UNASSIGNED: Diabetes and hypertension are known to co-exist frequently as adverse cardiovascular risk factors. Both can produce cardiac autonomic neuropathythat can be measured by ECG RR interval-based heart rate variability (HRV). We compared 5 minutes HRV in four groups based on diabetes and hypertension.
UNASSIGNED: A cross sectional study was done on 203 participants divided into four groups- diabetics, hypertensives, diabetic-hypertensives and normotensive-nondiabetics. They were evaluated for current disease control and five minutes HRV was done in supine condition following standard protocols by Variowin HR Software. HRV parameters of time domain, frequency domain and Poincare plot were compared between groups and associated with gender, glycaemic control and blood pressure control. Statistical significance was set at p<0.05.
UNASSIGNED: Three diseasedgroups had mean age in mid-fifties, mean duration of disease > 6 years, comparable BMI, poor glycaemic and blood pressure control. As compared to normal groups, three diseased groups exhibit reduced HRV with respect to all three domains of HRV with varying statistical significance. Among diseased groups, HRV was associated with blood pressure control better than glycaemic control but not with gender. LF /HF ratio was the most consistent HRV parameter showing statistical significance in tests.
UNASSIGNED: HRV is reduced in both diabetics more than hypertensives; related to blood pressure control more than glycaemic control. It points altered cardiac autonomic balance, and possibility of cardiovascular risk and early detection of it with timely intervention. It also calls for investigation of same for reinforcement of our observations and further exploration.

OBJECTIVE: Diabetic gastroenteropathy frequently causes debilitating gastrointestinal symptoms. Previous uncontrolled studies have shown that transcutaneous vagal nerve stimulation (tVNS) may improve gastrointestinal symptoms. To investigate the effect of cervical tVNS in individuals with diabetes suffering from autonomic neuropathy and gastrointestinal symptoms, we conducted a randomised, sham-controlled, double-blind (participants and investigators were blinded to the allocated treatment) study.
METHODS: This study included adults (aged 20-86) with type 1 or 2 diabetes, gastrointestinal symptoms and autonomic neuropathy recruited from three Steno Diabetes Centres in Denmark. Participants were randomly allocated 1:1 to receive active or sham stimulation. Active cervical tVNS or sham stimulation was self-administered over two successive study periods: 1 week of four daily stimulations and 8 weeks of two daily stimulations. The primary outcome measures were gastrointestinal symptom changes as measured using the gastroparesis cardinal symptom index (GCSI) and the gastrointestinal symptom rating scale (GSRS). Secondary outcomes included gastrointestinal transit times and cardiovascular autonomic function.
RESULTS: Sixty-eight participants were randomised to the active group, while 77 were randomised to the sham group. Sixty-three in the active and 68 in the sham group remained for analysis in study period 1, while 62 in each group were analysed in study period 2. In study period 1, active and sham tVNS resulted in similar symptom reductions (GCSI: -0.26 ± 0.64 vs -0.17 ± 0.62, p=0.44; GSRS: -0.35 ± 0.62 vs -0.32 ± 0.59, p=0.77; mean ± SD). In study period 2, active stimulation also caused a mean symptom decrease that was comparable to that observed after sham stimulation (GCSI: -0.47 ± 0.78 vs -0.33 ± 0.75, p=0.34; GSRS: -0.46 ± 0.90 vs -0.35 ± 0.79, p=0.50). Gastric emptying time was increased in the active group compared with sham (23 min vs -19 min, p=0.04). Segmental intestinal transit times and cardiovascular autonomic measurements did not differ between treatment groups (all p>0.05). The tVNS was well-tolerated.
CONCLUSIONS: Cervical tVNS, compared with sham stimulation, does not improve gastrointestinal symptoms among individuals with diabetes and autonomic neuropathy.
BACKGROUND: ClinicalTrials.gov NCT04143269 FUNDING: The study was funded by the Novo Nordisk Foundation (grant number NNF180C0052045).

Autonomic and sensory neuropathy have been observed in both prediabetes and manifest diabetes mellitus. However, there is a lack of available data regarding whether patients at a moderate or high risk of developing diabetes, yet without a current diagnosis of prediabetes or diabetes, exhibit an increased prevalence of neuropathy.
FINDRISC (Finnish Diabetes Risk Score) was used to classify individuals at risk (≥12 points, n = 44; control <12 points, n = 28). HbA1c levels >5.6% served as exclusion criteria, and patients with known medical conditions predisposing to neuropathy were also excluded. Cardiac autonomic function (Ewing tests) and peripheral sensory neuropathy (Neurometer and Q-sense) were assessed by standardized protocols, and their potential association with increased FINDRISC points was analyzed using a regression model.
Mean age was 46.7 ± 14.3 years in the control and 55.7 ± 14.1 years in the increased risk group. Male/female ratio did not differ. Individuals with increased risk of diabetes were more obese (BMI: 29.9 ± 12.5 kg/m2 vs. 25.9 ± 8.9 kg/m2). Additionally, hypertension was more frequent among them (68.2% vs. 17.9%), and their lipid parameters were also less favorable. Parasympathetic neuropathy was present in both groups (56.8% vs. 32.1%, respectively). Sympathetic neuropathy was not found. Sensory nerve dysfunction was of low prevalence in the high-risk group and did not occur in healthy controls. In multiple logistic regression analysis, HbA1c exhibited an independent association with parasympathetic neuropathy (OR: 5.9; 95% CI: 1.08-32.68; p < 0.041).
An increased risk of developing prediabetes/diabetes does not appear to have a strong correlation with an increased likelihood of developing autonomic or sensory neuropathy. However, the etiology behind the occurrence of parasympathetic autonomic neuropathy in healthy individuals remains unknown.

Background: Postural tachycardia syndrome (POTS) is a form of autonomic dysregulation. There is increasing evidence that the etiology may be immune-mediated in a subgroup of patients. Patients with POTS often experience an exacerbation of their symptoms associated with (viral) infections and often fear the same symptom aggravation after vaccination. In this report we describe the tolerability of messenger ribonucleic acid (mRNA) vaccines against coronavirus disease 19 (COVID-19) and the consequences of a COVID-19 infection on POTS symptoms in our cohort of patients with neuropathic POTS. Methods: We conducted a standardized, checklist-based interview with 23 patients and recorded the acute side effects of mRNA vaccination, acute symptoms of COVID-19 infection as well as the effects of vaccination and COVID-19 infection on POTS symptoms. Results: Of all included patients, 20 patients received two mRNA vaccines without having had a previous COVID-19 infection, and five patients in total had suffered a COVID-19 infection. Of these, three had COVID-19 without and two after being vaccinated. No increased frequency of side effects after both doses of mRNA vaccines was observed. Six patients reported a mild and short-term aggravation of their POTS symptoms beyond the duration of acute vaccine side effects. All five patients who suffered a COVID-19 infection subsequently reported a pronounced and persistent exacerbation of POTS symptoms. Conclusions: Our observations suggest that mRNA vaccines are not associated with a higher frequency of acute side effects in patients with POTS. Symptom exacerbation as a consequence of mRNA vaccination seems to be less frequent and of shorter duration compared to patients who suffered a COVID-19 infection.

To assess cardiac angiogenesis in type 2 diabetes by positron emission tomography (PET) tracer [68 Ga]Ga-NODAGA-E[(cRGDyK)]2 (68 Ga-RGD) imaging.
Cross-sectional study including 20 persons with type 2 diabetes and 10 non-diabetic controls (CONs). Primary prespecified outcome was difference in cardiac angiogenesis (cardiac 68 Ga-RGD mean target-to-background ratio [TBRmean ]) between type 2 diabetes and CONs. Secondary outcome was to investigate associations between cardiac angiogenesis and kidney function and other risk factors.
Participants with type 2 diabetes had a mean ± SD age of 61 ± 9 years, 30% were women, median (IQR) diabetes duration of 11 (6-19) years and 3 (15%) had a history of cardiovascular disease. The CONs had comparable age and sex distribution to the participants with type 2 diabetes, and none had a history of coronary artery disease. Myocardial flow reserve was lower in type 2 diabetes (2.7 ± 0.6) compared with CONs (3.4 ± 1.2) ( p  = 0.03) and coronary artery calcium score was higher (562 [142-905] vs. 1 [0-150] p  = 0.04). Cardiac 68 Ga-RGD TBRmean was similar in participants with type 2 diabetes (0.89 ± 0.09) and CONs (0.89 ± 0.10) ( p  = 0.92). Cardiac 68 Ga-RGD TBRmean was not associated with estimated glomerular filtration rate, urine albumin creatinine ratio, cardiovascular disease, coronary artery calcium score or baroreflex sensitivity, neither in pooled analyses nor in type 2 diabetes.
Cardiac angiogenesis, evaluated with 68 Ga-RGD PET, was similar in type 2 diabetes and CONs. Cardiac angiogenesis was not associated with kidney function or other risk markers in pooled analyses or in analyses restricted to type 2 diabetes.

OBJECTIVE: To investigate the effect of normalizing vitamin B12 (B12) levels with oral B12 (methylcobalamin) 1000 μg/day for one year in patients with diabetic neuropathy (DN).
METHODS: In this prospective, double-blind, placebo-controlled trial, 90 patients with type 2 diabetes on metformin for at least four years and both peripheral and autonomic DN were randomized to an active treatment group (n = 44) receiving B12 and a control group (n = 46) receiving a placebo. All patients had B12 levels less than 400 pmol/L. Subjects underwent measurements of sural nerve conduction velocity (SNCV), sural nerve action potential (amplitude) (SNAP), and vibration perception threshold (VPT), and they performed cardiovascular autonomic reflex tests (CARTs: mean circular resultant (MCR), Valsalva test, postural index, and orthostatic hypotension). Sudomotor function was assessed with the SUDOSCAN that measures electrochemical skin conductance in hands and feet (ESCH and ESCF, respectively). We also used the Michigan Neuropathy Screening Instrument Questionnaire and Examination (MNSIQ and MNSIE, respectively) and questionnaires to evaluate quality of life (QoL) and level of pain (pain score).
RESULTS: B12 levels increased from 232.0 ± 71.8 at baseline to 776.7 ± 242.3 pmol/L at follow-up, p < 0.0001, in the active group but not in the control group. VPT, MNSIQ, QoL, pain score, SNCV, SNAP, and ESCF significantly improved in the active group (p < 0.001, p = 0.002, p < 0.0001, p < 0.000, p < 0.0001, p < 0.0001, and p = 0.014, respectively), whereas CARTS and MNSIE improved but not significantly. MCR, MNSIQ, SNCV, SNAP, and pain score significantly deteriorated in the control group (p = 0.025, p = 0.017, p = 0.045, p < 0.0001, and p < 0.0001, respectively).
CONCLUSIONS: The treatment of patients with DN with 1 mg of oral methylcobalamin for twelve months increased plasma B12 levels and improved all neurophysiological parameters, sudomotor function, pain score, and QoL, but it did not improve CARTS and MNSIE.

Metformin has been shown to have both neuroprotective and neurodegenerative effects. The aim of this study was to investigate the effect of metformin in combination with insulin on cardiovascular autonomic neuropathy (CAN) and distal peripheral neuropathy (DPN) in individuals with type 2 diabetes (T2DM).
The study is a sub-study of the CIMT trial, a randomized placebo-controlled trial with a 2 × 3 factorial design, where 412 patients with T2DM were randomized to 18 months of metformin or placebo in addition to open-labelled insulin. Outcomes were measures of CAN: Changes in heart rate response to deep breathing (beat-to-beat), orthostatic blood pressure (OBP) and heart rate and vibration detection threshold (VDT) as a marker DPN. Serum levels of vitamin B12 and methyl malonic acid (MMA) were analysed.
After 18 months early drop in OBP (30 s after standing) was increased in the metformin group compared to placebo: systolic blood pressure drop increased by 3.4 mmHg (95% CI 0.6; 6.2, p = 0.02) and diastolic blood pressure drop increased by 1.3 mmHg (95% CI 0.3; 2.6, p = 0.045) compared to placebo. Beat-to-beat variation decreased in the metformin group by 1.1 beats per minute (95% CI - 2.4; 0.2, p = 0.10). Metformin treatment did not affect VDT group difference - 0.33 V (95% CI - 1.99; 1.33, p = 0.39) or other outcomes. Changes in B12, MMA and HbA1c did not confound the associations.
Eighteen months of metformin treatment in combination with insulin compared with insulin alone increased early drop in OBP indicating an adverse effect of metformin on CAN independent of vitamin B12, MMA HbA1c. Trial registration The protocol was approved by the Regional Committee on Biomedical Research Ethics (H-D-2007-112), the Danish Medicines Agency and registered with ClinicalTrials.gov (NCT00657943).

BACKGROUND: Falls represent one of the main complications of Parkinson\'s disease (PD), significantly lowering quality of life. Cardiovascular autonomic neuropathy (cAN) is one of the key contributing factors to PD-associated falls. However, a direct quantification of its impact on the risk of falling in PD is still lacking. In this 12-month prospective study, we sought to evaluate the association between cAN and falls.
METHODS: Fifty consecutive patients were evaluated with a standardized battery of autonomic testing, Unified Parkinson\'s Disease Rating Scale, push and release (P&R) test, timed up and go test, freezing of gait (FOG) questionnaire, Montreal cognitive assessment (MoCA). Dyskinesia severity and presence of REM sleep behavioral disorder (RBD) were additionally considered. Patients were followed-up for 12 months.
RESULTS: We observed a 38% prevalence of cAN. At baseline, 36% of patients reported at least one fall in the previous 6 months. This figure increased to 56% over the follow-up. After adjusting for age, disease duration, axial symptoms, MoCA and dopaminergic treatment, cAN was significantly associated with a 15-fold (OR 15.194) higher probability of falls; orthostatic hypotension (OH), the most common expression of cAN, with a 10-fold probability (OR 10.702). In addition P&R test (OR 14.021), RBD (OR 5.470) and FOG (OR 1.450) were independently associated with greater probability of falls.
CONCLUSIONS: cAN, including but not limited to OH, is a strong independent predictor of falls in PD. Future research endeavors clarifying to what extent pharmacological and non-pharmacological treatments targeting autonomic dysfunctions might reduce the risk of falls are warranted.

OBJECTIVE: Cardiovascular autonomic testing is time consuming when adopting the entire Ewing battery of tests, hence, clinicians usually adopt an empirically reduced number of tests which may give controversial results. Our purpose was to examine the reliability of the cardiovascular tests most commonly used in autonomic diagnoses.
METHODS: We tested 334 subjects, from an original group of 3745, who had shown an altered deep breathing test to both Lying to standing and Valsalva manoeuvre, assuming a value of postural hypotension of more than 15 mmHg as a sign of almost true dysautonomia.
RESULTS: VM showed the highest sensitivity (85%) and, when coupled to LS, highest specificity (83%).
CONCLUSIONS: VM could be useful when screening for possible or early autonomic neuropathy, VM + LS is useful as a diagnostic tool for probable or advanced autonomic neuropathy, and VM + LS + PH is useful for certain diagnosis of definite or late stage autonomic neuropathy.

To examine patient reported outcomes (PRO) in patients previously assessed for diabetic gastroparesis, and to investigate how symptoms of gastroparesis evolve over time. In addition, to further evaluate outcomes in those with versus without diabetic gastroparesis at baseline.
Thirty-four patients with diabetes and gastrointestinal (GI) symptoms, diagnosed with or without diabetic gastroparesis in 2011-2013, were included in this follow-up study. PRO were measured with the Patient assessment of upper gastrointestinal symptom severity index (PAGI-SYM), 36-Item Short Form Survey (SF-36), Patient assessment of upper gastrointestinal disorders-quality of life (PAGI-QOL) and Hospital Anxiety and Depression Scale (HADS). Demographic factors and clinical variables were also recorded.
Participants diagnosed with gastroparesis had improved glycemic control (p=0.04) and less GI symptoms (p=0.001), after a follow-up time of 3.2years (mean). Both groups reported severely impaired quality of life (QoL). In total 47% reported symptoms of anxiety, 38% symptoms of depression (scores≥8). GI symptom severity or other PRO could not differentiate between the two groups.
Patients diagnosed with diabetic gastroparesis, as well as those with gastroparesis symptoms - but normal gastric emptying, suffer from severely impaired QoL and a high burden of anxiety and depressive symptoms.