Cardiovascular Reflex Tests Research Articles

Post-Acute Effect of SARS-CoV-2 Infection on the Cardiac Autonomic Function.

BackgroundRecent studies reported a long-lasting effect of COVID-19 infection that extends beyond the active disease and disrupts various body systems besides the respiratory system. The current study aims to investigate the post-acute effect of SARS-CoV-2 infection on cardiovascular autonomic activity, reactivity and sensitivity in patients who had the infection at least 3 months before.MethodsThis was a comparative cross-sectional observational study. Fifty-nine subjects were allocated into two groups, controls (n=31), who had no history of positive COVID-19 infection, and the post-COVID patients (n=28) who were recruited 3 to 8 months after testing positive for SARS-CoV-2 by reverse transcription polymerase chain reaction (RT-PCR). Baseline cardiovascular autonomic activity was evaluated through recording of baseline heart rate variability (HRV), autonomic reactivity was determined through standard cardiovascular autonomic reflex tests (CART), and cardiac autonomic sensitivity was assessed through cardiac baroreceptor sensitivity (cBRS).ResultsHigher incidence of orthostatic hypotension was observed in post-COVID patients compared to controls (39.3% and 3.2%, respectively, p <0.001). Additionally, significantly reduced handgrip test, and heart rate response to head-up tilt was illustrated in the post-COVID group (p <0.001). About 85.7% of post-COVID participants had at least one abnormal cardiovascular reflex test (CART) compared to the control group (p <0.001). Although HRV parameters (TP, LF, HF, SDRR, RMSSD, pRR50), and the cBRS were numerically lower in the post-COVID-19 group, this did not reach the level of significance.ConclusionThe results of the present study are suggestive of altered cardiovascular reactivity in post-acute COVID patients and demand further investigation and longer term follow up.

Cardiovascular Autonomic Neuropathy Is Associated With Increased Glucose Variability in People With Type 1 Diabetes.

We investigated the association between the cardiovascular autonomic neuropathy (CAN) diagnosis and glucose variability (GV) in type 1 diabetes (T1D), as autonomic dysfunction previously has been associated with increased GV. CAN was assessed by three recommended cardiovascular reflex tests (CARTs). Glucose metrics were obtained from 10-day blinded continuous glucose monitoring (CGM). Between-group differences in GV indices were assessed by regression analyses in 24 participants with T1D with CAN and 24 matched control subjects without CAN. The CAN diagnosis was associated with 4.9% (95% CI 1.0, 8.7) higher coefficient of variation (CV) (P = 0.014), 0.7 mmol/L (0.3, 1.1) higher SD (P = 0.002) of glucose, and 1.4 mmol/mol (0.0, 2.7) higher mean amplitude of glycemic excursions (P = 0.047). Lower measures of CARTs were associated with higher CV, SD, and time above range values. The CAN diagnosis associates with a significantly higher GV in T1D, despite a high prevalence of routine CGM use.

Association between hypoglycaemic glucose variability and autonomic function in type1 diabetes with impaired hypoglycaemia awareness

Cardiovascular autonomic neuropathy (CAN) is suggested to underlie hypoglycaemic risk in impaired awareness of hypoglycaemia (IAH). We assessed the prevalence of CAN and the association between glucose variability (GV) and cardiovascular autonomic function in patients with type 1 diabetes (T1DM) and IAH.This study is a post-hoc-analysis of results obtained with the IN-CONTROL-trial, designed to assess the effects of continuous glucose monitoring (CGM) on glycaemia. Forty participants (aged 46.4 ± 11.4 years, diabetes duration 29.1 ± 13.5 years, HbA1c 7.5 ± 0.8%(58.2 ± 8.8 mmol/mol)) underwent 2-week blinded CGM measurements to obtain GV indices. Standardized cardiovascular reflex tests were used to determine the presence of CAN. Cardiovascular autonomic function was assessed with heart rate variability (HRV) measures.14(35%) participants were classified as having CAN. Participants with CAN had lower percentage time spent in hypoglycaemic range and low blood glucose index(LBGI). After correction for confounders, a significant positive association was found between the coefficient of variation (CV) or time spent in hypoglycaemic range and HRV measures SDRR or RMSSD, and between LBGI and RMSSD.In patients with T1DM and IAH, hypoglycaemic parameters were associated with better cardiovascular autonomic function and lower prevalence of CAN. This suggests that autonomic neuropathy does not seem to further deteriorate hypoglycaemic risk in patients with IAH.

458-P: Inflammatory Markers and Cardiovascular Autonomic Neuropathy in Type 1 Diabetes

Objective: We aimed to assess the role of chronic inflammation in the pathogenesis of cardiovascular autonomic neuropathy (CAN) , a serious complication of type 1 diabetes (T1D) . Methods: We leveraged an ongoing randomized, placebo-controlled clinical trial targeting inflammation with salsalate in individuals with T1D, to measure a panel of 40 inflammatory markers (Figure) in baseline samples. Measures of CAN included standardized cardiovascular autonomic reflex tests (CARTs) (E/I, Valsalva, 30/15 ratios) and indices of heart rate variability (HRV) . We used Spearman-rank to assess the correlations between inflammatory markers and CAN measures, and linear regression to adjust for age and hemoglobin A1c. Results: The Figure displays the correlation between biomarkers and CAN measures in 58 T1D participants (mean age 51 ± 13 years, and HbA1c 8.4 ± 1.8%) . Amongst all biomarkers, we noted a singular negative correlation between soluble urokinase plasminogen activator receptor (suPAR) and measures of CAN, which remained significant in multivariable analysis (E/I ratio p=0.005, Valsalva p=0.037, RFA p=0.019, LFA p=0.023) . Conclusion: Amongst a large panel of inflammatory markers, we found suPAR to have a notable association with CAN. SuPAR is an immune-mediated signaling glycoprotein which levels are strong predictors of risk in patients with diabetes, thus its role in CAN warrants further exploration. Disclosure L.Ang: None. L.Zhao: None. E.L.Feldman: None. S.Hayek: n/a. R.Pop-busui: Advisory Panel; Averitas Pharma, Inc., Boehringer Ingelheim International GmbH, Nevro Corp., Novo Nordisk, Reata Pharmaceuticals, Inc., Regenacy Pharmaceuticals, Inc. S.V.G.Gunaratnam: None. Y.Huang: None. K.R.Mizokami-stout: None. C.Martin: Advisory Panel; Nevro Corp. J.Reiss: n/a. A.Burant: None. A.Vasbinder: None. C.Launius: None. Funding NIH/NIDDK-1-R01-DK-107956-01

Clinical manifestations and evaluation of cardiac autonomic neuropathy in diabetes mellitus and metabolic syndrome

A serious complication of type 2 diabetes mellitus (T2DM) and metabolic syndrome (MetS) is a dysfunction of the autonomic nervous system, which requires early evaluation for the effective treatment. The possibilities of pulse oximetry, which allows to assess heart rate variability in screening of autonomic nervous system dysfunction in patients with T2DM and MetS, have not yet been studied sufficiently.Objective: to evaluate the pulse oximetry effectiveness by comparing its results with the data of quantitative autonomic testing (QAT) to detect cardiac autonomic neuropathy (CAN) and clarify its degree in patients with T2DM and MetS.Patients and methods. The study included 30 patients with T2DM (mean age 63±7.9 years), 30 patients with MetS (mean age 61.5±9.1 years), 30 subjects from the control group (mean age 49.7±9.3 years). Patients underwent pulse oximetry, basic cardiovascular reflex tests, assessment of subjective sensations according to the NSC questionnaire, the severity of neurological deficit in the legs according to the NIS-LL scale and neuropathic pain syndrome according to the NTSS-9 scale.Results and discussion. In the group of patients with T2DM, severe CAN was detected in 13.3% of patients, moderate – in 40%. In the group of patients with MetS, severe CAN was detected in 10% of patients, moderate – also in 10%. In the control group, signs of moderate CAN were detected only in 3.3% of patients. The results of pulse oximetry tests with deep breathing were comparable to the QAT results (p&lt;0.001). Conclusion. Pulse oximetry can be used to diagnose CAN.

Qpack-a Python package for QASAT-quantitative scale for grading cerebral blood flow, autonomic testing, and skin biopsies.

Quantitative grading of testing has research and clinical relevance. QASAT (quantitative scale for grading of cardiovascular reflex tests, transcranial Doppler, sudomotor testing, and small fiber densities from skin biopsies) is an objective instrument for grading dysautonomia, related small fiber neuropathy and cerebral blood flow. QASAT uses established autonomic tests (deep breathing, Valsalva maneuver, tilt test, sudomotor test) and skin biopsies for assessment of small fibers. Calculations of scores are complex. This paper presents a qpack-an open source software package that implements QASAT in a Python programming language. The qpack automatically generates reproducible scores of each test and reduces calculation errors. Datasets for verifying the correct qpack implementation are provided. The goal of qpack is to facilitate availability, reproducibility, and quality of autonomic studies and skin biopsies for assessment of small fibers. Qpack is easy to use with standard Python distributions, can be incorporated into routine clinical or research autonomic testing and it is freely available.

Cardiac Autonomic Neuropathy in Patients with Newly Diagnosed Carbohydrate Disturbances.

Cardiac autonomic neuropathy (CAN) is a serious complication of diabetes mellitus that can predispose patients to higher risk for cardiovascular death. The aim of the present study was to evaluate the presence of cardiac autonomic neuropathy and sudomotor dysfunction in patients with newly diagnosed carbohydrate disturbances (prediabetes or diabetes) and to assess their relationship to metabolic disturbances and cardiovascular risk. In the present study, we included 160 patients -78 with obesity without carbohydrate disturbances, 52 with prediabetes, and 30 with newly diagnosed diabetes. CAN was diagnosed using cardiovascular reflex tests and sudomotor function was evaluated by SUDOSCAN. Cardiovascular risk was calculated using SCORE and FRMINGHAM risk scores. The prevalence of cardiac autonomic neuropathy was significantly higher in patients with newly diagnosed diabetes. Independently of their glycemic status, the patients who had blood glucose on the 60th-minute of OGTT>8.5 mmol/l had significantly higher prevalence of cardiac autonomic neuropathy (30.2% vs 15.6%, р=0.044). Patients with high cardiovascular risk according to FRAMINGHAM and SCORE had worse heart rate variability scores. Autonomic neuropathy risk assessed by SUDOSCAN was a good predictor for the presence of CAN. In conclusion, CAN has a higher prevalence on patients with newly diagnosed diabetes compared to prediabetic and normoglycemic subjects, while the patients with blood glucose>8.5 mmol/l on the 60th-minute of OGTT have higher prevalence of CAN independently of their glycemic status. SUDOSCAN testing can be used to assess the risk of CAN and to select patients that should undergo further testing.

Thermal quantitative sensory testing as a screening tool for cardiac autonomic neuropathy in patients with diabetes mellitus.

IntroductionElectrophysiological diagnosis of cardiac autonomic neuropathy (CAN) is based on the evaluation of cardiovascular autonomic reflex tests (CARTs). CARTs are relatively time consuming and must be performed under standardized conditions. This study aimed to determine whether thermal quantitative sensory testing (TQST) can be used as a screening tool to identify patients with diabetes at a higher risk of CAN.MethodsEighty‐five patients with diabetes and 49 healthy controls were included in the study. Neurological examination, CARTs, TQST, biochemical analyses, and neuropathy symptom questionnaires were performed.ResultsCAN was diagnosed in 46 patients with diabetes (54%). CAN‐positive patients with diabetes had significantly higher warm detection thresholds (WDT) and significantly lower cold detection thresholds (CDT) in all tested regions (thenar, tibia, and the dorsum of the foot). CDT on the dorsum < 21.8°C in combination with CDT on the tibia < 23.15°C showed the best diagnostic ability in CAN prediction, with 97.4 % specificity, 60.9% sensitivity, 96.6% positive predictive value, and 67.3% negative predictive value.ConclusionTQST can be used as a screening tool for CAN before CART.

Study of Autonomic Neuropathy in Cardiovascular System in Chronic Renal Failure Patients on Maintenance Hemodialysis

Autonomic nervous system abnormalities are major causes of morbidity and mortality in patients with chronic renal failure (CRF) on hemodialysis and are generally considered a part of polyneuropathy. Postural hypotension, impotency, gastrointestinal disturbance, gastrointestinal motility, and sweating abnormalities are common symptoms. The most frequent complication in patients with CRF on hemodialysis is intradialytic hypotension, and it has been suggested that intradialytic hypotension is mostly related to autonomic neuropathy. The pathogenesis of autonomic neuropathy is unclear, but a reduced response to norepinephrine by the end organ and the toxic effect of metabolic toxins are considered to be some of the causes. Five cardiovascular reflex tests are generally used to determine autonomic neuropathy: the heart rate reaction to the Valsalva Maneuver, the heart rate variability during deep breathing, the heart rate response to standing up, the blood pressure response to standing up, and the blood pressure response to hand grip exercise.

Autonomic neuropathy in Rheumatoid Arthritis: Relationship with seropositivity of Rheumatoid factor and disease activity

Background: Autonomic neuropathy (AN) has been recognized as a strong predictor of sudden cardiac death in Rheumatoid Arthritis (RA). Autonomic neuropathy may be assessed by five cardiovascular reflex tests. Objective: To find out the prevalence and severity of AN in RA and also to assess the correlation of inflammatory markers, disease severity and serological factor, Rheumatoid factor (RF) with autonomic reflex test parameters. Method: This cross sectional study was conducted on sixty (60) female RA patients, age range 18-50 years enrolled from the Out- Patient Department of Rheumatology Wing, Department of Medicine, of Bangabandhu Sheikh Mujib Medical University (BSMMU). Age matched 30 apparently healthy females were control. Cardiac autonomic reactivity was assessed by five cardiovascular reflex tests as described by Ewing include heart rate response to standing, deep breathing, valsalva maneuver and blood pressure response to standing and sustained hand grip. Inflammatory activity in RA was assessed by serum rheumatoid factor (RF)level which was estimated by the latex agglutination test ,C-reactive protein(CRP) and ESR and marker of disease activity was assessed by Disease activity score(DAS- 28 score) value. For statistical analysis, independent sample ‘t’ test chi-square test, pearson correlation coefficient test, spearman correlation test were used. Results: Among 60 RA patients, 43 (71.6%) patients were RF positive. Frequency of AN in RA patients was significantly higher (p&lt; 0.001) compared to control. AN was detected in 78% of RA patients. Among the RA patients 17.38% showed severe,13.04% showed definite, 54.35% showed early involvement and 17.38% showed evidence of atypical pattern of AN. In addition, valsalva ratio and difference between maximum and minimum heart rate during deep breathing showed significant(p&lt;0.05) negative correlation with autoantibody Rheumatoid factor(RF) whereas no significant correlation of autonomic nerve reactivity parameters with DAS- 28, CRP and ESR were found. Conclusion: Autonomic neuropathy was associated with RA. Autonomic neuropathy may be related to the presence of autoantibody RF in RA patients. J Bngladesh Soc Physiol 2021;16(1): 70-76

Pragmatic Clinic-Based Investigation of Glycemic Variability in Patients With Type 1 Diabetes in Routine Clinical Practice and Its Association With Cardiovascular Autonomic Neuropathy: A Pilot Study

ObjectiveTo evaluate the relationship between markers of glycemic variability (GV), assessed by blinded continuous glucose monitoring (CGM), and cardiovascular autonomic neuropathy (CAN) in patients with type 1 diabetes (T1D). MethodsGV indices, such as SD and coefficient of variation were obtained by blinded CGM through an electrode inserted into the subcutaneous tissue for at least 3 consecutive days. CAN was assessed by cardiovascular reflex tests and HRV. ResultsFifteen T1D patients were included: 7 (46.7%) women, aged 47.1 ± 11.6 years, with a diabetes duration of 26 years (20 to 29.5 years). Five patients (25%) were excluded from our study. The majority of our patients presented glycated hemoglobin (60%), SD (86.3%), and coefficient of variation (60%) above the established goals. Patients with defined CAN had a longer diabetes duration, higher glycated hemoglobin levels, lower glomerular filtration rate, lower prevalence of indices related to hypoglycemic stress, and short-term GV indices compared with patients without CAN. ConclusionOur study showed an inverse association between GV and CAN. The most important risk factors associated with CAN were age, diabetes duration, and markers of chronic hyperglycemia. Furthermore, the difficulty in the interpretation of data extracted from the blinded CGM system, which also requires a minimum of 3 capillary blood glucose measurements for calibration, should be carefully analyzed to ensure the accuracy and usefulness of the blinded CGM system as a tool for diabetes management in developing countries. Further studies are necessary to establish the role of GV in the development of CAN in patients with T1D.

Elevated levels of interleukin-12/23p40 may serve as a potential indicator of dysfunctional heart rate variability in type 2 diabetes

BackgroundSystemic inflammatory processes plausibly contribute to the development of cardiovascular complications, causing increased morbidity and mortality in type 2 diabetes. Circulating inflammatory markers, i.e., interleukin (IL)-6 and tumour necrosis factor-α, are associated with neurocardiac measures. We examined a broad panel of various inflammatory and inflammation-related serum markers to obtain more detailed insight into the possible neuro-immune interaction between cardiovascular regulation and systemic level of inflammation.MethodsSerum samples from 100 participants with type 2 diabetes were analysed. Heart rate variability, cardiovascular autonomic reflex tests, and cardiac vagal tone tests were performed based on electrocardiographic readings. Data regarding covariates (demographic-, diabetes-, and cardiovascular risk factors) were registered.ResultsIncreased serum levels of IL-12/IL-23p40 (p < 0.01) and intercellular adhesion molecule (ICAM)-1 (p < 0.007) were associated with diminished heart rate variability measures. After all adjustments, the associations between IL-12/23p40, SDANN and VLF persisted (p = 0.001). Additionally, serum levels of vascular endothelial growth factor (VEGF)-C were associated with response to standing (p = 0.005).DiscussionThe few but robust associations between neurocardiac regulation and serum markers found in this study suggest systemic changes in proinflammatory, endothelial, and lymphatic function, which collectively impacts the systemic cardiovascular function. Our results warrant further exploration of IL-12/IL-23p40, ICAM-1, and VEGF-C as possible cardiovascular biomarkers in T2D that may support future decisions regarding treatment strategies for improved patient care.

A Study of Cardiovascular Autonomic Neuropathy in Adult Patients with Diabetes Mellitus at Levy Mwanawasa University Teaching Hospital

Cardiac autonomic neuropathy (CAN) is the diminished capacity of autonomic regulation of the cardiovascular system occurring in the presence of diabetes mellitus (DM) and in the absence of other aetiologies. Diabetes mellitus is a well- known cause of peripheral neuropathy. However, in comparison to somatic neuropathy, autonomic neuropathy is an under-diagnosed and under-treated chronic complication of diabetes mellitus despite its serious and significant contribution to morbidity and mortality in the diabetes mellitus population. A variety of tests, based on evaluation of the cardiovascular reflexes triggered by performing specific provocative manoeuvres, have been proposed to measure autonomic function. This study used four cardiovascular reflex tests to estimate appropriate autonomic function by examining heart rate, heart rate variation and the baroreceptor reflex. The aim of this study was to determine the presence of cardiovascular autonomic neuropathy in adult patients with diabetes mellitus at Levy Mwanawasa University Teaching Hospital in Lusaka, Zambia. Adult patients with diabetes mellitus, aged between 21 and 70 years, participated in this cross-sectional study. Four, non-invasive, cardiac autonomic reflex tests to assess for cardiac autonomic neuropathy were employed according to Ewing’s method. The parasympathetic function was analysed based on the heart rate response to paced deep breathing and to Valsalva manoeuvring. The sympathetic function was assessed by measuring heart rate and blood pressure response to postural change. Ewing`s criteria was used for the categorisation of cardiac autonomic neuropathy. Data were analysed using SPSS version 20. Continuous data were presented as means and standard deviation. Categorical data were analysed using a Fishers’ Exact Test (χ2) and a logistic regression was performed to verify the effects of diabetes mellitus’ duration, sex and age on the probability that the participants have cardiac autonomic neuropathy. A total of 52 patients participated in the study. The prevalence of Cardiac autonomic neuropathy was 48.1%. Out of 52 patients, 42.3% had definite cardiac autonomic neuropathy and 5.8% had severe cardiac autonomic neuropathy. Early cardiac autonomic neuropathy was observed in 34.6% of patients while 17.3% had no signs of cardiac autonomic neuropathy. The mean age of patients with cardiac autonomic neuropathy was 54.44 ± 10.90 years and the mean duration of diabetes mellitus from diagnosis was 5.36 ± 6.78 years. The probability of developing cardiac autonomic neuropathy increased with increasing age and hypertensive participants were more likely develop cardiac autonomic neuropathy (ѵ = 5.82, p = .001). In conclusion, cardiac autonomic neuropathy was present in a significant proportion of adult patients with diabetes mellitus at Levy Mwanawasa University Teaching Hospital, reflecting the increased morbidity encountered by this population. In order to improve patient quality of life and reduce disease burden, screening for cardiac autonomic neuropathy should be implemented using cardiovascular autonomic reflex tests which are relatively simple, safe and affordable.

Relationship between vitamin D status and cardiac autonomic neuropathy in prediabetes.

Studies have suggested that vitamin D deficiency is associated with impaired cardiac autonomic nerve function. This study explores the correlation between serum vitamin D and cardiac autonomic neuropathy (CAN) in prediabetes and reveals the protective effect of vitamin D against CAN. In total, 113 patients with prediabetes and definite CAN and 180 with prediabetes but without CAN were enrolled on the basis of their standard cardiovascular autonomic reflex test results. Chemiluminescence was used to measure 25(OH)D, the patients with CAN were divided into four groups, and the heart rate variability (HRV) of the study groups were compared. Relative to the 50≤25(OH)D<75-nmol/L group, the 25≤25(OH)D<50-nmol/L and 25(OH)D<25-nmol/L groups exhibited significant differences in the time and frequency domains of HRV (p< 0.05). Furthermore, we discovered that 25(OH)D is positively correlated with standard deviation of normal-to-normal RR intervals (SDNN) (β=0.566, p<0.05) and negatively correlated with low-to-high frequency ratio (LF/HF) (β=-0.199, p<0.05). A logistic regression reveals that CAN in prediabetes is significantly correlated with the 25(OH)D concentrations of <25 nmol/L (OR, 2.380 [1.208-4.691]; p<0.05) and 25≤25(OH)D<50 nmol/L (OR, 1.875 [1.064-3.751]; p<0.05). Serum 25(OH)D is significantly correlated with CAN in prediabetes, especially in the 25(OH)D <25-nmol/L group. Therefore, vitamin D deficiency may be related to the occurrence of CAN in prediabetes, and appropriate supplementation may provide protection against CAN.

The Association Between Cardiovascular Autonomic Function and Changes in Kidney and Myocardial Function in Type 2 Diabetes and Healthy Controls.

BackgroundThe mechanisms linking cardiovascular autonomic neuropathy, diabetic kidney disease and cardiovascular mortality in type 2 diabetes are widely unknown. We investigated the relationship between baseline cardiovascular autonomic function and changes in kidney and myocardial function over six years in patients with type 2 diabetes and healthy controls.Methods Post-hoc analysis of a cohort study in 24 patients with type 2 diabetes and 18 healthy controls. Baseline determinants were cardiovascular autonomic reflex tests (heart rate response to: standing (30:15); deep breathing (E:I); and the Valsalva test) and time- and frequency-domain heart rate variability indices. Outcomes were changes in estimated glomerular filtration rate (eGFR), albuminuria, myocardial flow reserve (MFR) measured by cardiac 82Rb Positron emission tomography computed tomography (PET/CT), and coronary artery calcium score (CACS).ResultsMean age at inclusion was 61 ± 10 years and 36% were female. Mean follow up time was 6 ± 0 years. A lower response in heart rate to the Valsalva test (corresponding to weaker autonomic function) was associated with a larger decline in eGFR (p=0.04), but not significantly after adjustment for sex, baseline age, smoking status, systolic blood pressure, heart rate, HbA1c, body mass index and baseline eGFR (p=0.12). A higher baseline response in heart rate to standing (30:15) was associated with a larger decline in myocardial flow reserve in the unadjusted analysis (p=0.02) and after adjustment (p=0.02). A higher response in heart rate to the Valsalva maneuver was associated with a larger increase in CACS (p = 0.02), but the association became insignificant after adjustment (p = 0.16).ConclusionA lower response in heart rate to the Valsalva test was associated with a larger decline in kidney function, indicating that autonomic dysfunction may predict future loss of kidney function. However, we did not find any association between lower values in cardiovascular autonomic function at baseline and a worsening in albuminuria, myocardial function, or atherosclerotic burden.

Diagnosis, staging, and associated conditions of cardiovascular autonomic neuropathy in Libyan patients with diabetes

Background: Cardiovascular autonomic neuropathy (CAN) can affect daily activities and patients' quality of life and evoke potentially life-threatening outcomes in diabetes mellitus (DM). Objectives: We aimed to identify and characterize CAN and associated disorders in Libyan patients with DM at National Diabetes Hospital. Patients and Methods: Ninety-nine patients with DM seen in the outpatient clinics from October 2017 to April 2018 at National Diabetes Hospital were prospectively evaluated. Assessments for CAN were made by clinical symptoms and signs, cardiovascular autonomic reflex tests, and echocardiogram. Patients with potentially confounding concomitant medical conditions were excluded. CAN is defined as possible (one abnormal cardiovagal test), confirmed (two abnormal such tests), and severe (with concomitant orthostatic hypotension and heart rate abnormality). Results: Sixty-two percent of the studied patients (mean age: 52 ± 1.5 years, 53% – female) with DM had CAN. CAN diagnosis was possible in 18% of these patients, confirmed in 6%, and severe in 38%. The presence of severe CAN was associated with hypoglycemic unawareness (P = 0.01), dyslipidemia (P = 0.012), and microvascular diabetic complications (P = 0.04). Conclusions: In this cohort of relatively old and high-risk cardiovascular disease, patients with diabetes, uncontrolled blood pressure, associated dyslipidemia, presence of microvascular complication of diabetes, and history of hypoglycemic unawareness were strongly associated with a severe form of cardiac autonomic neuropathy with potentially serious clinical consequences. Larger and more detailed studies are needed to elucidate further the complex association between hypoglycemia and cardiac autonomic dysfunction.

Neurogenic orthostatic hypotension in early stage Parkinson's disease: New insights from the first 105 patients of the BoProPark study

ObjectivesThe prevalence of neurogenic orthostatic hypotension (NOH, due to cardiovascular autonomic failure) at early stage of Parkinson's disease (PD) is unknown. The aims of this study are to prospectively evaluate in a cohort of PD patients recruited within 3 years from motor onset (1) cardiovascular autonomic functions by means of cardiovascular reflex tests (CRTs) and the occurrence of NOH; (2) the frequency of orthostatic symptoms with a validated questionnaire. MethodsWe included the first 105 PD patients of the prospective “BoProPark” study. Each patient underwent CRTs (head up tilt test; Valsalva manoeuvre; deep breathing; cold face test and handgrip test) under continuous blood pressure monitoring according to standardized procedures and SCOPA-Aut questionnaire at baseline (T0) and after 16 months (T1). A group of 50 age- and sex-matched controls was used for comparison. ResultsAt T0 (mean age 61 ± 9 years, disease duration 19 ± 9 months) NOH was detected in 4/105 (3.8%) patients, whereas at T1 in 8/105 (7.6%). CRTs responses assessing sympathetic function were impaired at T0 in PD patients compared to controls and progressively worsened at T1. Only 1 patient at T0 and 3 at T1 with NOH reported orthostatic symptoms with low frequency, while the majority of patients reporting these symptoms did not have OH at testing. ConclusionsOur prospective study shows that NOH is not common at early PD stage. Asymptomatic mild sympathetic impairment was observed at first evaluation and progressed with disease evolution. Secondary OH may account for the higher prevalence of OH in PD reported so far.

Leisure-Time Physical Activity and Glycemic Control Independently Predicts Cardiac Autonomic Neuropathy in Type 2 Diabetes Mellitus.

Though cardiac autonomic neuropathy (CAN) is a common complication of type 2 diabetes mellitus (T2DM); still, there is lack of clarity on pathophysiological correlates for its onset and progression. Therefore, the purpose of this study was to investigate the predictive ability of lifestyle and cardiometabolic risk factors for CAN in T2DM patients. A total of 105 Indian T2DM patients were recruited in the present study. Cardiometabolic risk factors, such as glycemic control, lipids, resting heart rate, systolic and diastolic blood pressure, and lifestyle risk parameters, such as physical activity levels and sleep quality were assessed. Standard cardiovascular autonomic reflex tests were performed for diagnosing CAN by Ewing's criteria. Leisure-time physical activity and glycosylated hemoglobin were significant independent predictors of CAN in T2DM. Leisure-time physical activity and glycosylated hemoglobin predicted the occurrence of CAN at cutoff values ≤4.68 metabolic equivalent-hours per week (P = .007) and >7.5% (P = .002), respectively. The T2DM patients should be encouraged to engage in leisure-time physical activity of at least 4.68 metabolic equivalent-hours per week (equivalent to 1.2h of walk or 0.6h of jog per week) and therapeutic strategies for controlling hyperglycemia in T2DM should aim to reduce glycosylated hemoglobin below 7.5% to reduce CAN occurrence.

Cardiovascular autonomic neuropathy and the impact on progression of diabetic kidney disease in type 1 diabetes

IntroductionWe investigated the association between cardiovascular autonomic neuropathy (CAN) and decline in kidney function in type 1 diabetes.Research design and methodsWe included 329 persons with type 1 diabetes. CAN was...

Normative data on cardiovascular autonomic function in Greenlandic Inuit

IntroductionDiabetes is increasing among Greenlandic Inuit; however, the prevalence of cardiovascular autonomic neuropathy (CAN) is yet unknown. The assessment of CAN requires an ability to differentiate between normal and abnormal....