Cardiovascular autonomic neuropathy in diabetes: Pathophysiology, clinical assessment and implications

Sudoscan® reclassifies cardiovascular risk in patients with type 2 diabetes mellitus according to the ESC 2023

Objectives

The objective of this study is to determine if the detection of DAN through Sudoscan® can reclassify cardiovascular risk in patients with T2DM according to the European Society of Cardiology guidelines 2023 (ESC 2023) compared to other risk scales.

Methods

A retrospective cross-sectional analytical study was conducted on 161 patients with T2DM who had undergone Sudoscan® in a Northern Mexico Hospital between December 2022 and July 2023. We compared the cardiovascular risk with SCORE-2, SMART, ADVANCE, ASCVD plus, and Globo Risk scales.

Results

Estimated cardiovascular risk according to the ESC 2023 without consideration of DAN was low for 91 (57%), moderate for 53 (33%), high for 11 (7%) and very high for 22 (3%) of patients. While inclusion of DAN resulted in low risk in 81 (51%), moderate in 46 (28%9, high in 9(5%) and very high risk for 25 ((16%), p = 0.004). The majority of patients were classified as low or moderate risk using other scales such as ASCVD plus, SCORE-2, Globo Risk, ADVANCE, and SMART.

Conclusions

Sudoscan® enhances cardiovascular risk assessment in T2DM by accurately diagnosing microvascular complications, ensuring comprehensive patient evaluation.

Prediction of hypertensive responses associated with interscalene block, a prospective cohort study

BACKGROUND

The aim was the effects of interscalene block (ISB) on blood pressure, focusing on identifying anatomical and clinical predictors of hypertensive responses. The aim is to improve the safety and effectiveness of ISB, especially in patients at increased risk of adverse hemodynamic events.

METHODS

We conducted a prospective cohort study including patients undergoing ISB. Key measurements included carotid intima-media thickness (CIMT), neck length, anterior scalene muscle thickness, BMI, age, history of diabetes mellitus, and hypertension. Blood pressure was monitored at multiple intervals, and logistic regression was used to identify independent systolic blood pressure elevation predictors.

RESULTS

A total of 110 patients were included in the study. Reduced anterior scalene muscle thickness (OR = 0.620, 95% CI = 0.462-0.833; p = 0.002), increased CIMT (OR = 1.006, 95% CI = 1.002-1.009; p = 0.001), and history of hypertension hypertension (OR = 4.31, 95% CI = 1.173-15.85; p = 0.028), were independent predictors of blood pressure elevation during ISB (p = 0.028, p = 0.001, p = 0.002). CIMT ≥ 750 μm and anterior scalene muscle thickness ≤ 12.75 mm were identified as critical cut-off values (p < 0.001 for both).

CONCLUSIONS

Preoperative evaluation of anatomical and clinical predictors, such as CIMT and anterior scalene muscle thickness, may improve patient safety, particularly for high-risk individuals during ISB. However, the moderate predictive ability of these factors suggests that they should be considered part of a comprehensive preoperative risk assessment.

TRIAL REGISTRATION

NCT06394960, date: January 25, 2024, first patient registration date: May 2, 2024.

Effects of canagliflozin preconditioning on post-resuscitation myocardial function in a diabetic rat model of cardiac arrest and cardiopulmonary resuscitation

BACKGROUND

Canagliflozin can reduce the risk of cardiovascular disease in patients except for its targeted antidiabetic effects. However, it remains unknown whether canagliflozin alleviates the post-resuscitation myocardial dysfunction (PRMD) in type 2 diabetes mellitus.

OBJECTIVE

To explore the effects and potential mechanisms of canagliflozin on myocardial function after cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) in a type 2 diabetic rat model.

METHODS

Twenty-four type 2 diabetic rats were randomized into four groups: (1) sham + canagliflozin, (2) sham + placebo, (3) CPR + placebo, and (4) CPR + canagliflozin. Except for the sham + canagliflozin and placebo groups, both the CPR + placebo and canagliflozin groups underwent 8 min of CPR after the induction of ventricular fibrillation for 6 min. Myocardial function and hemodynamics were assessed at baseline and within 6 h after autonomous circulation (ROSC) return. Left ventricular tissues were sampled to determine the expressions of relevant proteins in the NLRP3 inflammasome pathway.

RESULTS

The results demonstrated that the mean arterial pressure (MAP) was significantly improved in the CPR + canagliflozin group after ROSC compared with the CPR + placebo group (p < 0.05). Meanwhile, both ejection fraction (EF) and fraction shortening (FS) were dramatically increased in the CPR + canagliflozin group when compared with the CPR + placebo group at 2h, 4h, and 6h after ROSC (p < 0.05). In addition, the levels of NT-proBNP, cTn-I, and NLRP3 inflammatory inflammasome-associated proteins were significantly decreased in the CPR + canagliflozin group compared with the CPR + placebo group.

CONCLUSIONS

In type 2 diabetic rats, pretreatment of canagliflozin alleviates PRMD. The potential mechanisms may include inhibition of the NLRP3/caspase-1 signaling pathway.

Proarrhythmic Lipid Inflammatory Mediators: Mechanisms in Obesity Arrhythmias

The prevalence of obesity and associated metabolic disorders such as diabetes is rapidly increasing; therefore, concerns regarding their cardiovascular consequences, including cardiac arrhythmias, are rising. As obesity progresses, the excessively produced lipids accumulate in unconventional areas such as the epicardial adipose tissue (EAT) around the myocardium. Metabolic alterations in obesity contribute to the transformation of these ectopic fat deposits into arrhythmogenic substrates. However, despite advances in therapeutic approaches, particularly in lowering EAT volume and thickness through sodium-glucose co-transporter-2 (SGLT2) inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists, obese and diabetic patients still suffer from fatal arrhythmias that may lead to sudden cardiac death. Therefore, an investigation into how unappreciated underlying pathways such as lipid mediators contribute to the transformation of adipose tissues into proinflammatory and arrhythmogenic substrates is of significance. Leukotriene B4 (LTB4) is an eicosanoid derived from arachidonic acid and acts as a lipid mediator. LTB4 has recently been identified to be associated with cardiac ion channel modulations and arrhythmogenic conditions in diabetes. LTB4 increases circulatory free fatty acids (FFAs) and has been associated with adipocyte hypertrophy. LTB4 also interferes with insulin signaling pathways, instigating insulin resistance (IR). In addition, LTB4, as a potent chemoattractant, contributes to the mobilization of circulatory immune cells such as monocytes and promotes inflammatory macrophage polarization and macrophage dysfunction. Thus, this review provides a comprehensive overview of LTB4's underlying pathways in obesity; illustrates how these pathways might lead to alterations in cardiac ion channels, currents, and cardiac arrhythmias; and shows how they might pose a therapeutic target for metabolic-associated arrhythmias.

Sex Differences in the Association Between Cardiovascular Autonomic Neuropathy and Mortality in Patients With Type 2 Diabetes: The ACCORD Study

BACKGROUND

Cardiovascular autonomic neuropathy (CAN) is a severe complication of type 2 diabetes. Significant sex-related differences have been observed in type 2 diabetes consequences such as mortality. However, the effect of sex on the association between CAN and mortality in patients with type 2 diabetes is currently unknown.

METHODS AND RESULTS

We assessed 7866 participants in the ACCORD (Action to Control Cardiovascular Risk in Diabetes) trial, including 4730 men and 3136 women. CAN was diagnosed using a combination of heart rate variability and QT interval index, which has 3 different definitions. There were 1364 cases of all-cause mortality and 452 cases of cardiovascular disease mortality during a median follow-up of 9.7 years. We used multivariable Cox regression models to assess the association between different CAN definitions and mortality. In women, various CAN measures were statistically significant associated with an increased risk of all-cause mortality (CAN1: hazard ratio [HR], 1.64 [95% CI, 1.28-2.09]; CAN2: HR, 1.58 [95% CI, 1.17-2.15]; CAN3: HR, 1.78 [95% CI, 1.20-2.65]) and mortality (CAN1: HR, 2.25 [95% CI, 1.44-3.52]; CAN 2: HR, 2.22 [95% CI, 1.28-3.87]; CAN3: HR, 3.31 [95% CI, 1.67-6.57]). CAN was not significantly associated with mortality in men. A significant multiplicative interaction of CAN and sex was observed on both mortality outcomes (P<0.01).

CONCLUSIONS

Significant sex-related differences were observed in CAN and its associated mortality. In terms of mortality risk prevention, CAN should be given greater consideration in women with type 2 diabetes.

Electrodiagnostic assessment of autonomic nervous system in diabetic autonomic neuropathy: Case series in 72 diabetes patients

Diabetic autonomic neuropathy is one of the most common complications of diabetes which is asymptomatic in early stage. Hence HRV and AFT are performed to detect and prevent its progression to advanced stages. To discuss the HRV and AFT findings in diabetic patients. An observational study was conducted in Physiology department of AIIMS, Bhopal in collaboration with the Medicine department of the institute. Seventy-two diagnosed Type-2 Diabetes mellitus patients were examined using POWER LAB AND LAB CHART 8 BY AD INSTRUMENT: For recording heart rate variability (HRV) and Ewing's battery of tests: For Autonomic function testing. Microsoft Excel was utilized for data compilation and for result analysis. In the present study, based on HRV parameters sympathetic involvement was seen in 39% while parasympathetic involvement was seen in 15% of patients. Balanced state was observed in 46% of the patients. Based on AFT battery, normal early involvement was observed in 62% of the patients while definite and severe involvement was observed in 14 and 24%, respectively. Diabetic autonomic neuropathy was observed in 72% of the patients based on HRV and AFT testing. In severe involvement, orthostatic hypotension was seen. Severe involvement was observed in 24% of the patients in present study. Involvement of the vagal parasympathetic component of ANS was obvious evidenced by increase in resting heart rate, decrease in Valsalva ratio, E/I index, and standing ratio. Diabetic autonomic neuropathy was observed in majority of patients with normal early involvement seen predominantly and though majority of them were in balanced state, sympathetic involvement was also seen at large. HRV studies depicted a decrease of total power, decreased low frequency (LF) and high frequency (HF) with LF/HF and SD1/SD2 ratios depicting sympathetic involvement.

Mechanistic Relevance of Ventricular Arrhythmias in Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is increasing at an alarming rate worldwide, with limited effective therapeutic interventions in patients. Sudden cardiac death (SCD) and ventricular arrhythmias present substantial risks for the prognosis of these patients. Obesity is a risk factor for HFpEF and life-threatening arrhythmias. Obesity and its associated metabolic dysregulation, leading to metabolic syndrome, are an epidemic that poses a significant public health problem. More than one-third of the world population is overweight or obese, leading to an enhanced risk of incidence and mortality due to cardiovascular disease (CVD). Obesity predisposes patients to atrial fibrillation and ventricular and supraventricular arrhythmias-conditions that are caused by dysfunction in the electrical activity of the heart. To date, current therapeutic options for the cardiomyopathy of obesity are limited, suggesting that there is considerable room for the development of therapeutic interventions with novel mechanisms of action that will help normalize sinus rhythms in obese patients. Emerging candidates for modulation by obesity are cardiac ion channels and Ca-handling proteins. However, the underlying molecular mechanisms of the impact of obesity on these channels and Ca-handling proteins remain incompletely understood. Obesity is marked by the accumulation of adipose tissue, which is associated with a variety of adverse adaptations, including dyslipidemia (or abnormal systemic levels of free fatty acids), increased secretion of proinflammatory cytokines, fibrosis, hyperglycemia, and insulin resistance, which cause electrical remodeling and, thus, predispose patients to arrhythmias. Furthermore, adipose tissue is also associated with the accumulation of subcutaneous and visceral fat, which is marked by distinct signaling mechanisms. Thus, there may also be functional differences in the effects of the regional distribution of fat deposits on ion channel/Ca-handling protein expression. Evaluating alterations in their functional expression in obesity will lead to progress in the knowledge of the mechanisms responsible for obesity-related arrhythmias. These advances are likely to reveal new targets for pharmacological modulation. Understanding how obesity and related mechanisms lead to cardiac electrical remodeling is likely to have a significant medical and economic impact. Nevertheless, substantial knowledge gaps remain regarding HFpEF treatment, requiring further investigations to identify potential therapeutic targets. The objective of this study is to review cardiac ion channel/Ca-handling protein remodeling in the predisposition to metabolic HFpEF and arrhythmias. This review further highlights interleukin-6 (IL-6) as a potential target, cardiac bridging integrator 1 (cBIN1) as a promising gene therapy agent, and leukotriene B4 (LTB4) as an underappreciated pathway in future HFpEF management.

The Role of Coronary Computed Tomography Angiography in the Diagnosis, Risk Stratification, and Management of Patients with Diabetes and Chest Pain

Coronary artery disease (CAD) affects over 200 million individuals globally, accounting for approximately 9 million deaths annually. Patients living with diabetes mellitus exhibit an up to fourfold increased risk of developing CAD compared to individuals without diabetes. Furthermore, CAD is responsible for 40 to 80 percent of the observed mortality rates among patients with type 2 diabetes. Patients with diabetes typically present with non-specific clinical complaints in the setting of myocardial ischemia, and as such, it is critical to select appropriate diagnostic tests to identify those at risk for major adverse cardiac events (MACEs) and for determining optimal management strategies. Studies indicate that patients with diabetes often exhibit more advanced atherosclerosis, a higher calcified plaque burden, and smaller epicardial vessels. The diagnostic performance of coronary computed tomographic angiography (CCTA) in identifying significant stenosis is well-established, and as such, CCTA has been incorporated into current clinical guidelines. However, the predictive accuracy of obstructive CAD in patients with diabetes has been less extensively characterized. CCTA provides detailed insights into coronary anatomy, plaque burden, epicardial vessel stenosis, high-risk plaque features, and other features associated with a higher incidence of MACEs. Recent evidence supports the efficacy of CCTA in diagnosing CAD and improving patient outcomes, leading to its recommendation as a primary diagnostic tool for stable angina and risk stratification. However, its specific benefits in patients with diabetes require further elucidation. This review examines several key aspects of the utility of CCTA in patients with diabetes: (i) the diagnostic accuracy of CCTA in detecting obstructive CAD, (ii) the effect of CCTA as a first-line test for individualized risk stratification for cardiovascular outcomes, (iii) its role in guiding therapeutic management, and (iv) future perspectives in risk stratification and the role of artificial intelligence.

Cardiovascular and Respiratory Measures in Adults With Early-onset Type 2 Diabetes Mellitus Compared With Matched Controls

OBJECTIVES

The aim of the study was to compare cardiac and respiratory function at rest in participants with early-onset type 2 diabetes and a control group without diabetes, matched for age, sex, and body mass index (BMI).

METHODS

This study included 18 participants with early-onset type 2 diabetes (12 men and 6 women, age 34.9±6 years, diabetes duration 3.1±3.0 years) and 14 control participants without diabetes, matched for age, sex, and BMI (9 men and 5 women, age 32.9±5.2 years). Participants underwent resting echocardiography and pulmonary function tests. Fasting blood samples were analyzed for glycated hemoglobin, glucose, C-reactive protein, insulin, free fatty acids, and N-terminal pro-B-type natriuretic peptide.

RESULTS

Significant differences between groups were observed in left ventricular diastolic function at rest. Compared with controls, the group with early-onset type 2 diabetes had lower E/A (ratio between early [E] and late [A] ventricular filling velocity) (p=0.002), higher E/e' (representing left ventricular filling pressure) (p=0.017), lower e' (early myocardial relaxation velocity) (p<0.001), and lower diffusing capacity of the lung for carbon monoxide (p=0.003).

CONCLUSIONS

Subclinical left ventricular diastolic dysfunction and lower lung diffusing capacity were detected in participants with early-onset type 2 diabetes when compared with matched controls.

Reduced heart rate variability is associated with altered clinical laboratory profile in people living with HIV

Background

We compared heart rate variability (HRV) indices between people living with HIV (PLWH) and HIV-negative individuals to ascertain the independent association between HIV infection and reduced HRV, and further investigated whether distinct clinical laboratory profiles exist between PLWH with and without reduced HRV.

Methods

This cross-sectional analysis included 304 PLWH and 147 HIV-negative individuals with comparable age and sex. Thirty-two routine clinical laboratory indices (including hematology and biochemistry) closest to the survey were extracted from the Electronic Medical Record System. HRV indices were divided into two categories: low (lowest quartile, Q1) and moderate-to-high (combined, Q2‒Q4).

Results

The time domain indices, ln(SDNN), ln(RMSSD), and ln(PNN50), as well as the frequency domain indices, ln(HF), ln(LF), and ln(VLF), were all significantly reduced in PLWH versus HIV-negative individuals (all p < 0.05). These associations remained for ln(SDNN), ln(PNN50), ln(HF) and ln(LF) even after adjusting for potential confounders in multivariable models. PLWH with low HRV indices exhibited distinct clinical laboratory profiles that were characterized by an elevation in fasting plasma glucose, white blood cell count, neutrophil count, neutrophil%, and a reduction in albumin, total protein, urine creatinine, lymphocyte%, red blood cell count (RBC) and nadir CD4 count. The final stepwise logistic regression models for low SDNN included older age, decreased total cholesterol levels, elevated neutrophil count, and the use of antidiabetic medications, whereas the final model for low LF included older age, reduced RBC and the use of antidiabetic medications.

Conclusion

PLWH exhibit impaired parasympathetic activity, as evidenced by reduced SDNN, PNN50, LF and HF. Furthermore, PLWH who have reduced HRV indices exhibits distinct clinical laboratory profiles that are related to systematic inflammatory response and diabetes.

Deciphering interleukin-18 in diabetes and its complications: Biological features, mechanisms, and therapeutic perspectives

Interleukin-18 (IL-18), a potent and multifunctional pro-inflammatory cytokine, plays a critical role in regulating β-cell failure, β-cell death, insulin resistance, and various complications of diabetes mellitus (DM). It exerts its effects by triggering various signaling pathways, enhancing the production of pro-inflammatory cytokines and nitric oxide (NO), as well as promoting immune cells infiltration and β-cells death. Abnormal alterations in IL-18 levels have been revealed to be strongly associated with the onset and development of DM and its complications. Targeting IL-18 may present a novel and promising approach for DM therapy. An increasing number of IL-18 inhibitors, including chemical and natural inhibitors, have been developed and have been shown to protect against DM and diabetic complications. This review provides a comprehensive understanding of the production, biological functions, action mode, and activated signaling pathways of IL-18. Next, we shed light on how IL-18 contributes to the pathogenesis of DM and its associated complications with links to its roles in the modulation of β-cell failure and death, insulin resistance in various tissues, and pancreatitis. Furthermore, the therapeutic potential of targeting IL-18 for the diagnosis and treatment of DM is also highlighted. We hope that this review will help us better understand the functions of IL-18 in the pathogenesis of DM and its complications, providing novel strategies for DM diagnosis and treatment.

Association of Continuous Glucose Monitoring-Derived Glycemia Risk Index With Cardiovascular Autonomic Neuropathy in Patients With Type 1 Diabetes Mellitus: A Cross-sectional Study

BACKGROUND

The glycemia risk index (GRI) is a new composite continuous glucose monitoring (CGM) metric for weighted hypoglycemia and hyperglycemia. We evaluated the association between the GRI and cardiovascular autonomic neuropathy (CAN) and compared the effects of the GRI and conventional CGM metrics on CAN.

METHODS

For this cross-sectional study, three-month CGM data were retrospectively analyzed before autonomic function tests were performed in 165 patients with type 1 diabetes. CAN was defined as at least two abnormal results of parasympathetic tests according to an age-specific reference.

RESULTS

The overall prevalence of CAN was 17.1%. Patients with CAN had significantly higher GRI scores, target above range (TAR), coefficient of variation (CV), and standard deviation (SD) but significantly lower time in range (TIR) than those without CAN. The prevalence of CAN increased across higher GRI zones (P for trend <.001). A multivariate logistic regression analysis, adjusted for covariates such as HbA1c, demonstrated that the odds ratio (OR) of CAN was 9.05 (95% confidence interval [CI]: 2.21-36.96, P = .002) per 1-SD increase in the GRI. TIR and CV were also significantly associated with CAN in the multivariate model. The area under the curve of GRI for the prediction of CAN (0.85, 95% CI: 0.76-0.94) was superior to that of TIR (0.80, 95% CI: 0.71-0.89, P for comparison = .046) or CV (0.71, 95% CI: 0.57-0.84, P for comparison = .049).

CONCLUSIONS

The GRI is significantly associated with CAN in patients with type 1 diabetes and may be a better CGM metric than TIR for predicting CAN.

Quantification of lipoproteins by proton nuclear magnetic resonance spectroscopy (1H-NMRS) improves the prediction of cardiac autonomic dysfunction in patients with type 1 diabetes

AIMS

To assess if advanced characterization of serum glycoprotein and lipoprotein profile, measured by proton nuclear magnetic resonance spectroscopy (1H-NMRS) improves a predictive clinical model of cardioautonomic neuropathy (CAN) in subjects with type 1 diabetes (T1D).

METHODS

Cross-sectional study (ClinicalTrials.gov Identifier: NCT04950634). CAN was diagnosed using Ewing's score. Advanced characterization of macromolecular complexes including glycoprotein and lipoprotein profiles in serum samples were measured by 1H-NMRS. We addressed the relationships between these biomarkers and CAN using correlation and regression analyses. Diagnostic performance was assessed by analyzing their areas under the receiver operating characteristic curves (AUCROC).

RESULTS

Three hundred and twenty-three patients were included (46% female, mean age and duration of diabetes of 41 ± 13 years and 19 ± 11 years, respectively). The overall prevalence of CAN was 28% [95% confidence interval (95%CI): 23; 33]. Glycoproteins such as N-acetylglucosamine/galactosamine and sialic acid showed strong correlations with inflammatory markers such as high-sensitive C-reactive protein, fibrinogen, IL-10, IL-6, and TNF-α. On the contrary, we did not find any association between the former and CAN. A stepwise binary logistic regression model (R2 = 0.078; P = 0.003) retained intermediate-density lipoprotein-triglycerides (IDL-TG) [β:0.082 (95%CI: 0.005; 0.160); P = 0.039], high-density lipoprotein-triglycerides (HDL-TGL)/HDL-Cholesterol [β:3.633 (95%CI: 0.873; 6.394); P = 0.010], and large-HDL particle number [β: 3.710 (95%CI: 0.677; 6.744); P = 0.001] as statistically significant determinants of CAN. Adding these lipoprotein particles to a clinical prediction model of CAN that included age, duration of diabetes, and A1c enhanced its diagnostic performance, improving AUCROC from 0.546 (95%CI: 0.404; 0.688) to 0.728 (95%CI: 0.616; 0.840).

CONCLUSIONS

When added to clinical variables, 1H-NMRS-lipoprotein particle profiles may be helpful to identify those patients with T1D at risk of CAN.

Impact of Concurrent Exercise Training on Cardiac Autonomic Modulation, Metabolic Profile, Body Composition, Cardiorespiratory Fitness, and Quality of Life in Type 2 Diabetes with Cardiac Autonomic Neuropathy: A Randomized Controlled Trial

Background: Type 2 diabetes mellitus (T2DM) often leads to cardiac autonomic neuropathy (CAN), a severe complication affecting cardiovascular health. Exercise training is a proven intervention for improving metabolic control and cardiovascular health in T2DM, but the effects of concurrent exercise training (CET), combining aerobic and resistance exercises, on CAN are not fully understood. Objective: This randomized controlled trial investigates the impact of a structured CET program on cardiac autonomic modulation, metabolic profile, body composition, cardiorespiratory fitness (CRF), and quality of life (QoL) in individuals with T2DM and CAN. Methods: A total of 96 participants, aged 35-70 years, with T2DM and CAN, were randomized into CET (n = 48) and control (n = 48) groups. The CET group engaged in combined aerobic and resistance training three times per week for 13 weeks, while the control group received standard care. Primary outcomes included heart rate variability (HRV) and heart rate recovery (HRR). Secondary outcomes were metabolic profile, body composition, CRF, and QoL, which were assessed using standardized protocols and validated questionnaires. The trial was registered with the Clinical Trials Registry-India (CTRI/2021/09/036711). Results: Significant improvements were noted in the CET group compared to controls. HRV metrics (SDNN, RMSSD, pNN50, TP, LF power, HF power, and LF/HF ratio) and HRR metrics (HRR30s, HRR1, HRR2, and HRR3) all showed significant enhancements (p < 0.01). The CET group also exhibited substantial reductions in fasting blood glucose, postprandial blood glucose, HbA1c, waist circumference, hip circumference, and percentage body fat (p < 0.01). Improvements were observed in lipid profile markers and CRF (VO2max) (p < 0.01). QoL scores improved significantly in the CET group as per the ADDQoL-19 (p < 0.01). Conclusions: CET significantly enhances cardiac autonomic modulation, metabolic profile, body composition, CRF, and QoL in individuals with T2DM and CAN. These findings support the integration of CET into standard T2DM management to improve clinical outcomes and QoL. Further research is needed to explore the long-term benefits and broader applicability of CET in diverse diabetic populations.

Prevalence and Risk Factors of Cardiovascular Autonomic Neuropathy in Individuals with Type 1 Diabetes Mellitus: A Systematic Review and Meta-Analysis

Background

Cardiac autonomic neuropathy (CAN) is a severe complication of type 1 diabetes mellitus (T1DM). This meta-analysis aimed to synthesize relevant literature on the prevalence of CAN and its risk factors in individuals with T1DM.

Methods

We screened relevant literature from databases based on predefined search criteria until June 28, 2022. Data extraction and quality assessment were conducted independently by two reviewers. A meta-analysis was conducted to determine the prevalence of CAN and its risk factors in individuals with T1DM using a random-effects model. A subgroup analysis was conducted to assess variations in CAN prevalence based on diabetes duration, diagnostic criteria, study quality, study design, and geographic region of the participants.

Results

A total of 21 studies provided information on the prevalence of CAN, while 18 studies explored the potential risk factors for CAN. The overall estimated prevalence of CAN in individuals with T1DM was 25.8% (95% confidence interval (95% CI): 0.208-0.307), with no significant differences observed among the five regions. Additionally, smoking, lipid abnormalities, hypertension, duration of diabetes, increased body mass index, elevated glycated haemoglobin concentrations, and presence of chronic complications of diabetes, such as diabetic retinopathy, diabetic neuropathy, and diabetic nephropathy, were associated with a higher prevalence of CAN in individuals with diabetes.

Conclusions

CAN is prevalent in individuals with T1DM worldwide. Efforts should be made to improve early screening and intervention for CAN, as well as to implement strategies aimed at improving or controlling early risk factors associated with CAN.

Neutrophil-to-Lymphocyte Ratio as a Marker for Cardiac Autonomic Neuropathy in Egyptian Patients With Type 2 Diabetes: A Cross-Sectional Study

OBJECTIVE

Cardiac autonomic neuropathy (CAN) is one of the most serious complications of diabetes. This study aimed to analyze the correlation between neutrophil-to-lymphocyte ratio (NLR) and CAN in patients with type 2 diabetes (T2D) using 24-hour Holter ECG and to assess the relationship between NLR and severity of diabetic peripheral neuropathy (DPN).

SUBJECTS & METHODS

 This cross-sectional study included 90 T2D patients with DPN confirmed by nerve conduction study (NCS). A 24-hour Holter ECG was done to detect the decrease in heart rate variability (HRV). Laboratory parameters, including fasting blood glucose, creatinine, cholesterol, triglyceride, and glycosylated hemoglobin (HbA1c) levels, as well as CBC, neutrophils, lymphocytes, NLR, and platelet-to-lymphocyte ratio (PLR), were calculated accordingly. An albumin-to-creatinine ratio (ACR) test was done and the estimated glomerular filtration rate (eGFR) was calculated. Chronic kidney disease was diagnosed by the presence of albuminuria (≥30 mg/g creatinine) and/or eGFR less than 60.

RESULTS

Based on the 24-hour Holter ECG, 25 patients out of 90 (27.7%) had CAN. On comparing both the CAN and non-CAN groups, the CAN group had higher HbA1C (p = 0.005), higher NLR (p = 0.014), and higher neutrophils (p = 0.10). Also, PLR was higher in the CAN group than in the non-CAN group, but this was not statistically significant (p = 0.180). Receiver operator characteristic curve analysis revealed that NLR with a cutoff of 1.7 succeeded in detecting patients with CAN.

CONCLUSION

NLR can be used as an inexpensive and accessible marker to detect patients with diabetes at risk for developing CAN.

Sympathetic Overactivity and Parasympathetic Impairment in Type 2 Diabetes: An Analysis of Cardiovascular Autonomic Functions

Background Cardiovascular autonomic dysregulation is a known complication of Type 2 diabetes mellitus (T2DM), characterized by dysregulation in heart rate (HR) and blood pressure (BP). These disruptions in cardiovascular autonomic control can significantly influence the morbidity and mortality associated with the disease. Objectives This study aims to investigate how T2DM affects cardiovascular autonomic functions by comparing responses in HR, BP, and specific autonomic function tests between a control group without diabetes and a study group with diabetes. The research questions focus on assessing HR variability, baroreflex sensitivity, and other autonomic parameters to determine the extent of cardiovascular autonomic dysregulation in diabetic patients.  Methods This cross-sectional study involved 200 adults, divided equally between a control group (n = 100) and a T2DM study group (n = 100). The exclusion criteria included cardiovascular diseases and renal impairment. Data collection involved assessing baseline characteristics such as age and BMI. Cardiovascular measures, including HR, systolic blood pressure (SBP), and diastolic blood pressure (DBP), were recorded after a five-minute rest. Autonomic function tests assessed sympathetic and parasympathetic responses, including the cold pressor test and the isometric hand grip exercise test. The statistical analysis was conducted using IBM SPSS Statistics for Windows, Version 25 (Released 2017; IBM Corp., Armonk, New York, United States), focusing on independent t-tests to compare between groups, considering p-values <0.05 as significant. Potential confounding variables like age and BMI were accounted for in the analysis to ensure robust findings  Results The study group showed a higher average BMI (28.95 ± 5.60) compared to the control group (26.50 ± 5.70) and an increased resting HR (74.20 ± 8.60 bpm vs. 69.30 ± 9.10 bpm). The SBP was slightly higher in the study group (115.00 ± 19.00 mmHg vs. 114.50 ± 8.90 mmHg), while the DBP was lower (71.50 ± 10.70 mmHg vs. 72.80 ± 6.70 mmHg). The autonomic function tests showed a smaller increase in SBP (106.80 ± 11.00 mmHg) and a larger increase in DBP (75.90 ± 8.30 mmHg) upon standing in the study group compared to controls. The cold pressor test indicated increased sympathetic activity in the study group, with significant rises in SBP (133.70 ± 10.30 mmHg) and DBP (83.40 ± 9.00 mmHg) compared to the control group (SBP: 114.31 ± 11.87 mmHg, DBP: 71.85 ± 8.67 mmHg). These findings demonstrate marked differences in cardiovascular autonomic responses between the groups. Conclusions This study demonstrates that T2DM significantly impacts cardiovascular autonomic functions, with diabetic patients showing altered HR and BP indicative of increased sympathetic and decreased parasympathetic activity. These autonomic dysfunctions may heighten cardiovascular risk in diabetic individuals. Our findings highlight the importance of monitoring and managing cardiovascular autonomic functions in diabetic patients to reduce their risk of cardiovascular complications. Further research should investigate the underlying mechanisms and the effectiveness of interventions to improve autonomic function in this population.

Relationship between ultra-short heart rate variability and short-term mortality in hospitalized COVID-19 patients

OBJECTIVE

To assess the association between ultra-short heart rate variability (US-HRV) and short-term mortality in patients with COVID-19 and develop prognostic prediction models to identify high-risk patients as early as possible.

METHODS

A retrospective cohort study was performed on 488 patients diagnosed with COVID-19 and hospitalized in the First Affiliated Hospital of Fujian Medical University from December 2022 to January 2023. 10-s electrocardiogram (ECG) data were available for these patients. The US-HRV parameters including standard deviation of all normal-to-normal R-R intervals (SDNN) and root mean square of successive differences between normal-to-normal R-R intervals (rMSSD) were calculated using Nalong ECG software. The endpoint was short-term mortality, including in-hospital mortality or mortality within 1 week after discharge.

RESULTS

Of the 488 patients, 76 (15.6%) died. The SDNN and rMSSD in the death group were significantly lower than those in the survival group (P < 0.001). The area under the receiver operating characteristic (ROC) curve (AUC) for SDNN and rMSSD to predict mortality was 0.761 and 0.715, respectively. The combined use of SDNN and rMSSD had an AUC of 0.774. The mortality rate in the group with SDNN ≤7.5 ms was higher than that of SDNN >7.5 ms group (P < 0.05). With the decrease of SDNN, the mortality of patients showed an upward trend, and the mortality of patients with SDNN ≤2 ms was the highest (66.7%). Multivariate logistic regression analysis identified SDNN as an independent predictor of prognosis (odds ratio (OR) = 5.791, 95% confidential interval (CI) 1.615-20.765, P = 0.007). The AUC of Model 1 (simple model) was 0.866 (95% CI 0.826-0.905). The AUC of Model 2 (comprehensive model) was 0.914 (95% CI 0.881-0.947).

CONCLUSION

SDNN was associated with short-term mortality and provided the additional discriminatory power of the risk stratification model for hospitalized COVID-19 patients.

A Bibliometric Analysis of Study of Associations of Certain Genotypes with the Cardiovascular Form of Diabetic Neuropathy

This bibliometric analysis explores the landscape of research on the associations between specific genotypes and the cardiovascular form of diabetic neuropathy. Diabetes mellitus (DM) is a major contributor to premature mortality, primarily due to increased susceptibility to cardiovascular diseases. The global prevalence of DM is rising, with projections indicating further increases. Diabetic neuropathy, a complication of DM, includes the cardiovascular subtype, posing challenges in diagnosis and management. Understanding the genetic basis of cardiovascular diabetic neuropathy is crucial for targeted therapeutic interventions. The study utilizes bibliometric analysis to synthesize existing literature, identify trends, and guide future research. The Scopus database was searched, applying inclusion criteria for English articles related to genotypes and cardiovascular diabetic neuropathy. The analysis reveals a dynamic field with a notable impact, collaborative efforts, and multidimensional aspects. Publication trends over 1997-2023 demonstrate fluctuating research intensity. Top journals, authors, and affiliations are highlighted, emphasizing global contributions. Keyword analysis reveals thematic trends, and citation analysis identifies influential documents. Limitations include database biases, incomplete metadata, and search query specificity. The urgent need to explore genetic factors in cardiovascular diabetic neuropathy aligns with the increasing global diabetes burden. This analysis provides a comprehensive overview, contributing to the broader discourse on diabetic neuropathy research.

Clinical Implications of Diabetic Peripheral Neuropathy in Primary Infrapopliteal Angioplasty Approach for Neuro-Ischemic Foot Wounds

BACKGROUND

To assess the clinical effects of diabetic peripheral neuropathy (DPN) in patients with chronic limb-threatening ischemia (CLTI) treated by primary infrapopliteal angioplasty for neuro-ischemic Rutherford 5, foot wounds.

MATERIALS AND METHODS

Over a 10-year period (2009-2019), a series of 304 diabetic ischemic limbs adding or not evincible neuropathic affectation were treated by primary infrapopliteal angioplasty and their files were retrospectively reviewed. Mean length of treated arterial lesions was 6.1 cm (range 1-22 cm). Inferior limb vibration perception threshold diagnostic was performed for comparing and scoring detectable DPN in all studied diabetic patients (classed from 0 to 10 points). There were 19% limbs with normal (0-1 points) perception (group 1), 55% others with "mild" and "moderate" (2-6 points) neuropathic impairment (group 2), and 26% limbs showing "severe" (7-10 points) DPN (group 3).

RESULTS

Primary infrapopliteal angioplasty succeeded in 89% cases in group 1, in 82% in group 2, and in 68% of limbs in group 3. This latest group assembled the heaviest neuropathic affectation and arterial calcifications and proved the lowest clinical benefit at 36 months: 35% (95% confidence interval [CI]=22% to 48%) of primary patency, 36% (95% CI=22% to 50%) wound healing, and 54% (95% CI=39% to 69%) limb preservation rates. A comparison between groups 1 vs 3 and 2 vs 3 of primary patency (p=0.014 and p=0.043), tissue healing (p=0.049 and p=0.01), and limb salvage (p=0.006 and p=0.023) proved significant, yet without statistical weight for group 1 vs 2 (p>0.05). Overall survival was not significantly affected between groups (p=0.34).

CONCLUSION

The presence of severe DPN may jeopardize the results of infrapopliteal angioplasty in terms of patency, tissue cicatrization, and limb preservation, yet without significance on survival of these patients. When present, DPN requires appropriate stratification as specific indicator in CLTI treatment.

Silent Myocardial Ischemia Revisited, Another Silent Killer, Emphasis on the Diagnostic Value of Stress Echocardiography with Focused Update and Review

Silent myocardial ischemia (SMI) is a relatively common phenomenon in patients with coronary artery disease (CAD). The original description of SMI dates back to the 1970s. We performed an extensive search of the literature starting from 2000, using MEDLINE or PubMed, and 676 documents were analyzed, and only 45 articles found suitable for the study were selected. Data regarding the prevalence and risk factors of SMI were discussed, along with the different mechanistic processes behind it; also, methods for screening and diagnosis are exposed, namely electrocardiographic stress test, stress echocardiography, and single-photon emission computed tomography (SPECT). The silent nature of the condition presumes that patients are diagnosed at a more advanced stage, and screening high-risk patients for early management is essential. Education of patients is necessary, and medical management along with cardiac rehabilitation is valid for mild cases, whereas patients with moderate-to-severe myocardial ischemia might require a more invasive approach. SMI is relatively common, diagnostic approach offers data regarding the presence of ischemia along with its anatomic extent, providing important prognostic value. Given its silent and critical nature, future directions for better screening and management must be searched and implemented extensively.

Comparison of western diet-induced obesity and streptozotocin mouse models: insights into energy balance, somatosensory dysfunction, and cardiac autonomic neuropathy

Metabolic disorders such as obesity and type 2 diabetes (T2D) are increasingly prevalent worldwide, necessitating a deeper comprehension of their underlying mechanisms. However, translating findings from animal research to human patients remains challenging. This study aimed to investigate the long-term effects of Streptozotocin (STZ) on metabolic, cardiac, and somatosensory function in mice fed a Western diet (WD) of high fat, sucrose, and cholesterol with low doses of STZ administration compared to mice fed WD alone. In our research, we thoroughly characterized energy balance and glucose homeostasis, as well as allodynia and cardiac function, all of which have been previously shown to be altered by WD feeding. Notably, our findings revealed that the treatment of WD-fed mice with STZ exacerbated dysfunction in glucose homeostasis via reduced insulin secretion in addition to impaired peripheral insulin signaling. Furthermore, both WD and WD + STZ mice exhibited the same degree of cardiac autonomic neuropathy, such as reduced heart rate variability and decreased protein levels of cardiac autonomic markers. Furthermore, both groups developed the same symptoms of neuropathic pain, accompanied by elevated levels of activating transcription factor 3 (Atf3) in the dorsal root ganglia. These discoveries enhance our understanding of metabolic activity, insulin resistance, neuropathy, and cardiac dysfunction of diet-induced models of obesity and diabetes. The exacerbation of impaired insulin signaling pathways by STZ did not lead to or worsen cardiac and somatosensory dysfunction. Additionally, they offer valuable insights into suitable diet induced translational mouse models, thereby advancing the development of potential interventions for associated conditions.

Diabetic Neuropathies

OBJECTIVE

This article provides an up-to-date review of the diagnosis and management of the most common neuropathies that occur in patients with diabetes.

LATEST DEVELOPMENTS

The prevalence of diabetes continues to grow worldwide and, as a result, the burden of diabetic neuropathies is also increasing. Most diabetic neuropathies are caused by hyperglycemic effects on small and large fiber nerves, and glycemic control in individuals with type 1 diabetes reduces neuropathy prevalence. However, among people with type 2 diabetes, additional factors, particularly metabolic syndrome components, play a role and should be addressed. Although length-dependent distal symmetric polyneuropathy is the most common form of neuropathy, autonomic syndromes, particularly cardiovascular autonomic neuropathy, are associated with increased mortality, whereas lumbosacral radiculoplexus neuropathy and treatment-induced neuropathy cause substantial morbidity. Recent evidence-based guidelines have updated the recommended treatment options to manage pain associated with distal symmetric polyneuropathy of diabetes.

ESSENTIAL POINTS

Identifying and appropriately diagnosing the neuropathies of diabetes is key to preventing progression. Until better disease-modifying therapies are identified, management remains focused on diabetes and metabolic risk factor control and pain management.

A High intensity Interval training (running and swimming) and resistance training intervention on heart rate variability and the selected biochemical factors in boys with type 1 diabetes

OBJECTIVE

The purpose of this research is to investigate the effect of High Intensity Interval Training and Resistance training (HIITR) on heart rate variability (HRV), blood glucose, and plasma biomarkers levels in adolescents with type 1 diabetes (T1D).

RESEARCH DESIGN AND METHODS

24 boys with T1D (FBS: 274.66 ± 52.99, age: 15.2 ± 1.78 years, and BMI = 19.61 ± 1.11) and 12 healthy boys (FBS: 92.75 ± 5.22, age: 15.08 ± 1.67 years, and BMI = 20.26 ± 2.66) were divided into three groups: Diabetes Training (DT, n = 12), Diabetes Control (DC, n = 12), and Healthy Control (HC, n = 12). HRV (24 h) was computed in time and frequency domains, anthropometric, biochemical parameters at rest, and aerobic capacity (VO2peak) obtained during a graded exercise testing (GXT). All variables were evaluated at the baseline and following 12 weeks of exercise training, done 3 days weekly. The statistical method used for data analysis was analysis of covariance (ANCOVA) test.

RESULTS

HRV, Hemoglobin A1c (HbA1c) and Fasting blood sugar (FBS), VO2peak, norepinephrine (NEP), and HDL-C indicated significant differences between both T1D groups compared to HC at baseline (p < 0.001). BMI, LDL-C, TC, and TG parameters were similar in all groups. HRV parameters, VO2peak and HDL-C, and NEP were significantly improved by exercise training, and HbA1c and FBS levels were significantly reduced (p < 0.001). There is a negative and significant correlation between LF/HF Ratio Difference (post-test minus pre-test) and VO2Peak Difference variables (post-test minus pre-test) (p < 0.001).

CONCLUSIONS

The present study suggests the importance of early screening for CVD risk factors in adolescent males with T1D. Also, it was revealed HIITR training compared to other training patterns, and cardiovascular health improves via enhancement of autonomic modulation, VO2peak, plasma lipids, and catecholamine levels.

Chest pain symptoms during myocardial infarction in patients with and without diabetes: a systematic review and meta-analysis

OBJECTIVE

Chest pain (CP) is key in diagnosing myocardial infarction (MI). Patients with diabetes mellitus (DM) are at increased risk of an MI but may experience less CP, leading to delayed treatment and worse outcomes. We compared the prevalence of CP in those with and without DM who had an MI.

METHODS

The study population was people with MI presenting to healthcare services. The outcome measure was the absence of CP during MI, comparing those with and without DM. Medline and Embase databases were searched to 18 October 2021, identifying 9272 records. After initial independent screening, 87 reports were assessed for eligibility against the inclusion criteria, quality and risk of bias assessment (Strengthening the Reporting of Observational Studies in Epidemiology and Newcastle-Ottawa criteria), leaving 22 studies. The meta-analysis followed Meta-analysis Of Observational Studies in Epidemiology criteria and reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Pooled ORs, weights and 95% CIs were calculated using a random-effects model.

RESULTS

This meta-analysis included 232 519 participants from 22 studies and showed an increased likelihood of no CP during an MI for those with DM, compared with those without. This was 43% higher in patients with DM in the cohort and cross-sectional studies (OR: 1.43; 95% CI: 1.26 to 1.62), and 44% higher in case-control studies (OR: 1.44; 95% CI: 1.11 to 1.87).

CONCLUSION

In patients with an MI, patients with DM are less likely than those without to have presentations with CP recorded. Clinicians should consider an MI diagnosis when patients with DM present with atypical symptoms and treatment protocols should reflect this, alongside an increased patient awareness on this issue.

PROSPERO REGISTRATION NUMBER

CRD42017058223.

Cardiac innervations in diabetes mellitus-Anatomical evidence of neuropathy

The extensive innervations of the heart include a complex network of sympathetic, parasympathetic, and sensory nerves connected in loops that serve to regulate cardiac output. Metabolic dysfunction in diabetes affects many different organ systems, including the cardiovascular system; it causes cardiac arrhythmias, silent myocardial ischemia, and sudden cardiac death, among others. These conditions are associated with damage to the nerves that innervate the heart, cardiac autonomic neuropathy (CAN), which is caused by various pathophysiological mechanisms. In this review, the main facts about the anatomy of cardiac innervations and the current knowledge of CAN, its pathophysiological mechanisms, and its diagnostic approach are discussed. In addition, anatomical evidence for CAN from human and animal studies has been summarized.

The Role of Echocardiography in Evaluating Cardiovascular Diseases in Patients with Diabetes Mellitus

Patients with diabetes mellitus are highly susceptible to cardiovascular complications, which are directly correlated with cardiovascular morbidity and mortality. In addition to coronary artery disease, there is growing awareness of the risk and prevalence of heart failure (HF) in patients with diabetes. Echocardiography is an essential diagnostic modality commonly performed in patients with symptoms suggestive of cardiovascular diseases (CVD), such as dyspnea or chest pain, to establish or rule out the cause of symptoms. Conventional echocardiographic parameters, such as left ventricular ejection fraction, are helpful not only for diagnosing CVD but also for determining severity, treatment strategy, prognosis, and response to treatment. Echocardiographic myocardial strain, a novel echocardiographic technique, enables the detection of early changes in ventricular dysfunction before HF symptoms develop. This article aims to review the role of echocardiography in evaluating CVD in patients with diabetes mellitus and how to use it in patients with suspected cardiac diseases.

Polyneuropathy Associated with Age of Starting the Transfusion and Serum Ferritin Level in Iranian Patients with Thalassemia Major and Intermedia

Considering the importance of managing patients with β-thalassemia and the importance of early detection of disease complications, we examined the rate of sensorimotor neuropathy in patients with β-thalassemia and the risk factors related to it. This cross-sectional study included 44 blood transfusion-dependent β-thalassemia patients aged 5 years and older. Nerve conduction studies (NCSs) were performed via standard procedures for both motor and sensory nerves. Neuropathy was observed in 14 patients (31.8%). NCS results for sensorimotor nerves in patients were within normal range. In motor NCS results, increased ulnar nerve amplitude was observed in patients with increasing age, and peroneal nerve delay in patients with an increase in serum ferritin level (p < 0.05). In sensory NCS results, delayed ulnar and sural nerves latencies were found in patients with an increase in serum ferritin level (p < 0.05). We provide data that sensorimotor neuropathy exists in thalassemia patients. It seems that with the increase of serum ferritin level and the age of patients, neuropathy becomes more obvious, while other factors such as gender, body mass index, and the number of transfusions may not be associated with neuropathy.

A Comparative Cross-Sectional Study of Cardiac Autonomic Status by Five Minute Heart Rate Variability among Type 2 Diabetics, Hypertensives and Normotensive-Nondiabetics

Background

Diabetes and hypertension are known to co-exist frequently as adverse cardiovascular risk factors. Both can produce cardiac autonomic neuropathythat can be measured by ECG RR interval-based heart rate variability (HRV). We compared 5 minutes HRV in four groups based on diabetes and hypertension.

Methodology

A cross sectional study was done on 203 participants divided into four groups- diabetics, hypertensives, diabetic-hypertensives and normotensive-nondiabetics. They were evaluated for current disease control and five minutes HRV was done in supine condition following standard protocols by Variowin HR Software. HRV parameters of time domain, frequency domain and Poincare plot were compared between groups and associated with gender, glycaemic control and blood pressure control. Statistical significance was set at p<0.05.

Results

Three diseasedgroups had mean age in mid-fifties, mean duration of disease > 6 years, comparable BMI, poor glycaemic and blood pressure control. As compared to normal groups, three diseased groups exhibit reduced HRV with respect to all three domains of HRV with varying statistical significance. Among diseased groups, HRV was associated with blood pressure control better than glycaemic control but not with gender. LF /HF ratio was the most consistent HRV parameter showing statistical significance in tests.

Conclusion

HRV is reduced in both diabetics more than hypertensives; related to blood pressure control more than glycaemic control. It points altered cardiac autonomic balance, and possibility of cardiovascular risk and early detection of it with timely intervention. It also calls for investigation of same for reinforcement of our observations and further exploration.

Sex differences and sex steroids influence on the presentation and severity of cardiovascular autonomic neuropathy of patients with type 1 diabetes

BACKGROUND

Sex differences characterize cardiovascular outcomes in patients with type 1 diabetes. Cardioautonomic neuropathy is a common complication of type 1 diabetes that associates increased morbi-mortality. Data regarding the interplay between sex and cardiovascular autonomic neuropathy are scarce and controversial in these patients. We aimed to address sex-related differences in the prevalence of seemingly asymptomatic cardioautonomic neuropathy in type 1 diabetes, and their associations with sex steroids.

METHODS

We conducted a cross-sectional study including 322 consecutively recruited patients with type 1 diabetes. Cardioautonomic neuropathy was diagnosed using Ewing's score and power spectral heart rate data. We assessed sex hormones by liquid chromatography/tandem mass spectrometry.

RESULTS

When considering all subjects as a whole, asymptomatic cardioautonomic neuropathy prevalence was not significantly different between women and men. When age was taken into account, the prevalence of cardioautonomic neuropathy was similar among young men and those > 50 years. However, in women > 50 years, the prevalence of cardioautonomic neuropathy doubled that of young women [45.8% (32.6; 59.7) vs. 20.4% (13.7; 29.2), respectively]. The OR of having cardioautonomic neuropathy was 3.3 higher in women > 50 years than in their younger counterparts. Furthermore, women presented more severe cardioautonomic neuropathy than men. These differences were even more marked when women were classified according their menopausal status instead of age. Peri- and menopausal women had an OR 3.5 (1.7; 7.2) of having CAN compared with their reproductive-aged counterparts [CAN prevalence: 51% (37; 65) vs. 23% (16; 32), respectively]. A binary logistic regression model (R²: 0.161; P = 0.001) displayed age > 50 years as a significant determinant of cardioautonomic neuropathy only in women. Androgens were positively associated with heart rate variability in men, and negatively in women. Accordingly, cardioautonomic neuropathy was associated with increased testosterone/estradiol ratio in women but to decreased testosterone concentrations in men.

CONCLUSIONS

Menopause in women with type 1 diabetes is accompanied by an increase in the prevalence of asymptomatic cardioautonomic neuropathy. This age-related excess risk of cardioautonomic neuropathy is not observed in men. Men and women with type 1 diabetes have opposite associations between circulating androgens and indexes of cardioautonomic function. Trial registration ClinicalTrials.gov Identifier: NCT04950634.

Diabetes Mellitus and Heart Failure: Epidemiology, Pathophysiologic Mechanisms, and the Role of SGLT2 Inhibitors

Diabetes mellitus (DM) and heart failure (HF) are frequently encountered afflictions that are linked by a common pathophysiologic background. According to landmark studies, those conditions frequently coexist, and this interaction represents a poor prognostic indicator. Based on mechanistic studies, HF can be propagated by multiple pathophysiologic pathways, such as inflammation, oxidative stress, endothelial dysfunction, fibrosis, cardiac autonomic neuropathy, and alterations in substrate utilization. In this regard, DM may augment myocardial inflammation, fibrosis, autonomic dysfunction, and lipotoxicity. As the interaction between DM and HF appears critical, the new cornerstone in DM and HF treatment, sodium-glucose cotransporter-2 inhibitors (SGLT2i), may be able to revert the pathophysiology of those conditions and lead to beneficial HF outcomes. In this review, we aim to highlight the deleterious pathophysiologic interaction between DM and HF, as well as demonstrate the beneficial role of SGLT2i in this field.

Renal Sympathetic Hyperactivity in Diabetes Is Modulated by 5-HT1D Receptor Activation via NO Pathway

Renal vasculature, which is highly innervated by sympathetic fibers, contributes to cardiovascular homeostasis. This renal sympathetic outflow is inhibited by 5-HT in normoglycaemic rats. Considering that diabetes induces cardiovascular complications, we aimed to determine whether diabetic state modifies noradrenergic input at renal level and its serotonergic modulation in rats. Alloxan diabetic rats were anaesthetized (pentobarbital; 60 mg/kg i.p.) and prepared for in situ autoperfusion of the left kidney to continuously measure systemic blood pressure (SBP), heart rate (HR), and renal perfusion pressure (RPP). Electrical stimulation of renal sympathetic outflow induces frequency-dependent increases (Δ) in RPP (23.9 ± 2.1, 59.5 ± 1.9, and 80.5 ± 3.5 mm Hg at 2, 4, and 6 Hz, respectively), which were higher than in normoglycaemic rats, without modifying HR or SBP. Intraarterial bolus of 5-HT and 5-CT (5-HT_1/5/7 agonist) reduced electrically induced ΔRPP. Only L-694,247 (5-HT_1D agonist) reproduced 5-CT inhibition on sympathetic-induced vasoconstrictions, whereas it did not modify exogenous noradrenaline-induced ΔRPP. 5-CT inhibition was exclusively abolished by i.v. bolus of LY310762 (5-HT_1D antagonist). An inhibitor of guanylyl cyclase, ODQ (i.v.), completely reversed the L-694,247 inhibitory effect. In conclusion, diabetes induces an enhancement in sympathetic-induced vasopressor responses at the renal level. Prejunctional 5-HT_1D receptors, via the nitric oxide pathway, inhibit noradrenergic-induced vasoconstrictions in diabetic rats.

Home-based exercise program in the indeterminate form of Chagas disease (PEDI-CHAGAS study): A study protocol for a randomized clinical trial

Background

Chagas disease (CD) is a neglected endemic disease with worldwide impact due to migration. Approximately 50-70% of individuals in the chronic phase of CD present the indeterminate form, characterized by parasitological and/or serological evidence of Trypanosoma cruzi infection, but without clinical signs and symptoms. Subclinical abnormalities have been reported in indeterminate form of CD, including pro-inflammatory states and alterations in cardiac function, biomarkers and autonomic modulation. Moreover, individuals with CD are usually impacted on their personal and professional life, making social insertion difficult and impacting their mental health and quality of life (QoL). Physical exercise has been acknowledged as an important strategy to prevent and control numerous chronic-degenerative diseases, but unexplored in individuals with the indeterminate form of CD. The PEDI-CHAGAS study (which stands for "Home-Based Exercise Program in the Indeterminate Form of Chagas Disease" in Portuguese) aims to evaluate the effects of a home-based exercise program on physical and mental health outcomes in individuals with indeterminate form of CD.

Methods and design

The PEDI-CHAGAS is a two-arm (exercise and control) phase 3 superiority randomized clinical trial including patients with indeterminate form of CD. The exclusion criteria are <18 years old, evidence of non-Chagasic cardiomyopathy, musculoskeletal or cognitive limitations that preclude the realization of exercise protocol, clinical contraindication for regular exercise, and regular physical exercise (≥1 × per week). Participants will be assessed at baseline, and after three and 6 months of follow-up. The primary outcome will be QoL. Secondary outcomes will include blood pressure, physical fitness components, nutritional status, fatigability, autonomic modulation, cardiac morphology and function, low back pain, depression and anxiety, stress, sleep quality, medication use and adherence, and biochemical, inflammatory and cardiac biomarkers. Participants in the intervention group will undergo a home-based exercise program whilst those in the control group will receive only general information regarding the benefits of physical activity. Both groups will receive the same general nutritional counseling consisting of general orientations about healthy diets.

Conclusion

The findings from the present study may support public health intervention strategies to improve physical and mental health parameters to be implemented more effectively in this population.

Clinical trial registration

[https://ensaiosclinicos.gov.br/rg/RBR-10yxgcr9/], identifier [U1111-1263-0153].

Point-of-care sural nerve conduction could predict the presence of cardiovascular autonomic neuropathy in type 1 diabetes mellitus

AIMS

Assessment for cardiovascular autonomic neuropathy (CAN) in patients with type 1 diabetes mellitus remains time-consuming in the clinical setting. We aimed to examine the diagnostic performance of a portable point-of-care diagnostic tool (POCD) for assessing sural nerve conduction during the screening of CAN.

METHODS

Nerve amplitude (AMPPOCD ) and conduction velocity (CVPOCD ) were measured in a cross-sectional study including 198 asymptomatic patients with type 1 diabetes. CAN was diagnosed by the Ewing score and power spectral heart rate [low-frequency (LF) and high-frequency (HF) activity]. Diagnostic accuracy was determined by ROC curves.

RESULTS

CVPOCD and AMPPOCD showed positive correlations with LF and HF, and a negative correlation with age. Overall, AMPPOCD had an 81.7% accuracy in identifying CAN [AUC = 0.817 (95% CI 0.692-0.942)] with an AMPPOCD  ≤6 μV showing 90% sensitivity and 73% specificity. In a stepwise binary logistic regression analysis, the model (R2 : 0.297; P < 0.001) retained the duration of type 1 diabetes [β: 1.131 (95% CI: 1.051-1.216); P = 0.001) and A1c [β: 2.131 (95% CI: 1.060-4.283); P = 0.034) as significant predictors of CAN. The combination of AMPPOCD  ≤6 μV + a type 1 diabetes duration of ≥8 years maximized the sensitivity, showing a diagnostic performance of 87% [AUC = 0.867 (95% CI 0.769-0.965)] with 90%, 76%, and 99%, sensitivity, specificity, and NPV, respectively. Adding A1c  ≥ 7% to this model maintained accuracy [AUC = 0.867 (95% CI: 0.788-0.963) and NPV (99%), while increasing specificity to 84%.

CONCLUSIONS

The combination of AMPPOCD with A1c and the duration of type 1 diabetes mellitus showed a good performance for the detection of asymptomatic CAN, making POCD an easy and rapid test for its routine screening in the clinical setting.

Age and Disease Duration Independent Cardiac Autonomic Neuropathy in Patients with Diabetic Foot Complications: Case-Control Study

INTRODUCTION

Cardiac autonomic neuropathy (CAN) in people with diabetes is associated with high mortality. We aimed to study age and disease duration, independent prevalence of CAN in people with diabetic foot complications.

METHODS

530 patients with diabetes were screened to undergo CAN assessment (automated CANS-analyser). CAN was defined as "early", "definite," or "severe" according to the Toronto consensus. History pertaining to autonomic symptoms, prior cardiovascular events (CVE), and assessment for peripheral neuropathy was done. Participants were grouped into those with diabetic foot complication (group A, n = 82) [Charcot foot (n = 42), diabetic foot ulcer (n = 40)]; with DPN without foot complications (group B, n = 82); and without DPN or foot complications (group C, n = 82).

RESULTS

Symptoms of autonomic dysfunction were prominent in people with foot complications than the other groups. Resting heart rate was significantly greater in those with foot complications [99.89 ± 26.71 (group A) vs. 86.99 ± 22.24 (group B) vs. 88.32 ± 17.08 (group C); P = 0.001]. The prevalence of CAN was 75.6% in group A (51.2% early, 12.2% definite, 12.2% severe), 57.2% in group B (45.1% early, 12.2% severe) and 58.5% in group C (43.9% early, 1.2% definite, 13.4% severe) (P = 0.002). Patients with foot complications were more likely to have CAN (75.6% vs. 57.9%, P < 0.001). Charcot foot had higher prevalence of CAN (78.6%) as compared with those with DFU (72.5%) or without DFU or DPN (57.9%), P < 0.001.

CONCLUSION

CAN is present in more than two-third of patients with diabetes and foot complications with highest prevalence in Charcot neuroarthropathy.

Fluoxetine Treatment Decreases Cardiac Vagal Input and Alters the Serotonergic Modulation of the Parasympathetic Outflow in Diabetic Rats

Comorbid diabetes and depression constitutes a major health problem, worsening associated cardiovascular diseases. Fluoxetine's (antidepressant) role on cardiac diabetic complications remains unknown. We determined whether fluoxetine modifies cardiac vagal input and its serotonergic modulation in male Wistar diabetic rats. Diabetes was induced by alloxan and maintained for 28 days. Fluoxetine was administered the last 14 days (10 mg/kg/day; p.o). Bradycardia was obtained by vagal stimulation (3, 6 and 9 Hz) or i.v. acetylcholine administrations (1, 5 and 10 μg/kg). Fluoxetine treatment diminished vagally-induced bradycardia. Administration of 5-HT originated a dual action on the bradycardia, augmenting it at low doses and diminishing it at high doses, reproduced by 5-CT (5-HT_1/7 agonist). 5-CT did not alter the bradycardia induced by exogenous acetylcholine. Decrease of the vagally-induced bradycardia evoked by high doses of 5-HT and 5-CT was reproduced by L-694,247 (5-HT_1D agonist) and blocked by prior administration of LY310762 (5-HT_1D antagonist). Enhancement of the electrical-induced bradycardia by 5-CT (10 μg/kg) was abolished by pretreatment with SB269970 (5-HT₇ receptor antagonist). Thus, oral fluoxetine treatment originates a decrease in cardiac cholinergic activity and changes 5-HT modulation of bradycardic responses in diabetes: prejunctional 5-HT₇ receptors augment cholinergic-evoked bradycardic responses, whereas prejunctional 5-HT_1D receptors inhibit vagally-induced bradycardia.

Diabetes modulation of the myocardial infarction- acute kidney injury axis

Since there is crosstalk in functions of the heart and kidney, acute or chronic injury in one of the two organs provokes adaptive and/or maladaptive responses in both organs, leading to cardiorenal syndrome (CRS). Acute kidney injury (AKI) induced by acute heart failure is referred to as type 1 CRS, and a frequent cause of this type of CRS is acute myocardial infarction (AMI). Diabetes mellitus increases the risk of AMI and also the risk of AKI of various causes. However, there have been only a few studies in which animal models of diabetes were used to examine how diabetes modulates AMI-induced AKI. In this review, we summarize findings regarding the mechanisms of type 1 CRS and the impact of diabetes on both AMI and renal susceptibility to AKI and we discuss mechanisms by which diabetes modulates AMI-induced AKI. Hemodynamic alterations induced by AMI could be augmented by diabetes via its detrimental effect on infarct size and contractile function of the non-infarcted region in the heart. Diabetes increases susceptibility of renal cells to hypoxia and oxidative stress by modulation of signaling pathways that regulate cell survival and autophagy. Recent studies have shown that diabetes mellitus even at early stage of cardiomyopathy/nephropathy predisposes the kidney to AMI-induced AKI, in which activation of toll-like receptors and reactive oxygen species derived from NADPH oxidases are involved. Further analysis of crosstalk between diabetic cardiomyopathy and diabetic kidney disease is necessary for obtaining a more comprehensive understanding of modulation of the AMI-AKI axis by diabetes.