Analysis of a Screening System for Diabetic Cardiovascular Autonomic Neuropathy in China

Correlations of cardiovascular autonomic neuropathy with urinary albumin excretion rate and cardiac function in patients with type 2 diabetes mellitus

BACKGROUND

The associations of cardiovascular autonomic neuropathy (CAN) with diabetic nephropathy and heart disease remain elusive. The aim of this study was to explore the correlations of CAN with urinary albumin excretion rate (UAER) and cardiac function in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 225 T2DM patients were assigned into CAN and non-CAN groups using cardiovascular reflex tests (CARTs). They were divided into macroalbuminuria, microalbuminuria and normoalbuminuria groups according to urinary albumin/creatinine ratio (UACR), or left ventricular diastolic dysfunction and normal groups based on left ventricular peak E/A velocity ratio (E/A). The correlations of CAN with albuminuria and left ventricular diastolic dysfunction, and the predictive values of UACR and E/A were analyzed.

RESULTS

Compared with non-CAN group, CAN group had older age, longer T2DM duration, higher serum urine acid (SUA) level, UACR, systolic and diastolic pressure differences between supine and standing positions, and lower other CARTs parameters and E/A (P<0.001). Macroalbuminuria group had largest positional systolic and diastolic pressure differences, and lowest other CARTs parameters (P<0.001). Compared with normal group, left ventricular diastolic dysfunction group had larger positional systolic and diastolic pressure differences, and lower other CARTs parameters (P<0.001). CAN in T2DM patients was positively correlated with albuminuria and left ventricular diastolic dysfunction (P<0.001). Age, SUA, UACR and E/A were independent predictive factors (P=0.031, P=0.005, P<0.001, P<0.001). UACR and E/A had high predictive values.

CONCLUSIONS

In T2DM patients, CAN is positively correlated with declined UAER and cardiac function. UACR and E/A have high predictive values.

Clinical scoring systems for the risk of cardiovascular autonomic neuropathy in type 1 and type 2 diabetes: a simple tool

BACKGROUND AND AIMS

This study was aimed at developing a clinical risk score for cardiovascular autonomic neuropathy (CAN) for type 1 and type 2 diabetes.

METHODS

In a retrospective cross-sectional one-centre study in an unselected population, 115 participants with type 1 diabetes (age 41.1±12.2 years), and 161 with type 2 diabetes (age 63.1±8.9 years), well-characterised for clinical variables, underwent standard cardiovascular reflex tests (CARTs). Strength of associations of confirmed CAN (based on 2 abnormal CARTs) with clinical variables was used to build a CAN risk score.

RESULTS

CAN risk score was based on resting heart rate, HbA1c, retinopathy, nephropathy, cardiovascular disease in both type 1 and type 2 diabetes, and on HDL cholesterol, systolic blood pressure, and smoking in type 1 diabetes or insulin treatment and physical activity in type 2 diabetes (range 0-10). In type 1 diabetes, CAN risk score showed an area under the ROC curve (AUC) of 0.890±0.034, and at cut-off of 4 sensitivity of 88%, specificity of 74.4%, and negative predictive value (NPV) of 95.7% for confirmed CAN. In type 2 diabetes, CAN risk score showed an AUC of 0.830±0.051 and at the cut-off of 4 sensitivity and specificity of 78.6% and 73.5%, respectively, and NPV of 97.3% for confirmed CAN.

INTERPRETATION

These newly developed CAN risk scores are accessible in clinical practice and, if confirmed in a validation study, they might identify asymptomatic individuals with diabetes at greater risk of CAN to be referred to CARTs, thus limiting the burden of a universal screening. This article is protected by copyright. All rights reserved.

Cardiovascular Autonomic Reflex Tests and 7 Heart Rate Variability Indices for Early Diagnosis of Cardiovascular Autonomic Neuropathy in Type 2 Diabetes Individuals

BACKGROUND

Cardiovascular autonomic neuropathy (CAN) is a common complication of type 2 Diabetes mellitus (T2D), and prevalence varies according to the methodology used. CAN should be diagnosed in the subclinical stage when an intensive treatment of T2D could avoid the progression to irreversible phases.

OBJECTIVE

Determine the prevalence of early involvement (EI) of CAN in T2D individuals comparing two methodologies.

METHODS

This was a cross-sectional study that included 183 T2D individuals who were monitored in a Tertiary centre. The diagnosis of CAN was based on the results of four cardiovascular autonomic reflex tests (CARTs: expiration-inspiration index, Valsalva maneuver, orthostatic test, and changes in blood pressure after standing) and of seven heart rate variability (7HRV) indices (CARTs plus the spectral analysis). The findings were validated in an independent cohort comprised of 562 T2D individuals followed in a Primary care setting.

RESULTS

With the use of 7HRV, 30.6% and 77.8% of individuals in the Tertiary and in the Primary centers, respectively, were classified as without CAN; 25.1% and 15.3% as EI and 44.3% and 6.9% as definitive CAN, respectively. The use of CARTs decreased the proportion of individuals without CAN in both centers (7.1% and 47%) and increased the frequency of EI (30.6% and 36.6%) and definitive CAN (62.3% and 16.4%), respectively. The concordance between both evaluated methodologies was weak.

CONCLUSION

Higher proportions of T2D individuals were diagnosed with EI and with definitive CAN with the use of CARTs.

Impact of lower limb muscle strength on walking function beyond aging and diabetes

Objective

This study was performed to investigate the influence of lower limb muscle strength on the walking function of advanced-age patients with diabetes.

Methods

In this cross-sectional descriptive study, data were collected from 202 advanced-age patients with diabetes. All patients completed questionnaires, the one-leg stance test, the timed up-and-go test, the 30-s sit-to-stand test, and plantar pressure platform measurements. The patients were divided in two groups according to their lower limb muscle strength: those with declining muscle strength and those with normal muscle strength.

Results

Walking function was significantly abnormal in the patients with declining lower limb muscle strength. The gait trajectories were abnormal, mainly with respect to a shortage of driving force.

Conclusion

The lower limb muscle strength can affect the static balance and dynamic balance in advanced-age patients with declining lower limb muscle strength.

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.

Improved long-term cardiovascular outcomes after intensive versus standard screening of diabetic complications: an observational study

BACKGROUND

Complication screening is recommended for patients with type 2 diabetes (T2D), but the optimal screening intensity and schedules are unknown. In this study, we evaluated whether intensive versus standard complication screening affects long-term cardiovascular outcomes.

METHODS

In this observational study, we included 368 T2D patients referred for intensive screening provided as a 1-day session of clinical-instrumental evaluation of diabetic complications, followed by dedicated counseling. From a total of 4906 patients, we selected control T2D patients who underwent standard complication screening at different visits, by 2:1 propensity score matching. The primary endpoint was the 4p-MACE, defined as cardiovascular mortality, or non-fatal myocardial infarction, stroke, or heart failure. The Cox proportional regression analyses was used to compare outcome occurrence in the two groups, adjusted for residual confounders.

RESULTS

357 patients from the intensive screening group (out of 368) were matched with 683 patients in the standard screening group. Clinical characteristics were well balanced between the two groups, except for a slightly higher prevalence of microangiopathy in the intensive group (56% vs 50%; standardized mean difference 0.11, p = 0.1). Median follow-up was 5.6 years. The adjusted incidence of 4p-MACE was significantly lower in the intensive versus standard screening group (HR 0.70; 95% CI 0.52-0.95; p = 0.02). All components of the primary endpoint had nominally lower rates in the intensive versus standard screening group, which was particularly significant for heart failure (HR 0.43; 95% CI 0.22-0.83; p = 0.01).

CONCLUSION

Among T2D patients attending a specialist outpatient clinic, intensive complication screening is followed by better long-term cardiovascular outcomes. No significant effect was noted for cardiovascular and all-cause mortality and the benefit was mainly driven by a reduced rate of hospitalization for heart failure.

Development of clinical risk models for diabetic cardiovascular autonomic neuropathy in a Chinese population using logistic regression analysis

Background: We developed clinical risk models for predicting diabetic cardiovascular autonomic neuropathy (DCAN) in Chinese diabetic patients.

Methods: A Chinese cohort of 455 diabetic participants underwent a short heart rate variability (HRV) test which was recruited between 2011 and 2013. Clinical risk models were developed that included independent and significant risk factors by using multiple variable stepwise regressions. These clinical risk models were tested in another independent cohort of Chinese individuals.

Results: The clinical risk models included age, fasting plasma glucose, 2-h plasma blood glucose, triglycerides, resting HRs, and duration of diabetes mellitus. The area under the receiver-operating characteristic (ROC) curve of the study group was 0.794. In the model with the continuous variables, the area under the ROC curve was 0.810. A cutoff score of 12.54 which produced the optimal sensitivity (68.20%) and specificity (76.80%) and identified the percentage (35.77%) of the population that required subsequent testing.

Conclusions: The clinical risk models showed high sensitivity and specificity for the prediction of DCAN in Chinese diabetic patients.