation method of pathological weight loss effect of aerobic exercise based on telemedicine monitoring

INTRODUCTION: Pathological obesity seriously endangers human health. OBJECTIVES: A multi index evaluation method of pathological weight loss effect of aerobic exercise based on telemedicine monitoring is proposed to evaluate the pathological weight loss effect of aerobic exercise by using telemedicine monitoring system. METHODS: According to the indexes of aerobic exercise affecting weight loss effect, a multi index evaluation system of pathological weight loss effect of aerobic exercise was established. The medical sensor of the telemedicine monitoring system is used to collect the index data in the multi index evaluation system of pathological obese personnel. The medical sensor uses the wireless node to transmit the collected data to the remote monitoring center. The evaluation module of the remote monitoring center uses the collected data and selects the fuzzy comprehensive evaluation method to evaluate the pathological weight loss effect of aerobic exercise. RESULTS: The experimental results show that this method can effectively use the telemedicine monitoring system to collect the physiological parameters of pathological obese people, and use the parameter collection results to evaluate the effect of aerobic exercise on pathological weight loss. CONCLUSION: The proposed methods can provide basis for human aerobic exercise pathological weight loss.

Subclinical Cardiac Dysfunction is Associated with Reduced Cardiorespiratory Fitness and Cardiometabolic Risk Factors in Firefighters

BACKGROUND

Past studies have documented the ability of cardiopulmonary exercise testing to detect cardiac dysfunction in symptomatic patients with coronary artery disease. Firefighters are at high risk for work-related cardiac events. This observational study investigated the association of subclinical cardiac dysfunction detected by cardiopulmonary exercise testing with modifiable cardiometabolic risk factors in asymptomatic firefighters.

METHODS

As part of mandatory firefighter medical evaluations, study subjects were assessed at 2 occupational health clinics serving 21 different fire departments. Mixed effects logistic regression analyses were used to estimate odds ratios (ORs) and account for clustering by fire department.

RESULTS

Of the 967 male firefighters (ages 20-60 years; 84% non-Hispanic white; 14% on cardiovascular medications), nearly two-thirds (63%) had cardiac dysfunction despite having normal predicted cardiorespiratory fitness (median peak VO₂ = 102%). In unadjusted analyses, cardiac dysfunction was significantly associated with advanced age, obesity, diastolic hypertension, high triglycerides, low high-density lipoprotein (HDL) cholesterol, and reduced cardiorespiratory fitness (all P values < .05). After adjusting for age and ethnicity, the odds of having cardiac dysfunction were approximately one-third higher among firefighters with obesity and diastolic hypertension (OR = 1.39, 95% confidence interval [CI] = 1.03-1.87 and OR = 1.36, 95% CI = 1.03-1.80) and more than 5 times higher among firefighters with reduced cardiorespiratory fitness (OR = 5.41, 95% CI = 3.29-8.90).

CONCLUSION

Subclinical cardiac dysfunction detected by cardiopulmonary exercise testing is a common finding in career firefighters and is associated with substantially reduced cardiorespiratory fitness and cardiometabolic risk factors. These individuals should be targeted for aggressive risk factor modification to increase cardiorespiratory fitness as part of an outpatient prevention strategy to improve health and safety.

Resveratrol in Treating Diabetes and Its Cardiovascular Complications: A Review of Its Mechanisms of Action

Diabetes mellitus (DM) is one of the most prevalent chronic diseases worldwide. High morbidity and mortality caused by DM are closely linked to its complications in multiple organs/tissues, including cardiovascular complications, diabetic nephropathy, and diabetic neuropathy. Resveratrol is a plant-derived polyphenolic compound with pleiotropic protective effects, ranging from antioxidant and anti-inflammatory to hypoglycemic effects. Recent studies strongly suggest that the consumption of resveratrol offers protection against diabetes and its cardiovascular complications. The protective effects of resveratrol involve the regulation of multiple signaling pathways, including inhibition of oxidative stress and inflammation, enhancement of insulin sensitivity, induction of autophagy, regulation of lipid metabolism, promotion of GLUT4 expression, and translocation, and activation of SIRT1/AMPK signaling axis. The cardiovascular protective effects of resveratrol have been recently reviewed in the literature, but the role of resveratrol in preventing diabetes mellitus and its cardiovascular complications has not been systematically reviewed. Therefore, in this review, we summarize the pharmacological effects and mechanisms of action of resveratrol based on in vitro and in vivo studies, highlighting the therapeutic potential of resveratrol in the prevention and treatment of diabetes and its cardiovascular complications.

Association of ambulatory blood pressure with coronary microvascular and cardiac dysfunction in asymptomatic type 2 diabetes

Background

Type 2 diabetes (T2D) and hypertension commonly coexist and are associated with subclinical myocardial structural and functional changes. We sought to determine the association between blood pressure (BP) and left ventricular (LV) remodeling, systolic/diastolic function, and coronary microvascular function, among individuals with T2D without prevalent cardiovascular disease.

Methods

Participants with T2D and age-, sex-, and ethnicity-matched controls underwent comprehensive cardiovascular phenotyping including fasting bloods, transthoracic echocardiography, cardiovascular magnetic resonance imaging with quantitative adenosine stress/rest perfusion, and office and 24-h ambulatory BP monitoring. Multivariable linear regression was performed to determine independent associations between BP and imaging markers of remodeling and function in T2D.

Results

Individuals with T2D (n = 205, mean age 63 ± 7 years) and controls (n = 40, mean age 61 ± 8 years) were recruited. Mean 24-h systolic BP, but not office BP, was significantly greater among those with T2D compared to controls (128.8 ± 11.7 vs 123.0 ± 13.1 mmHg, p = 0.006). Those with T2D had concentric LV remodeling (mass/volume 0.91 ± 0.15 vs 0.82 ± 0.11 g/mL, p < 0.001), decreased myocardial perfusion reserve (2.82 ± 0.83 vs 3.18 ± 0.82, p = 0.020), systolic dysfunction (global longitudinal strain 16.0 ± 2.3 vs 17.2 ± 2.1%, p = 0.004) and diastolic dysfunction (E/e’ 9.30 ± 2.43 vs 8.47 ± 1.53, p = 0.044) compared to controls. In multivariable regression models adjusted for 14 clinical variables, mean 24-h systolic BP was independently associated with concentric LV remodeling (β = 0.165, p = 0.031), diastolic dysfunction (β = 0.273, p < 0.001) and myocardial perfusion reserve (β = − 0.218, p = 0.016). Mean 24-h diastolic BP was associated with LV concentric remodeling (β = 0.201, p = 0.016).

Conclusion

24-h ambulatory systolic BP, but not office BP, is independently associated with cardiac remodeling, coronary microvascular dysfunction, and diastolic dysfunction among asymptomatic individuals with T2D. (Clinical trial registration. URL: https://clinicaltrials.gov/ct2/show/NCT03132129 Unique identifier: NCT03132129).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01528-2.

Microvascular Dysfunction in Heart Failure with Preserved Ejection Fraction: Pathophysiology, Assessment, Prevalence and Prognosis

Heart failure with preserved ejection fraction (HFpEF) currently accounts for approximately half of all new heart failure cases in the community. HFpEF is closely associated with chronic lifestyle-related diseases, such as obesity and type 2 diabetes, and clinical outcomes are worse in those with than without comorbidities. HFpEF is pathophysiologically distinct from heart failure with reduced ejection fraction, which may explain, in part, the disparity of treatment options available between the two heart failure phenotypes. The mechanisms underlying HFpEF are complex, with coronary microvascular dysfunction (MVD) being proposed as a potential key driver in its pathophysiology. In this review, the authors highlight the evidence implicating MVD in HFpEF pathophysiology, the diagnostic approaches for identifying MVD (both invasive and non-invasive) and the prevalence and prognostic significance of MVD.

Functional role of miR-34a in diabetes and frailty

Emerging evidence has shown that microRNAs (miRNAs) play critical role in the pathogenesis of several disorders. In the present minireview, we focus our attention on the functional role of a specific miRNA, namely miR-34a, in the pathophysiology of frailty and diabetes mellitus. Based on the current literature, we speculate that this miRNA may serve as a potential biomarker of frailty in diabetic older adults. Additionally, its actions on oxidative stress might represent a druggable target to obtain new potentials treatments.

Role of inflammation in diabetic cardiomyopathy

The prevalence of type 2 diabetes (T2D) has reached a pandemic scale. Systemic chronic inflammation dominates the diabetes pathophysiology and has been implicated as a causal factor for the development of vascular complications. Heart failure (HF) is regarded as the most common cardiovascular complication of T2D and the diabetic diagnosis is an independent risk factor for HF development. Key molecular mechanisms pivotal to the development of diabetic cardiomyopathy include the NF-κB pathway and renin-angiotensin-aldosterone system, in addition to advanced glycation end product accumulation and inflammatory interleukin overexpression. Chronic myocardial inflammation in T2D mediates structural and metabolic changes, including cardiomyocyte apoptosis, impaired calcium handling, myocardial hypertrophy and fibrosis, all of which contribute to the diabetic HF phenotype. Advanced cardiovascular magnetic resonance imaging (CMR) has emerged as a gold standard non-invasive tool to delineate myocardial structural and functional changes. This review explores the role of chronic inflammation in diabetic cardiomyopathy and the ability of CMR to identify inflammation-mediated myocardial sequelae, such as oedema and diffuse fibrosis.

Impact of diabetes on cardiopulmonary function: the added value of a combined cardiopulmonary and echocardiography stress test

Type 2 diabetes mellitus (T2DM) represents a major health issue worldwide, as patients with T2DM show an excess risk of death for cardiovascular causes, twice as high as the general population. Among the many complications of T2DM, heart failure (HF) deserves special consideration as one of the leading causes of morbidity and reduced life expectancy. T2DM has been associated with different phenotypes of HF, including HF with reduced and preserved ejection fraction. Cardiopulmonary exercise testing (CPET) can evaluate the metabolic and ventilatory alterations related to myocardial dysfunction and/or peripheral impairment, representing a unique tool for the clinician to study the whole HF spectrum. While CPET allows for a thorough evaluation of functional capacity, it cannot directly differentiate central and peripheral determinants of effort intolerance. Combining CPET with imaging techniques could provide even higher accuracy and further insights into the progression of the disease since signs of left ventricular systolic and diastolic dysfunction can be detected during exercise, even in asymptomatic diabetic individuals. This review aims to dissect the alterations in cardiopulmonary function characterising patients with T2DM and HF to improve patient risk stratification.

Mechanisms of reduced peak oxygen consumption in subjects with uncomplicated type 2 diabetes

Background

Type 2 diabetes mellitus (T2D) increases the risk of incident heart failure (HF), whose earliest fingerprint is effort intolerance (i.e. impaired peak oxygen consumption, or VO_2peak). In the uncomplicated T2D population, however, the prevalence of effort intolerance and the underpinning mechanistic bases are uncertain. Leveraging the multiparametric characterization allowed by imaging-cardiopulmonary exercise testing (iCPET), the aim of this study is to quantify effort intolerance in T2D and to dissect the associated cardiopulmonary alterations.

Methods

Eighty-eight adults with well-controlled and uncomplicated T2D and no criteria for HF underwent a maximal iCPET with speckle tracking echocardiography, vascular and endothelial function assessment, as well as a comprehensive biohumoral characterization. Effort intolerance was defined by a VO_2peak below 80% of maximal predicted oxygen uptake.

Results

Forty-eight patients (55%) had effort intolerance reaching a lower VO_2peak than T2D controls (16.5 ± 3.2 mL/min/kg, vs 21.7 ± 5.4 mL/min/kg, p < 0.0001). Despite a comparable cardiac output, patients with effort intolerance showed reduced peak peripheral oxygen extraction (11.3 ± 3.1 vs 12.7 ± 3.3 mL/dL, p = 0.002), lower VO₂/work slope (9.9 ± 1.2 vs 11.2 ± 1.4, p < 0.0001), impaired left ventricle systolic reserve (peak S’ 13.5 ± 2.8 vs 15.2 ± 3.0, p = 0.009) and global longitudinal strain (peak-rest ΔGLS 1.7 ± 1.5 vs 2.5 ± 1.8, p = 0.03) than subjects with VO_2peak above 80%. Diastolic function, vascular resistance, endothelial function, biohumoral exams, right heart and pulmonary function indices did not differ between the two groups.

Conclusions

Effort intolerance and reduced VO_2peak is a severe and highly prevalent condition in uncomplicated, otherwise asymptomatic T2D. It results from a major defect in skeletal muscle oxygen extraction coupled with a subtle myocardial systolic dysfunction.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01314-6.

Cardiovascular and systemic determinants of exercise capacity in people with type 2 diabetes mellitus

The global burden of heart failure (HF) is on the rise owing to an increasing incidence of lifestyle related diseases, predominantly type 2 diabetes mellitus (T2D). Diabetes is an independent risk factor for cardiovascular disease, and up to 75% of those with T2D develop HF in their lifetime. T2D leads to pathological alterations within the cardiovascular system, which can progress insidiously and asymptomatically in the absence of conventional risk factors. Reduced exercise tolerance is consistently reported, even in otherwise asymptomatic individuals with T2D, and is the first sign of a failing heart. Because aggressive modification of cardiovascular risk factors does not eliminate the risk of HF in T2D, it is likely that other factors play a role in the pathogenesis of HF. Early identification of individuals at risk of HF is advantageous, as it allows for modification of the reversible risk factors and early initiation of treatment with the aim of improving clinical outcomes. In this review, cardiac and extra-cardiac contributors to reduced exercise tolerance in people with T2D are explored.

Clinical associations with stage B heart failure in adults with type 2 diabetes

BACKGROUND

There is a high prevalence of asymptomatic (American Heart Association Stage B) heart failure (SBHF) in people with type 2 diabetes (T2D). We aimed to identify associations between clinical characteristics and markers of SBHF in adults with T2D, which may allow therapeutic interventions prior to symptom onset.

METHODS

Adults with T2D from a multi-ethnic population with no prevalent cardiovascular disease [n = 247, age 52 ± 12 years, glycated haemoglobin A1c (HbA1c) 7.4 ± 1.1% (57 ± 12 mmol/mol), duration of diabetes 61 (32, 120) months] underwent echocardiography and adenosine stress perfusion cardiovascular magnetic resonance imaging. Multivariable linear regression analyses were performed to identify independent associations between clinical characteristics and markers of SBHF.

RESULTS

In a series of multivariable linear regression models containing age, sex, ethnicity, smoking history, number of glucose-lowering agents, systolic blood pressure (BP) duration of diabetes, body mass index (BMI), HbA1c, serum creatinine, and low-density lipoprotein (LDL)-cholesterol, independent associations with: left ventricular mass:volume were age (β = 0.024), number of glucose-lowering agents (β = 0.022) and systolic BP (β = 0.027); global longitudinal strain were never smoking (β = -1.196), systolic BP (β = 0.328), and BMI (β = -0.348); myocardial perfusion reserve were age (β = -0.364) and male sex (β = 0.458); and aortic distensibility were age (β = -0.629) and systolic BP (β = -0.348). HbA1c was not independently associated with any marker of SBHF.

CONCLUSIONS

In asymptomatic adults with T2D, age, systolic BP, BMI, and smoking history, but not glycaemic control, are the major determinants of SBHF. Given BP and BMI are modifiable, these may be important targets to reduce the development of symptomatic heart failure.

Cardiorespiratory fitness in patients with type 2 diabetes: A missing piece of the puzzle

Functional capacity represents an important predictor for cardiovascular and all-cause mortality in patients with diabetes mellitus (DM). Impaired cardiopulmonary fitness is frequently seen in DM patients, and it might partly explain morbidity and mortality in these patients. There are several potential reasons that could explain impaired functional capacity in DM patients: hyperglycemia, insulin resistance, endothelial dysfunction, inflammation, microvascular impairment, myocardial dysfunction, and skeletal muscle changes. These changes are partly reversible, and improvement of any of these components might increase functional capacity in DM patients and improve their outcome. Physical activity is related with decreased cardiovascular disease and all-cause mortality in patients with type 2 DM. Diabetic cardiomyopathy is the most important clinical entity in DM patients that involves left ventricular diastolic dysfunction and cardiac autonomic neuropathy, which potentially induce heart failure with preserved ejection fraction. Development of diabetic cardiomyopathy may slow oxygen uptake kinetics and affect the cardiorespiratory fitness in DM patients, but it can also induce development of heart failure. Improvement of functional capacity in DM patients represents an important therapeutic task, and it can be achieved mainly with exercise training and significantly less with pharmacological treatment. Exercise training reduces body weight and improves glycemic control, as well as left ventricular structure and function. The aim of this review was to summarize current knowledge about importance of functional capacity in DM patients, as well as possible mechanisms that could explain the relationship between DM and oxygen kinetics.