Risk factors for autonomic and somatic nerve dysfunction in different stages of glucose tolerance

Independent and interactive associations of heart rate and obesity with type 2 diabetes mellites: A population-based study

BACKGROUND

Although obesity and heart rate (HR) were closely related to the prevalence and development of type 2 diabetes mllitus (T2DM), few studies have shown a co-association effect of them on T2DM. We aimed at assessing the interactive effects of HR and obesity with prevalence of T2DM in Chinese population, providing the exact cutpoint of the risk threshold for blood glucose with high HR.

MATERIALS AND METHODS

In the Risk Evaluation of cAncers in Chinese diabeTic Individuals: a lONgitudinal study (REACTION) cohorts (N = 8398), the relationship between HR and T2DM was explored by linear regression, logistic regression, and restricted cubic spline, and odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Interaction terms between HR and body mass index (BMI) and HR and waist circumference (WC) were introduced into the logistic regression model.

RESULTS

In those with HR > 88.0 beats/min, fasting plasma glucose and oral glucose tolerance tests were significantly correlated with HR, and the prevalence of T2DM was highly correlated with HR (all p < .05). There were interactive associations of HR and obesity in patients with T2DM with HR < 74 beats/min.

CONCLUSION

High HR was in interaction with obesity, associating with prevalence of T2DM. The newly subdivided risk threshold for HR with T2DM might be HR > 88 beats/minute.

Cardiac Autonomic Neuropathy in Newly Diagnosed Patients With Type 2 Diabetes Mellitus

INTRODUCTION

Cardiac autonomic neuropathy (CAN) is a debilitating complication in diabetes mellitus, leading to life-threatening arrhythmias and various impairments. Its prevalence varies widely, and early detection and management are crucial. This study investigates the prevalence of CAN in newly diagnosed type 2 diabetes mellitus patients in Central India, comparing them to a control group.

METHODOLOGY

This case-control study included 35 newly diagnosed type 2 diabetes mellitus patients and 35 age-matched healthy controls from the general population. Cardiac autonomic function testing (AFT) was done by heart rate variability (HRV), the deep breathing test (DBT), the cold pressor test (CPT), and the lying-to-standing test (LST). Parameters were recorded and analyzed using statistical tests.

RESULTS

Patients with type 2 diabetes mellitus had significantly higher weight, BMI, fasting blood sugar, post-prandial blood sugar, urine albumin-creatinine ratios, and systolic and diastolic blood pressure than controls. Abnormalities in HRV and E: I ratio during the DBT and CPT were more prevalent in these patients. Parasympathetic dysfunction (delta HR) and a lower E: I ratio were also significantly high in this group. Also, LST results suggested a greater likelihood of orthostatic symptoms in the patients' group.

CONCLUSION

This study highlights the importance of AFT in diagnosing early CAN in newly diagnosed patients. Early diagnosis and management of diabetic CAN are essential to prevent complications.

The Association of Depression With QT Duration: A Comparison Between Individuals Younger or Older Than 65 Years

OBJECTIVE

The electrocardiogram-derived corrected QT (QTc) interval is an indicator of cardiac autonomic activity that has been proposed as a biological measure to investigate the interplay between depression and cardiovascular diseases. This study assesses whether depression is associated with a longer QTc interval across age groups.

METHODS

Assessment of depressive symptoms was performed in 1637 participants of the cross-sectional Corinthia study with the Zung Self-Rating Depression Scale in those younger than 65 years (group 1) and with the Geriatric Depression Scale in elderly individuals (≥65 years, group 2). The QT interval was obtained from electrocardiogram recordings and corrected for heart rate (QTc).

RESULTS

Individuals in group 1 with depression were predominantly women and had a higher prevalence of coronary artery disease and diabetes mellitus. Group 1 individuals with depression had longer QTc duration (no depression versus depression, 389.3 [27.0] versus 401.1 [32.9] milliseconds; p < .001) and percentage of abnormal QTc (no depression versus depression, 2.0% versus 10.8%; p = .001) compared with those without depression. Elderly individuals (group 2) had similar values of QTc and percentage of abnormal QTc irrespective of depression status. Even after adjustment for known QT-prolonging factors, the presence of depression in younger individuals was associated with an increased QTc by 11.1 milliseconds and with an approximately 10.6-fold higher prevalence of abnormal QTc duration.

CONCLUSIONS

Depression was associated with a longer QTc interval especially in individuals younger than 65 years. These findings may indicate an interrelationship between depression and autonomic dysregulation as potential risk factors for cardiovascular disease and sudden cardiac death.

Cost-effectiveness of two screening strategies based on Chinese diabetes risk score for pre-diabetes in China

Objective

Studies have shown that screening for pre-diabetes mellitus (pre-DM) is essential to prevent type 2 diabetes mellitus (T2DM). This study evaluates the cost-effectiveness of two screening strategies that apply the Chinese Diabetes Risk Score (CDRS) to screen for pre-DM in China.

Methods

A Markov microsimulation model was conducted from a social perspective, and the input parameters were obtained from published literature or publicly available data. Two screening strategies for pre-DM based on CDRS were built and compared with the control group to determine the cost-effective strategy. The screening strategy of the control group was screening for pre-DM by fasting plasma glucose (FPG) test in adults undergoing annual health examination and no screening in adults without an annual health examination (status quo). Two screening strategies were strategy 1: screening for pre-DM using CDRS in all adults (including with or without an annual health examination); and strategy 2: supplemental self-screening for pre-DM using CDRS in adults without an annual health examination, based on the status quo. We focus on the cumulative prevalence of T2DM and the incremental cost-effectiveness ratio which signifies the cost per case of T2DM prevented. We also evaluated the cost-effectiveness from the health system perspective. One-way and probabilistic sensitivity analyses were conducted to verify the robustness of the results.

Results

The costs a case of T2DM prevented for strategy 1 compared with the control group and strategy 2 were $299.67 (95% CI 298.88, 300.46) and $385.89 (95% CI 381.58, 390.20), respectively. In addition, compared with the control group, the cost of strategy 2 to prevent a case of T2DM was $272.23 (95% CI 271.50, 272.96).

Conclusions

Screening for pre-DM using CDRS in all adults was the most cost-effective health policy. We suggest that medical institutions replace FPG with CDRS for pre-DM screening; at the same time, self-screening for pre-DM using CDRS is widely promoted among adults without an annual health examination. There were still some disputes about how CDRS is included in the health examination projects, so strategy 2 should be considered as an alternative screening strategy. Findings provide a reference for the application of the CDRS in pre-DM screening and contribute to T2DM prevention.

Cardiovascular Risk Among Saudi Adults with Prediabetes: A Sub-Cohort Analysis from the Heart Health Promotion (HHP) Study

Background

This study aimed to estimate the prevalence of prediabetes among Saudi adults and to evaluate their risk of developing cardiovascular diseases.

Methods

This is a cohort of 2470 Saudi adults attending employee clinics in the university hospital. WHO-STEPs approach was used to collect sociodemographic (age, gender, and education), clinical (body mass index and blood pressure) and laboratory data (HbA1c, lipid profile and vitamin D concentration). Prediabetes was defined according to HbA1c level of 5.7–6.4%. Cardiovascular risk (CVR) scores were evaluated using the Framingham Risk Score. SPSS was used for data analysis to investigate the relation between different CVR and prediabetes.

Results

Prediabetes affected 25.1% of the study population. Males had higher rates of prediabetes than females (27.5% versus 23.5%). The prevalence of prediabetes increased from 11.6% among young individuals (18–29 years) to 56.0% among participants 60 years and older. Prediabetes patients exhibited considerably higher levels of all cardiovascular risk factors and nearly half of them (49.3%) had at least two risk factors. The prevalence of intermediate CVR among prediabetics was 13.2% compared to just 2.9% among the normal group, and high CVR was defined in 3.7% among prediabetics compared to only 1.7% in the normal group. Having prediabetes increased the odds to develop higher CVR of 2.64 times compared to those without prediabetes (OR = 2.64, 95% CI = 1.51–4.64) and the level of vitamin D did not affect the odds of CVR.

Conclusion

Prediabetes is quite prevalent among Saudi adults, and they are at a higher risk of cardiovascular diseases. Patients with prediabetes have higher cardiac risk scores when compared to normal participants across the whole spectrum of (25(OH)D) concentrations. Additionally, no significant correlation was observed between HbA1c and (25(OH)D) levels in prediabetics or normoglycemic subjects.

Cardiac Autonomic Neuropathy in Patients with Newly Diagnosed Carbohydrate Disturbances

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

Profile of Diabetic Foot Ulcer Patients at Tertiary Care Hospital in Surabaya, Indonesia

Background: Diabetic Foot Ulcer (DFU) has been associated with a high mortality rate of Diabetes Mellitus (DM) patients. Both behavioral and biological factors cause predisposition to DFU. Purpose: This research describes the profile of hospitalized DFU patients at a tertiary care hospital in Surabaya. Methods: A retrospective descriptive study that analyzed medical records of hospitalized T2DM patients with DFU in Dr. Soetomo General Hospital. Sampled respondents were patients ≥ 21 years old who were hospitalized between 2016–2018. Demographic data, clinical characteristics, medical histories, length of hospital stay, laboratory results, precipitating factors, microorganism culture results, treatment, and outcome were analyzed. Descriptive analysis is presented in the form of narratives, tables, and diagrams. Results: 9.08% of hospitalized Type 2 DM (T2DM) cases were related to foot ulcers. The average patient age was 57.00 ± 9.83 years with no gender predominance. DM was poorly controlled (Mean HbA1C 9.78±2.83%; RBG 251.83 ± 158.15 mg/dL). The majority of patients had sepsis (68.26%) and renal function impairment (62.72%). Ulcers with Wagner grades of 4–5 were frequent (41.31%). The highest percentage of sepsis (80.49%) and the average leukocyte level (22.60±11.95 x109/L) were found in gangrenous feet. Anemia was more predominant and severe in ulcers with higher Wagner grades. Trauma and Escherichia coli were the most common precipitating factors and microorganisms isolated, respectively. Amputation was performed for 82.36% of patients who were admitted to hospital with gangrene. The Lower Extremity Amputation (LEA) and mortality rates were 14.11% and 40.93%, respectively. Conclusion: DFUs were found to have a relatively high prevalence among T2DM patients, and must never be neglected due to the high associated mortality rate.

The determinants of complication trajectories in American Indians with type 2 diabetes

BACKGROUNDWe aimed to determine whether metabolic syndrome (MetS) affects longitudinal trajectories of diabetic complications, including neuropathy, cardiovascular autonomic neuropathy (CAN), and kidney disease in American Indians with type 2 diabetes.METHODSWe performed a prospective study where participants underwent annual metabolic phenotyping and outcome measurements. The updated National Cholesterol Education Program criteria were used to define MetS and its individual components, using BMI instead of waist circumference. Neuropathy was defined using the Michigan Neuropathy Screening Instrument index, CAN with the expiration/inspiration ratio, and kidney disease with glomerular filtration rate. Mixed-effects models were used to evaluate associations between MetS and these outcomes.RESULTSWe enrolled 141 participants: 73.1% female, a mean (±SD) age of 49.8 (12.3), and a diabetes duration of 19.6 years (9.7 years) who were followed for a mean of 3.1 years (1.7 years). MetS components were stable during follow-up except for declining obesity and cholesterol. Neuropathy (point estimate [PE]: 0.30, 95% CI: 0.24, 0.35) and kidney disease (PE: -14.2, 95% CI: -16.8, -11.4) worsened over time, but CAN did not (PE: -0.002, 95% CI: -0.006, 0.002). We found a significant interaction between the number of MetS components and time for neuropathy (PE: 0.05, 95% CI: 0.01-0.10) but not CAN (PE: -0.003, 95% CI: -0.007, 0.001) or kidney disease (PE: -0.69, 95% CI: -3.16, 1.76). Systolic blood pressure (SBP, unit = 10 mmHg) was associated with each complication: neuropathy (PE: 0.23, 95% CI: 0.07, 0.39), CAN (PE: -0.02, 95% CI: -0.03, -0.02), and kidney disease (PE: -10.2, 95% CI: -15.4, -5.1).CONCLUSIONIn participants with longstanding diabetes, neuropathy and kidney disease worsened during follow-up, despite stable to improving MetS components, suggesting that early metabolic intervention is necessary to prevent complications in such patients. Additionally, the number of MetS components was associated with an increased rate of neuropathy progression, and SBP was associated with each complication.FUNDINGThe following are funding sources: NIH T32NS0007222, NIH R24DK082841, NIH R21NS102924, NIH R01DK115687, the Intramural Program of the NIDDK, the NeuroNetwork for Emerging Therapies, the Robert and Katherine Jacobs Environmental Health Initiative, the Robert E. Nederlander Sr. Program for Alzheimer's Research, and the Sinai Medical Staff Foundation.TRIAL REGISTRATIONClinicalTrials.gov, NCT00340678.

Prevalence of peripheral neuropathy in pre-diabetes: a systematic review

There is growing evidence of excess peripheral neuropathy in pre-diabetes. We aimed to determine its prevalence, including the impact of diagnostic methodology on prevalence rates, through a systematic review conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A comprehensive electronic bibliographic search was performed in MEDLINE, EMBASE, PubMed, Web of Science and the Cochrane Central Register of Controlled Trials from inception to June 1, 2020. Two reviewers independently selected studies, extracted data and assessed risk of bias. An evaluation was undertaken by method of neuropathy assessment. After screening 1784 abstracts and reviewing 84 full-text records, 29 studies (9351 participants) were included. There was a wide range of prevalence estimates (2%-77%, IQR: 6%-34%), but the majority of studies (n=21, 72%) reported a prevalence ≥10%. The three highest prevalence estimates of 77% (95% CI: 54% to 100%), 71% (95% CI: 55% to 88%) and 66% (95% CI: 53% to 78%) were reported using plantar thermography, multimodal quantitative sensory testing and nerve conduction tests, respectively. In general, studies evaluating small nerve fiber parameters yielded a higher prevalence of peripheral neuropathy. Due to a variety of study populations and methods of assessing neuropathy, there was marked heterogeneity in the prevalence estimates. Most studies reported a higher prevalence of peripheral neuropathy in pre-diabetes, primarily of a small nerve fiber origin, than would be expected in the background population. Given the marked rise in pre-diabetes, further consideration of targeting screening in this population is required. Development of risk-stratification tools may facilitate earlier interventions.

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.

Correlation of staging and risk factors with cardiovascular autonomic neuropathy in patients with type II diabetes mellitus

The impairment of cardiovascular autonomic control among the underdiagnosed complication of diabetes mellitus (DM) with a high prevalence rate of up to 60% in type 2 DM (T2DM). Cardiac autonomic neuropathy (CAN) is an independent risk factor for cardiovascular mortality, arrhythmia, silent ischemia, any major cardiovascular event, and heart failure. We aimed to evaluate cardiovascular autonomic activity by different physiological maneuvers, study risk factors for diabetic CAN including age, gender, duration of diabetes, body mass index (BMI), and glycemic control, and correlate CAN stage with risk factors. One hundred and forty-two T2DM patients consisted of 62 males and 80 females and 100 volunteers as a control sample. Cardiac autonomic functions were assessed by Ewing's tests. Glycated hemoglobin (HbA1c), body weight, height, body mass index (BMI), and waist-hip ratio (WHR) were also measured. Cardiovascular autonomic functions and Ewing scores were significantly different in people with diabetes when compared with control healthy subjects. Ewings test values and Ewing scores were significantly different between diabetics with and without CAN and within patients with different CAN staging. People with diabetes with CAN have a significantly longer duration of disease when compared to those without CAN. A strong association has been found between CAN severity and patient age, duration of disease, HbA1c severity, and the WHR (P < 0.001) but not with BMI. The duration of disease and HbA1c level appear to be associated with the development of CAN (P = 0.001 and P = 0.008, respectively). The poorer glycemic control and the longer the duration of the disease, the higher the prevalence of CAN in T2DM. Age, duration of disease, WHR, and HbA1c are well correlated with the severity of CAN. Parasympathetic impairment is more sensitive to the detection of autonomic dysfunctions than do sympathetic impairment.

The prevalence of cardiac autonomic neuropathy in prediabetes: a systematic review

AIMS/HYPOTHESIS

Cardiac autonomic neuropathy (CAN) is independently associated with silent myocardial ischaemia, major cardiovascular events, myocardial dysfunction and cardiovascular mortality. Several studies have highlighted the increased prevalence of CAN in prediabetes (impaired glucose tolerance and/or impaired fasting glucose). Considering the exponential rise of prediabetes, we aimed to determine the prevalence of CAN through a systematic literature review.

METHODS

This systematic review was registered with PROSPERO (CRD42019125447). An electronic literature search was performed using MEDLINE, EMBASE, PubMed, Web of Science, Scopus and Cochrane databases. Published full text, English language articles that provide CAN prevalence data of studies in individuals with prediabetes and aged over 18 years were included. Prevalence data for normal glucose tolerance and diabetes were also extracted from the selected articles, if present. All articles were screened by two independent reviewers using a priori criteria. Methodological quality and risk of bias were evaluated using a critical appraisal tool.

RESULTS

Database searches found 4500 articles; subsequently, 199 full text articles were screened, 11 of which fulfilled the inclusion criteria (4431 total participants, 1730 people with prediabetes, 1999 people with normal glucose tolerance [NGT] and 702 people with predominantly type 2 diabetes). Six of the selected studies reported definite CAN prevalence data (9-39%). Only a single large population-based study by Ziegler et al (KORA S4 study, 1332 participants) determined definite CAN based on two or more positive autonomic function tests (AFTs), with a mean prevalence of 9% in all prediabetes groups (isolated impaired glucose tolerance 5.9%; isolated impaired fasting glucose 8.1%; impaired fasting glucose plus impaired glucose tolerance 11.4%), which was higher than NGT (4.5%). This study is most likely to provide a reliable population-specific estimate of CAN in prediabetes. There was a higher than expected prevalence of CAN in prediabetes (9-38%) when compared with normal glucose tolerance (0-18%) within the same studies (n = 8). There was a wide prevalence of possible CAN based on one positive AFT (n = 5). There was heterogeneity between the studies with variations in the definition of CAN, methodology and characteristics of the populations, which likely contributed to the diversity of prevalence estimates. The overall risk of bias was low.

CONCLUSIONS/INTERPRETATION

There is a higher than expected prevalence of CAN in prediabetes. Early detection of CAN in prediabetes through population screening needs careful consideration in view of the excess morbidity and mortality risk associated with this condition. Graphical abstract.

Assessment of sudomotor function in hypertensive with/without type-2 diabetes patients using SUDOSCAN: An electrophysiological study

Objective

Electrochemical skin conductance (ESC) test is a simple and non-invasive screening test can detect dysfunction of the peripheral sudomotor, and indirectly estimates the function of cardiac autonomic nerves. This study aimed to assess the ESC values in hypertensive patients with/without type-2 diabetes by using SUDOSCAN technology. Moreover, this study evaluated the role of cardiometabolic risk factors on the results of ESC test.

Methods

This cross-sectional study was carried on three groups of participants, including healthy subjects (Group I, n = 49), hypertensive without type-2 diabetes (Group II, n = 75) patients, and hypertensive with type-2 diabetes (Group III, n = 76) patients. Body mass index (BMI), blood pressure (systolic, diastolic and pulse pressure index), fasting serum glucose, and lipid profile were determined. ESC test as a measurement sudomotor function was determined by applying a small direct current at low voltage to hands and feet sensor plates through SUDOSCAN device.

Results

ESC values of the peripheral sudomotor nerves in the Group II and III patients were significantly lower than the corresponding values of Group I. SUDOSCAN results of Group II and III. Significant discriminators of cardiac autonomic neuropathy (≥30 score) that determined by the area under the curve (AUC) with 95% confidence interval (95% C.I.) were, duration of the disease, BMI, and mean blood pressure in Group II, while the duration of the disease and the BMI were significant discriminators in Group III.

Conclusions

SUDOSCAN is a simple, useful device, which can detect the impairment of peripheral autonomic small nerve fibers and the risk of cardiac autonomic neuropathy in hypertension. Moreover, the duration of the disease and the associated cardiometabolic risk factors are important predictors of significant SUDOSCAN findings.

Significance

ESC test is useful in detecting subclinical neuropathy in hypertensive patients as well as in type 2 diabetes.

Assessment of sudomotor function in hypertensive with/without type-2 diabetes patients using SUDOSCAN: An electrophysiological study

•

SUDOSCAN is a simple non-invasive device that can assess the sudomotor nerves.

•

Hypertensive patients have sub-clinical impairment of peripheral and autonomic nerve fibers function.

•

Cardio-metabolic risk factors are important discriminators of abnormal SUDOSCAN data.

Objective

Electrochemical skin conductance (ESC) test is a simple and non-invasive screening test can detect dysfunction of the peripheral sudomotor, and indirectly estimates the function of cardiac autonomic nerves. This study aimed to assess the ESC values in hypertensive patients with/without type-2 diabetes by using SUDOSCAN technology. Moreover, this study evaluated the role of cardiometabolic risk factors on the results of ESC test.

Methods

This cross-sectional study was carried on three groups of participants, including healthy subjects (Group I, n = 49), hypertensive without type-2 diabetes (Group II, n = 75) patients, and hypertensive with type-2 diabetes (Group III, n = 76) patients. Body mass index (BMI), blood pressure (systolic, diastolic and pulse pressure index), fasting serum glucose, and lipid profile were determined. ESC test as a measurement sudomotor function was determined by applying a small direct current at low voltage to hands and feet sensor plates through SUDOSCAN device.

Results

ESC values of the peripheral sudomotor nerves in the Group II and III patients were significantly lower than the corresponding values of Group I. SUDOSCAN results of Group II and III. Significant discriminators of cardiac autonomic neuropathy (≥30 score) that determined by the area under the curve (AUC) with 95% confidence interval (95% C.I.) were, duration of the disease, BMI, and mean blood pressure in Group II, while the duration of the disease and the BMI were significant discriminators in Group III.

Conclusions

SUDOSCAN is a simple, useful device, which can detect the impairment of peripheral autonomic small nerve fibers and the risk of cardiac autonomic neuropathy in hypertension. Moreover, the duration of the disease and the associated cardiometabolic risk factors are important predictors of significant SUDOSCAN findings.

Significance

ESC test is useful in detecting subclinical neuropathy in hypertensive patients as well as in type 2 diabetes.

Peripheral and Autonomic Neuropathy Status of Young Patients With Type 1 Diabetes Mellitus at the Time of Transition From Pediatric Care to Adult-Oriented Diabetes Care

INTRODUCTION

The prevalence of neuropathic lesions in young patients with type 1 diabetes mellitus (T1DM) at the time of transition from pediatric care to adult-oriented diabetes care is poorly studied. A comparative study with healthy volunteers to assess the possible neuropathic condition of this special population and to identify the potential early screening needs has not been performed yet. The results may provide important feedback to pediatric diabetes care and a remarkable baseline reference point for further follow up in adult diabetes care.

PATIENTS AND METHODS

Twenty-nine young patients with T1DM [age: 22.4 ± 2.9 years; HbA1c: 8.5 ± 2.1%, diabetes duration: 12.2 ± 5.8 years; (mean ± SD)] and 30 healthy volunteers (age: 21.5 ± 1.6 years; HbA1c: 5.3 ± 0.3%) were involved in the study. Autonomic function was assessed by standard cardiovascular reflex tests. Complex peripheral neuropathic testing was performed by Neurometer^®, Neuropad^®-test, Tiptherm^®, Monofilament^®, and Rydel-Seiffer tuning fork tests.

RESULTS

T1DM patients had significantly higher diastolic blood pressure than controls (80 ± 9 vs. 74 ± 8 mmHg, p < 0.01), but there was no significant difference in systolic blood pressure (127 ± 26 vs. 121 ± 13 mmHg). Cardiovascular reflex tests had not revealed any significant differences between the T1DM patients and controls. No significant differences with Neurometer^®, Neuropad^®-test, and Monofilament^® were detected between the two groups. The vibrational sensing on the radius on both sides was significantly impaired in the T1DM group compared to the controls with Rydel-Seiffer tuning fork test (right: 7.5 ± 1.0 vs. 7.9 ± 0.3; left: 7.5 ± 0.9 vs. 7.9 ± 0.3, p < 0.05). The Tiptherm^®-test also identified a significant impairment in T1DM patients (11 sensing failures vs. 1, p < 0.001). In addition, the neuropathic complaints were significantly more frequently present in the T1DM patient group than in the controls (9 vs. 0, p < 0.01).

CONCLUSION

In this young T1DM population, cardiovascular autonomic neuropathy and cardiac morphological alterations could not be found. However, Rydel-Seiffer tuning fork and Tiptherm^®-tests revealed peripheral sensory neurological impairments in young T1DM patients at the time of their transition to adult diabetes care.

What Is in the Field for Genetics and Epigenetics of Diabetic Neuropathy: The Role of MicroRNAs

Despite the high prevalence of diabetic neuropathy, its early start, and its impact on quality of life and mortality, unresolved clinical issues persist in the field regarding its screening implementation, the understanding of its mechanisms, and the search for valid biomarkers, as well as disease-modifying treatment. Genetics may address these needs by providing genetic biomarkers of susceptibility, giving insights into pathogenesis, and shedding light on how to select possible responders to treatment. After a brief summary of recent studies on the genetics of diabetic neuropathy, the current review focused mainly on microRNAs (miRNAs), including the authors' results in this field. It summarized the findings of animal and human studies that associate miRNAs with diabetic neuropathy and explored the possible pathogenetic meanings of these associations, in particular regarding miR-128a, miR-155a, and miR-499a, as well as their application for diabetic neuropathy screening. Moreover, from a genetic perspective, it examined new findings of polymorphisms of miRNA genes in diabetic neuropathy. It considered in more depth the pathogenetic implications for diabetic neuropathy of the polymorphism of MIR499A and the related changes in the downstream action of miR-499a, showing how epigenetic and genetic studies may provide insight into pathogenetic mechanisms like mitochondrial dysfunction. Finally, the concept and the data of genotype-phenotype association for polymorphism of miRNA genes were described. In conclusion, although at a very preliminary stage, the findings linking the genetics and epigenetics of miRNAs might contribute to the identification of exploratory risk biomarkers, a comprehensive definition of susceptibility to specific pathogenetic mechanisms, and the development of mechanism-based treatment of diabetic neuropathy, thus addressing the goals of genetic studies.

Epigenetic Regulation of PDX-1 in Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is a metabolic disease characterized by hyperglycemia which is caused by insufficient insulin secretion or insulin resistance. Interaction of genetic, epigenetic and environmental factors plays a significant role in the development of T2DM. Several environmental factors including diet and lifestyle, as well as age have been associated with an increased risk for T2DM. It has been demonstrated that these environmental factors may affect global epigenetic status, and alter the expression of susceptible genes, thereby contributing to the pathogenesis of T2DM. In recent years, a growing body of molecular and genetic studies in diabetes have been focused on the ways to restore the numbers or function of β-cells in order to reverse a range of metabolic consequences of insulin deficiency. The pancreatic duodenal homeobox 1 (PDX-1) is a transcriptional factor that is essential for the development and function of islet cells. A number of studies have shown that there is a significant increase in the level of DNA methylation of PDX-1 resulting in reduced activity in T2DM islets. The decrease in PDX-1 activity may be a critical mediator causing dysregulation of pancreatic β cells in T2DM. This article reviews the epigenetic mechanisms of PDX-1 involved in T2DM, focusing on diabetes and DNA methylation, and discusses some potential strategies for the application of PDX-1 in the treatment of diabetes.

The relationship between QT interval indices with cardiac autonomic neuropathy in diabetic patients: a case control study

BACKGROUND

Long QT interval (QT) and abnormal QT dispersion (QTd) are associated with sudden death. The relationship between cardiac autonomic neuropathy (CAN) and QT indices in type 2 diabetic patients were investigated.

METHODS

Totally 130 diabetic subjects (mean age 50.87 ± 13.9 years) were included (70 individuals with and 60 individuals without CAN). All participants had sinus cardiac rhythm. The patients who had diseases or take drugs that cause orthostatic hypotension (OH), cardiac arrhythmia and QT prolongation were excluded. After interview and examination, standard and continuous ECG was taken in supine position with deep breathing and standing up position. CAN diagnosis was based on Ewing's tests. QT, QT corrected (QTc), minimum QT (QT min), maximum QT (QT max) and mean ± SD of QT (QT mean) and QTd were assessed from standard ECG. QTc was calculated by Bazett's formula from V2 lead. QTc > 440 ms in men and QTc > 460 ms in women and QTd > 80 ms were considered abnormal.

RESULTS

In patients with CAN, 21.5% were symptomatic. The prevalence of abnormal QTc and QTd was 11.3% and 28.7%, respectively. There was no significant difference between the patients with or without CAN in terms of long QTc and abnormal QTd. However, the mean ± SD of QT max, QT mean and QTd was higher in the patients with CAN (P value < 0.03). The used cut points for QTc and QTd have high specificity (79% for both) and low sensitivity (30% and 37%, respectively). To use QTc and QTd as screening test for CAN in T2DM patients, the cutoff points 380 and 550 ms are suggested, respectively.

CONCLUSION

The prevalence of asymptomatic CAN was 3.7 times that of symptomatic CAN. In patients with CAN the QT max, QT mean and QTd were higher than those without CAN. There was no association between CAN and long QTc and abnormal QTd.

Chronic Microvascular Complications in Prediabetic States-An Overview

A prediabetic state is a major risk factor for the development of diabetes, and, because of an identical pathophysiological background of both conditions, their prevalence increases parallelly and equally fast. Long-term hyperglycemia is the main cause inducing chronic complications of diabetes, yet the range of glucose levels at which they start has not been yet unequivocally determined. The current data show that chronic microvascular complications of diabetes can be observed in patients with abnormal glucose metabolism in whom glycaemia is higher than optimal but below diagnostic criteria for diabetes. Prediabetes is a heterogenous nosological unit in which particular types are differently characterized and show different correlations with particular kinds of complications. Analysis of the latest research results shows the need to continue studies in a larger population and can imply the need to verify the currently employed criteria of diagnosing diabetes and chronic complications of diabetes in people with prediabetes.

Is there cardiac autonomic neuropathy in prediabetes?

Although there is considerably more data showing an association between type 2 diabetes mellitus (T2DM) and autonomic neuropathy, accumulating evidence indicates that cardiovascular autonomic neuropathy (CAN) is common in persons with impaired glucose tolerance (IGT). Furthermore, CAN may occur early after a metabolic insult and obesity, especially among mean, and seems to play an important role in the early pathogenesis of CAN. Autonomic symptoms are common in subjects with IGT. In addition to defects in CAN, in subjects with IGT, there is impaired sudomotor function and abnormalities of endothelial peripheral vasoreactivity. At the present time, the only interventions that may be effective in preventing or reversing IGT associated autonomic neuropathy are lifestyle improvement. These include a tailored diet and exercise program. Other approaches that may be beneficial include modulation of oxidative stress and improvement of metabolic regulation in subjects with IGT. Interventions are most likely to be effective early in the course of disease and therefore it is extremely important to have early diagnosis of IGT and autonomic neuropathy.

Prediabetes Deserves More Attention: A Review

Evidence increasingly demonstrates that prediabetes is a toxic state, as well as a risk factor for diabetes, and is associated with pathophysiological changes in several tissues and organs. Unfortunately, use of available evidence-based treatments for prediabetes is low. This review seeks to explain why prediabetes must be viewed and treated as a serious pathological entity in its own right. It offers an overview of the pathophysiology and complications of prediabetes and describes how this condition can be reversed if all treatment avenues are deployed early in its course.

The Compound Expression of HSP90 and INOS in the Testis of Diabetic Rats as Cellular and Pathologic Adverse Effects of Diabetes

Introduction

Diabetes is increasingly prevalent at global level and associated with various impacts including the male reproductive system.

Aims

This research is aimed at investigating the influence of diabetes on the localization and expression of HSP90 and iNOS in the testicular tissue of diabetic rats.

Methods

A diabetic model was developed through a single injection of alloxan monohydrate intraperitoneally (purchased from Sigma-Aldrich) 120 mg/kg body weight following fasting for 12 hrs. The experiment involved two groups, the control and diabetic groups with 10 albino rats in each group. Diabetes was considered if glucose concentration was ≥200 mg/dl. The experiment duration was for one month. After the experiment had finished, all rats were terminated and prepared for routine histological and immunohistochemical examination.

Results

The results revealed that diabetes caused morphological changes at histological level in testicular tissue. Immunohistochemical examination showed that diabetes significantly upregulated the expression of both HSP90 and iNOS in the testicular tissue of diabetic rats as compared with that of the control group (p < 0.001).

Conclusion

Diabetes may induce adverse health effects on the male reproduction through upregulation of HSP90 and iNOS in the testicular tissue of diabetic rats.

Evaluation of the relationship between cardiac autonomic function and glucose variability and HOMA-IR in prediabetes

AIMS

The present study aims to investigate the relationship between cardiac autonomic function (CAF) and glucose variability (GV) and HOMA-IR in subjects with prediabetes and normal glucose tolerance (NGT).

MATERIAL AND METHODS

Ninety-two subjects (59 with prediabetes and 33 with NGT), of mean age 50.3 ± 11.5 years, mean BMI 30.4 ± 6.0 kg/m², were included in this cross-sectional study. Glucose tolerance was assessed by OGTT according to WHO 2006 criteria. Glucose, HbA1c, insulin, oxLDL, and 3-Nitrotyrosine were measured. CGM was performed with a blinded sensor (FreeStyle Libre Pro). CAF was assessed by ANX-3.0 technology.

RESULTS

GV indices were increased in prediabetes. CAF was suppressed in subjects with any stage of dysglycemia. The prevalence of cardiac autonomic dysfunction was higher in prediabetes -20.3% as compared to NGT -3.0%, p = 0.028. HOMA-IR [OR 1.5 (95% CI: 1.1-2.1), p = 0.010] and time in target range [OR 0.8 (95% CI: 0.67-0.97), p = 0.021] were found to be predictive variables for impaired CAF. Sympathetic and parasympathetic activity negatively correlated with mean glycemia and GV indices and were independently related to JINDEX in prediabetes (F[1, 47] = 5.76, p = 0.021 and F[1, 47] = 5.94, p = 0.019, respectively); and to time above target range in NGT (F[1, 18] = 4.48, p = 0.049 and F[1, 18] = 4.65, p = 0.046, respectively).

CONCLUSION

CAF is declined in prediabetes and seems to be related to GV and HOMA-IR at early stages of dysglycemia.

The haptoglobin 2-2 genotype is associated with cardiac autonomic neuropathy in type 1 diabetes: the RETRO HDLc study

AIM

The haptoglobin (Hp) 2-2 genotype has been shown to increase the risk of coronary artery disease, kidney dysfunction and mortality from cardiovascular and renal causes in type 1 diabetes (T1D). Similar associations, however, have not been observed in those without diabetes. As cardiac autonomic neuropathy (CAN) is a cardiovascular disease risk factor, we assessed the presence of an association between the Hp 2-2 genotype and CAN.

METHODS

The study included 216 individuals with childhood-onset T1D and 200 individuals with normal glucose tolerance (NGT) of similar age and gender distribution to their counterparts with T1D. CAN was assessed using an electrocardiogram as an abnormal, age-specific, heart rate response to deep breathing. Multivariable logistic regression models were used to assess the association between the Hp 2-2 genotype and CAN.

RESULTS

Compared with NGT, participants with T1D had a similar proportion of Hp 2-2 carriers (41.5% vs. 32.0%, p = 0.05) but a greater CAN prevalence (28.2% vs. 5.0%, p < 0.0001). In multivariable logistic regression models, those carrying the Hp 2-2 genotype had significantly higher odds of CAN compared with Hp 1-1 or Hp 2-1 carriers (OR = 2.27, p = 0.01). The presence of T1D (OR = 4.20, p = 0.0003), hypertension (OR = 2.08, p = 0.03), eGFR (OR = 0.98, p = 0.01) and WBC count (OR = 1.21, p = 0.02) were also associated with CAN. There was no T1D by Hp interaction (p = 0.92), although in stratified analyses, the Hp-CAN association was significant only in T1D.

CONCLUSIONS

The Hp 2-2 genotype was independently associated with greater odds of CAN in T1D though no definitive conclusions could be made in NGT.

Cardiac Autonomic Neuropathy in Obesity, the Metabolic Syndrome and Prediabetes: A Narrative Review

Cardiac autonomic neuropathy (CAN) is a major complication of type 1 and type 2 diabetes mellitus (T1DM and T2DM). The increased morbidity, cardiovascular and all-cause mortality associated with CAN is established from numerous epidemiological studies. However, CAN is increasingly recognised in people with prediabetes (pre-DM) and the metabolic syndrome (MetS) with a reported prevalence up to 11% and 24% respectively. CAN is associated with components of MetS including hypertension and obesity, predating hyperglycaemia. The aetiology of CAN is multifactorial and there is a reciprocal relationship with insulin resistance and MetS. Obstructive sleep apnoea (OSA) is also associated with CAN possibly through MetS and an independent mechanism. An estimated global prevalence of the impaired glucose tolerance (IGT) form of pre-DM of 587 million people by 2045 means CAN will become a major clinical problem. CAN is independently associated with silent myocardial ischaemia, major cardiovascular events, myocardial dysfunction and cardiovascular mortality. Screening for CAN in pre-DM using risk scores with analysis of heart rate variability (HRV) or Sudoscan is important to allow earlier treatment at a reversible stage. The link between obesity and CAN highlights the therapeutic potential of lifestyle interventions including diet and physical activity to reverse MetS and prevent CAN. Weight loss achieved using these dietary and exercise lifestyle interventions improves the sympathetic and parasympathetic HRV indices of cardiac autonomic function. Further research is needed to identify high-risk populations of people with pre-DM or obesity that might benefit from targeted pharmacotherapy including metformin, sodium/glucose cotransporter 2 (SGLT2) inhibitors and glucagon-like peptide 1 (GLP-1) analogues. Bariatric surgery also improves HRV through weight loss which might also prevent CAN in severe obesity. This article reviews the literature on CAN in obesity, pre-DM and MetS, to help determine a rationale for screening, early intervention treatment and formulate future research questions in this highly prevalent condition.

Update on the Impact, Diagnosis and Management of Cardiovascular Autonomic Neuropathy in Diabetes: What Is Defined, What Is New, and What Is Unmet

The burden of diabetic cardiovascular autonomic neuropathy (CAN) is expected to increase due to the diabetes epidemic and its early and widespread appearance. CAN has a definite prognostic role for mortality and cardiovascular morbidity. Putative mechanisms for this are tachycardia, QT interval prolongation, orthostatic hypotension, reverse dipping, and impaired heart rate variability, while emerging mechanisms like inflammation support the pervasiveness of autonomic dysfunction. Efforts to overcome CAN under-diagnosis are on the table: by promoting screening for symptoms and signs; by simplifying cardiovascular reflex tests; and by selecting the candidates for screening. CAN assessment allows for treatment of its manifestations, cardiovascular risk stratification, and tailoring therapeutic targets. Risk factors for CAN are mainly glycaemic control in type 1 diabetes mellitus (T1DM) and, in addition, hypertension, dyslipidaemia, and obesity in type 2 diabetes mellitus (T2DM), while preliminary data regard glycaemic variability, vitamin B12 and D changes, oxidative stress, inflammation, and genetic biomarkers. Glycaemic control prevents CAN in T1DM, whereas multifactorial intervention might be effective in T2DM. Lifestyle intervention improves autonomic function mostly in pre-diabetes. While there is no conclusive evidence for a disease-modifying therapy, treatment of CAN manifestations is available. The modulation of autonomic function by SGLT2i represents a promising research field with possible clinical relevance.

Improvement in Neuropathy Outcomes With Normalizing HbA1c in Patients With Type 2 Diabetes

OBJECTIVE

To investigate the impact of normalizing HbA_1c by extensive HbA_1c control (EHC) on neuropathy outcome measures (NOMs), nephropathy, and retinopathy in type 2 diabetes.

RESEARCH DESIGN AND METHODS

Detailed clinical and neurological examinations were performed in two cohorts of 38 patients with uncontrolled type 2 diabetes (HbA_1c 9.6% [81.4 mmol/mol]) at baseline and after glycemic control (GC) with or without EHC by diet restriction and hypoglycemic agents over 4 years along with 48 control subjects with normal glucose tolerance (NGT) and 34 subjects with impaired glucose tolerance (IGT) only at baseline. EHC patients, control subjects, and subjects with IGT underwent oral glucose tolerance tests. Glycemic variability (GV) was evaluated by SD and coefficient of variation of monthly measured HbA_1c levels and casual plasma glucose.

RESULTS

In the EHC cohort, HbA_1c levels over 4.3 years and the last 2 years improved to 6.1% (43.2 mmol/mol) and 5.8% (39.9 mmol/mol) with 7.3 kg body wt reduction, and 50% and 28.9% of patients returned to IGT and NGT, respectively, at end point. Baseline neurophysiological and corneal nerve fiber (CNF) measures were impaired in patients. Normalized HbA_1c with EHC improved neurophysiological and CNF measures to be similar for those for IGT, while GC without EHC (mean HbA_1c level 7.0% [53.5 mmol/mol]) improved only vibration perception. The mean normalized HbA_1c levels by EHC determined NOM improvements. The high GV and baseline HbA_1c levels compromised NOMs. Albumin excretion rate significantly decreased, while retinopathy severity and frequency insignificantly worsened on EHC.

CONCLUSIONS

Normalizing HbA_1c in type 2 diabetes of short duration improves microvascular complications including neuropathy and nephropathy more effectively than standard GC but not retinopathy.

Prevalence of cardiovascular autonomic neuropathy and gastroparesis symptoms among patients with type 2 diabetes who attend a primary health care center

Introduction

Cardiovascular autonomic neuropathy (CAN) and gastroparesis are two types of diabetic autonomic neuropathy which could affect patients' quality of life and carry significant morbidity and mortality outcomes. The aim of this study was to estimate the prevalence and risk factors of both CAN and gastroparesis symptoms among patients with type 2 diabetes mellitus (T2DM) at primary health care level.

Methods

A cross-sectional study was conducted among 400 adults with T2DM from April 1, 2017 to March 20, 2018. CAN was defined by the presence of any of the followings: resting tachycardia, orthostatic hypotension or prolonged corrected QT interval in the electrocardiogram. Gastroparesis symptoms were assessed using a validated questionnaire: the Gastroparesis Cardinal Symptom Index.

Results

The mean age of study participants and disease duration were 55.26 ± 10.65 years and 10.77 ± 6.89 years, respectively. CAN was present in 15.3% of the participants. Hypertension, smoking, antihypertensive use, body mass index, dyslipidemia and albuminuria were significantly higher in participants with CAN than those without CAN (p<0.05). Prolonged disease duration (p = 0.007) and hypertension (p = 0.004) were independently associated with CAN. Gastroparesis symptoms were present in 6.3% of study participants and were significantly associated with those of female gender (P<0.05). Metformin use emerged as an independent predictor of the presence of at least one symptom (p = 0.001).

Conclusion

Among Saudi adults with T2DM at primary care level, the prevalence of CAN is significant and is independently related to disease duration and hypertension, indicating the importance of CAN screening, especially for those with prolonged disease duration, and the importance of controlling blood pressure in order to prevent CAN or its consequences. The prevalence of gastroparesis symptoms is 6% and is independently related to metformin use, and therefore, symptomatic screening is required to decide which patients need further evaluation.

Vascular factors and neuropathy in lower limb of diabetic patients

Asymmetric clinical presentation in some patients with diabetic polyneuropathy may result from the different vascular environments in both lower limbs. The aim of the study is to determine the association of neuropathy with vascular factors in each lower limb of diabetic patients. A total of 102 patients (204 lower limbs) given a diagnosis of diabetic polyneuropathy were enrolled. The primary end points are sensory nerve action potential (SNAP) amplitude and conduction velocity (CV) of the sural nerve and independent variables are vascular and nonvascular factors. Vascular factors include mean arterial pressure and pulse pressure at the ankle, ankle-brachial index, and arterial stiffness assessed by pulse wave velocity. Nonvascular factors include age, gender, height, body weight, body mass index, total cholesterol, and hemoglobin A₁C. Age, hemoglobin A₁C, and ankle pulse pressure were inversely correlated with SNAP amplitude of the sural nerve, while no factors were correlated with CV of the sural nerve. Increased arterial stiffness was significant in the limbs group with abnormal SNAP amplitude of the sural nerve, while increased height was significant in the limbs group with abnormal CV of the sural nerve. Vascular factors were more significantly associated with decreased SNAP amplitude rather than decreased CV of the sural nerve in the nerve conduction study of diabetic patients.

Sexual functioning and depressive symptoms in men with various types of prediabetes: a pilot study

No study has compared sexual functioning and depressive symptoms in male subjects with various types of prediabetes. Our study included four age- and weight-matched groups of apparently healthy men (25-50 years old): subjects with isolated impaired fasting glucose (IFG) (n = 16), men with isolated impaired glucose tolerance (n = 17), individuals with the presence of both IFG and impaired glucose tolerance (n = 16), as well as men with normal glucose tolerance (n = 18). All included men completed questionnaires evaluating male sexual functioning (IIEF-15) and assessing the presence and severity of depressive symptoms (BDI-II). Men with both IFG and impaired glucose tolerance obtained lower domain scores for erectile function, sexual desire, and overall satisfaction, as well as the higher overall BDI-II score. Individuals with isolated impaired glucose tolerance (IGT) and IFG were characterized by lower domain score only for sexual desire. In all study groups, domain score for erectile function correlated with the BDI-II score, while scores for erectile function and sexual desire correlated with a degree of insulin resistance. The obtained results suggest that prediabetes may impair sexual functioning in young men. The risk is particularly high in individuals with the presence of both IFG and IGT.

Nerve function varies with hemoglobin A1c in controls and type 2 diabetes

AIMS

To determine the cross-sectional threshold at which hemoglobin A1c (HbA1c) is associated with polyneuropathy in healthy controls, and the values associated with the most pronounced decline in nerve function in patients with diabetes.

METHODS

We used data from a cross-sectional cohort study of healthy controls and type 2 diabetes patients assessed between November 2010 and May 2013. Healthy controls and patients with diabetes were compared at different HbA1c ranges: <5.5%, 5.5-5.9%, and 6-6.4% for controls, and 6.5-7.4% and >7.5% for patients with diabetes.

RESULTS

The total cohort included 53 controls and 164 patients with diabetes. Subclinical small nerve fiber impairments were observed in controls at HbA1c levels of 5.5-6%, compared with HbA1c <5.5%, for example: lower Laser Doppler flare imaging area of 2.8 ± 1.4 versus 3.9 ± 2 mm². The most prominent decline in both small and large nerve fiber function was seen with less impaired glycemic control and shorter duration of diabetes, i.e. at HbA1c levels of 6.5-7.4%, compared with >7.5%.

CONCLUSIONS

These findings underscore the importance of early treatment at the prediabetes and early diabetes stages to prevent nerve fiber decline that is likely irreversible.

Vitamin D in the Spectrum of Prediabetes and Cardiovascular Autonomic Dysfunction

Vitamin D is a fat-soluble secosteroid hormone with pleiotropic effects. 1,25-Dihydroxyvitamin D coordinates the biosynthesis of neurotransmitters in the central nervous system, which regulate cardiovascular autonomic function and may explain its putative role in the development of cardiovascular autonomic neuropathy (CAN). CAN is an independent risk factor for mortality in patients with diabetes and prediabetes and is associated with an increased risk of developing type 2 diabetes and cardiovascular disease. Accumulating data indicate the presence of peripheral nerve injury at these early stages of dysglycemia and its multifactorial pathogenesis. Prediabetes is associated with vitamin D insufficiency. Vitamin D is proposed to prevent the progression of glucose intolerance. The putative underlying mechanisms include maintenance of the intracellular calcium concentration, direct stimulation of insulin receptor expression, and enhancement of the insulin response to glucose transporters. Vitamin D exerts a protective effect on peripheral nerve fibers by decreasing the demyelination process and inducing axonal regeneration. The effects of vitamin D supplementation on glucose tolerance and related autonomic nerve dysfunction have been a recent focus of scientific interest. Although well-designed observational studies are available, the causative relation between vitamin D deficiency, glucose intolerance, and CAN is still debatable. One reason might be that interventional studies are unpersuasive with regard to the beneficial clinical effects of vitamin D supplementation. Because of its favorable side effect profile, vitamin D supplementation might represent an attractive therapeutic option for treating the pandemic prevalence of prediabetes and vitamin D deficiency. Vitamin D supplementation can improve glucose tolerance and cardiovascular autonomic function and can thus reduce cardiovascular mortality among subjects with different stages of glucose intolerance and autonomic dysfunction. However, more patient-centered trials on the use of vitamin D supplementation in different conditions are needed.

Clinical characteristics and mortality in patients treated in a Multidisciplinary Diabetic Foot Unit

BACKGROUND AND OBJECTIVE

This study reviews the clinical characteristics of patients with diabetic foot ulcer treated in a Multidisciplinary Diabetic Foot Unit (MDFU) and analyzes the mortality and factors associated with its survival.

MATERIAL AND METHODS

Data from all patients who attended the MDFU for the first time for a diabetic foot ulcer during the 2008-2014 period were analized. The patients were followed until their death or until June 30, 2016, for up to 8 years.

RESULTS

A total of 345 patients were included, with a median age (P25-P75) of 71 (61.5-80) years, and 321 (93%) had type 2 diabetes. They were characterized as patients with inadequate glycemic control, 48% had HbA1c ≥ 8% and high prevalence of chronic complications: 60.2% retinopathy, 43.8% nephropathy and 47.2% ischemic heart disease and/or cerebrovascular disease. A total of 126 (36.5%) patients died and 69 (54.8%) were due to cardiovascular disease. Survival measured by Kaplan-Meier declined over time to 69, 60 and 45% at 3, 5 and 7 years respectively. Cox's multivariate regression analysis showed the following variables associated with mortality, HR (95% CI): age 1.08 (1.05-1.11); previous amputation 2.24 (1.34-3.73); active smoking 2.10 (1.12-3.97); cerebrovascular disease 1.75 (1.05-2.92); renal dysfunction 1.65 (1.04-2.61) and ischemic heart disease 1.60 (1.01-2.51).

CONCLUSIONS

Patients with diabetic foot ulcer are characterized by high morbidity and mortality, with cardiovascular disease being the most frequent cause of death. It is necessary to pay more attention to this risk group, tailoring objectives and treatments to their situation and life expectancy.

Cardiac autonomic neuropathy in patients with diabetes mellitus: current perspectives

Cardiac autonomic neuropathy (CAN) is a common and often-underdiagnosed complication of diabetes mellitus (DM). CAN is associated with increased mortality, cardiovascular disease, chronic kidney disease, and morbidity in patients with DM, but despite these significant consequences CAN often remains undiagnosed for a prolonged period. This is commonly due to the disease being asymptomatic until the later stages, as well as a lack of easily available screening strategies. In this article, we review the latest developments in the epidemiology, pathogenesis, diagnosis, consequences, and treatments of CAN in patients with DM.