Diabetic cardiovascular autonomic neuropathy

Corneal confocal microscopy identifies early and definite diabetic cardiac autonomic neuropathy

OBJECTIVE

Advanced cardiac autonomic neuropathy (CAN) is associated with increased mortality in people with diabetes. Early identification and reduction of risk factors can limit the progression of CAN. However, the diagnosis of early CAN relies on cardiac autonomic reflex testing (CART's) which is not widely available. We have compared the diagnostic utility of corneal confocal microscopy (CCM) to CART's in diagnosing CAN.

RESEARCH DESIGN AND METHODS

Two-hundred and thirty eight individuals with type 1 and type 2 diabetes and thirty seven healthy controls were assessed using CARTs and CCM.

RESULTS

There was a progressive and significant reduction in DB-HRV, E:I ratio, 30:15 ratio, corneal nerve fibre density (CNFD), corneal nerve branch density (CNBD) and corneal nerve fibre length (CNFL) with increasing severity of CAN. The receiver operating characteristic (ROC) area under the curve (AUC) and sensitivity/specificity of CCM were comparable to those of CARTs for identifying early and definite CAN.

CONCLUSION

CCM is a rapid, non-invasive ophthalmic test which could be used to detect early and established CAN.

The effects of SGLT2i on cardiac metabolism in patients with HFpEF: Fact or fiction?

The rising prevalence of Type 2 diabetes (T2D) has been closely associated with an increased incidence of cardiovascular diseases, particularly heart failure with preserved ejection fraction (HFpEF). Cardiometabolic disturbances in T2D, such as insulin resistance, hyperglycemia, and dyslipidemia, contribute to both microvascular and macrovascular complications, thereby intensifying the risk of heart failure. Sodium-glucose cotransporter-2 inhibitors (SGLT2i), initially developed as glucose-lowering agents for T2D, have demonstrated promising cardiovascular benefits in patients with heart failure, including those with preserved ejection fraction (HFpEF), regardless of T2D status. These benefits include reduced heart failure hospitalization rates and improvements in various metabolic parameters. This review aims to critically examine the effects of SGLT2i on cardiac metabolism in HFpEF, evaluating whether the observed benefits can truly be attributed to their impact on myocardial energy regulation or whether they represent other, potentially confounding, mechanisms. We will focus on the key metabolic processes possibly modulated by SGLT2i, including myocardial glucose utilization, fatty acid oxidation, and mitochondrial function, and explore their effects on heart failure pathophysiology. Additionally, we will address the role of SGLT2i in other pathogenetic factors involved in HFpEF, such as sodium and fluid balance, inflammation, and fibrosis, and question the extent to which these mechanisms contribute to the observed clinical benefits. By synthesizing the current evidence, this review will provide an in-depth analysis of the mechanisms through which SGLT2i may influence cardiac metabolism in HFpEF, assessing whether their effects are supported by robust scientific data or remain speculative. We will also discuss the potential for personalized treatment strategies, based on individual patient characteristics, to optimize the therapeutic benefits of SGLT2i in managing both T2D and cardiovascular risk. This review seeks to clarify the true clinical utility of SGLT2i in the management of cardiometabolic diseases and HFpEF, offering insights into their role in improving long-term cardiovascular outcomes.

Intensive Glycemic Treatment Mitigates Cardiovascular and Mortality Risk Associated With Cardiac Autonomic Neuropathy in Type 2 Diabetes

BACKGROUND

Hyperglycemia is one of the proposed risk factors for cardiac autonomic neuropathy (CAN). CAN is associated with increased cardiovascular and mortality risk. But it remains unclear whether cardiovascular and mortality risk associated with CAN is mitigated by intensive glycemic treatment.

METHODS AND RESULTS

This secondary analysis included 7866 patients from the ACCORDION (Action to Control Cardiovascular Risk in Diabetes Follow-On) study. CAN was defined using ECG-derived measures. End points included primary outcome (composite of cardiovascular events) and total deaths. During a median follow-up of 8.9 years, a total of 1341 cardiovascular events and 1364 all-cause deaths were ascertained. Compared with standard treatment, intensive treatment reduced risk of primary outcome and total deaths among patients with CAN but not among those without CAN. Compared with absence of CAN, the presence of CAN was associated with increased risk of primary outcome and total deaths in the standard group but not in the intensive group. Significant interactions were found between CAN status and treatment arms on risk of primary outcome and total deaths. Incidence rates per 100 person-years of primary outcome and total deaths were similar between patients without CAN and those with CAN undergoing intensive treatment.

CONCLUSIONS

Intensive glycemic treatment mitigates cardiovascular and mortality risk associated with CAN and may serve as an effective way in the management of CAN.

SGLT-2 inhibitors on cardiac autonomic function in individuals with and without type 2 diabetes mellitus

Sodium-glucose cotransporter-2 (SGLT-2) inhibitors have emerged as key therapeutic agents in managing type 2 diabetes mellitus (T2DM) and obesity, offering benefits that extend beyond glycemic control. This review examines the role of SGLT-2 inhibitors in modulating cardiac autonomic function, with a particular focus on heart rate variability (HRV) as a biomarker of autonomic balance. These agents improve metabolic profiles through enhanced glucosuria, natriuresis, and weight loss, while concurrently reducing blood pressure. Importantly, they also attenuate sympathetic nervous system overactivity and promote parasympathetic modulation, which may lower the risk of adverse cardiovascular events. The underlying mechanisms include not only the metabolic effects but also anti-inflammatory and antioxidative actions, which together contribute to improved endothelial function and vascular health. Advanced HRV analyses, encompassing traditional time and frequency domain methods as well as nonlinear approaches, have proven valuable in detecting early autonomic dysfunction in high-risk populations. Some studies suggest that SGLT-2 inhibitors may be associated with improvements in HRV parameters, such as increased SDNN and RMSSD and a reduced LF/HF ratio. However, findings are inconsistent across studies, and further research is needed to determine the extent and mechanisms of these potential effects. Although these findings are promising, further standardized, long-term studies are essential to clarify the mechanisms and optimal therapeutic strategies involving SGLT-2 inhibitors in the management of autonomic dysfunction. Future research should also explore the synergistic potential of combining SGLT-2 inhibitors with other cardiometabolic therapies to enhance cardiovascular outcomes in individuals with and without T2DM.

Clinical implications of fracture severity risk with pioglitazone: a systematic review and meta-analysis of clinical randomized trials

Introduction

Pioglitazone, a thiazolidinedione, effectively reduces stroke and cardiovascular events in individuals with type 2 diabetes, insulin resistance, and/or stroke. However, its potential to increase fracture risk, particularly among women and those with pre-existing skeletal conditions, has not yet been completely understood. This meta-analysis aims to clarify fracture risk associated with pioglitazone, thereby focusing on individuals with a history of stroke.

Methods

A systematic review was performed for clinical trials conducted up to March 2024, focusing on trials comparing pioglitazone to placebo or other antihyperglycemic drugs that reported fracture outcomes.

Results

From 860 trials identified, 78 satisfied the inclusion criteria: 34 with a high risk of bias, 8 with unclear risk, and 36 with low risk. The meta-analysis revealed an association between pioglitazone and a significant increase in fracture risk (risk ratio [RR] 1.21; 95% CI 1.01-1.45; P = 0.04), including non-serious (RR 1.25; 95% CI 1.03-1.51; P = 0.02) and serious fractures (RR 1.48; 95% CI 1.10-1.98; P = 0.01). Notably, the risk was exacerbated for low-energy fractures, particularly resulting from falls (RR 1.49; 95% CI 1.20-1.87; P = 0.0004), in insulin resistance individuals (RR 0.87; 95% CI 0.43-1.76; P = 0.69), and stroke survivors (RR 1.41; 95% CI 1.09-1.83; P = 0.008). Fractures were most frequently observed in lower extremities (RR 1.85; 95% CI 1.33-2.56; P = 0.0002), with women at a greater risk (RR 1.56; 95% CI 1.20-2.02; P = 0.0008). When compared with other antihyperglycemic drugs, no significant difference in fracture risk was noted (RR 1.08; 95% CI 0.73-1.59; P = 0.70), except rosiglitazone, which showed higher fracture risk (RR 1.42; 95% CI 1.23-1.64; P < 0.00001). Fracture risk was significant in the fixed-effect model but not in the random-effects model.

Discussion

Though pioglitazone offers several cardiovascular benefits, its association with increased fracture risk, especially among women and non-diabetic individuals post-stroke, warrants careful consideration. Individualized treatment interventions balancing cardiovascular and skeletal outcomes are essential, and further research is needed to optimize therapeutic strategies in this population.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42016038242, identifier CRD42016038242.

Resolution of hypertension after kidney transplantation is associated with improved kidney transplant outcomes: a nationwide cohort study

OBJECTIVES

Patients with advanced chronic kidney disease suffer from hypertension, and kidney transplantation (KT) has potential to induce hypertension resolution. We hypothesized that hypertension resolution after KT is associated with better KT outcomes.

METHODS

We identified KT recipients (2006-2015) who had pretransplant hypertension. They were categorized into two groups based on their hypertension status after KT: persistent vs. resolved hypertension, using data from the Korea National Health Insurance System. Cox proportional hazard analyses were performed to assess the risk of graft failure and mortality, adjusting for various clinical factors.

RESULTS

Among 11 317 KT recipients with pretransplant hypertension, 7269 (64%) remained hypertensive, while 4048 (36%) experienced hypertension resolution. Recipients with resolved hypertension exhibited a lower prevalence of delayed graft function and major comorbidities, including diabetes, ischemic heart disease, and stroke. Graft failure and mortality rates were significantly lower in resolved hypertension group. After adjusting for multiple covariates, hazard ratios of resolved hypertension were 0.61 (95% confidence interval 0.52-0.72) for graft failure and 0.68 (0.56-0.81) for all-cause mortality.

CONCLUSIONS

A significant proportion of patients experienced hypertension resolution after KT, which is associated with improved graft and overall survival. The post-KT hypertension resolution can be used as a prognostic indicator for predicting better KT outcomes.

Prevalence and Prognostic Impact of Diabetes in Takotsubo Syndrome: Insights from the Tokyo Cardiovascular Care Unit Network Registry

Diabetes is a major risk factor for cardiovascular diseases. However, some reports have shown that diabetes has a low prevalence and is associated with favorable outcomes in takotsubo syndrome (TTS). This phenomenon, known as the "diabetes paradox," in which diabetes plays a protective role in the development of TTS, remains controversial. Therefore, we investigated the prevalence of diabetes and the prognostic impact of diabetes and glycemic control in patients with TTS. Using the Tokyo Cardiovascular Care Unit Network registry between 2015 and 2021, we identified 1,226 eligible patients with TTS (median age 77 years, male proportion 21%). The prevalence of diabetes, its clinical characteristics, and its association with in-hospital mortality were assessed. The prevalence of diabetes was 17.0% in TTS and 15.8% in the general population, with no significant difference (p = 0.445). Patients with diabetes were older and had higher body mass index, brain natriuretic peptide, and C-reactive protein levels than patients without diabetes. Patients with diabetes tended to have a higher in-hospital mortality rate than those without (6.3% vs 3.4%, p = 0.057). The multivariable analysis revealed that neither diabetes (odds ratio 1.83, 95% confidence interval 0.88 to 3.80, p = 0.106) nor hemoglobin A1c level was significantly associated with in-hospital mortality. In conclusion, diabetes is not uncommon and not a good prognostic factor in this multicenter registry. Our observations do not support a protective effect of diabetes on the emergence and outcomes of TTS.

Cardiac autonomic neuropathy is associated with ectopic fat distribution in autoimmune but not in type 2 diabetes

BACKGROUND

Cardiac autonomic neuropathy (CAN) is a life-threatening complication of diabetes. While obesity is a well-known risk factor of dysautonomia, the association between CAN and body fat distribution has not been fully clarified, especially in autoimmune diabetes (AD).

AIM

To evaluate if the association between CAN and body fat distribution differs between AD and type 2 diabetes (T2D).

METHODS

Body fat distribution was evaluated by Dual X-Ray Absorptiometry in 143 people with diabetes (44 with ADand 99 with T2D) undergoing clinical screening for CAN. The association of CAN with markers of ectopic fat distribution was evaluated in multivariate regression models adjusting for confounders and testing for the interaction between diabetes type and CAN.

RESULTS

A significant interaction between CAN and diabetes type was found with respect to markers of ectopic fat distribution. Specifically, people with CAN had significantly higher amount of visceral adipose tissue (530 [376-665]g versus 251[189-360]g, p = 0.001), total fat mass (22708[20200-27845]g versus 15434[12981-21879]g, p = 0,016), and trunk-to-leg ratio (0.88 [0.75-1.04] versus 0.70 [0.56-0.78], p = 0,023) compared to those without CAN only in participants with AD, but not in T2D (p-values for interaction < 0.05 for all comparisons).

CONCLUSION

Ectopic fat distribution is more strongly associated with CAN in AD than in T2D. This highlights the distinct role of fat distribution in the cardiometabolic health of people with AD, suggesting the need for further studies to better understand the pathophysiology and implications of overweight in this population.

Effect of exercise training on cardiac autonomic function in type 2 diabetes mellitus: a systematic review and meta-analysis

BACKGROUND

Cardiac autonomic neuropathy (CAN) is an underdiagnosed complication of type 2 diabetes mellitus (T2DM) and is associated with cardiovascular morbidity and mortality. Cardiac autonomic reflex tests (CARTs) are the gold standard; they are non-invasive and clinically feasible for screening CAN. The objective of the present meta-analysis was to examine exercise's effect on cardiac autonomic function using CARTs in T2DM.

METHODS

The Preferred Reporting Items for Systematic Review and Meta-Analysis Checklist (PRISMA) was used. Electronic databases were systematically used to retrieve relevant studies after title and abstract screening. Studies utilizing exercise training with cardiac autonomic function (CARTs) outcomes in individuals with type 2 diabetes mellitus were included. The meta-analysis was conducted using RevMan 5.4.1, using the random effects model, and appropriate tests for heterogeneity. The Cohrane ROB-2 tool was used for randomized controlled trials (RCTs) and the ROBINS-I tool for non-RCT for risk of bias assessment were used.

RESULTS

Three studies were included (two for meta-analysis), considering the outcome of the E:I ratio, 30:15 ratio, and Valsalva ratio. The studies did not show any influence on the E:I and 30:15 ratio in the pooled analysis with a low risk of ineffectiveness for the exercise intervention. Exercise training significantly affected the Valsalva ratio. A different type of exercise intervention was utilized in all three studies. There was a low to moderate certainty for the evidence.

CONCLUSION

The results indicate that further robust and high-quality randomized controlled trials utilizing cardiac autonomic reflex tests (which have clinical and physiological relevance) in type 2 diabetes mellitus are required for drawing conclusions.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42023445561.

Normative data on measures of cardiovascular autonomic neuropathy and the effect of pretest conditions in a large Danish non-diabetic CVD-free population from the Lolland-Falster Health Study

PURPOSE

Cardiovascular autonomic neuropathy (CAN) is a common diabetic complication associated with excess morbidity and mortality. CAN is also seen in conditions such as Parkinson's disease. Normative reference data for cardiovascular autonomic function are used to stratify individuals into those with and without CAN. However, reference thresholds for both cardiovascular autonomic reflex tests (CARTs) and heart rate variability (HRV) are scarce and based on small sample sizes. The aim of the study was to establish contemporary normative reference thresholds based on a large non-diabetic population free of cardiovascular disease (CVD).

METHODS

Cardiovascular autonomic function, CARTs and 5-min HRV indices were assessed in individuals without diabetes and CVD from the Lolland-Falster Health Study (2018-2020) by applying the point-of-care device Vagus™. Age-specific normative reference thresholds were estimated by using log-transformed quantile regression models at the 5th and 10th percentile, with adjustments made for sex. Models assessing the association between age and HRV indices were further adjusted for heart rate.

RESULTS

We present age-specific normative reference thresholds for cardiovascular autonomic function, including CARTs and HRV, for 875 individuals (48% females) aged 15-85 years. The reference thresholds are presented for both the 5th and 10th lower percentile. Higher age was inversely associated with all outcomes. Females tended to have a higher parasympathetic drive compared to males. Pre-test conditions did not affect CARTs significantly.

CONCLUSIONS

The presented age-related normative reference thresholds for both CARTs and HRV indices based on a large Danish cohort may facilitate improved quality of research and treatment.

Cardiac Autonomic Neuropathy in Diabetes Mellitus: Pathogenesis, Epidemiology, Diagnosis and Clinical Implications: A Narrative Review

Background: Cardiac autonomic neuropathy (CAN) is a serious but sometimes underdiagnosed complications of Diabetes Mellitus (DM). Because of the subtle onset and non-specific symptoms that can be mistaken for other conditions, CAN is frequently underdiagnosed despite the serious consequences that can appear. Its significance as an independent risk factor for cardiovascular events, including arrhythmias, sudden cardiac death, and silent myocardial ischemia, is being demonstrated by recent studies. The objective of this review article is to highlight the reasons why CAN is underdiagnosed and its association with decreased cardiovascular risk and promote clinical awareness. This review article summarizes the epidemiology, influence on the cardiovascular system and diagnostic methods of CAN, and the clinical implications of diabetic neuropathy. This review analyzes available data from papers relevant to the topic of diabetic neuropathy, cardiac autonomic neuropathy, and cardiovascular system implications. Conclusions: CAN is still underdiagnosed despite its clinical impact because routine screening is lacking, and healthcare providers are not aware of it. To improve outcomes for people with DM, it is necessary to introduce standardized diagnostic procedures into clinical practice and increase the knowledge about CAN.

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.

Orthostatic test shows higher systolic blood pressure and sympathetic response in uncomplicated type 1 diabetes patients with normal V̇O2max vs. healthy controls

PURPOSE

Cardiovascular autonomic neuropathy remains underdiagnosed in type 1 diabetes mellitus, posing a risk for severe complications, particularly in patients with lowered V̇O2max, compared to controls. This study aimed to determine whether heart rate variability during cardiovascular autonomic reflex tests reveals early signs of cardiovascular autonomic neuropathy in patients with uncomplicated type 1 diabetes mellitus and normal cardiovascular fitness, compared to healthy controls.

METHODS

A type 1 diabetes mellitus group (n = 14) with no other diagnosed diseases (diabetes duration 15 ± 7 years) and a control group (n = 31) underwent deep breathing test, passive orthostatic test, and cardiopulmonary exercise test. Participants were assessed for heart rate variability, heart rate, blood pressure, and V̇O2max (mL/min/kg).

RESULTS

Participant characteristics, including V̇O2max (mL/min/kg), showed no significant differences. The type 1 diabetes mellitus group had higher systolic blood pressure during the supine phase of the orthostatic test than healthy controls (131.6 ± 14.7 mmHg vs. 122.4 ± 10.8 mmHg, p = 0.022). After 5 mins in the upright position, systolic blood pressure (132.2 ± 20.6 mmHg vs. 118.7 ± 11.7 mmHg, p = 0.036), heart rate (85 (76; 89) bpm vs. 75 (72; 83) bpm, p = 0.013), and the root mean square of successive RR interval differences (20.22 (11.22; 27.42) vs. 27.11 (19.90; 35.52), p = 0.033) were significantly different compared to controls.

CONCLUSION

Patients with uncomplicated type 1 diabetes mellitus, despite having normal cardiorespiratory fitness, exhibited higher systolic pressure and greater sympathetic activation in orthostatic tests, suggesting subclinically altered cardiovascular autonomic function.

Cardiac autonomic neuropathy: impact on severe hypoglycemic unawareness and orthostatic hypotension in diabetic dysautonomia, a case series and review

Diabetic autonomic neuropathy (DAN) and its associated cardiovascular autonomic neuropathy (CAN) can lead to potentially fatal complications. We analyzed two distinct cases of DAN/CAN based on comprehensive cardiovascular autonomic reflex tests (CARTs). Case 1 involves a 27-year-old patient with T1DM suffering from recurrent severe hypoglycemic unawareness due to DAN. After implementing an automated insulin delivery system, the glucose management improved significantly. Case 2 describes a 60-year-old patient with type 2 diabetes experiencing debilitating orthostatic hypotension. The initiation of Midodrine and Fludrocortisone markedly improved symptoms and capacity of daily activities. This observational study highlights the critical yet frequently overlooked severe manifestations of DAN/CAN, specifically hypoglycemic unawareness and orthostatic hypotension. CARTs play a pivotal role in confirming the diagnosis and guiding therapeutic decisions. Tailored interventions, including advanced technologies like automated insulin delivery systems for T1DM and pharmacotherapy targeting neurogenic orthostasis, can significantly improve patient outcomes and quality of life.

Cardiovascular autonomic neuropathy in diabetes: an update with a focus on management

Cardiovascular autonomic neuropathy (CAN) is an under-recognised yet highly prevalent microvascular complication of diabetes. CAN affects approximately 20% of people with diabetes, with recent studies highlighting the presence of CAN in prediabetes (impaired glucose tolerance and/or impaired fasting glucose), indicating early involvement of the autonomic nervous system. Understanding of the pathophysiology of CAN continues to evolve, with emerging evidence supporting a potential link between lipid metabolites, mitochondrial dysfunction and genetics. Recent advancements, such as streamlining CAN detection through wearable devices and monitoring of heart rate variability, present simplified and cost-effective approaches for early CAN detection. Further research on the optimal use of the extensive data provided by such devices is required. Despite the lack of specific pharmacological interventions targeting the underlying pathophysiology of autonomic neuropathy, several studies have suggested a favourable impact of newer glucose-lowering agents, such as sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide-1 receptor agonists, where there is a wealth of clinical trial data on the prevention of cardiovascular events. This review delves into recent developments in the area of CAN, with emphasis on practical guidance to recognise and manage this underdiagnosed condition, which significantly increases the risk of cardiovascular events and mortality in diabetes.

Diabetes Mellitus and Cardiovascular Disease: Exploring Epidemiology, Pathophysiology, and Treatment Strategies

Diabetes mellitus (DM) affects 537 million people as of 2021, and is projected to rise to 783 million by 2045. This positions DM as the ninth leading cause of death globally. Among DM patients, cardiovascular disease (CVD) is the primary cause of morbidity and mortality. Notably, the prevalence rates of CVD is alarmingly high among diabetic individuals, particularly in North America and the Caribbean (46.0%), and Southeast Asia (42.5%). The predominant form of CVD among diabetic patients is coronary artery disease (CAD), accounting for 29.4% of cases. The pathophysiology of DM is complex, involving insulin resistance, β-cell dysfunction, and associated cardiovascular complications including diabetic cardiomyopathy (DCM) and cardiovascular autonomic neuropathy (CAN). These conditions exacerbate CVD risks underscoring the importance of managing key risk factors including hypertension, dyslipidemia, obesity, and genetic predisposition. Understanding the genetic networks and molecular processes that link diabetes and cardiovascular disease can lead to new diagnostics and therapeutic interventions. Imeglimin, a novel mitochondrial bioenergetic enhancer, represents a promising medication for diabetes with the potential to address both insulin resistance and secretion difficulties. Effective diabetes management through oral hypoglycemic agents (OHAs) can protect the cardiovascular system. Additionally, certain antihypertensive medications can significantly reduce the risk of diabetes-related CVD. Additionally, lifestyle changes, including diet and exercise are vital in managing diabesity and reducing CVD risks. These interventions, along with emerging therapeutic agents and ongoing clinical trials, offer hope for improved patient outcomes and long-term DM remission. This study highlights the urgent need for management strategies to address the overlapping epidemics of DM and CVD. By elucidating the underlying mechanisms and risk factors, this study aims to guide future perspectives and enhance understanding of the pathogenesis of CVD complications in patients with DM, thereby guiding more effective treatment strategies.

Metabolic targets in the Postural Orthostatic Tachycardia Syndrome: A short thematic review

Postural Orthostatic Tachycardia Syndrome (POTS) is a chronic autonomic condition hallmarked by orthostatic intolerance and tachycardia in the upright position. POTS impacts approximately 1-3 million people in the U.S. alone, in which the majority of patients are premenopausal women. The etiology of POTS is multi-factorial with three primary clinical subtypes, including neuropathic, hyperadrenergic, and hypovolemic POTS. Recent evidence suggests potential metabolic associations with POTS pathophysiology, particularly involving insulin resistance and abnormal vasoactive gut hormones. This review aims to characterize POTS phenotypes and explore potential metabolic links, focusing on insulin resistance and vasoactive gut hormones. Understanding the metabolic aspects of POTS pathophysiology could provide novel insights into its mechanisms and guide therapeutic approaches.

A Case of Severe Advanced Diabetic Cardiac Autonomic Neuropathy: Severe Orthostatic Hypotension Complicated With Episodes of Nocturnal Supine Hypertensive Emergency Episodes

Diabetic cardiac autonomic neuropathy (CAN) is caused by damage to the autonomic nerve fibers that innervate the heart and blood vessels, leading to abnormalities in heart rate control and vascular dynamics. CAN encompasses symptoms such as exercise intolerance, orthostatic hypotension, cardiac denervation syndrome, and nocturnal hypertension. Neurogenic orthostatic hypotension (nOH), resulting from severe diabetic CAN, can cause symptomatic orthostatic hypotension. The management of orthostatic hypotension primarily focuses on preventing severe symptoms, such as syncope and falls. It is equally important to address nocturnal supine hypertension, as it can exacerbate morning orthostatic hypotension. The management strategies for these conditions often complicate each other, highlighting the intricate and delicate nature of treating severe orthostatic hypotension associated with diabetic CAN. We present the case of a 55-year-old male with symptomatic orthostatic hypotension and coexisting nocturnal supine hypertension caused by severe, advanced diabetic CAN.

Data-based modeling of cerebral hemodynamics quantifies impairment of cerebral blood flow regulation in type-2 diabetes

We studied the regulation dynamics of cerebral blood velocity (CBv) at middle cerebral arteries (MCA) in response to spontaneous changes of arterial blood pressure (ABP), termed dynamic cerebral autoregulation (dCA), and end-tidal CO2 as proxy for blood CO2 tension, termed dynamic vasomotor reactivity (DVR), by analyzing time-series data collected at supine rest from 36 patients with Type-2 Diabetes Mellitus (T2DM) and 22 age/sex-matched non-diabetic controls without arterial hypertension. Our analysis employed a robust dynamic modeling methodology that utilizes Principal Dynamic Modes (PDM) to estimate subject-specific dynamic transformations of spontaneous changes in ABP and end-tidal CO2 (viewed as two "inputs") into changes of CBv at MCA measured via Transcranial Doppler ultrasound (viewed as the "output"). The quantitative results of PDM analysis indicate significant alterations in T2DM of both DVR and dCA in terms of two specific PDM contributions that rise to significance (p < 0.05). Our results further suggest that the observed DVR and dCA alterations may be due to reduction of cholinergic activity (based on previously published results from cholinergic blockade data) that may disturb the sympatho-vagal balance in T2DM. Combination of these two model-based "physio-markers" differentiated T2DM patients from controls (p = 0.0007), indicating diabetes-related alteration of cerebrovascular regulation, with possible diagnostic implications.

Dysautonomia and Postural Orthostatic Tachycardia Syndrome: A Critical Analysis of Dysautonomia: How to Diagnose and Treat

A significant number of physicians are unclear of the vast clinical manifestations of dysautonomia and imbalance of the autonomic nervous system, specifically the parasympathetic and sympathetic nervous systems. The major obstacle has been an inability to determine the mechanism of action as well as multisystem dysfunction and a lack of clear-cut testing. Dysautonomia, a pathophysiological malfunction of the sympathetic and parasympathetic nerves in our bodies, can present as altered clinical functions of heart rate (tachycardia/bradycardia), altered breathing patterns, blood pressure (hypertension/hypotension), sweating, digestion, syncope, etc. These symptoms have caused specialists to miss this diagnosis because of relative nonspecificity. Our current analysis of patients demonstrates significant delays in diagnosis, misdiagnosis, and the development of chronic syndromes because of the above. We demonstrate that monitoring of heart rate and blood pressure with changes in position and respiration can be easily and quickly performed without orthostatic stress and can demonstrate the entities of sympathetic withdrawal, cholinergic excessive aspects as well as tachycardia, blood pressure dips with posture, etc. This analysis takes less than an hour without the need for injections or medication, thus more quickly informing the cardiologist/neurologist of the correct diagnosis. We will attempt to demystify these issues so that clinicians and the scientific community will have a better understanding of this entity and consider a diagnosis of dysautonomia earlier in the differential diagnostic process and start treatment approaches sooner.

Multi-modal characterisation of early-stage, subclinical cardiac deterioration in patients with type 2 diabetes

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a major risk factor for heart failure with preserved ejection fraction and cardiac arrhythmias. Precursors of these complications, such as diabetic cardiomyopathy, remain incompletely understood and underdiagnosed. Detection of early signs of cardiac deterioration in T2DM patients is critical for prevention. Our goal is to quantify T2DM-driven abnormalities in ECG and cardiac imaging biomarkers leading to cardiovascular disease.

METHODS

We quantified ECG and cardiac magnetic resonance imaging biomarkers in two matched cohorts of 1781 UK Biobank participants, with and without T2DM, and no diagnosed cardiovascular disease at the time of assessment. We performed a pair-matched cross-sectional study to compare cardiac biomarkers in both cohorts, and examined the association between T2DM and these biomarkers. We built multivariate multiple linear regression models sequentially adjusted for socio-demographic, lifestyle, and clinical covariates.

RESULTS

Participants with T2DM had a higher resting heart rate (66 vs. 61 beats per minute, p < 0.001), longer QTc interval (424 vs. 420ms, p < 0.001), reduced T wave amplitude (0.33 vs. 0.37mV, p < 0.001), lower stroke volume (72 vs. 78ml, p < 0.001) and thicker left ventricular wall (6.1 vs. 5.9mm, p < 0.001) despite a decreased Sokolow-Lyon index (19.1 vs. 20.2mm, p < 0.001). T2DM was independently associated with higher heart rate (beta = 3.11, 95% CI = [2.11,4.10], p < 0.001), lower stroke volume (beta = -4.11, 95% CI = [-6.03, -2.19], p < 0.001) and higher left ventricular wall thickness (beta = 0.133, 95% CI = [0.081,0.186], p < 0.001). Trends were consistent in subgroups of different sex, age and body mass index. Fewer significant differences were observed in participants of non-white ethnic background. QRS duration and Sokolow-Lyon index showed a positive association with the development of cardiovascular disease in cohorts with and without T2DM, respectively. A higher left ventricular mass and wall thickness were associated with cardiovascular outcomes in both groups.

CONCLUSION

T2DM prior to cardiovascular disease was linked with a higher heart rate, QTc prolongation, T wave amplitude reduction, as well as lower stroke volume and increased left ventricular wall thickness. Increased QRS duration and left ventricular wall thickness and mass were most strongly associated with future cardiovascular disease. Although subclinical, these changes may indicate the presence of autonomic dysfunction and diabetic cardiomyopathy.

Low muscle strength rather than low muscle mass is associated with cardiovascular autonomic neuropathy in patients with type 2 diabetes

Several studies have investigated whether sarcopenia is associated with diabetic microvascular complications, but very few have examined associations between sarcopenia and cardiovascular autonomic neuropathy (CAN) in patients with type 2 diabetes mellitus (T2DM). Therefore, we investigated associations of muscle strength (handgrip strength [HGS]) and mass (appendicular skeletal muscle mass index [ASMI]) and CAN in patients with T2DM. We enrolled 342 patients in this retrospective, cross-sectional study. Cardiovascular reflex tests were used to assess CAN according to Ewing's protocol. Relative HGS was determined after normalizing absolute HGS to body weight (HGS/body weight [kg]). We defined low HGS and low ASMI according to a consensus report of the Asian Group for Sarcopenia. Logistic regression analyses were carried out to assess the associations between relative HGS or ASMI quartiles and the presence of CAN in patients with T2DM. The prevalence rates of CAN, low HGS, and low ASMI in the study subjects were 34.8%, 17.3%, and 18.7%, respectively. Low HGS was significantly more prevalent in patients with CAN than those without CAN (23.5% vs. 13.9%, p = 0.025). The CAN scores were significantly and negatively correlated with relative HGS but not with ASMI. Relative HGS was negative correlated with age, glycated hemoglobin, fasting plasma glucose, hsCRP, body mass index, and HOMA-IR and positively correlated with ASMI. The prevalence of CAN gradually increased with decreasing quartile of relative HGS (28.4% in Q4, 31.8% in Q3, 34.2% in Q2, and 45.3% in Q1, p = 0.02 for trend). Multivariable-adjusted prevalence ratios (PRs) for CAN, determined by comparing the first, second, and third quartiles with the fourth quartile of relative HGS, were 4.4 with a 95% confidence interval (95% CI) of [1.1 to 17.3]), 2.3 (95% CI [0.8 to 6.9]), and 1.2 (95% CI [0.4 to 3.7]), respectively. The prevalence of CAN and the PRs (95% [CI]) for CAN based on ASMI were not statistically significant. Our findings suggest that low muscle strength rather than low muscle mass was significantly associated with the presence of CAN. Therefore, HGS testing could help identify patients who would benefit from screening for earlier diagnosis of CAN.

Sudden cardiac death due to ventricular arrhythmia in diabetes mellitus: A bench to bedside review

Diabetes mellitus (DM) confers an increased risk of sudden cardiac death (SCD) independent of its associated cardiovascular comorbidities. DM induces adverse structural, electrophysiologic, and autonomic cardiac remodeling that can increase one's risk of ventricular arrhythmias and SCD. Although glycemic control and prevention of microvascular and macrovascular complications are cornerstones in the management of DM, they are not adequate for the prevention of SCD. In this narrative review, we describe the contribution of DM to the pathophysiologic mechanism of SCD beyond its role in atherosclerotic cardiovascular disease and heart failure. On the basis of this pathophysiologic framework, we outline potential preventive and therapeutic strategies to mitigate the risk of SCD in this population of high-risk patients.

Cardiovascular autonomic neuropathy and the risk of diabetic kidney disease

Background

Cardiovascular autonomic neuropathy (CAN) is known to affect patients with diabetes mellitus (DM) and cause adverse renal outcomes. We aimed to analyze the association between CAN and diabetic kidney disease (DKD).

Method

We enrolled 254 DM patients (mean age, 56.7 ± 15.2 years; male: female ratio, 1.17:1) with 19 (7.5%) type 1 DM patients and 235 (92.5%) type 2 DM patients. All patients had undergone cardiovascular autonomic function tests between January 2019 and December 2021 in a tertiary hospital in Korea. Cardiovascular autonomic neuropathy was categorized as normal, early, or definite after measuring three heart rate variability parameters. Diabetic kidney disease refers to a persistently elevated urinary albumin-creatinine ratio (uACR ≥30 mg/g) or reduced estimated glomerular filtration rate (eGFR <60 mL/min/1.73 m2). Logistic and Cox regression analyses were performed.

Results

Patients with elevated uACR (n=107) and reduced eGFR (n=32) had a higher rate of definite CAN. After adjusting for covariates, definite CAN was associated with elevated uACR (OR=2.4, 95% CI 1.07-5.36) but not with reduced eGFR (OR=3.43, 95% CI 0.62-18.90). A total of 94 patients repeated uACR measurements within 2 years (mean follow-up, 586.3 ± 116.8 days). Both definite and early CAN were independent risk factors for elevated uACR (HR=8.61 and 8.35, respectively; both p<0.05). In addition, high-density lipoprotein cholesterol, ACE inhibitors/angiotensin receptor blockers and glucagon-like peptide-1 receptor agonists were independent protective factors for elevated uACR (HR=0.96, 0.25, and 0.07, respectively; all p<0.05).

Conclusion

Cardiovascular autonomic neuropathy is a potential indicator of DKD. Comprehensive management of DKD in the early stages of CAN may prevent microalbuminuria.

Cardiac Autonomic Neuropathy in Graves' Disease: Smoking and Age as Predictive Factors

OBJECTIVES

Hypermetabolic state in Graves' disease (GD) has a great impact on heart homeostasis, acting directly on the heart muscle and modulating the autonomic nervous system. To characterize cardiac autonomic neuropathy (CAN) as a possible complication in patients with GD.

METHODS

We evaluated euthyroid GD patients and a control group of healthy euthyroid people. CAN was assessed using autonomic tests of cardiovascular reflex and heart rate variability: respiratory, Valsalva, orthostatic and orthostatic hypotension tests, high frequency, low frequency, and very low-frequency bands. Transthoracic echocardiography was performed in GD patients.

RESULTS

Sixty GD patients and 50 people in control group were assessed. CAN was diagnosed in 20% of GD and 14% in the control group. Among GD, 13.3% presented incipient, and 6.7% established CAN, while in the control group, it was verified incipient in 8% and established in 6% (P = .7479). All GD patients with CAN presented an alteration in the deep breathing test. Age and smoking were evidenced as factors associated with the presence of CAN, while higher TRAb values at diagnosis decreased the chance of CAN.

CONCLUSIONS

The prevalence of CAN in euthyroid GD patients was 20%. Changes in the cardiac autonomic nervous system were identified, pointing to the importance of evaluating this complication in these patients. Smoking was a predictive factor for CAN, increasing its relationship with conditions that aggravate GD.

Cardiac autonomic neuropathy modified the association between obesity and hypoglycemia in type 2 diabetes

BACKGROUND

Previous studies have shown that increasing body mass index (BMI) was associated with decreased hypoglycemia in type 2 diabetes, but it remains uncertain whether this finding could be applied to patients with and without cardiac autonomic neuropathy (CAN).

METHODS

The study included 7789 participants with type 2 diabetes from action to control cardiovascular risk in diabetes (ACCORD) trail. CAN was defined as SDNN < 8.2 ms and RMSSD < 8.0 ms. Obesity was defined as BMI ≥ 30 kg/m2. Outcomes were identified as severe hypoglycemia requiring any assistance (HAA) or requiring medical assistance (HMA). We assessed the association between obesity and severe hypoglycemia in type 2 diabetes with or without CAN using COX regression models adjusted for baseline characteristics.

RESULTS

Over a median follow-up of 4.7 years, a total of 893 participants developed HAA and 584 participants developed HMA. Compared with non-obesity, obesity was associated with lower risk of severe hypoglycemia (HAA: hazard ratio [HR] 0.51, 95% confidence interval [CI] 0.38-0.68, P < 0.001; HMA: HR 0.57, 95% CI 0.40-0.82, P = 0.002) in CAN present group, but not in CAN absent group (HAA: HR 0.98, 95% CI 0.83-1.16, P = 0.830; HMA: HR 0.97, 95% CI 0.79-1.19, P = 0.754). Similarly, increasing BMI was associated with reduced severe hypoglycemic events in participants with CAN, but not in participants without CAN.

CONCLUSIONS

CAN modifies the association between obesity and hypoglycemia in type 2 diabetes. Type 2 diabetic individuals with CAN who are under weight control should pay attention to hypoglycemic events.

TRIAL REGISTRY

http://www.

CLINICALTRIALS

gov . Unique identifier: NCT00000620.

Compromised cardiac autonomic function in non-diabetic subjects with 1 h post-load hyperglycemia: a cross-sectional study

BACKGROUND

A compromised cardiac autonomic function has been found in subjects with insulin resistance related disorders such as obesity, impaired glucose tolerance (IGT) and type 2 diabetes and confers an increased risk of adverse cardiovascular outcomes. Growing evidence indicate that 1 h plasma glucose levels (1hPG) during an oral glucose tolerance test (OGTT) ≥ 155 mg/dl identify amongst subjects with normal glucose tolerance (NGT) a new category of prediabetes (NGT 1 h-high), harboring an increased risk of cardiovascular organ damage. In this study we explored the relationship between 1 h post-load hyperglycemia and cardiac autonomic dysfunction.

METHODS

Presence of cardiac autonomic neuropathy (CAN) defined by cardiovascular autonomic reflex tests (CARTs) and heart rate variability (HRV), assessed by 24-h electrocardiography were evaluated in 88 non-diabetic subjects subdivided on the basis of OGTT data in: NGT with 1 h PG < 155 mg/dl (NGT 1 h-low), NGT 1 h-high and IGT.

RESULTS

As compared to subjects with NGT 1 h-low, those with NGT 1 h-high and IGT were more likely to have CARTs defined CAN and reduced values of the 24 h time domain HVR parameters including standard deviation of all normal heart cycles (SDNN), standard deviation of the average RR interval for each 5 min segment (SDANN), square root of the differences between adjacent RR intervals (RMSSD), percentage of beats with a consecutive RR interval difference > 50 ms (PNN50) and Triangular index. Univariate analyses showed that 1hPG, but not fasting and 2hPG, was inversely associated with all the explored HVR parameters and positively with CARTs determined presence of CAN. In multivariate regression analysis models including several confounders we found that 1hPG was an independent contributor of HRV and presence of CAN.

CONCLUSION

Subjects with 1hPG ≥ 155 mg/dl have an impaired cardiac autonomic function.

Effect of Piracetam and Iron Treatment on Heart Rate Variability in Patients With Breath-Holding Spell

BACKGROUND

Breath-holding spells are a benign condition primarily seen in 3% to 5% of healthy children aged between six months and five years. Although no specific treatment is recommended due to its benign nature, iron and piracetam are used in severe or recurrent cases. We planned to compare the heart rate variability (HRV) before and after treatment with 24-hour Holter monitoring in patients receiving iron and piracetam treatment and investigate the treatment's effectiveness.

METHODS

Twenty-five patients who applied to the outpatient clinic between 2013 and 2015 due to breath-holding spells were included in the study. The patients who received piracetam and iron therapy and underwent 24-hour rhythm Holter monitoring were evaluated retrospectively.

RESULTS

Fourteen (56%) of these patients were evaluated as having cyanotic-type and 11 (44%) patients were assessed as having pale-type breath-holding spells. A significant difference was found only between hourly peak heart rate and total power in the group receiving iron treatment. Significant differences were also found among the minimum heart rate, mean heart rate, the standard deviation of RR intervals, the mean square root of the sum of the squares of their difference between adjacent RR intervals, spectpow, and low frequency before and after the treatment in the patients who started piracetam treatment (P < 0.05).

CONCLUSIONS

Our study is critical as it is the first to investigate the effects of treatment options on various HRV in patients with breath-holding spells. There were statistically significant changes in HRV parameters in patients receiving piracetam, and the number of attacks decreased significantly. Piracetam treatment contributes positively to the breath-holding spell with regard to efficacy and HRV, therefore it can be used to treat breath-holding spells.

Contemporary prevalence of diabetic neuropathies in individuals with type 1 and type 2 diabetes in a Danish tertiary outpatient clinic

BACKGROUND

Population-based prevalence estimates of distal symmetric polyneuropathy (DPN) and diabetic autonomic neuropathy (DAN) are scares. Here we present neuropathy estimates and describe their overlap in a large cohort of people with type 1 and type 2 diabetes.

METHODS

In a large population of outpatient participants, DPN was assessed using vibration perception threshold, sural nerve function, touch, pain and thermal sensation. Definite DPN was defined by the Toronto Consensus Criteria. Painful DPN was defined by Douleur Neuropathique 4 Questions. DAN measures were: cardiovascular reflex tests, electrochemical skin conductance, and gastroparesis cardinal symptom index.

RESULTS

We included 822 individuals with type 1 (mean age (±SD) 54 ± 16 years, median [IQR] diabetes duration 26 [15-40] years) and 899 with type 2 diabetes (mean age 67 ± 11 years, median diabetes duration 16 [11-22] years). Definite DPN was prevalent in 54 % and 68 %, and painful DPN was in 5 % and 15 % of type 1 and type 2 participants, respectively. The prevalence of DAN varied between 6 and 39 % for type 1 and 9-49 % for type 2 diabetes. DPN without other neuropathy was present in 45 % with T1D and 50 % with T2D.

CONCLUSION

The prevalence of DPN and DAN was high. DPN and DAN co-existed in only 50 % of cases.

Trends in ST-elevation myocardial infarction hospitalization among young adults: a binational analysis

BACKGROUND

ST-segment myocardial infarction (STEMI) is typically associated with increased age, but there is an important group of patients who suffer from STEMI under the age of 50 who are not well characterized in studies.

METHODS AND RESULTS

We analysed results from Myocardial Ischemia National Audit Project (MINAP) from the United Kingdom (UK) between 2010 and 2017 and the National Inpatient Sample (NIS) from the United States of America (USA) between 2010 and 2018. After exclusion criteria, there were 32 719 STEMI patients aged ≤50 from MINAP, and 238 952 patients' ≤50 from the NIS. We analysed temporal trends in demographics, management, and mortality. The proportion of females increased, 15.6% (2010-2012) to 17.6% (2016-2017) (UK) and 22.8% (2010-2012) to 23.1% (2016-2018) (USA). The proportion of white patients decreased, from 86.7% (2010) to 79.1% (2017) (UK) and 72.1% (2010) to 67.1% (2017) (USA). Invasive coronary angiography (ICA) rates increased in UK (2010-2012: 89.0%, 2016-2017: 94.3%), while decreased in USA (2010-2012: 88.9%, 2016-2018: 86.2% (USA). After adjusting for baseline characteristics and management strategies, there was no difference in all-cause mortality in the UK in 2016-2017 compared to 2010-2012 (OR:1.21, 95% CI:0.60-2.40), but there was a decrease in the USA in 2016-2018 compared to 2010-2012 (OR: 0.84, 95% CI: 0.79-0.90).

CONCLUSION

The demographics of young STEMI patients have temporally changed in the UK and USA, with increased proportions of females and ethnic minorities. There was a significant increase in the frequency of diabetes mellitus over the respective time periods in both countries.

The Relationship between the Ewing Test, Sudoscan Cardiovascular Autonomic Neuropathy Score and Cardiovascular Risk Score Calculated with SCORE2-Diabetes

Background and Objectives: Cardiac autonomic neuropathy (CAN) is a severe complication of diabetes mellitus (DM) strongly linked to a nearly five-fold higher risk of cardiovascular mortality. Patients with Type 2 Diabetes Mellitus (T2DM) are a significant cohort in which these assessments have particular relevance to the increased cardiovascular risk inherent in the condition. Materials and Methods: This study aimed to explore the subtle correlation between the Ewing test, Sudoscan-cardiovascular autonomic neuropathy score, and cardiovascular risk calculated using SCORE 2 Diabetes in individuals with T2DM. The methodology involved detailed assessments including Sudoscan tests to evaluate sudomotor function and various cardiovascular reflex tests (CART). The cohort consisted of 211 patients diagnosed with T2DM with overweight or obesity without established ASCVD, aged between 40 to 69 years. Results: The prevalence of CAN in our group was 67.2%. In the study group, according SCORE2-Diabetes, four patients (1.9%) were classified with moderate cardiovascular risk, thirty-five (16.6%) with high risk, and one hundred seventy-two (81.5%) with very high cardiovascular risk. Conclusions: On multiple linear regression, the SCORE2-Diabetes algorithm remained significantly associated with Sudoscan CAN-score and Sudoscan Nephro-score and Ewing test score. Testing for the diagnosis of CAN in very high-risk patients should be performed because approximately 70% of them associate CAN. Increased cardiovascular risk is associated with sudomotor damage and that Sudoscan is an effective and non-invasive measure of identifying such risk.

The Predictive Potential of Heart Rate Variability for Depression

Heart rate variability (HRV),a measure of the fluctuations in the intervals between consecutive heartbeats, is an indicator of changes in the autonomic nervous system. A chronic reduction in HRV has been repeatedly linked to clinical depression. However, the chronological and mechanistic aspects of this relationship, between the neural, physiological, and psychopathological levels, remain unclear. In this review we present evidence by which changes in HRV might precede the onset of depression. We describe several pathways that can facilitate this relationship. First, we examine a theoretical model of the impact of autonomic imbalance on HRV and its role in contributing to mood dysregulation and depression. We then highlight brain regions that are regulating both HRV and emotion, suggesting these neural regions, and the Insula in particular, as potential mediators of this relationship. We also present additional possible mediating mechanisms involving the immune system and inflammation processes. Lastly, we support this model by showing evidence that modification of HRV with biofeedback leads to an improvement in some symptoms of depression. The possibility that changes in HRV precede the onset of depression is critical to put to the test, not only because it could provide insights into the mechanisms of the illness but also because it may offer a predictive anddiagnosticphysiological marker for depression. Importantly, it could also help to develop new effective clinical interventions for treating depression.

Genetic markers of cardiac autonomic neuropathy in the Kazakh population

BACKGROUND

Cardiac autonomic neuropathy (CAN) is a complication of diabetes mellitus (DM) that increases the risk of morbidity and mortality by disrupting cardiac innervation. Recent evidence suggests that CAN may manifest even before the onset of DM, with prediabetes and metabolic syndrome potentially serving as precursors. This study aims to identify genetic markers associated with CAN development in the Kazakh population by investigating the SNPs of specific genes.

MATERIALS AND METHODS

A case-control study involved 82 patients with CAN (cases) and 100 patients without CAN (controls). A total of 182 individuals of Kazakh nationality were enrolled from a hospital affiliated with the RSE "Medical Center Hospital of the President's Affairs Administration of the Republic of Kazakhstan". 7 SNPs of genes FTO, PPARG, SNCA, XRCC1, FLACC1/CASP8 were studied. Statistical analysis was performed using Chi-square methods, calculation of odds ratios (OR) with 95% confidence intervals (CI), and logistic regression in SPSS 26.0.

RESULTS

Among the SNCA gene polymorphisms, rs2737029 was significantly associated with CAN, almost doubling the risk of CAN (OR 2.03(1.09-3.77), p = 0.03). However, no statistically significant association with CAN was detected with the rs2736990 of the SNCA gene (OR 1.00 CI (0.63-1.59), p = 0.99). rs12149832 of the FTO gene increased the risk of CAN threefold (OR 3.22(1.04-9.95), p = 0.04), while rs1801282 of the PPARG gene and rs13016963 of the FLACC1 gene increased the risk twofold (OR 2.56(1.19-5.49), p = 0.02) and (OR 2.34(1.00-5.46), p = 0.05) respectively. rs1108775 and rs1799782 of the XRCC1 gene were associated with reduced chances of developing CAN both before and after adjustment (OR 0.24, CI (0.09-0.68), p = 0.007, and OR 0.43, CI (0.22-0.84), p = 0.02, respectively).

CONCLUSION

The study suggests that rs2737029 (SNCA gene), rs12149832 (FTO gene), rs1801282 (PPARG gene), and rs13016963 (FLACC1 gene) may be predisposing factors for CAN development. Additionally, SNPs rs1108775 and rs1799782 (XRCC1 gene) may confer resistance to CAN. Only one polymorphism rs2736990 of the SNCA gene was not associated with CAN.

Baroreflex Sensitivity as a Surrogate Biomarker for Concurrently Assessing the Severity of Arterial Stiffness and Cardiovascular Autonomic Neuropathy in Individuals with Type 2 Diabetes

This study aimed to investigate whether baroreflex sensitivity (BRS) could serve as a reliable metric for assessing cardiovascular autonomic neuropathy (CAN) and concurrently act as a surrogate biomarker for evaluating the severity of arterial stiffness and CAN in individuals diagnosed with type 2 diabetes mellitus (T2DM). Participants underwent brachial-ankle pulse wave velocity (baPWV) as well as autonomic function evaluations encompassing the Sudoscan-based modified composite autonomic scoring scale (CASS), baroreflex sensitivity, and heart rate variability in time domains and frequency domains. Linear regression analysis was performed to evaluate the influence of independent variables on baPWV and modified CASS. Participants with higher baPWV values were older, with longer diabetes duration, lower body weight, body mass index, waist circumference, elevated systolic and diastolic blood pressure, and mean arterial blood pressure. They also exhibited a higher prevalence of retinopathy as the underlying disease and reduced estimated glomerular filtration rate. Multiple linear regression analysis revealed that age and BRS were significantly associated with baPWV while diabetes duration, UACR, and BRS were significantly associated with modified CASS. Our study confirms the significant association of BRS with baPWV and modified CASS in T2DM, highlighting its pivotal role in linking microvascular and macrovascular complications. This supports BRS as a surrogate marker for assessing both the severity of arterial stiffness and cardiovascular autonomic neuropathy in T2DM, enabling the early identification of complications.

Predictive value of heart rate variability and electrochemical skin conductance measurements for cardiovascular autonomic neuropathy persistence in type 2 diabetes and prediabetes: A 3-year follow-up study

OBJECTIVE

The study aimed to explore risk stratification approaches for cardiovascular autonomic neuropathy (CAN) in individuals with prediabetes and type 2 diabetes (T2DM) over a three-year follow-up period.

METHODS

Participants underwent evaluations of autonomic function encompassing cardiovascular autonomic reflex tests (CARTs), baroreflex sensitivity (BRS), heart rate variability (HRV) in time domains (standard deviation of all normal RR intervals (SDNN)) and frequency domains (high frequency/low frequency ratio), and electrochemical skin conductance (ESC). The diagnosis of CAN relied on abnormal CART results. Subjects were categorized into 4 groups, based on their assessment of cardiac autonomic function at 3-year follow-up, relative to the presence or absence of CAN at baseline assessment: Persistent absence of CAN; Resolution of CAN; Progression to CAN; and Persistent CAN.

RESULTS

Participants with T2DM/prediabetes (n = 91/7) were categorized as: Persistent absence of CAN (n = 25), Resolution of CAN (n = 10), Progression to CAN (n = 18), and Persistent CAN (n = 45) groups. The Persistent absence of CAN group showed significant associations with SDNN. The Resolution of CAN group exhibited notable associations with mean HbA1C (follow-up), while the Progression to CAN group displayed a significant link with baseline estimated glomerular filtration rate. The Persistent CAN group demonstrated significant associations with SDNN and Sudoscan CAN risk score. Screening recommendations involve biennial to annual assessments based on risk levels, aiding in CAN detection and subsequent comprehensive and time-intensive autonomic function tests for confirmation. The study's findings offer improved risk categorization approaches for detecting CAN, which has relevance for shaping public health strategies.

Impaired Cardiovagal Activity as a Link Between Hyperglycemia and Arterial Stiffness in Adults With Type 2 Diabetes Mellitus Among an Eastern Indian Population: A Cross-sectional Study

OBJECTIVES

Cardiac autonomic neuropathy (CAN) is one of the most common yet overlooked complications of type 2 diabetes mellitus (T2DM). Individuals with T2DM with CAN have a 5-fold higher rate of cardiovascular morbidity and mortality. The presence of CAN in T2DM could potentially lead to arterial stiffness. However, only sparse data are available suggesting any association between autonomic dysfunction and arterial stiffness in T2DM.

METHODS

We recruited 80 people with T2DM and 74 healthy controls for our study. Heart rate variability (HRV) testing was performed to assess autonomic function. Assessment of arterial stiffness was done by measuring the brachial pulse wave velocity (baPWV) and augmentation index (AI).

RESULTS

The time-domain parameters were significantly decreased (p<0.001) and frequency-domain parameters, such as total power and high-frequency band expressed as a normalized unit, were found to be significantly reduced in people with T2DM (p<0.001). Both baPWV and AI were significantly higher in people with T2DM compared with healthy controls (p<0.001). We observed a moderate correlation between standard deviation of normal to normal interval (SDNN) and baPWV (r=-0.437, p=0.002) and AI (r=-0.403, p=0.002). A multiple linear regression model showed an association between SDNN and arterial stiffness parameters, such as baPWV and AI, which were statistically significant (p<0.05) in a fully adjusted model that included the conventional risk factors for atherosclerosis.

CONCLUSIONS

Impaired cardiovagal activity is an independent risk factor for the development of arterial stiffness. Incorporation of HRV testing into the diabetes management protocol would have potential benefits for identifying individuals at high risk of developing cardiovascular events. Hence, preventive measures can be taken as early as possible to improve patient outcomes.

Accuracy and clinical utility of heart rate variability derived from a wearable heart rate monitor in patients undergoing major abdominal surgery

Low heart rate variability (HRV) can potentially identify patients at risk of intraoperative hypotension. However, it is unclear whether cheaper, readily accessible consumer heart rate (HR) monitors can provide similar utility to clinical Holter electrocardiograph (ECG) monitors. The objectives of this study were (1) to assess the validity of using the Polar H10 HR monitor as an alternative to a clinical Holter ECG and (2) to test total power (TP) as a predictor of intraoperative hypotension. The primary outcome was the level of agreement between Polar H10 and Holter ECG. Twenty-three patients undergoing major abdominal surgery with general anesthesia had 5-minute HR recordings taken concurrently with both devices during a pre-anesthetic consultation. Agreement between Polar H10 and Holter ECG was compared via Bland-Altman analysis and Lin's Concordance Correlation Coefficient. Patients were divided into groups based on TP <  500 m s 2 and TP >  500 m s 2 . Intraoperative hypotension was defined as MAP < 60 mmHg, systolic blood pressure < 80 mmHg, or 35% decrease in MAP from baseline. There was substantial agreement between Polar H10 and Holter ECG for average R-R interval, TP and other HRV indices. Reduced TP (< 500 ms 2 ) had a high sensitivity (80%) and specificity (100%) in predicting intraoperative hypotension. Patients with reduced TP were significantly more likely to require vasoactive drugs to maintain blood pressure.The substantial agreement between Polar H10 and Holter ECG may justify its use clinically. The use of preoperative recordings of HRV has the potential to become part of routine preoperative assessment as a useful screening tool to predict hemodynamic instability in patients undergoing general anesthesia.

Sudomotor dysfunction is associated with impaired left ventricular diastolic function in persons with type 2 diabetes: a cross-sectional study

BACKGROUND

The incidence of preserved ejection fraction heart failure has significantly increased in persons with type 2 diabetes mellitus (T2DM). Left ventricular (LV) diastolic dysfunction is an early and important manifestation of preserved ejection fraction heart failure. The onset of heart failure in persons with diabetes is associated with diabetic neuropathy. However, the relationship among sudomotor function, which is an early manifestation of small fiber neuropathy, and LV diastolic function remains unclear. This study aimed to explore the association between sudomotor function and LV diastolic function in persons with T2DM.

METHODS

In total, 699 persons with T2DM were enrolled and divided into three groups according to electrochemical skin conductance (ESC) assessed using the SUDOSCAN device: "no dysfunction" group (NSF), "moderate dysfunction" group (MDF), and "severe dysfunction" group (SDF). LV diastolic function was assessed using Doppler echocardiography. To evaluate the relationship between ESC and echocardiographic parameters, Pearson's correlation analysis was performed. Additionally, logistic regression analysis was used to determine the association between LV diastolic function and ESC. A receiver operating characteristic (ROC) curve was constructed to evaluate the performance of sudomotor function indicators in detecting impaired cardiac diastolic function.

RESULTS

There were 301 persons (43.06%) in the NSF group, 232 (33.19%) in the MDF group, and 166 (23.75%) in the SDF group. Compared to the NSF group, the MDF and SDF groups had higher A and E/e' and lower e' values (all p < 0.05). Pearson's correlation analysis showed that A and E/e' were negatively associated with foot ESC (FESC) and hand ESC (HESC), whereas e' was positively associated with FESC and HESC (all p < 0.05). After adjusting for confounding factors, binary logistic regression analysis showed that ESC was independently associated with impaired LV diastolic function (p = 0.003). The area under the ROC curve values for FESC and HESC were 0.621 and 0.635, respectively (both p < 0.05).

CONCLUSIONS

Deteriorating sudomotor function was associated with reduced diastolic function indicators. ESC can be used as a biomarker for detecting LV diastolic impairment.

Prevalence and prognostic significance of cardiac autonomic neuropathy in community-based people with type 2 diabetes: the Fremantle Diabetes Study Phase II

BACKGROUND

There is a paucity of contemporary data on the prevalence and prognostic significance of cardiac autonomic neuropathy (CAN) from community-based cohorts with type 2 diabetes assessed using gold standard methods. The aim of this study was to assess these aspects of CAN in the longitudinal observational Fremantle Diabetes Study Phase II (FDS2).

METHODS

FDS2 participants were screened at baseline using standardised cardiovascular reflex tests (CARTs) of heart rate variation during deep breathing, Valsalva manoeuvre and standing. CAN (no/possible/definite) was assessed from the number of abnormal CARTs. Multinomial regression identified independent associates of CAN status. Cox proportional hazards modelling determined independent baseline predictors of incident heart failure (HF) and ischaemic heart disease (IHD), and all-cause mortality.

RESULTS

Of 1254 participants assessed for CAN, 86 (6.9%) were outside CART age reference ranges and valid CART data were unavailable for 338 (27.0%). Of the remaining 830 (mean age 62.3 years, 55.3% males, median diabetes duration 7.3 years), 51.0%, 33.7% and 15.3% had no, possible or definite CAN, respectively. Independent associates of definite CAN (longer diabetes duration, higher body mass index and resting pulse rate, antidepressant and antihypertensive therapies, albuminuria, distal sensory polyneuropathy, prior HF) were consistent with those reported previously. In Kaplan-Meier analysis, definite CAN was associated with a lower likelihood of incident IHD and HF versus no/possible CAN (P < 0.001) and there was a graded increase in all-cause mortality risk from no CAN to possible and definite CAN (P < 0.001). When CAN category was added to the most parsimonious models, it was not a significant independent predictor of IHD (P ≥ 0.851) or HF (P ≥ 0.342). Possible CAN (hazard ratio (95% CI) 1.47 (1.01, 2.14), P = 0.046) and definite CAN (2.42 (1.60, 3.67), P < 0.001) increased the risk of all-cause mortality versus no CAN.

CONCLUSIONS

Routine screening for CAN in type 2 diabetes has limited clinical but some prognostic value.

The Importance of Evaluating Sudomotor Function in the Diagnosis of Cardiac Autonomic Neuropathy

INTRODUCTION

 Cardiac autonomic neuropathy (CAN) is a disorder affecting the autonomic nerves that regulate the cardiovascular system, leading to irregular heart rate and blood pressure control. It is commonly associated with diabetes mellitus but can also result from other conditions such as autoimmune disorders, chronic kidney disease, alcohol abuse, and certain medications. Screening for CAN is essential, particularly in individuals with poor glycemic control, cardiovascular risk factors, or complications. Early identification of CAN is vital for timely intervention to prevent or manage cardiovascular complications effectively. Regular screening helps detect CAN before symptoms emerge, enabling early intervention to slow or halt its progression. This study examined the relationship between sudomotor function and cardiovascular reflex tests.

MATERIAL AND METHODS

 This was a cross-sectional study conducted between June 2019 and June 2020. The study included 271 subjects aged 18 years and above who provided informed consent, were diagnosed with type 2 diabetes mellitus (T2DM), and were overweight or obese. Exclusion criteria encompassed patients with other types of diabetes, pregnant women, those with recent neoplasm diagnoses, stroke sequelae, history of myocardial infarction, or pelvic limb amputations. The assessment of cardiac autonomic neuropathy involved conducting an electrocardiogram and evaluating the QTc interval in the morning before taking medication. Additionally, cardiovascular reflex tests (CART) were conducted, including assessments of heart rate variability during deep breathing, the Valsalva maneuver, and changes in orthostatic position. Simultaneously, the diagnosis of CAN was assessed by performing a sweat test using a Sudoscan assessment (Impeto Medical, Moulineaux, France).  Results: More than half of the participants (52%, n=143) were female. Significant differences in statistical measures were noted between females and males regarding age, systolic blood pressure, fasting blood glucose, A1c level, total cholesterol, triglycerides, gamma-glutamyl transferase, and bilirubin levels. Within the CAN-diagnosed group (CAN+), 40.92% were classified as mild cases (n=90), 47.27% as moderate cases (n=104), and 11.81% as severe cases (n=26). Among the CAN+ group, 54% (n=119) were women. Electrochemical skin conductance was lower in the CAN+ group than the CAN- group in hands (67.34±15.51 μS versus 72.38±12.12 μS, p=0.008) and feet (73.37±13.38 μS versus 82.84 ±10.29 μS, p<0.001). The Sudoscan-CAN score significantly correlated with Ewing scores (r= 0.522, p<0.001). In multiple linear regression analysis, the Sudoscan-CAN score remained significantly associated with age, high BMI, long-standing diabetes, and Ewing score.

CONCLUSIONS

 Sudoscan demonstrates potential in identifying patients with an increased risk of CAN. Its integration into clinical practice can improve patient outcomes through early detection, risk stratification, and personalized treatment approaches. Its non-invasive, portable, and user-friendly features render it suitable for utilization in outreach programs or resource-constrained settings as part of screening efforts designed to pinpoint high-risk individuals for additional assessment.

The double burden: type 1 diabetes and heart failure-a comprehensive review

Heart failure (HF) is increasing at an alarming rate, primary due to the rising in aging, obesity and diabetes. Notably, individuals with type 1 diabetes (T1D) face a significantly elevated risk of HF, leading to more hospitalizations and increased case fatality rates. Several risk factors contribute to HF in T1D, including poor glycemic control, female gender, smoking, hypertension, elevated BMI, and albuminuria. However, early and intensive glycemic control can mitigate the long-term risk of HF in individuals with T1D. The pathophysiology of diabetes-associated HF is complex and multifactorial, and the underlying mechanisms in T1D remain incompletely elucidated. In terms of treatment, much of the evidence comes from type 2 diabetes (T2D) populations, so applying it to T1D requires caution. Sodium-glucose cotransporter 2 inhibitors have shown benefits in HF outcomes, even in non-diabetic populations. However, most of the information about HF and the evidence from cardiovascular safety trials related to glucose lowering medications refer to T2D. Glycemic control is key, but the link between hypoglycemia and HF hospitalization risk requires further study. Glycemic variability, common in T1D, is an independent HF risk factor. Technological advances offer the potential to improve glycemic control, including glycemic variability, and may play a role in preventing HF. In summary, HF in T1D is a complex challenge with unique dimensions. This review focuses on HF in individuals with T1D, exploring its epidemiology, risk factors, pathophysiology, diagnosis and treatment, which is crucial for developing tailored prevention and management strategies for this population.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION

ARISE-HF, NCT04083339.

The handgrip test - A historical test for diabetic autonomic neuropathy or a marker of something else?

Cardiovascular autonomic neuropathy (CAN) is a frequent complication of diabetes mellitus and is associated with increased morbidity and mortality in patients with diabetes. Hence, early and correct diagnosis of CAN is crucial. Standard cardiovascular reflex rests (CARTs) have been the gold standard of CAN assessment. Originally, CARTs consisted of five reflex tests, but measuring diastolic blood pressure response to sustained handgrip exercise has no longer been suggested as an established clinical test. Increasing body of evidence suggests that isometric handgrip test should no longer be used for the evaluation of sympathetic dysfunction during cardiovascular autonomic neuropathy assessment in diabetic patients. The associations of isometric handgrip test results with parameters of hypertension and markers of hypertension-related target-organ damage in diabetic and non-diabetic individuals point toward its potential role as a screening tool to identify patients with high cardiovascular risk. The current review summarizes historical view of standard cardiovascular reflex tests and latest data on isometric handgrip test.

Integrative care: acupuncture based neuromodulation therapy for diabetes and heart failure

The relationship between heart failure and diabetes is intricate and bidirectional. Individuals with diabetes face an elevated risk of developing heart failure due to factors like insulin resistance, chronic inflammation, and metabolic irregularities. Elevated blood sugar levels can harm blood vessels and nerves, culminating in the buildup of fatty deposits in arteries, atherosclerosis, and hypertension, which significantly contribute to heart failure. Furthermore, diabetes can adversely impact the structure and function of the heart muscle, impairing its pumping capacity. Conversely, heart failure can also contribute to the onset of diabetes by disrupting the body's metabolic processes and amplifying insulin resistance. The complex interaction between these conditions mandates a comprehensive approach to managing individuals with both diabetes and heart failure, underscoring the importance of addressing both aspects for enhanced patient outcomes. Although existing pharmacological treatments are limited and frequently associated with undesirable side effects, acupuncture has established itself as a traditional practice with a legacy. It remains a supplementary option for treating cardiovascular diseases. Heart failure and diabetes are both heavily associated with chronic upregulation of the sympathetic nervous system, which has been identified as a pivotal factor in the progression of disease. Mechanistic interplays such as the attenuation of central nitric oxide signaling may interfere with the production or availability of nitric oxide in key areas of the central nervous system, including the brainstem and hypothalamus. This review will delve into the current understanding of acupuncture on the autonomic nervous system and offer insights into its potential role in the future treatment landscape for diabetes and heart failure.

Predictors of Cardiac Autonomic Dysfunction in Obesity-Related Hypertension

INTRODUCTION

Cardiac Autonomic Dysfunction (CAD) is an overlooked cardiovascular risk factor in individuals with obesity-related hypertension. Despite its clinical significance, there is a notable lack of clarity regarding the pathophysiological correlates involved in its onset and progression.

AIM

The present study aimed to identify potential predictors of CAD in obesity-related hypertension.

METHODS

A total of 72 participants (34 men and 38 women) were enrolled. Comprehensive evaluations were conducted, including cardiac autonomic function assessments, body composition estimation and biochemical analysis. Participants were categorized as CAD-positive or CAD-negative based on Ewing's criteria for autonomic dysfunction. Univariate logistic regression analysis was performed to identify potential predictors for CAD. Multivariate logistic regression models were further constructed by adjusting clinically relevant covariates to identify independent predictors of CAD.

RESULTS

Multivariate logistic regression analysis revealed that resting heart rate (HRrest), (odds ratio, confidence interval: 0.85, 0.78-0.93; p = 0.001) and percentage body fat (BF%), (odds ratio, confidence interval: 0.78, 0.64-0.96; p = 0.018) were significant independent predictors of CAD. Receiver Operating Characteristic curve analysis depicted optimal cut-off values for HRrest and BF% as > 74.1 bpm and > 33.6%, respectively. Multicolinearity analysis showed variance inflation factors (VIF) below the cautionary threshold of 3.

CONCLUSIONS

The HRrest and BF% emerged as significant independent predictors of CAD in obesity-related hypertension. Therapeutic strategies should target HRrest < 74.1 bpm and BF% < 33.6% to mitigate CAD risk in this population. Future trials are required to establish causal relationships and may consider additional confounding variables in obesity-related hypertension.

Evaluation of association between time in range, a continuous glucose monitoring metric, and cardiac autonomic neuropathy in type 2 diabetes patients

Introduction

Time in range (TIR), a metric of continuous glucose monitoring (CGM) provides better information regarding the individual's glycemic variability than a static measure like glycated hemoglobin (HbA1c). TIR is emerging as an independent risk factor for diabetic complications, both microvascular and macrovascular complications independent of HbA1c. Hence, this study evaluates the association between TIR and cardiac autonomic neuropathy (CAN) in type 2 diabetic patients.

Materials and Methods

A total of 42 patients with type 2 diabetes mellitus were enrolled in this study and underwent a 3-day CGM using the "FreeStyle Libre Pro Flash Glucose Monitoring System Sensor" along with tests for CAN within the 3 days of attaching the CGM.

Results

Out of 42 patients, 36 patients (85.7%) were diagnosed with CAN (early CAN 57.1% and definite CAN 28.6%) and the mean TIR was 64.4% ±23.5%. Out of those with TIR <70%, 42.9% were affected with definite CAN compared to only 14.3% among those with TIR >70%. Patients with more severe CAN were found to have a lower TIR (P = 0.115).

Conclusion

The study found a high prevalence of cardiac autonomic neuropathy (CAN) of around 85.7% in type 2 diabetes patients. Lower TIR values were associated with a higher incidence of definite CAN (42.9% vs. 14.3% in TIR <70% vs. >70% groups). The findings suggest TIR is inversely associated with the presence and severity of cardiac autonomic neuropathy in type 2 diabetic patients and also a potential link between TIR and CAN severity.

Cardiovascular autonomic nervous function in children conceived by assisted reproductive technology with frozen or fresh embryo transfer

As a result of epigenetic changes, children conceived by assisted reproduction may be at risk of premature cardiovascular aging with notably increased blood pressures. Their cardiovascular autonomic nervous function is unknown. Therefore, this study investigated the cardiovascular autonomic nervous function in 8-12-yr-old children (51% girls) conceived naturally (n = 33) or by assisted reproduction with frozen (n = 34) or fresh (n = 38) embryo transfer by evaluating heart rate variability, during rest; from provocation maneuvers; and from baroreflex function. Heart rate and blood pressure response to provocation maneuvers and baroreflex function were comparable between children conceived naturally or by assisted reproduction. The mean RR-interval and high-frequency component of heart rate variability were lower in children conceived by assisted reproduction than in children conceived naturally. Children conceived by fresh embryo transfer had ∼17% lower heart rate-corrected standard deviation of normal-to-normal R-R intervals; ∼22% lower heart rate-corrected square root of the mean of the squared difference between successive R-R intervals; and ∼37% higher low-frequency/high-frequency ratio than naturally conceived children. Children conceived by assisted reproduction still had lower heart rate variability and vagal modulation than naturally conceived children after adjustment for confounders. Thus, these results raise the possibility of sympathetic predominance in children conceived by assisted reproduction. Therefore, it is important to reproduce these results in larger and older cohorts as sympathetic predominance relates with cardiovascular and metabolic diseases.NEW & NOTEWORTHY We observed that children conceived by assisted reproductive technology (both frozen and fresh embryo transfer) had lowered heart rate variability during rest as compared with children conceived naturally. During physiological stress maneuvers, however, the cardiovascular autonomic nervous regulation was comparable between children conceived by assisted reproductive technologies and naturally. Our findings highlight the potential that lowered heart rate variability during rest in children conceived by assisted reproductive technologies may precede premature hypertension.

Lurasidone and risk of metabolic syndrome: results from short and long-term studies in patients with bipolar depression

OBJECTIVE

The elevated prevalence of metabolic syndrome (MetS) in patients with depression has been associated with increased mortality. This post hoc analysis assessed the effect of treatment with lurasidone on risk of MetS in patients with bipolar depression.

METHODS

Data used in the current analyses consisted of 3 double-blind (DB), placebo-controlled, 6-week studies in adults with bipolar I depression (N = 1192), consisting of 1 monotherapy, and 2 adjunctive trials (lithium or valproate). Also analyzed was a 6-month open-label (OL) extension study (monotherapy, N = 316; adjunctive therapy, N = 497); and a 5-month, OL, stabilization phase followed by randomization to a 28-week DB, placebo-controlled, adjunctive therapy study with lurasidone (N = 490). MetS was defined based on NCEP ATP III criteria (2005 revision).

RESULTS

The proportion of patients with new-onset MetS was similar for lurasidone vs placebo in the short-term studies (monotherapy, 13.9% vs 15.3%; adjunctive therapy, 13.6% vs 11.0%); and remained stable during both the 6-month extension phase study (monotherapy, 15.2%; adjunctive therapy, 16.9%), and the 5-month stabilization study (adjunctive therapy, 12.2%). After 28 weeks of DB treatment (following 5-month treatment in the stabilization study), new onset MetS was observed at endpoint (OC) in 26.2% of the lurasidone group, and 30.8% of the placebo group.

CONCLUSIONS

This post hoc analysis found that both short and long-term treatment with lurasidone was associated with a relatively low risk for the development of MetS in patients with bipolar I disorder. These findings are consistent with similar analyses in patients with schizophrenia.