Cardiovascular Autonomic Tests Research Articles

Prevalence of cardiovascular autonomic neuropathy in an admixed population of patients with type 1 diabetes. Lessons from a pioneer multicentre study in Brazil

AIMSTo evaluate the prevalence of cardiovascular autonomic neuropathy (CAN) and its associated factors in Brazilian patients with type 1 diabetes (T1D). MethodsThis cross-sectional, multicentre study was conducted in 14 public clinics in ten Brazilian cities. From 1760 patients, 1712 were included (97.3 %): 953 females (55.7 %), 930 (54.3 %) Caucasians, aged 29.9 ±11.9 years and with diabetes duration of 15.4 ± 9.2 years. CAN was evaluated using cardiovascular autonomic reflex tests. ResultsThe prevalence of CAN was 23.4 %. Multivariable hierarchical logistic regression showed CAN associated with age, smoking, lower socioeconomic status, higher yearly medical appointments, insulin therapeutic regimens, higher levels of HbA1c, total cholesterol, uric acid, diastolic blood pressure and heart rate, presence of retinopathy, diabetic kidney disease and a tendency to be associated with severe hypoglycemia. Lower health-related quality of life was also found in univariate analysis in these patients. ConclusionsPatients with T1D presented an important prevalence of CAN that was associated with other diabetes-related chronic complications, and also with demographic, clinical and laboratorial traditional risk factors. Considering lack of formal policy, our data could be used for guiding public health approach to awareness and CAN’s screening, diagnosis and clinical management in patients with T1D in Brazil.

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

ObjectiveThe 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. MethodsParticipants 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. ResultsParticipants 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.

Does the Relationship of the Autonomic Symptoms Questionnaire COMPASS 31 with Cardiovascular Autonomic Tests Differ between Type 1 and Type 2 Diabetes Mellitus?

The aim was to investigate if autonomic symptoms questionnaire Composite Autonomic Symptom Score (COMPASS) 31 has different association with cardiovascular autonomic neuropathy (CAN) and diagnostic performance between type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). Seventy-nine participants with T1DM and 140 with T2DM completed COMPASS 31 before cardiovascular reflex tests (CARTs) for CAN, and assessment of symptoms, signs, vibration, and thermal perception thresholds for diabetic polyneuropathy (DPN) diagnosis. COMPASS 31 total weighted score (TWS) was similar in the two groups, but significantly associated with confirmed CAN only in T1DM (P=0.0056) and not T2DM group (P=0.1768) and correlated with CARTs score more strongly in T1DM (rho=0.356, P=0.0016) than in T2DM group (rho=0.084, P=0.3218) (P=0.016). Only in T1DM and not T2DM group, the area under the receiver operating characteristic curve (AUC) reached a fair diagnostic accuracy (>0.7) for confirmed CAN (0.73±0.07 vs. 0.61±0.08) and DPN (0.75±0.06 vs. 0.68±0.05), although without a significant difference. COMPASS 31 TWS (cut-off 16.44) reached acceptable diagnostic performance in T1DM, with sensitivity for confirmed CAN 81.2% and sensitivity and specificity for DPN 76.3% and 78%, compared to T2DM group (all <70%). AUC for DPN of orthostatic intolerance domain was higher in T1DM compared to T2DM group (0.73±0.05 vs. 0.58±0.04, P=0.027). COMPASS 31 is more weakly related to CAN in T2DM than in T1DM, with a fair diagnostic accuracy for confirmed CAN only in T1DM. This difference supports a multifactorial origin of symptoms and should be considered when using COMPASS 31.

Impacts of Chemerin Levels and Antioxidant Capacity on the Severity of Cardiovascular Autonomic Neuropathy in Patients with Type 2 Diabetes and Prediabetes.

Existing evidence supports an association between chemerin levels and cardiovascular risk, while reduced thiol levels are linked to diabetes mellitus. It is hypothesized that chemerin may contribute to autonomic dysfunction and cardiovascular risk in type 2 diabetes mellitus (T2DM), potentially mediated by the antioxidant capacity of patients with well-controlled T2DM and prediabetes. Comprehensive cardiovascular autonomic testing and biomarker assessments were conducted for all participants. The severity of cardiovascular autonomic neuropathy (CAN) was evaluated using the composite autonomic scoring scale (CASS). A mediation model was employed to explore the potential relationships among chemerin levels, antioxidant capacity (indicated by thiol levels), and CAN severity (indicated by CASS values). A total of 184 participants were enrolled in this study, comprising 143 individuals with T2DM and 40 individuals with prediabetes. The findings reveal a significant negative association between thiols levels (r = -0.38, p < 0.0001) and the CASS values, while a positive association is observed between chemerin levels (r = 0.47, p < 0.0001) and the CASS values. Linear regression analysis identified chemerin and thiols as independent variables significantly associated with CASS values. Subsequent mediation analysis elucidated that thiols levels act as mediators in the relationship between elevated chemerin levels and an increased CASS value. This study shows that poor cardiovascular function, higher chemerin levels, and reduced antioxidant capacity coexist in individuals with T2DM and prediabetes. Mediation analysis suggests a pathophysiological link between high chemerin levels and low antioxidant capacity, adversely impacting CAN severity.

Increased levels of circulating endostatin are linked to orthostatic hypotension

Abstract Background Orthostatic hypotension (OH) occurs when blood pressure regulation fails. The underlying molecular mechanism of OH remain largely unexplored. Endostatin is a biologically active molecule cleaved by matrix metalloproteinases, elastases and cathepsins from collagen XVIII in the extracellular matrix and inhibits angiogenesis. Circulating levels of endostatin have been proposed to be involved in blood pressure (BP) regulation, by inducing nitric oxide release. To date, the relationship between endostatin and OH have not been examined. Purpose We aimed to investigate circulating levels of endostatin in patients with verified OH by tilt test at a tertiary syncope unit compared with healthy age- and sex-matched controls from the same geographical region. Methods We performed an age- and sex-matched case-control study in 150 patients with OH verified by positive head-up tilt-testing and other cardiovascular autonomic tests at a tertiary syncope unit, and 150 healthy controls with negative active standing tests and no history of syncope, orthostatic intolerance, and endocrine disease. High-sensitivity chemiluminescence sandwich immunoassay was used to measure circulating levels of endostatin in a blinded fashion. Receiver operating characteristic curves were constructed to analyze the discriminative ability of endostatin in OH compared with healthy controls. Multivariate logistic regression was used to assess the association between endostatin, OH and hemodynamic variables adjusting for age and sex. Results Study characteristics are displayed in the Table. Patients with OH had significantly higher absolute levels of circulating endostatin compared with healthy controls (59,024 ± 2513 vs. 44,090 ± 1978 pg/mL, p&amp;lt;0.001). Multivariate-adjusted logistic regression analysis controlling for age, sex, minimum systolic and minimum diastolic BP during tilt, identified endostatin as an independent determinant for OH (beta-coefficient 0.80, p=0.025). The obtained area under the curve was 0.70, P&amp;lt;0.001, Figure). Conclusions Our findings indicate that patients with orthostatic hypotension have increased circulating levels of endostatin, independent of age, sex, and hemodynamic variables. Our results highlight the relevance of investigating the molecular pathways related to orthostatic hypotension. Further studies are warranted to assess the prognostic and therapeutic role of endostatin assessment in individuals with orthostatic hypotension.Tablestudy characteristicsFigureROC Curve

Quantitative autonomic testing after recovery from acute COVID-19 infection: comparison with findings in controls and individuals with neurogenic autonomic dysfunction

Abstract Background/Introduction Cardiovascular autonomic dysfunction (CvAD) is believed to contribute to the persistence of troublesome symptoms following apparent recovery from an acute COVID-19 infection. Common complaints in this setting include cognitive impairment (‘brain fog’), fatigue, and both postural and exertional intolerance with a sensation of excessive rapid heart beating. However, while the occurrence of CvAD post-acute COVID-19 has been widely recognized, its quantitative assessment remains largely unexplored. Purpose The purpose of this study was to determine whether quantitative cardiovascular autonomic testing in post-acute COVID-19 patients differ from findings in Controls and are more similar to individuals with Neurogenic CvAD, such as those with Pure Autonomic Failure. Methods Quantitative autonomic testing was prospectively undertaken in two patient groups: post-acute COVID-19 and Neurogenic CvAD patients, and in control subjects. Acute COVID-19 was documented by the nasopharyngeal PCR method and all affected patients had recovered at least 1 week prior to their autonomic study. Neurogenic CvAD patients were studied as part of their diagnostic evaluation, and none had a COVID-19 infection prior to their study. Measurements included i) heart rate (HR) and blood pressure (BP) responses during active standing (AS), ii) time to BP nadir and time to BP recovery during AS, iii) Valsalva ratio (VR), and iv) respiratory sinus arrhythmia (RSA). The unpaired student t-test and Mann Whitney U test were used to analyze normally and non-normally distributed data, respectively, between post-acute COVID patients and the Control and Neurogenic CvAD patients. All variables were continuous and presented as means with corresponding standard deviations (SD) when normally distributed or interquartile ranges (IQR) when non-normally distributed. A p-value of &amp;lt;0.05 was considered statistically significant. Results Post-acute COVID-19 patients (N=55, 83.6% female) and Controls (N=82, 86.6% female) were of similar age (39 [IQR 27.3, 49.2] vs. 33 [IQR 21.4, 40.0] years, respectively, p=0.034). Neurogenic CvAD patients (N=27, 51.9% female) were older (68 [IQR 62.9, 74.3], p&amp;lt;0.00001). The main findings (Table 1, mean [SD]) indicate that post-acute COVID-19 patients exhibited HR and BP responses during AS similar to the Control group; on the other hand, average VR, maximum systolic BP drop during AS, and maximum HR increase during AS in COVID-19 patients trended towards findings in Neurogenic CvAD patients. Conclusion Recovered post-acute COVID-19 patients referred for autonomic dysfunction evaluation due to persisting symptoms exhibit autonomic testing findings similar to control subjects but trending towards observations in neurogenic CvAD.

Pain associated with COVID-19 vaccination is unrelated to skin biopsy abnormalities.

Previous clinical observations raised the possibility that COVID-19 vaccination might trigger a small-fibre neuropathy. In this uncontrolled observational study, we aimed to identify small fibre damage in patients complaining of generalized sensory symptoms and pain after COVID-19 vaccination. We collected clinical data, including a questionnaire for assessing autonomic symptoms (Composite Autonomic Symptom Score-31), and investigated quantitative sensory testing (QST) and skin biopsy in 15 prospectively enrolled patients with generalized sensory symptoms and pain after COVID-19 vaccination. Nine patients complaining of orthostatic intolerance also underwent cardiovascular autonomic tests. We found that all patients experienced widespread pain, and most of them (11 of 15) had a fibromyalgia syndrome. All patients had normal skin biopsy findings, and in the 9 patients with orthostatic intolerance, cardiovascular autonomic tests showed normal findings. Nevertheless, 5 patients had cold and warm detection abnormalities at the QST investigation. In our study, most patients complaining of generalized sensory symptoms and pain after COVID-19 vaccination had clinical and diagnostic test findings compatible with a fibromyalgia syndrome. Although the abnormal QST findings we found in 5 patients might be compatible with a small-fibre neuropathy, they should be cautiously interpreted given the psychophysical characteristics of this diagnostic test. Further larger controlled studies are needed to define precisely the association between small fibre damage and COVID-19 vaccination.

The Composite Autonomic Symptom Score 31 Questionnaire: A Sensitive Test to Detect Risk for Autonomic Neuropathy.

Autonomic neuropathy is a common but often neglected complication of diabetes, prediabetes, and even in individuals with an elevated risk of diabetes. The Composite Autonomic Symptom Score (COMPASS) 31 is a validated and easy-to-use questionnaire regarding autonomic symptoms. We aimed to use a digitally, Norwegian version of the COMPASS 31 in people with different durations of diabetes and healthy controls to consider feasibility and to investigate if scores could discriminate between positive and negative outcomes for established tests for diabetic neuropathy, including cardiovascular autonomic neuropathy (CAN) and a novel method of examining the gastrointestinal visceral sensitivity. We included 21 participants with longstanding type 2 diabetes, 15 with early type 2 diabetes, and 30 matched controls. The mean age for all groups was 69 years. Participants were phenotyped by cardiovascular autonomic reflex tests, electrical skin conductance, sural nerve electrophysiology, and the monofilament test. As a proxy for gastrointestinal visceral and autonomic nerve function, evoked potentials were measured following rapid rectal balloon distention. Participants with longstanding diabetes scored a median (IQR) of 14.9 (10.8-28.7) points, early diabetes of 7.3 (1.6-15.2), and matched controls of 8.6 (4.1-21.6), p = 0.04. Women and men scored 14.4 (5.5-28.7) and 7.8 (3.6-14.6) points, respectively, p = 0.01. Participants with definite or borderline CAN scored 14.3 (10.4-31.9) points, compared to participants with no CAN, 8.3 (3.2-21.5), p = 0.04. Lowering the diagnostic cut-off from 16 to 10 points increased the sensitivity from 0.33 to 0.83, with a decreased specificity from 0.68 to 0.55. We successfully used COMPASS 31 in Norwegian. Thus, following the guidelines, we suggest clinical implementation for the assessment of autonomic neuropathy. Participants with longstanding diabetes had an increased likelihood of symptoms and signs of autonomic neuropathy. For screening purposes, the sensitivity was improved by lowering the cut-off to 10 points, with a lower score nearly excluding the diagnosis.

Definitive aetiology of unexplained syncope after cardiovascular autonomic tests in a tertiary syncope unit.

Syncope is a common condition with many possible causes, ranging from benign to life-threatening aetiologies. Establishing a diagnosis can be difficult, and specialized syncope units, using cardiovascular autonomic tests (CATs), including a head-up tilt test, can increase the diagnostic yield. However, up to one-fifth of examined patients have inconclusive CAT results. The aim of the present study was to investigate the predictive value of history, and clinical findings for unexplained syncope after CAT and characterize the group with negative results. Consecutive syncope patients [n = 2663, 61% women, median age 52 (32-69) years] were evaluated and CAT explained aetiology of syncope in 79% of cases, whereas 21% remained unexplained. Predictors of negative CAT were older age at first syncope (+8% higher odds per 10-year increment, P = 0.042), higher supine heart rate (HR; +12% per 10 b.p.m.; P = 0.003), absence of prodromes (+48%; P < 0.001), hypertension (+45%; P = 0.003), diabetes (+82%; P < 0.001), heart failure (+98%; P = 0.014), and coronary artery disease (+51%; P = 0.027). Compared with vasovagal syncope, patients with negative CAT were older, reported more often the absence of prodromes, and had a higher burden of cardiovascular comorbidities. A cardiovascular autonomic test established the cause of syncope in 79% of patients evaluated in a syncope unit. Syncope without prodromes and cardiovascular comorbidities were significant predictors of failure to reveal an aetiology from assessment by CAT. These are known risk factors for cardiac syncope and patients with inconclusive CAT warrant further investigation.

Cardiac autonomic neuropathy as risk factor of diabetic complications progression

Introduction. Diabetes mellitus (DM) is the most common and incapacitating endocrine disorder. Diabetic foot syndrome (DFS) is one of the most serious complications of DM, which is the main cause of nontraumatic lower-extremity amputations. Despite the efforts of the entire medical community, the survival rate of DFS patients with non-healing ulcers and after foot surgery does not exceed 50% over 5 years and is comparable to the survival rates of patients with colorectal cancer.Aim. It has been demonstrated that postsurgical diabetic foot wounds tend to chronization of inflammatory process. The diabetic autonomic neuropathy can be involved in diabetic foot damages. We hypothesized that progression of cardiovascular autonomic neuropathy (CAN) leads to aggressive microvascular complications of diabetes and delay the postsurgical wound healing in diabetic foot patients during 2 years of observation.Materials and methods. We examined 94 outpatients with postsurgical diabetic foot wounds and observation period of two years. The clinical neurological examination and standard cardiovascular autonomic reflex tests with identification of severe/advanced abnormalities were performed at baseline and after 2 years. The progression of CAN was diagnosed in cases of an increase in the amount of cardiovascular autonomic reflex tests by 1 score and more. The unsatisfactory result of wound treatment was detected in patients with wound healing delay and new cases of surgery debridement, foot amputations and Charcot foot during 2 years of observation.Results. The mean duration of diabetes was 10.7 year, HbA1c 8.3%, LDL-Chol 3.3 mmol/l, TG 1.8 mmol/l. The 51.1% patients had been amputated in the level of foot, 48.9% patients had surgery debridement. All patients had CAN, confirmed/severe forms in 57.4% cases. The progression of CAN was found in 22.3% patients, the most of them with functional stage at baseline. The aggressive course of CAN increased the risk of progression of diabetic sensomotor neuropathy (OR = 14.6; 95% CI 3.0–70.5; p = 0.0006), nephropathy (OR = 22.4; 95% CI 3.4–147.4; p = 0.0009) and unsatisfactory result of wound treatment (OR = 40; 95% CI 6.0–268.5; p = 0.0001).Conclusions. The patients with diabetic foot surgery wounds has high risk of confirmed/severe CAN and its progression during 2 years. The aggressive course of CAN associates with unsatisfactory result of wound treatment and progression of microvascular diabetic complications.

487-P: Cardiovascular Autonomic Function in Long COVID-19 Individuals With and Without Diabetes

Coronavirus disease 2019 (COVID-19) has been associated with a broad spectrum of long-term complications. These include the development and progression of severe autonomic dysfunction, particularly among people with diabetes. We evaluated cardiovascular autonomic (CAN) function in a cross-sectional study in 47 adults with long COVID-19 with (N=21, mean age 61 years, 43% women, mean A1c 6.2%) and without type 2 diabetes mellitus (T2DM) (N=26, mean age 58 years, 65% women) and compared them with T2DM without COVID-19 (N=45, mean age 57 years, 42% women, mean A1c 7.8%). CAN was assessed with cardiovascular autonomic reflex tests (30:15 ratio, E.I ratio, Valsalva ratio) and indices of heart rate variability (SDNN, RMSSD). We used pairwise comparison and Analysis of Covariance (ANCOVA) both adjusted for age, gender, race, and BMI to compare the groups. In a pairwise comparison higher heart rate (HR) and lower CAN measures (SDNN, RMSSD, Valsalva) were found in T2DM with COVID-19 compared to T2DM without COVID-19. Lower HR and lower Valsalva were found in COVID-19 individuals without T2DM compared to T2DM without COVID-19. When comparing the three groups, lower Valsalva were found in COVID-19 individuals with and without T2DM compared to T2DM without COVID-19 (Figure). These data suggest that COVID-19 exacerbates CAN in patients with T2DM and impacts CAN in people without T2DM at a magnitude similar to that of T2DM patients. Disclosure J.Fleischer: None. A.Vasbinder: None. S.Hayek: None. R.Busui: Board Member; American Diabetes Association, Consultant; Averitas Pharma, Inc., Lexicon Pharmaceuticals, Inc., Nevro Corp., Novo Nordisk, Roche Diagnostics, Procter &amp; Gamble, Research Support; Novo Nordisk, Medtronic, National Institutes of Health. S.V.G.Gunaratnam: None. Y.Huang: None. L.Ang: None. M.Charles: Research Support; Novo Nordisk Foundation, Speaker's Bureau; Novo Nordisk A/S, Boehringer-Ingelheim. A.Katona: None. N.Baker: None. K.R.Mizokami-stout: None. Y.Lin: None. Funding National Institute of Diabetes and Digestive and Kidney Diseases (U01DK119083, P30DK020572); Steno North American Fellowships 2021; Novo Nordisk Foundation (21OC0072180)

Novel inflammatory biomarkers in postural orthostatic tachycardia syndrome

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Postural Orthostatic Tachycardia Syndrome (POTS) is a disorder characterized by excessive orthostatic tachycardia and orthostatic intolerance. While traditional inflammatory biomarkers tend to be normal, a subclinical inflammatory process may be present in POTS. Purpose We aimed to analyse novel inflammatory biomarkers in POTS patients: Growth Differentiation Factor 15 (GDF15), Neutrophil Gelatinase Associated Lipocalin (NGAL), Intercellular Adhesion Molecule 1 (ICAM-1), Tumour Necrosis Factor Receptor 1 (TNFR1) and Tumour Necrosis Factor Receptor 2 (TNFR2) and compared them to healthy controls. These inflammatory biomarkers have been shown to be independent predictors of major adverse cardiovascular events in other populations. Methods An age- and sex-matched case-control study included 65 patients verified to have POTS by positive head-up tilt-testing and cardiovascular autonomic tests, and 65 healthy controls (mean age: 31.1 vs 31.5 years, 84% females) with negative active standing tests and no history of syncope, orthostatic intolerance, or endocrine disease. High-sensitivity chemiluminescence sandwich immunoassay was used to measure plasma levels of inflammatory biomarkers in a blinded fashion. Descriptive statistics compared groups and a univariate ANOVA was employed. Biomarker values were log-transformed. A score incorporating all biomarkers was generated to see if the totality of biomarkers discriminated POTS patients from controls. Results Baseline characteristics are displayed in Table 1. Mean levels of GDF15 (p=0.01), NGAL (p=0.003), ICAM-1 (p=0.04) and TNFR1 (p=0.03) were significantly higher in POTS vs controls, whereas TNFR2 (p=0.04) was significantly lower in POTS (p=0.04). The product of four upregulated biomarkers divided by TNFR2 produced a receiver operator curve (ROC) with an area under the curve (AUC) of 0.703 (p&amp;lt;0.001) (Fig.1). Conclusion POTS patients had increased GDF15, NGAL, TNFR1 and ICAM-1 levels and reduced TNFR2 levels suggesting underlying, yet undefined, subclinical inflammatory processes involving neutrophil and endothelial activation.

Cardiovascular autonomic neuropathy is associated with increased glycemic variability driven by hyperglycemia rather than hypoglycemia in patients with diabetes

AimCardiac autonomic neuropathy (CAN) has been suggested to be associated with hypoglycemia and impaired hypoglycemia unawareness. We have assessed the relationship between CAN and extensive measures of glucose variability (GV) in patients with type 1 and type 2 diabetes. MethodsParticipants with diabetes underwent continuous glucose monitoring (CGM) to obtain measures of GV and the extent of hyperglycemia and hypoglycemia and cardiovascular autonomic reflex testing. ResultsOf the 40 participants (20 T1DM and 20 T2DM) (aged 40.70 ± 13.73 years, diabetes duration 14.43 ± 7.35 years, HbA1c 8.85 ± 1.70%), 23 (57.5%) had CAN. Despite a lower coefficient of variation (CV) (31.26 ± 11.87 vs. 40.33 ± 11.03, P = 0.018), they had a higher CONGA (8.42 ± 2.58 vs. 6.68 ± 1.88, P = 0.024) with a lower median LBGI (1.60 (range: 0.20–3.50) vs. 4.90 (range: 3.20–7.40), P = 0.010) and percentage median time spent in hypoglycemia (4 (range:4–13) vs. 1 (range:0–5), P = 0.008), compared to those without CAN. The percentage GRADEEuglycemia (3.30 ± 2.78 vs. 5.69 ± 3.09, P = 0.017) and GRADEHypoglycemia (0.3 (range: 0 – 3.80) vs. 1.8 (range: 0.9–6.5), P = 0.036) were significantly lower, while the percentage median GRADEHyperglycemia (95.45 (range:93–98) vs. 91.6 (82.8–95.1), P = 0.013) was significantly higher in participants with CAN compared to those without CAN. ConclusionCAN was associated with increased glycemic variability with less time in euglycemia attributed to a greater time in hyperglycemia but not hypoglycemia.

"Arterial stiffness is not associated with changes in the circadian pattern of blood pressure in patients with type 1 diabetes mellitus and cardiovascular autonomic dysfunction".

Cardiovascular autonomic neuropathy (CAN) associates an abnormal circadian pattern in blood pressure (BP) regulation that might be aggravated by the coexistence of arterial stiffness. We aimed to evaluate the effect of arterial stiffness in the circadian rhythm of BP in patients with type 1 diabetes and CAN. Cross-sectional study including 56 consecutive patients with type 1 diabetes and CAN, with (n = 28) or without (n = 24) arterial stiffness as defined by an ankle-brachial index above 1.2. CAN was diagnosed by BP and heart rate responses to active standing and cardiovascular autonomic reflex tests. Absence of nocturnal decrease in BP-"non-dipping" pattern- was defined by a daytime to nighttime decrease in mean BP smaller than 10%. The study's subjects mean age was 40 ± 11 years-old, their mean duration of diabetes was 22 ± 10 years, and their mean A1c was 7.9 ± 1.5%. A "non-dipping" pattern was observed in 28 patients (54%) regardless of the presence or absence of arterial stiffness. Age, waist circumference, body mass index, and A1c, were introduced as independent variables into a multiple regression analysis. The stepwise model (R2: 0.113, p = 0.016) retained only A1c levels (β: ‒ 0.333, 95% confidence interval [CI]: -3.10 to -0.33) as significant predictor of the percentage of nighttime decrease in mean BP. A non-dipping pattern in BP is very common in patients with type 1 diabetes presenting with subclinical CAN and is associated with a poorer metabolic control. On the contrary, coexistence of arterial stiffness is not associated with abnormalities in circadian BP regulation.

Cardiovascular autonomic reflex tests using a handheld device in the diagnosis of cardiovascular autonomic neuropathy in patients with schizophrenia

Study objectiveThis study investigated whether schizophrenia and the duration of schizophrenia were associated with cardiovascular autonomic neuropathy (CAN) by using heart rate variability (HRV) as a marker. DesignCross-sectional study. SettingThe examinations were conducted at the Centre for Psychosis Research and at the Department of Cardiology, Aalborg University Hospital, Aalborg, Denmark. Participants240 patients with first-episode and chronic schizophrenia and 180 controls. InterventionsCAN was assessed by the cardiovascular reflex tests (CARTs): HR, RS ratio, E:I ratio, and VM using a handheld device. Main outcome measuresOne abnormal CART was interpreted as borderline CAN and ≥2 abnormal CARTs established definitive CAN. Borderline CAN and definitive CAN together was categorized as overall CAN. Analyses were adjusted for age, sex, smoking, overweight, and hypercholesterolemia. ResultsA total of 240 patients with schizophrenia (median age 42.5 [28.8, 52.3], 42.9 % women) and 180 controls (median age 45.8 [24.0, 60.1], 47.8 % women) were included, with 50.8 % of patients with schizophrenia having overall CAN compared to 27.2 % among controls. Dividing patients into patients with first-episode and chronic schizophrenia, 32.9 % vs 10 % (p < 0.001) and 59.1 % vs 41 % (p < 0.001) had overall CAN compared with controls, respectively. Schizophrenia was significantly associated with overall CAN (OR, 2.80; 95%CI, 1.75–4.50), with an OR of 2.31 (95%CI, 1.14–4.68) for first-episode schizophrenia and an OR of 2.97 (95%CI, 1.81–4.87) for chronic schizophrenia. ConclusionIt was demonstrated that a diagnosis of schizophrenia was associated with CAN. Patients with chronic schizophrenia had a significantly higher prevalence of CAN compared to patients with first-episode schizophrenia, suggesting an association between the duration of schizophrenia and CAN.

Cardiovascular reflex tests detect autonomic dysfunction in symptomatic and pre-symptomatic subjects with hereditary transthyretin amyloidosis.

Autonomic dysfunction is a distinctive but undervalued feature of hereditary transthyretin amyloidosis (ATTRv). It may predate the onset of polyneuropathy and cardiomyopathy, thereby providing crucial prognostic and therapeutic information. The objective of this study was to assess autonomic function by means of the standardized cardiovascular autonomic reflex tests (CRTs) in a cohort of subjects with genetically proven ATTRv from non-endemic areas who were in the symptomatic and pre-symptomatic stages. All subjects enrolled in this cross-sectional study had genetically proven ATTRv. They underwent the head-up tilt test, Valsalva manoeuvre, deep breathing test, cold face test and handgrip test while under continuous blood pressure and heart rate monitoring. Based on the results of the nerve conduction study, the subjects were divided into two groups: those with polyneuropathy (ATTRv-wPN) and those without polyneuropathy (ATTRv-woPN). Age- and sex-matched healthy controls (HC) were used for comparison. Thirty-seven ATTRv subjects (19 with ATTRv-wPN, 18 with ATTRv-woPN) and 41 HC performed the CRTs. Of these 37 subjects with ATTRv, four (11%) presented neurogenic orthostatic hypotension the during head-up tilt test. Based on the results of the CRTs, autonomic dysfunction characterized by either sympathetic or parasympathetic impairment was detected in 37% and 63% of ATTRv-wPN subjects, respectively. Subjects with ATTRv-woPN presented a significant impairment of autonomic responses to the Valsalva manoeuvre compared to the HC (overshoot p = 0.004; Valsalva ratio p = 0.001). Autonomic dysfunctions are frequent in subjectswith ATTRv when investigated by means of standardized CRTs, and are also relevant in the pre-symptomatic stage. Cardiovagal functions are the primary functions affected, among others. This may be crucial in defining the proper diagnostic workout for early diagnosis and improving the likelihood of providing the patient with prompt administration of disease-modifying treatments.

Cardiac Autonomic Neuropathy in Prediabetes: A Case-Control Study.

Early detection and diagnosis of diabetic autonomic neuropathy, especially cardiac autonomic neuropathy (CAN), have gained attention recently because of their elevated cardiovascular mortality risk. Although the connection between type 2 diabetes mellitus and autonomic neuropathy is well established, evidence is emerging that the association might predate the stage of prediabetes. The present study was undertaken to compare the prevalence of CAN in prediabetes versus that in normoglycemic controls. The study population was selected by purposive sampling from individuals attending a tertiary care hospital from January 2018 to June 2019. Fifty individuals with prediabetes diagnosed by the American Diabetes Association's glycated haemoglobin criteria and 50 age- and gender-matched healthy controls were recruited. CAN was assessed by standard cardiovascular reflex tests, as described by Ewing and Clarke. Changes in R-R with deep breathing, Valsalva manoeuver, and changes in blood pressure (BP) in response to standing and sustained handgrip were evaluated. Three-time domains [standard deviation of normal-to-normal intervals (SDNN), root mean square of successive RR intervals (rMSSD) and percentage of successive normal to normal R-R (NN) intervals that differ by more than 50 ms (pNN50)] and four frequency domain indices [very low-frequency band (VLF), low-frequency band (LF), high-frequency band (HF), LF/HF ratio) of heart rate variability (HRV)] were examined. The mean heart rate was 71.37 ± 7.94 and 65.59 ± 8.73 beats/min in patients with prediabetes and controls, respectively (P < 0.05). All three-time-domain indices of HRV were significantly lower in persons with prediabetes compared to controls. The peak frequency of LF, peak power of LF, normalised unit of LF, and LF/HF ratio was significantly lower in subjects with prediabetes than in controls. There was no difference in the traditional cardiovascular autonomic reflex testing. Our study demonstrates the presence of subclinical autonomic dysfunction in persons with prediabetes. Early detection of CAN in prediabetes can have future implications for cardiovascular risk reduction.

Skin advanced glycation end products as a screening tool of neuropathy in type 2 diabetes mellitus

Aim of the studyTo examine the diagnostic utility of skin advanced glycation end products (AGEs) as screening tool of neuropathy in type 2 diabetes mellitus (T2DM). Patients and methodsWe included 132 participants (88 men) with a mean age of 64.57 years and median T2DM duration of 14.5 years. Skin AGEs were measured with AGE reader mu connect (Diagnoptics) on the dominant arm and were interpreted as normal vs. elevated. Distal sensorimotor polyneuropathy (DSPN) was diagnosed by the Neuropathy Disability Score. Cardiovascular autonomic neuropathy (CAN), sympathetic and parasympathetic nervous system impairment were diagnosed by cardiovascular autonomic reflex tests. ResultsFor DSPN, AGEs yielded high sensitivity (82.8%) and NPV (80.4 %) with moderate specificity (55.4 %). For CAN, they yielded relatively high sensitivity (75.0 %) and NPV (74.5 %) with low specificity (48.7 %). For sympathetic nervous system impairment, AGEs yielded relatively high sensitivity (75.0 %) and high NPV (84.3 %) with low specificity (43.9 %). For parasympathetic nervous system impairment, they yielded high PPV (81.0 %) with moderately high sensitivity (66.7 %) and moderate specificity (55.9 %). ConclusionsIn a simplified approach, skin AGEs may be used as a screening tool of DSPN and CAN (including sympathetic and parasympathetic nervous system impairment) in T2DM.

Synergistic effect of chronic kidney disease, neuropathy, and retinopathy on all-cause mortality in type 1 and type 2 diabetes: a 21-year longitudinal study

BackgroundThe prognostic value of common and frequently associated diabetic microvascular complications (MVC), namely chronic kidney disease (CKD), cardiac autonomic neuropathy (CAN), peripheral neuropathy (DPN), and retinopathy (DR), is well established. However, the impact of their different combinations on long-term mortality has not been adequately assessed.MethodsWe retrospectively analyzed 21-year longitudinal data from 303 patients with long-standing type 1 (T1D) or type 2 diabetes (T2D), who were thoroughly characterized at baseline for the presence of MVC using 99mTc-DTPA dynamic renal scintigraphy, overnight urine collection, cardiovascular autonomic tests, monofilament testing, and dilated fundus oculi examination.ResultsAfter a 5,244 person-years follow-up, a total of 133 (43.9%) deaths occurred. The presence of CKD and CAN, regardless of other MVC, increased the adjusted all-cause mortality risk by 117% (HR 2.17 [1.45–3.26]) and 54% (HR 1.54 [1.01–2.36]), respectively. Concomitant CKD&CAN at baseline were associated with the highest mortality risk (HR 5.08 [2.52–10.26]), followed by CKD&DR (HR 2.95 [1.63–5.32]), and CAN&DR (HR 2.07 [1.11–3.85]). Compared with patients free from MVC, the mortality risk was only numerically higher in those with any isolated MVC (HR 1.52 [0.87–2.67]), while increased by 203% (HR 3.03 [1.62–5.68]) and 692% (HR 7.92 [2.93–21.37]) in patients with two and three concomitant MVC, respectively.ConclusionsOur study demonstrates the long-term, synergistic, negative effects of single and concomitant diabetic MVC on all-cause mortality, which should encourage comprehensive screenings for MCV in both T1D and T2D to improve risk stratification and treatment.

INvesTigating the Abnormality of detrusor ConTractility by uroflowmetry in diabetic children (INTACT Trial): protocol of a prospective, observational study

IntroductionBladder emptying abnormalities and cardiovascular autonomic dysfunction are manifestations of autonomic dysfunction in people with diabetes mellitus (DM), which are major causes of morbidity and mortality. Since they can reduce...