Autonomic neuropathy: its diagnosis and prognosis

Unveiling autonomic failure in synucleinopathies: Significance in diagnosis and treatment

Autonomic failure is frequently encountered in synucleinopathies such as multiple system atrophy (MSA), Parkinson's disease (PD), Lewy body disease, and pure autonomic failure (PAF). Cardiovascular autonomic failure affects quality of life and can be life threatening due to the risk of falls and the increased incidence of myocardial infarction, stroke, and heart failure. In PD and PAF, pathogenic involvement is mainly post-ganglionic, while in MSA, the involvement is mainly pre-ganglionic. Cardiovascular tests exploring the autonomic nervous system (ANS) are based on the analysis of continuous, non-invasive recordings of heart rate and digital blood pressure (BP). They assess facets of sympathetic and parasympathetic activities and provide indications on the integrity of the baroreflex arc. The tilt test is widely used in clinical practice. It can be combined with catecholamine level measurement and analysis of baroreflex activity and cardiac variability for a detailed analysis of cardiovascular damage. MIBG myocardial scintigraphy is the most sensitive test for early detection of autonomic dysfunction. It provides a useful measure of post-ganglionic sympathetic fiber integrity and function and is therefore an effective tool for distinguishing PD from other parkinsonian syndromes such as MSA. Autonomic cardiovascular investigations differentiate between certain parkinsonian syndromes that would otherwise be difficult to segregate, particularly in the early stages of the disease. Exploring autonomic failure by gathering information about residual sympathetic tone, low plasma norepinephrine levels, and supine hypertension can guide therapeutic management of orthostatic hypotension (OH).

Urine flow acceleration in healthy children: A retrospective cohort study

AIMS

To establish normal reference values of urine flow acceleration (Q_acc ) in healthy children, as there is a lack of nomograms for normative reference values of Q_acc by voided volumes in the pediatric population so far. Q_acc might be an early indicator of autonomic neuropathy in children and adolescents.

METHODS

Data were retrospectively collected from healthy children who underwent uroflowmetry between 1990 and 1992. Exclusion criteria were voided volume less than 20 ml, and postvoid residual more than 15%. Baseline characteristics and uroflowmetry parameters were collected from girls and boys aged between 6 and 18 years. Voided volume, voiding time, time to maximum flow rate, and maximum and average flow rates of urine were measured, and Q_acc was calculated. Postvoid bladder diameter was measured by ultrasonography and converted to volume.

RESULTS

Uroflowmetry parameters of 208 children (≤18 years old, 45.2% girls, mean age 9.68 ± 3.09 years) who performed 404 micturition were analyzed. Median voided volume, voiding time, time to Q_max , Q_ave , Q_max , Q_acc , and postvoid residual volume were 130 [20-460] ml, 10 [3-56] s, 3 [1-14] s, 11.7 [2.5-36.6] ml/s, 20.5 [5-50] ml/s, 6 [0.81-25] ml/s² , and 1.83 [0-38.62] ml, respectively. Q_acc nomograms were given in centile forms for girls and boys separately, which show an inversely proportional correlation between voided volumes.

CONCLUSIONS

These are the first nomograms for normative reference values of Q_acc in the pediatric population (girls and boys separately) by voided volumes in centile forms. These may be useful to interpret abnormal Q_acc values and diagnose lower urinary tract diseases over a wide range of voided volumes.

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

INTRODUCTION

Bladder 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 the quality of life, they are urgent to be addressed before resulting in complications. As uroflowmetry might determine autonomic neuropathy earlier than cardiovascular autonomic dysfunction symptoms occur, our aim is to detect early abnormalities in bladder muscle function in children with DM. We investigate the diagnostic accuracy of uroflowmetry. As a secondary aim, we compare the prevalence of uroflowmetry abnormalities to the appearance of measures of cardiovascular autonomic neuropathy. Finally, as an ancillary study, we examine the association of uroflowmetry with the appearance of peripheral neuropathy. These three aims, we feel, will put our results regarding uroflowmetry into an overall context of nerve disease early in the course of type 1 DM. To our knowledge, such an approach has heretofore not been performed.

METHODS AND ANALYSIS

This will be a prospective, observational, single-centre clinical study. Patients with DM fulfilling the inclusion criteria and healthy controls will have uroflowmetry examination, cardiovascular autonomic dysfunction tests (heart rate response to deep breathing, to Valsalva manoeuvre, blood pressure and heart rate response to standing up, and to sustained handgrip) and nerve conduction test. The autonomic nervous system function will be examined by the reproducible and standardised cardiovascular reflex tests described by Ewing et al. During the examination, electrocardiogram (ECG) and blood pressure values will be recorded continuously. Heart rate response to deep inspiration will be executed to investigate the parasympathetic nervous system. Peripheral neuropathy will be evaluated by nerve conduction test. After a pilot period, when the first 50 diabetic and 50 healthy children will be assessed, sample size calculation will be carried out. The primary objective of this trial is to evaluate the diagnostic accuracy (sensitivity, specificity, positive and negative predictive value) of uroflowmetry. To do so, we compare uroflowmetry to the gold standard neuropathy tests, which are cardiovascular autonomic dysfunction tests (heart rate response to deep breathing, to Valsalva manoeuvre, blood pressure and heart rate response to standing up and to sustained handgrip).

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Scientific and Research Ethics Committee of the Heim Pál National Paediatric Institute in Budapest, Hungary (registration number KUT-37/2021). Results will be submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT05247840.

Autonomic nervous system dysfunction correlates with microvascular damage in systemic sclerosis patients

OBJECTIVES

Cardiac autonomic neuropathy is among the known cardiovascular complications of systemic sclerosis and may affect the whole prognosis of the disease. The aim of our study was to assess cardiac autonomic neuropathy prevalence in our cohort of systemic sclerosis patients and compare its main features with clinical and epidemiological data, particularly with the severity of microvascular damage, as detected by nailfold videocapillaroscopy.

METHODS

Twenty-six patients with definite systemic sclerosis were consecutively enrolled at our outpatient rheumatology clinic. All patients underwent physical examination, nailfold videocapillaroscopy, and autonomic neuropathy diagnostic tests (orthostatic hypotension test, deep breathing test, lying-to-standing, and Valsalva maneuvers).

RESULTS

Cardiac autonomic neuropathy prevalence was 50% (13 cases). On univariate analysis, cardiac autonomic neuropathy was shown to be significantly associated with an active pattern on nailfold videocapillaroscopy (odds ratio 5.86, 95% confidence interval 1.59-9.24; p = 0.032), whereas anti-Scl-70 positivity (odds ratio, 0.24; 95% confidence interval, 0.03-2.12; p = 0.049) and C-reactive protein (odds ratio, 19.32; 95% confidence interval, 1.79-56.71; p = 0.036) reached only a borderline statistical association. The time-dependent Cox multivariate regression model showed cardiac autonomic neuropathy development to be independently associated with an active pattern on nailfold videocapillaroscopy (odds ratio, 7.19; 95% confidence interval, 1.87-8.96; p = 0.042) and anti-Scl-70 positivity (odds ratio, 5.92; 95% confidence interval, 1.06-18.43; p = 0.048).

CONCLUSIONS

Severe microvascular damage, as detected by nailfold videocapillaroscopy, may suggest the coexistence of autonomic dysfunction and should be considered as a red flag for the identification of patients particularly at risk of cardiac morbidity and mortality.

Relationship between Pancreas Exocrine Insufficiency and Cardiac Autonomic Neuropathy in Patients with Type 2 Diabetes Mellitus

BACKGROUND

The exocrine function of the pancreas is controlled by the autonomic nervous system (ANS), and autonomic neuropathy is a common and serious complication of diabetes. There are many factors contributing to the development of autonomic neuropathy in diabetic patients. Cardiovascular tests have been developed to evaluate the function of the ANS. This study investigated the relationship between cardiovascular autonomic neuropathy (CAN) and pancreas exocrine insufficiency (PEI) in diabetic patients.

METHODS

This study evaluated 110 individuals with type 2 diabetes mellitus (T2DM) and 40 healthy volunteers. Autonomous neuropathy tests were utilized to diagnose patients, and Ewing and Clarke's criteria were employed to assess the severity of autonomous dysfunction. Stool samples were also collected from patients to measure fecal elastase-1 (FE-1).

RESULTS

A 65.5% incidence of PEI was observed in DM patients. There was no significant correlation among the duration of disease, C-peptide, HbA1c, and PEI, respectively (P = .782, P = .521, P = .580). However, a significant difference between DM patients and controls in terms of cardiac dysautonomia (P = .001) was seen. Moreover, a statistically significant correlation between the degree of cardiac dysautonomia and FE-1 level was observed within the patient group (P =.001).

CONCLUSION

It is possible that the disruption of exocrine hormone secretion in the pancreas due to the impairment of enteropancreatic reflexes is secondary to diabetic autonomic neuropathy and resulting in PEI. This study also showed that autonomic neuropathy might develop and cause PEI in diabetic patients without known added confounding factors.

Autonomic nervous system dysfunction in schizophrenia: impact on cognitive and metabolic health

Schizophrenia (SCZ) is a psychiatric disorder characterized by a wide range of positive, negative and cognitive symptoms, along with an increased risk of metabolic syndrome and cardiovascular disease that contribute to a 15-20-year reduced life expectancy. Autonomic dysfunction, in the form of increased sympathetic activity and decreased parasympathetic activity, is postulated to be implicated in SCZ and its treatment. The aim of this narrative review is to view SCZ through an autonomic lens and synthesize the evidence relating autonomic dysfunction to different domains of SCZ. Using various methods of assessing autonomic activity, autonomic dysfunction was found to be associated with multiple aspects of SCZ pathophysiology, including symptom severity, cognitive impairment, and the development of cardiometabolic comorbidities, such as metabolic syndrome and high BMI. The strongest association of low heart rate variability was noted among patients on antipsychotic treatment with high-affinity muscarinic antagonism (i.e., clozapine, olanzapine and quetiapine). The review will also suggest ways in which studying autonomic dysfunction can help reduce morbidity and mortality associated with SCZ and its treatment.

Efficacy and tolerability of DPP4 inhibitor, teneligliptin, on autonomic and peripheral neuropathy in type 2 diabetes: an open label, pilot study

BACKGROUND

Diabetic neuropathy increases risk of cardiovascular disease, peripheral artery disease, foot amputation and overall mortality. Not only hyperglycaemia induced nerve damage is harder to repair using currently approved medications, but also, the use of these agents is often limited by the extent of pain relief provided and side effects.

METHODOLOGY

In this prospective, open-label, pilot study, 20 type-2 diabetes mellitus patients (male/female=13/7, mean age- 56.1±8.04 years), meeting inclusion/exclusion criteria, were treated with dipeptidyl peptidase-4 (DPP-4) inhibitor, Teneligliptin, 20mg once a day for three months. Efficacy parameters: Sudomotor function (Sudoscan score); parasympathetic dysfunction assessed using Ewing's criteria i.e. heart rate response to -standing (HRS), -valsalva (HRV) and -deep breath (HRD); sympathetic dysfunction assessed as blood pressure response to -standing (BPS) and -handgrip (BPH); ankle brachial index (ABI), vibration perception threshold (VPT), C-reactive protein, glycemic profile and health related quality of life (HRQoL); and, tolerability parameters: complete blood count, liver function tests, serum creatinine, thyroid stimulating hormone, QT- interval and serum vitamin B12 levels, were measured.

RESULTS

There was no statistical difference in BMI, SBP, DBP, HRD, BPH and all safety parameters. After 12 weeks treatment, there was improvement in HRS (p<0.01) and HRV (p<0.01), but not in HRD (p=0.12). BPS was significantly lowered (p <0.01), but not the BPH (p =0.06). Sudoscan score was increased, while VPT was significantly decreased (both p<0.01).

CONCLUSION

Teneligliptin not only improves the glycemic status but also improves sudomotor function, peripheral and autonomic neuropathy, and reduces vascular inflammation in type 2 diabetes.

Prevalence and Correlates of Cardiovascular Autonomic Neuropathy Among Patients with Diabetes in Uganda: A Hospital-Based Cross-sectional Study

Background

Cardiovascular autonomic neuropathy (CAN) is a common complication in individuals with diabetes mellitus (DM) but often overlooked in clinical practice. The burden and correlates of CAN have not been extensively studied in low-income countries, particularly in sub-Saharan Africa.

Objectives

To determine the prevalence and correlates of CAN among adults in ambulatory diabetes care in southwestern Uganda.

Method

We conducted a cross-sectional study among adults with diabetes from November 2018 to April 2019. CAN was assessed using the five autonomic function tests: deep breathing, Valsalva maneuver, postural index on standing, change in blood pressure during standing and diastolic blood pressure response to isometric exercise. We estimated the prevalence of CAN and fit regression models to identify its demographic and clinical correlates.

Results

We enrolled 299 individuals. The mean age was 50.1 years (SD ± 9.8), mean HbA1c was 9.7 (SD ± 2.6) and 69.6% were female. CAN was detected in 156/299 (52.2%) of the participants on the basis of one or more abnormal cardiovascular autonomic reflex tests. Out of 299 participants, 88 (29.4%) were classified as early CAN while 61/299 (20.4%) and 7/299 (2.3%) were classified as definite and severe (advanced) CAN respectively. In multivariable regression models, age over 50 years (aOR 3.48, 95%CI 1.35 -8.99, p = 0.010), duration of diabetes over 10 years (aOR 4.09, 95%CI 1.78 -9.38, p = 0.001), and presence of diabetic retinopathy (aOR 2.25, 95%CI 1.16 -4.34, p = 0.016) were correlated with CAN.

Conclusions

Our findings reveal a high prevalence of CAN among individuals in routine outpatient care for diabetes mellitus in Uganda. Older age, longer duration of diabetes and coexistence of retinopathy are associated with CAN. Future work should explore the clinical significance and long term outcomes associated with CAN in this region.

Supplementation with extract of Gynostemma pentaphyllum leaves reduces anxiety in healthy subjects with chronic psychological stress: A randomized, double-blind, placebo-controlled clinical trial

BACKGROUND

The ethanol extract of Gynostemma pentaphyllum Makino leaves (EGP) has been reported recently to have anxiolytic effects on chronically stressed mice models.

PURPOSE

We aimed to investigate the efficacy and safety of EGP on anxiety level in healthy Korean subjects under chronic stressful conditions.

STUDY DESIGN

Double-blind, placebo-controlled trial.

METHODS

This study was conducted with 72 healthy adults who had perceived chronic stress and anxiety with a score on the State-Trait Anxiety Inventory (STAI) from 40 to 60. Participants were randomly assigned to receive either EGP (200 mg, twice a day, N = 36) or placebo (N = 36). All participants were exposed to repetitive loads of stress by performing the serial subtraction task for 5 min every second day during the 8-week intervention. Primary outcome of Trait-STAI and secondary outcomes of State-STAI, total score of STAI, Hamilton Anxiety Inventory (HAM-A), Beck Anxiety Inventory (BAI), blood norepinephrine and adrenocorticotropic hormone (ACTH), salivary cortisol and alpha-amylase, cardiovascular autonomic nervous system (ANS) functional test, and heart rate variability (HRV) test were measured before and after intervention.

RESULTS

After the 8-week intervention, the EGP significantly lowered the score of the Trait Anxiety Scale of the STAI (T-STAI) by 16.8% compared to the placebo (p = 0.041). The total score on the STAI decreased by 17.8% in the EGP group and tended to improve compared with that of the placebo group (p = 0.067). There were no significant differences in the changes in score of S-STAI, HAM-A, BAI, and other parameters from baseline between the two groups. There was no causal relationship between the ingestion of EGP and adverse drug reactions.

CONCLUSION

We found that supplementation with EGP reduced "anxiety proneness" in subjects under chronic psychological stress, as shown by a decrease in the score of T-STAI and the tendency for decrease in the total score of STAI. This result suggests that EGP supplementation can be used as a regimen to safely reduce stress and anxiety; however, more studies are needed to establish the long-term safety and effectiveness.

The prevalence of cardiovascular autonomic neuropathy and its influence on post induction hemodynamic variables in patients with and without diabetes; A prospective cohort study

Background

Cardiovascular autonomic neuropathy (CAN) is a known complication of diabetes, but is also diagnosed in patients without diabetes. CAN may be related to perioperative hemodynamic instability. Our objective was to investigate if patients with diabetes would have a higher prevalence of CAN compared to patients without diabetes undergoing surgery. We further studied its relation to changes in post-induction hemodynamic variables.

Methods

We prospectively included 82 adult patients, 55 with DM, 27 without DM, scheduled for major abdominal or cardiac surgery. Patients performed four autonomic function tests on the day before surgery. Primary outcomes were the prevalence of CAN and the relation between CAN and severe post-induction hypotension, defined as mean arterial pressure (MAP) < 50 mmHg or ≥ 50% decrease from baseline. Secondary outcomes were the relation between CAN, intraoperative hypotension, MAP < 65 mmHg for more than 13 minutes, and the use of vasopressor therapy.

Results

The prevalence of CAN in patients with or without DM was 71% versus 63%, (p = 0.437). CAN was not associated with severe post induction hypotension (CAN+ vs. CAN–: 21% vs. 19.2%, p = 0.819) nor with intraoperative hypotension (16% vs. 15%, p = 0.937). Patients with definite CAN received more norepinephrine in the perioperative period compared to patients with mild CAN or no CAN (0.07 mcg kg^-1 min^-1 (0.05–0.08) vs. 0.03 (0.01–0.07) vs. 0.02 (0.01–0.06) respectively, p = 0.001).

Conclusions

The majority of patients studied had mild to moderate CAN, regardless of the presence of DM. Assessing CAN before surgery did not identify patients at risk for post induction and intraoperative hypotension in our cohort.

Trial registration

Dutch Trial Registry (www.trialregister.nl) NTR4976.

Severe abnormal Heart Rate Turbulence Onset is associated with deterioration of liver cirrhosis

Background

In patients with liver cirrhosis, cardiac dysfunction is frequent and is associated with increased morbidity and mortality. Cardiac dysfunction in cirrhosis seems to be linked to autonomic dysfunction. This study investigates the role of autonomic dysfunction assessed by Heart Rate Turbulence (HRT) analyses in patients with liver cirrhosis.

Methods and patients

Inclusion criteria was (1) diagnosis of cirrhosis by clinical, imaging or biopsy and (2) evaluation by standard 12-lead-ECG and 24h holter monitoring and (3) at least 3 premature ventricular contractions. The exclusion criterion was presence of cardiac diseases, independent of liver cirrhosis. Biochemical parameters were analysed using standard methods. HRT was assessed using Turbulence onset (TO) and slope (TS). The endpoint was deterioration of liver cirrhosis defined as increased MELD and readmission for complications of liver cirrhosis.

Results

Out of 122 cirrhotic patients, 82 patients (63% male) with median Child score of 6 (range 5–12) and median MELD score of 10 (range 6–32) were included. Increasing Child score, INR and decreasing albumin were correlated with TO. In addition, decompensated patients with ascites showed more abnormal TO and TS. During the observation period, patients with more abnormal TO showed significantly higher rate of rising MELD Score at 6 months (p = 0.03). Nevertheless, at least in our collective HRT-parameters were not independent predictors of deterioration of cirrhosis.

Conclusion

Parameters of HRT are closely associated with deterioration of cirrhosis and might be helpful in its prediction.

Clozapine-Induced Cardiovascular Side Effects and Autonomic Dysfunction: A Systematic Review

Background: Clozapine is the antipsychotic of choice for treatment-resistant schizophrenia and has minimal risk for extrapyramidal symptoms. Therapeutic benefits, however, are accompanied by a myriad of cardiometabolic side-effects. The specific reasons for clozapine's high propensity to cause adverse cardiometabolic events remain unknown, but it is believed that autonomic dysfunction may play a role in many of these.

Objective: This systematic review summarizes the literature on autonomic dysfunction and related cardiovascular side effects associated with clozapine treatment.

Method: A search of the EMBASE, MEDLINE, and EBM Cochrane databases was conducted using the search terms antipsychotic agents, antipsychotic drug^*, antipsychotic^*, schizophrenia, schizophren^*, psychos^*, psychotic^*, mental ill^*, mental disorder^*, neuroleptic^*, cardiovascular^*, cardiovascular diseases, clozapine^*, clozaril^*, autonomic^*, sympathetic^*, catecholamine^*, norepinephrine, noradrenaline, epinephrine, adrenaline.

Results: The search yielded 37 studies that were reviewed, of which only 16 studies have used interventions to manage cardiovascular side effects. Side effects reported in the studies include myocarditis, orthostatic hypotension and tachycardia. These were attributed to sympathetic hyperactivity, decreased vagal contribution, blockade of cholinergic and adrenergic receptors, reduced heart rate variability and elevated catecholamines with clozapine use. Autonomic neuropathy was identified by monitoring blood pressure and heart rate changes in response to stimuli and by spectral analysis of heart rate variability. Metoprolol, lorazepam, atenolol, propranolol, amlodipine, vasopressin and norepinephrine infusion were used to treat tachycardia and fluctuations in blood pressure, yet results were limited to case reports.

Conclusion: The results indicate there is a lack of clinical studies investigating autonomic dysfunction and a limited use of interventions to manage cardiovascular side effects associated with clozapine. As there is often no alternative treatment for refractory schizophrenia, the current review highlights the need for better designed studies, use of autonomic tests for prevention of cardiovascular disease and development of novel interventions for clozapine-induced side effects.

Evaluation of cardiac autonomic functions in myasthenia gravis

OBJECTIVE

We aimed to comprehensively evaluate cardiac autonomic function in patients with MG and to investigate the relationship between this disorder and disease duration, thymoma and acetylcholine receptor antibody positivity in cases of cardiac autonomic disorder.

METHODS

The study included 30 patients with MG and 30 age-matched healthy control subjects. Haemodynamic parameters (heart rate, systolic and diastolic blood pressure) and autonomic parameters (low frequency [LF], high-frequency [HF], sympathovagal balance [LF/HF], baroreceptor reflex sensitivity [BRS]) of the patients were automatically measured at rest and in a tilted position with the Task Force Monitor.

RESULTS

The mean systolic and diastolic blood pressure measurements obtained at rest and during the tilt test were higher in patients with MG. Sympathovagal balance has been disturbed in favour of sympathetic tone, and parasympathetic insufficiency has become more prominent. When baroreceptor sensitivity was used as the second parameter to evaluate autonomic heart functions, BRS at rest and during the tilt test was lower in the MG group compared with the control group.

DISCUSSION

These results suggest that sympathovagal balance has been disturbed in favour of sympathetic tone and that parasympathetic insufficiency has become more prominent. The current findings support the presence of cardiac autonomic involvement in patients with MG. The determination of cardiac autonomic function via noninvasive methods among patients with MG has high predictive value. The identification of autonomic dysfunction at an early stage and the early treatment of cardiovascular diseases can reduce morbidity and mortality.

Predictors of Cardiovascular Autonomic Neuropathy Onset and Progression in a Cohort of Type 1 Diabetic Patients

AIM

The prevalence of cardiovascular autonomic neuropathy (CAN) in diabetes mellitus is well documented. However, the rate and predictors of both the development and progression of CAN have been less studied. Hereby, we assessed the rate and the major risk factors for CAN initiation and progression in a cohort of type 1 diabetic patients followed over a three-year period.

METHODS

175 type 1 diabetic patients (mean age: 50 ± 11 years; female/male: 76/99) with positive bedside screening for CAN were included and underwent 2 standardized autonomic testings using 4 standardized tests (deep breathing, Valsalva maneuver, 30/15 ratio, and changes in blood pressure during standing), separated by 3 ± 1 years. CAN staging was achieved according to the Toronto Consensus Panel on Diabetic Autonomic Neuropathy into 4 categories: absent, possible, confirmed, or severe CAN.

RESULTS

Out of the 175 patients included, 31.4% were free of CAN, 34.2% had possible CAN, 24.6% had confirmed CAN, and 9.7% exhibited severe CAN at the first assessment. Among the 103 patients with nonsevere CAN at inclusion, forty-one (39.8%) had an increase of at least one category when reassessed and 62 (60.2%) remained stable. A bivariate analysis indicated that only BMI and exposure to selective serotonin reuptake inhibitors (SSRIs) were significantly different in both groups. A multivariate analysis indicated that lower BMI (OR: 0.15, CI 95%: 0.05-0.48, p = 0.003) and SSRI exposure (OR: 4.18, CI 95%: 1.03-16.97, p = 0.04) were the sole predictors of CAN deterioration. In the 55 patients negative for CAN at the first laboratory assessment, 12 became positive at the second assessment.

CONCLUSION

No clear predictive factor for CAN onset was identified. However, once present, CAN progression was related to low BMI and SSRI exposure.

Long-Acting GLP-1 Receptor Agonist Exenatide Influence on the Autonomic Cardiac Sympatho-Vagal Balance

Long-acting glucagon-like peptide 1 receptor agonists are increasingly used to treat type 2 diabetes. An increase of heart rate (HR) has been observed with their use. To elucidate the role of the cardiac sympatho-vagal balance as a possible mediator of the reported increase in HR, we performed power spectral analysis of HR variability (HRV) in patients receiving exenatide extended-release (ER). Twenty-eight ambulatory patients with type 2 diabetes underwent evaluation at initiation of exenatide-ER and thereafter at 3 and at 6 months. To obtain spectral analyses of HRV, a computerized acquisition of 10 minutes of RR electrocardiogram intervals (mean values of ~700 RR intervals) were recorded both in lying and in standing positions. All patients showed a substantial increase of HR both in lying and in standing positions. Systolic blood pressure, body weight, and glycated hemoglobin A1c significantly decreased both at 3 and 6 months compared with basal levels. The low-frequency/high-frequency ratio varied from 3.05 ± 0.4 to 1.64 ± 0.2 (P < 0.001) after 3 months and to 1.57 ± 0.3 (P < 0.001) after 6 months in a lying position and from 4.56 ± 0.8 to 2.24 ± 0.3 (P < 0.001) after 3 months and to 2.38 ± 0.4 (P < 0.001) after 6 months in a standing position compared with basal values, respectively. HR variations, induced by exenatide-ER treatment, do not appear to be related to sympathetic autonomic tone. Of note, we observed a relative increase of vagal influence on the heart.

Linear and nonlinear parameters of heart rate variability in ischemic stroke patients

INTRODUCTION

Cardiovascular system presents cortical modulation. Post-stroke outcome can be highly influenced by autonomic nervous system disruption. Heart rate variability (HRV) analysis is a simple non-invasive method to assess sympatho-vagal balance.

OBJECTIVES

The purpose of this study was to investigate cardiac autonomic activity in ischemic stroke patients and to asses HRV nonlinear parameters beside linear ones.

METHODS

We analyzed HRV parameters in 15 right and 15 left middle cerebral artery ischemic stroke patients, in rest condition and during challenge (standing and deep breathing). Data were compared with 15 age- and sex-matched healthy controls.

RESULTS

There was an asymmetric response after autonomic stimulation tests depending on the cortical lateralization in ischemic stroke patients. In resting state, left hemisphere stroke patients presented enhanced parasympathetic control of the heart rate (higher values for RMSSD, pNN50 and HF in normalized units). Right hemisphere ischemic stroke patients displayed a reduced cardiac parasympathetic modulation during deep breathing test. Beside time and frequency domain, using short-term ECG monitoring, cardiac parasympathetic modulation can also be assessed by nonlinear parameter SD1, that presented strong positive correlation with time and frequency domain parameters RMSSD, pNN50, HFnu, while DFA α1 index presented negative correlation with the same indices and positive correlation with the LFnu and LF/HF ratio, indicating a positive association with the sympatho-vagal balance.

CONCLUSIONS

Cardiac monitoring in clinical routine using HRV analysis in order to identify autonomic imbalance may highlight cardiac dysfunctions, thus helping preventing potential cardiovascular complications, especially in right hemisphere ischemic stroke patients with sympathetic hyperactivation.

Orthostatic Hypotension and Risk of Incident Dementia: Results From a 12-Year Follow-Up of the Three-City Study Cohort

Several studies indicate a potential link between orthostatic hypotension (OH) and incident dementia but without substantial evidence to date. Our objective is to study the association between OH and dementia in a cohort of elderly individuals. To do so, baseline lying and standing blood pressure measurements were taken from 7425 subjects in the Three-City study. These subjects were then followed-up for 12 years. Cox proportional hazard models, adjusted for potential confounders, were used to estimate the risk of incident dementia according to OH status. Sensitivity analysis was performed using the so-called illness-death model, a specific statistical method which takes into account competitive risk with death. OH frequency was found to be around 13%, and 760 cases of dementia were diagnosed during follow-up. We observed significant associations between the presence of OH at baseline and the occurrence of dementia during the follow-up, with an increased risk of at least 25% observed regardless of the OH threshold and the statistical method used. In conclusion, there is an association between OH and dementia. Considering that OH is a common condition and is easy to measure, OH measurements could help to identify subjects with higher risk of dementia. Moreover, reducing OH could be a step to prevent conversion to dementia.

Cortical modulation of cardiac autonomic activity in ischemic stroke patients

The cardiovascular system is regulated by the autonomic nervous system, under cortical modulation. Stroke can induce cardiac autonomic imbalance, therefore, causing secondary cardiovascular complications. Heart rate variability (HRV) analysis is a simple method to appraise the autonomic nervous function. The purpose of this study was to investigate the cardiac autonomic activity in patients that suffered an ischemic stroke in middle cerebral artery (MCA) territory. Using Biopac Acquisition System, we monitored ECG in rest condition and during Ewing's tests. From these measurements, HRV parameters (using time and frequency domain analysis) were determined in 20 right MCA and 20 left MCA ischemic stroke patients, in the first 6 months after the acute event. Data were compared with 20 age- and sex-matched healthy controls. All the patients were right handed. In ischemic stroke patients, HRV parameters were significantly modified compared to controls (p < 0.05) and we found asymmetric responses to different stimulation autonomic tests between right and left hemisphere. Parameters illustrating the parasympathetic predominance in time domain (RMSSD) and frequency domain (HF) analysis were higher in left hemisphere stroke compared to right hemisphere stroke patients (p < 0.01) in resting state. From Ewing's battery test, patients with left hemisphere ischemic stroke showed predominance of parasympathetic activity to deep breathing (p < 0.01), while HRV parameters in right hemisphere ischemic stroke patients described a reduced cardiac parasympathetic innervation (p < 0.01). Cardiac autonomic imbalance occurs more often after right hemisphere ischemic stroke. HRV study may highlight cardiac dysfunctions that increase the risk of cardiovascular complications and portends a poor long-term outcome.

Predictors of autonomic neuropathy in rheumatoid arthritis

OBJECTIVE

Autonomic dysfunction occurs in rheumatoid arthritis (RA). However, the association between the autonomic dysfunction and inflammation has not been investigated in RA. We investigated the relationship between inflammation and ANS function in RA.

METHODS

In this cross-sectional study, 25 RA patients and 25 age and sex-matched healthy controls were recruited. Autonomic function assessed by five cardiovascular reflex tests according to Ewing. Parasympathetic dysfunction established by applying three tests: heart rate response to deep breath (HRD) and standing (HRS) and Valsalva tests. Sympathetic dysfunction examined by applying two tests: BP response to standing and handgrip test. Peripheral sympathetic autonomic function assessed by Sudoscan through measurement of electrochemical skin conductance of hands and feet. Sudoscan investigates the sweat gland activity and used as a surrogate to study the damage of sympathetic sudomotor nerves in neuropathy. It is an indirect assessment tool of sudomotor function. Disease-specific and inflammatory measures (DAS 28, ESR, CRP, TNF-α, IL-6 and IL-1) were determined.

RESULTS

RA patients had significantly impaired HRD, HRS, BP response to hand grip and sudomotor function as compared to healthy controls. Pro-inflammatory cytokines were significantly higher in RA as compared to healthy controls (p<0.05). DAS 28 significantly correlated with HRD in RA. ESR significantly correlated with HRD and HRS. TNF-α significantly correlated with HRD, HRS, BP response to standing and sudomotor function. Significant correlation was found between IL-6 and HRS. Seropositive patients had more pronounced CAN and sudomotor dysfunction.

CONCLUSION

Autonomic dysfunction in RA is related to disease activity, seropositivity and pro-inflammatory cytokines.

Diabetic autonomic neuropathy

Diabetes mellitus is the commonest cause of an autonomic neuropathy in the developed world. Diabetic autonomic neuropathy causes a constellation of symptoms and signs affecting cardiovascular, urogenital, gastrointestinal, pupillomotor, thermoregulatory, and sudomotor systems. Several discrete syndromes associated with diabetes cause autonomic dysfunction. The most prevalent of these are: generalized diabetic autonomic neuropathy, autonomic neuropathy associated with the prediabetic state, treatment-induced painful and autonomic neuropathy, and transient hypoglycemia-associated autonomic neuropathy. These autonomic manifestations of diabetes are responsible for the most troublesome and disabling features of diabetic peripheral neuropathy and result in a significant proportion of the mortality and morbidity associated with the disease.

Disease-modifying antirheumatic drugs improve cardiovascular autonomic neuropathy in psoriatic arthritis

BACKGROUND

Cardiovascular autonomic neuropathy (CAN) is a significant risk predictor for sudden cardiac death in autoimmune rheumatic diseases. As yet, there is no therapeutic treatment of CAN in psoriatic arthritis (PsA). Even now, the impact of the most commonly employed disease-modifying antirheumatic drug (DMARD) therapy on CAN in PsA is not known. Hence, we investigated the impact of DMARDs on CAN in PsA.

METHODS

In this prospective, cross-sectional study, 20 patients of PsA and 20 age- and sex-matched healthy controls were recruited. CAN was diagnosed by applying the five cardiovascular reflex tests according to Ewing. Parasympathetic dysfunction was established by performing three tests: heart-rate response to deep breathing, standing, and Valsalva tests. Sympathetic dysfunction was examined by applying two tests: blood pressure response to standing, and handgrip tests. Disease severity was assessed by the 28-joint-count disease activity score (DAS-28) and the disease activity score in psoriatic arthritis (DAPSA).

RESULTS

Cardiovascular reflex tests were impaired significantly among the PsA patients compared with well-matched healthy subjects (p < 0.05). Parasympathetic dysfunction was more prominent than sympathetic dysfunction. After 12 weeks treatment, parasympathetic dysfunction (heart rate response to deep breath and standing) significantly (p < 0.05) improved in patients with PsA, while there was no significant improvement in sympathetic function.

CONCLUSION

These study results suggests parasympathetic autonomic dysfunction is more prominent than sympathetic dysfunction in PsA. Synthetic DMARDs improved parasympathetic dysfunction in PsA.

Prevalence of Cardiovascular Autonomic Neuropathy in a Cohort of Patients With Newly Diagnosed Type 2 Diabetes: The Verona Newly Diagnosed Type 2 Diabetes Study (VNDS)

OBJECTIVE

Cardiovascular autonomic diabetic neuropathy (CAN) is a serious complication of diabetes. No reliable data on the prevalence of CAN among patients with newly diagnosed type 2 diabetes are available. Therefore, the aim of this study was to estimate the prevalence of CAN among patients with newly diagnosed type 2 diabetes.

RESEARCH DESIGN AND METHODS

A cohort of 557 patients with newly diagnosed type 2 diabetes with cardiovascular autonomic test results available was selected. Early and confirmed neuropathy were assessed using a standardized methodology and their prevalences determined. A multivariate logistic regression analysis was modeled to study the factors associated with CAN.

RESULTS

In the entire cohort, the prevalence of confirmed CAN was 1.8%, whereas that of early CAN was 15.3%. Prevalence did not differ between men and women. In the multivariate analyses BMI results were independently and significantly associated with CAN after adjusting for age, sex, hemoglobin A1c, pulse pressure, triglyceride-to-HDL cholesterol ratio, kidney function parameters, and antihypertensive treatment.

CONCLUSIONS

CAN could be detected very early in type 2 diabetes. This study may suggest the importance of performing standardized cardiovascular autonomic tests after diagnosis of type 2 diabetes.

Considerations for assessing the potential effects of antidiabetes drugs on cardiac ventricular repolarization: A report from the Cardiac Safety Research Consortium

Thorough QT studies conducted according to the International Council on Harmonisation E14 guideline are required for new nonantiarrhythmic drugs to assess the potential to prolong ventricular repolarization. Special considerations may be needed for conducting such studies with antidiabetes drugs as changes in blood glucose and other physiologic parameters affected by antidiabetes drugs may prolong the QT interval and thus confound QT/corrected QT assessments. This review discusses potential mechanisms for QT/corrected QT interval prolongation with antidiabetes drugs and offers practical considerations for assessing antidiabetes drugs in thorough QT studies. This article represents collaborative discussions among key stakeholders from academia, industry, and regulatory agencies participating in the Cardiac Safety Research Consortium. It does not represent regulatory policy.

Disease-modifying anti-rheumatic drugs improve autonomic neuropathy in arthritis: DIANA study

Autonomic neuropathy (AN) is a risk predictor for sudden cardiac death in rheumatoid arthritis (RA) and ankylosing spondylitis (AS). However, the impact of most commonly employed disease-modifying anti-rheumatic drug (DMARD) therapy on autonomic neuropathy in rheumatic diseases is not known. Hence, we investigated the efficacy of DMARDs on autonomic neuropathy in RA and AS. We performed autonomic function assessment in 60 patients in this open-label, 12-week pilot study including 42 patients with RA, 18 with AS, and 30 aged-matched healthy subjects. The methodology included assessment of cardiovascular autonomic reflex tests according to Ewing. Parasympathetic dysfunction was established by performing three tests: heart rate response to deep breathing, standing, and Valsalva tests. Sympathetic dysfunction was examined by applying two tests: blood pressure response to standing and handgrip tests. Sudomotor function was assessed by Sudoscan. Cardiovascular reflex tests were impaired significantly among the patients as compared to healthy subjects (p < 0.05). Autonomic neuropathy was more pronounced in biologic-naive RA and AS patients. After treatment with combination synthetic DMARDs, parasympathetic, and sudomotor dysfunction significantly (p < 0.05) improved in RA and AS. Biologic DMARDs significantly improved parasympathetic, sympathetic and peripheral sympathetic autonomic neuropathy (p < 0.05) in biologic-naive RA and AS patients. In conclusion, synthetic DMARDs improved parasympathetic and sudomotor dysfunction in both DMARD-naive RA and AS patients. However, biologic DMARDs improved parasympathetic, sympathetic and sudomotor dysfunction to a greater extent than synthetic DMARDs in both RA and AS patients.

Association between visceral, cardiac and sensorimotor polyneuropathies in diabetes mellitus

AIMS

Gastrointestinal complaints are common in diabetes mellitus. However, its association to peripheral sensorimotor and autonomic neuropathies is not well investigated. The aim was to assess skin, muscle, bone and visceral sensitivity in diabetes patients with sensorimotor neuropathy, and correlate these with gastrointestinal symptoms and degree of cardiac autonomic neuropathy.

METHODS

Twenty patients with sensorimotor neuropathy (65% type 2 diabetes, aged 58.3±12.0 years, diabetes duration 15.8±10.0 years) and 16 healthy controls were recruited. Cutaneous sensitivity to von Frey filaments, mechanical allodynia, muscle/bone/rectosigmoid sensitivities, and heart rate variability were examined. Gastrointestinal symptom scores (PAGI-SYM) and health-related quality of life (SF-36) were also recorded.

RESULTS

Patients displayed hypesthesia to von Frey filaments (p=0.028), but no difference to muscle and bone pain sensitivities. Also, patients were hyposensitive to multimodal rectal stimulations (all p<0.05), although they suffered more gastrointestinal complaints. Heart rate variability was reduced in the patient cohort. Rectal mechanical and cutaneous sensitivities correlated (p<0.001), and both were associated with heart rate variability as well as PAGI-SYM and SF-36 scores (p<0.01).

CONCLUSIONS

In diabetic sensorimotor neuropathy there is substantial evidence of concomitant cutaneous, cardiac and visceral autonomic neuropathies. The neuropathy may reduce quality of life and explain the higher prevalence of gastrointestinal complaints.

Socioeconomic deprivation independently predicts symptomatic painful diabetic neuropathy in type 1 diabetes

INTRODUCTION

Painful peripheral neuropathy in people with type 1 diabetes is a disabling and costly complication. A greater understanding of predisposing factors and prescribing may facilitate more effective resource allocation.

METHODS

The Townsend index of deprivation (numerically higher for greater disadvantage) was examined in the pseudonymised records of 1621 (684 females) individuals with type 1 diabetes and related to prevalence of drug treated severe diabetes related neuropathic pain.

RESULTS

Treatment for neuropathic pain was initiated in 280 patients, who were older at 57.1 vs 45.6 years and had greater BMI (29.8 vs 27.8kg/m(2); p<0.0001). HbA1C was similar between groups, whilst eGFR was lower in the neuropathic pain group. Amitriptyline was the most commonly prescribed agent (46.8% of total prescriptions). Duloxetine (60mg daily) was prescribed in 9.3% of cases. There were significant differences between the groups for the Townsend index, with a greater proportion (34.3% vs 21.7%) of patients with treated neuropathic pain having a score of ≥1 (X(2)=19.9, p<0.001). Multivariate logistic regression analyses indicated that each unit increment in Townsend index was associated with a 11% increased odds of requiring neuropathic pain treatment [odds ratio (95% CI) 1.11 (1.05-1.17), p<0.001]. This was independent of age: 1.04 (1.02-1.05), BMI: 1.03 (1.01-1.05), HbA1C: 1.15 (1.05-1.24), male gender: 0.74 (0.55-0.98), systolic BP and eGFR. Inclusion of depression and mixed anxiety/depressive disorder did not change the risk estimates.

CONCLUSION

Amitriptyline was the most commonly used agent for treatment of diabetes related neuropathic pain with Duloxetine much less used. A higher level of socioeconomic deprivation may predispose to severe neuropathic pain in diabetes. Differential allocation of resources may benefit this group.

Minocycline improves peripheral and autonomic neuropathy in type 2 diabetes: MIND study

Diabetic peripheral neuropathy and diabetic autonomic neuropathy are serious and common complications of diabetes associated with increased risk of mortality and cardiovascular disease. We sought to evaluate the safety and efficacy of minocycline in type 2 diabetic patients with diabetic peripheral and autonomic neuropathy. In a randomized placebo controlled study, 50 outpatients were randomly assigned to receive 100 mg minocycline or placebo. Outcome measures included the vibration perception threshold (VPT), Leeds assessment of neuropathic symptoms and signs (LANSS), Pain Disability Index (PDI), Visual Analog Scale (VAS), beck depression inventory (BDI), health assessment questionnaire (HAQ) and autonomic neuropathy, assessed by cardiovascular reflex tests according to Ewing and peripheral sympathetic autonomic function was assessed by FDA approved Sudoscan. At baseline there were no significant differences between demographic variables and the neuropathy variables in the minocycline and placebo groups. After treatment, VPT significantly improved in the minocycline group as compared to the placebo group. Mean posttreatment scores on the LANSS, PDI and HAQ were significantly lower in the minocycline group compared with the placebo group. However, BDI and VAS significantly (p = 0.01) improved in both minocycline and placebo groups (Table 2). After treatment with minocycline, heart rate (HR) response to standing significantly improved, while there was a borderline significance toward a reduction in HR response to deep breath. These finding indicate that 6-week oral treatment with minocycline is safe, well tolerated and significantly improves peripheral and autonomic neuropathy in type 2 diabetic patients.

[Autonomic nervous system alteration in multiple sclerosis patients with urinary symptoms. Clinical, urodynamic and cardiovascular study]

OBJECTIVE

To assess symptoms related to autonomic nervous system alteration in a population of patients suffering from multiple sclerosis (MS) and presenting with urinary symptoms.

PATIENTS AND METHODS

We investigated 65 patients (mean age 47.5 years) suffering from MS, and presenting with urological dysfunction by means of symptom scores, urodynamic investigation, cardiovascular autonomic function tests (orthostatic hypotension testing, Valsalva test, deep breath test, cold pressor test) and sympathetic skin responses.

RESULTS

Forty-five (69%) patients suffered from overactive bladder, 48 (73%) from voiding dysfunction, 14 (21%) from urinary retention and 13 (20%) from fecal incontinence. Urodynamic investigation demonstrated overactive detrusor in 46 (70%) cases, and underactive detrusor in four (6%) cases. Twenty-five (38%) patients had dysautonomia without correlation neither with clinical or urodynamic data, nor gravity of multiple sclerosis (EDSS).

CONCLUSION

In this series, the prevalence of dysautonomia was high in patients suffering from MS and presenting with urinary disorders.

Heart rate variability as a measure of autonomic dysfunction in men with advanced cancer

Autonomic dysfunction is common in patients with cancer and may have considerable negative effects on quality of life and mortality. This study retrospectively compared heart rate variability measured by the standard deviation of normal-to-normal intervals (SDNN) to Ewing test score, a composite score from a battery of five defined autonomic tests, in detection of autonomic dysfunction in 47 men with advanced cancer. The Ewing test score has been validated for diagnosis of autonomic dysfunction but is time-consuming and requires considerable patient co-operation; we hypothesised that SDNN, a much simpler test, is a useful alternative. The patients were categorised into three groups according to Ewing score: ≤ 2 (mild or no autonomic dysfunction), 2.5-3 (moderate) and ≥ 3.5 (severe). The SDNN (mean ± SD) for the three groups were 57.1 ± 26.9 ms 62.3 ± 22.4 ms and 37.7 ± 20.3 ms respectively. A significant negative correlation was found between Ewing score and SDNN (r = -0.40, P = 0.005). A SDNN of ≤ 40 ms had 63% sensitivity and 75% specificity in the diagnosis of severe autonomic dysfunction (i.e. Ewing score ≥ 3.5). The positive predictive value of SDNN ≤ 40 ms in predicting moderate/severe autonomic dysfunction was 89%.

Peripheral and central nervous contribution to gastrointestinal symptoms in diabetic patients with autonomic neuropathy

BACKGROUND & AIMS

Long-term diabetes mellitus (DM) has been associated with neuronal changes in the enteric, peripheral and/or central nervous system. Moreover, abnormal visceral sensation and gastrointestinal (GI) symptoms are seen in up to 75% of patients. To explore the role of diabetic autonomic neuropathy (DAN) in patients with long-standing DM, we investigated psychophysical responses and neuronal activity recorded as evoked brain potentials and dipolar source modelling.

METHODS

Fifteen healthy volunteers and 14 type-1 DM patients with DAN were assessed with a symptom score index characterizing upper GI abnormalities. Multichannel (62) electroencephalography was recorded during painful electrical stimulation of the lower oesophagus. Brain activity to painful stimulations was modelled using Brain Electrical Source Analysis (besa).

RESULTS

Diabetic patients had higher stimulus intensities to evoke painful sensation (p ≤ 0.001), longer latencies of N2 and P2 components (both p ≤ 0.001), and lower amplitudes of P1-N2 and N2-P2 complexes (p ≤ 0.001; p = 0.02). Inverse modelling of brain sources showed deeper bilateral insular dipolar source localization (p = 0.002). Symptom score index was negatively correlated with the depth of insular activity (p = 0.004) and positively correlated with insular dipole strength (p = 0.03).

CONCLUSION

DM patients show peripheral and central neuroplastic changes. Moreover, the role of abnormal insular processing may explain the appearance and persistence of GI symptoms related to DAN. This enhanced understanding of DAN may have future clinical and therapeutical implications.

Preliminary findings of the effects of autonomic dysfunction on functional outcome after acute ischemic stroke

BACKGROUND AND PURPOSE

Impaired autonomic function is common in the acute poststroke phase but little is known about its effects on functional outcome after acute ischemic stroke. This study sought to investigate the impact of autonomic dysfunction by Ewing's classification on functional outcome 2 months after acute ischemic stroke.

METHODS

34 consecutive acute ischemic stroke patients within 7 days after onset were enrolled. On admission, autonomic function was assessed by Ewing's battery tests. Stroke severity was assessed by the National Institutes of Health Stroke Scale (NIHSS), autonomy in activities of daily living by the Barthel Index (BI), and global disability by the modified Rankin Scale (mRS). BI and mRS were also evaluated 2 months after ischemic stroke onset.

RESULTS

On admission, eight patients were diagnosed as minor autonomic dysfunction and 26 patients as relatively severe autonomic dysfunction. The prevalence of relatively severe autonomic dysfunction in ischemic stroke patients was 76.5%. There were no significant differences in baseline characteristics between the minor and severe autonomic dysfunction groups. 2 months after stroke onset, the mean BI score of patients with minor autonomic dysfunction and severe autonomic dysfunction increased from 76.3±15.3 on admission to 95.0±7.1, 66.5±15.2 on admission to 74.8±15.9 respectively. The mean BI score after 2-month stroke onset and the change in BI from admission to 2-month outcome (delta BI) in patients with severe autonomic dysfunction were lower than those in patients with minor autonomic dysfunction (all P<0.05).

CONCLUSIONS

Autonomic dysfunction occurs in acute stroke patients. Relatively severe autonomic dysfunction is related to an unfavorable functional outcome in patients with acute ischemic stroke.

Autonomic dysfunction in chronic liver disease

It is becoming increasingly clear that quality of life (QOL) is impaired in those with chronic liver disease (CLD). One of the most important contributors to impaired QOL is the symptomatic burden which can range from slight to debilitating. Autonomic dysfunction accounts for a significant proportion of these symptoms, which can be common, non-specific and challenging to treat. Investigating the autonomic nervous system can be straight forward and can assist the clinician to diagnose and treat specific symptoms. Evidence-based treatment options for autonomic symptoms, specifically in CLD, can be lacking and must be extrapolated from other studies and expert opinion. For those with severely impaired quality of life, liver transplantation may offer an improvement; however, more research is needed to confirm this.

Long-term neurotoxicity of chemotherapy in adolescents and young adults treated for bone and soft tissue sarcomas

Purpose. To study the long-term neurotoxicity of chemotherapy in adolescents and young adults treated for bone and soft tissue sarcomas.

Patients and Methods. Thirty-six adolescents and young adults (median age 17 years) were examined following chemotherapy for bone and soft tissue sarcomas. Twenty-nine (29/36) had received cisplatin (median 400 mg/m²), 15/36 ifosfamide (median 20 g/m²), and 12/36 vincristine (median 16 mg). Neurotoxicity was assessed at a median of 8 months (range, 1–54 months) after completion of chemotherapy by clinical examination, nerve conduction studies, audiograms and autonomic function tests. The same nerve conduction studies were carried out in 20 normal volunteers to define normal ranges in this age group.

Results. Sixteen patients (44%) had a significant reduction in deep tendon reflexes, and this clinical parameter correlated well with abnormalities detected in nerve conduction studies. Vibration perception threshold (VPT) was raised in 20/36 patients (55%) and this was the most sensitive single test in the assessment of neuropathy. There was a significant correlation between VPT and cumulative cisplatin dose received in mg/m^-2 (r=0.607, p<0.01). Ten of 29 patients (35%) had abnormal nerve conduction studies with a pattern characteristic of sensory axonal neuropathy. No patient complained of auditory symptoms, but minor high tone hearing loss was detected by audiograms in 5/28 patients who had received cisplatin. No patients had symptoms of autonomic neuropathy, but autonomic function tests showed minor abnormalities in 4/22 patients tested, and all had received cisplatin.

Conclusions. This study demonstrates significant, although asymptomatic, long-term neurotoxicity of cisplatin in adolescents and young adults receiving chemotherapy for bone and soft tissue sarcomas. Follow-up studies are planned to assess whether these neurological deficits improve with time.

Autonomic changes in preoperative uncomplicated diabetic patients with postural changes

Diabetic autonomic neuropathy is a critical complication frequently encountered in anaesthetic and surgical practice. Power spectral analysis is a noninvasive tool for monitoring frequency analysis of heart rate variability (HRV) and autonomic control of the heart. This study examined HRV changes in preoperative diabetic patients without overt signs of autonomic dysfunction and in matched controls (n=18 per group). HRV values at -15 degrees, 0 degrees, 15 degrees, 45 degrees and sitting positions were compared between groups and for each position. HRV in diabetic patients was lower than in controls at all positions (absolute units). Low-frequency power (normalized units) and the low-frequency/high-frequency ratio increased significantly at 45 degrees and in sitting positions in controls but not in diabetic patients. Pre-existing autonomic derangements in diabetic patients without overt clinical symptoms can be aggravated by high-degree tilting or sitting positions. Consequently, great care should be taken during the intra- and perioperative management of these patients.

Gastrointestinal symptoms in type-1 diabetes: is it all about brain plasticity?

BACKGROUND AND AIMS

Autonomic neuropathy seems to play a central role in the development of gastrointestinal symptoms in diabetes. In order to explore the neuronal mechanisms behind the symptoms we evaluated the brain processing of painful visceral stimuli.

METHODS

Evoked brain potentials were recorded to assess the response to painful oesophageal electrical stimuli in 15 healthy volunteers and 14 type-1 diabetes patients with autonomic neuropathy and related gastrointestinal symptoms. Source reconstruction analysis (fixed Multiple Signal Classification (MUSIC) algorithm) was applied to estimate the location of the evoked electrical activity in the brain.

RESULTS

The patients had increased oesophageal sensory thresholds compared to the controls (P=0.004). The latencies of the evoked brain potentials at vertex (Cz) were increased (P=0.007) and amplitudes reduced (P=0.011) in diabetics. Compared with controls the patients had a posterior shift of the electrical sources in the anterior cingulate cortex at 54 ms, and additional sources close to the posterior insula at 95 ms and in medial frontal gyrus at 184 ms.

CONCLUSIONS

There is evidence of altered central processing to visceral stimulation, and both peripheral and central mechanisms seem involved. Central neuronal reorganisation may contribute to our understanding of the gastrointestinal symptoms in patients with diabetic autonomic neuropathy and this may guide development and evaluation of new treatment modalities.

The association between autonomic dysfunction and survival in male patients with advanced cancer: a preliminary report

CONTEXT

Autonomic nervous system dysfunction (AD) is a common syndrome in patients with advanced cancer. It is associated with decreased survival in several patient populations, including diabetes mellitus, heart failure, and neurological diseases. Based on this evidence, we hypothesized that autonomic dysfunction is associated with decreased survival in patients with advanced cancer.

OBJECTIVES

The objective of this preliminary study was to test the association between AD, as measured by the standardized Ewing test and heart rate variability (HRV) measures, and survival in this patient population.

METHODS

We examined the relationship between survival and parameters of AD in subjects who participated in a prospective study of autonomic dysfunction and hypogonadism in male patients with advanced cancer. Eligibility criteria were defined based on the prospective study protocol. We collected demographic information, date of death (obtained from the online Social Security Death Index database), date of study entry, and Ewing and HRV scores. We defined survival as the interval between study entry and date of death. A survival analysis was used to test the association between survival (in days) and Ewing test (0-5) and measures of HRV, including time domain (standard deviation of normal to normal beat interval [SDNN]) and frequency domain (ultra low, very low, low, and high). Four patients were still alive at the time of this study and included in the survival analysis as being censored.

RESULTS

Forty-seven male patients were included in this study. Median age was 59 years (range: 20-79), and 30 out of 47 (63%) were Caucasians. AD, defined as Ewing score greater than 2, was present in 38 out of 47 (80%) of the patients. Median Ewing score was 3 (1-5), indicating moderate to severe AD. Spearman correlation for Ewing score and SDNN was 0.44 (P = 0.002). There was a significant association between abnormal Ewing score and survival (P < 0.0001) and abnormal SDNN HRV and survival (P = 0.056).

CONCLUSION

AD is associated with shorter survival in male patients with advanced cancer. Further longitudinal research in a large cohort is justified based on.

Central processing of gut pain in diabetic patients with gastrointestinal symptoms

OBJECTIVE

To evaluate the brain's responses to painful visceral and somatic stimuli in diabetic patients with gastrointestinal symptoms.

RESEARCH DESIGN AND METHODS

The sensitivity to electrical esophageal and median nerve stimulations was assessed in 15 healthy volunteers and 14 type 1 diabetic patients with autonomic neuropathy and gastrointestinal symptoms using a euglycemic-hyperinsulinemic clamp. Evoked brain potentials were recorded.

RESULTS

Patients had reduced sensitivity to esophageal (48%; P < 0.001) and median nerve (80%; P < 0.001) stimulations. They also had increased (8.8%; P = 0.007) and nonreproducible (P = 0.006) latencies of evoked potentials in response to esophageal stimulations, with 26% reduction in amplitude (P = 0.011). No potential differences were seen to median nerve stimulations. In diabetic patients, the topographic location of the first peak in potentials was more central (P < 0.001) and gastrointestinal symptoms correlated with characteristics of brain potentials (P = 0.049).

CONCLUSIONS

This study supports that diabetes induces changes in peripheral visceral nerves as well as in the central nervous system.

Review: Mechanisms of silent myocardial ischaemia: with particular reference to diabetes mellitus

Angina occurs relatively late following the onset of ischaemia: after the development of left ventricular dysfunction and electrocardiographic changes. Most ischaemic episodes are not severe enough or long enough to fully stimulate the anginal pain pathway. They are therefore clinically silent. More severe and prolonged episodes of ischaemia can also be silent. Pain thresholds vary between individuals and this is due to differences in gating mechanisms at the level of the thalamus. This gating appears to be modulated by levels of endogenous endorphins, among other mechanisms. This seems to have a relation to personality type. Silent ischemia is especially common in diabetic patients, and is often due to cardiac autonomic neuropathy.

Probabilistic assessment of Autonomic Nervous System fluctuations during tilt table tests

A number of reports have advocated the use of Heart Rate Variability (HRV) as a non invasive method of monitoring the Autonomic Nervous System (ANS). In the anesthesia and critical care monitoring settings, the development of an instrument able to provide real-time information about the ANS state at different stages of any procedure would provide improved safety for patients undergoing diagnostic or therapeutic interventions. However, real-time analysis of HRV can be particularly challenging since larger effective lengths of observation provide better spectral resolution. Our study explores a probabilistic approach that analyzes changes in HRV parameters obtained from an autoregressive (AR) model technique using Burg's methods to evaluate very short observation windows while preserving appropriate frequency resolution. These HRV parameters are continuosly compared to a baseline state, and a probability trend is updated during provocative maneuvers. Preliminary results show that trends from classical parameters such as RMSSD and LFn are consistent and reliable instruments capable of providing significant information about ANS fluctuations in a timely fashion.

A possible new risk factor in diabetic patients with erectile dysfunction: homocysteinemia

INTRODUCTION AND OBJECTIVE

Increasing levels of homocysteine (Hcys) are related to decreased nitric oxide synthesis in the vascular endothelium and also to erectile dysfunction (ED). We investigated the traditional risk factors of ED and plasma levels of Hcys in diabetic patients.

METHODS

Sixty-two men with type 2 diabetes and ages of between 40 and 70 years were included in the study. Detailed medical and sexual history and physical examination were performed. Erectile function was assessed with the International Index of Erectile Function. All participants were evaluated for fasting and postprandial plasma glucose, HbA1c, total cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, apolipoprotein A, apolipoprotein B-100, vitamin B(12), folic acid, and plasma Hcys levels. Patients were evaluated for diabetic neuropathy. Colored penile Doppler ultrasonography was used to detect vascular abnormalities in diabetic patients with ED.

RESULTS

Fasting plasma glucose, postprandial plasma glucose, and HbA1c levels were significantly higher in diabetic patients with ED (P<.05). In addition, Hcys levels were slightly high in diabetic patients with ED (P=.079). Logistic regression analysis revealed that high levels of HbA1c (P<.01) and Hcys (P<.05), and smoking status (P<.01) were the main determinants of the presence of ED in our diabetic population.

CONCLUSION

We conclude that traditional risk factors, poor metabolic control, and smoking are important in ED generation in diabetic patients. In addition, Hcys, which is an important risk factor in atherogenesis, seems to be important in ED generation in diabetic patients.

Effect of oral amino acids on counterregulatory responses and cognitive function during insulin-induced hypoglycemia in nondiabetic and type 1 diabetic people

OBJECTIVE

Amino acids stimulate glucagon responses to hypoglycemia and may be utilized by the brain. The aim of this study was to assess the responses to hypoglycemia in nondiabetic and type 1 diabetic subjects after ingestion of an amino acid mixture.

RESEARCH DESIGN AND METHODS

Ten nondiabetic and 10 diabetic type 1 subjects were studied on three different occasions during intravenous insulin (2 mU . kg(-1) . min(-1)) plus variable glucose for 160 min. In two studies, clamped hypoglycemia (47 mg/dl plasma glucose for 40 min) was induced and either oral placebo or an amino acid mixture (42 g) was given at 30 min. In the third study, amino acids were given, but euglycemia was maintained.

RESULTS

Plasma glucose and insulin were no different in the hypoglycemia studies with both placebo and amino acids (P > 0.2). After the amino acid mixture, plasma amino acid concentrations increased to levels observed after a mixed meal (2.4 +/- 0.13 vs. placebo study 1.7 +/- 0.1 mmol/l, P = 0.02). During clamped euglycemia, ingestion of amino acids resulted in transient increases in glucagon concentrations, which returned to basal by the end of the study. During clamped hypoglycemia, glucagon response was sustained and increased more in amino acid studies versus placebo in nondiabetic and diabetic subjects (P < 0.05), but other counter-regulatory hormones and total symptom score were not different. Beta-OH-butyrate was less suppressed after amino acids (200 +/- 15 vs. 93 +/- 9 micromol/l, P = 0.01). Among the cognitive tests administered, the following indicated less deterioration after amino acids than placebo: Trail-Making part B, PASAT (Paced Auditory Serial Addition Test) (2 s), digit span forward, Stroop colored words, and verbal memory tests for nondiabetic subjects; and Trail-Making part B, digit span backward, and Stroop color tests for diabetic subjects.

CONCLUSIONS

Oral amino acids improve cognitive function in response to hypoglycemia and enhance the response of glucagon in nondiabetic and diabetic subjects.