The relationship between diabetic autonomic neuropathy and diabetic risk factors in a Taiwanese population

A systematic review and meta-analysis of the serum lipid profile in prediction of diabetic neuropathy

Whether the lipid profile in diabetic patients is associated with diabetic neuropathy (DN) development remains ambiguous, as does the predictive value of serum lipid levels in the risk of DN. Here, we performed the first meta-analysis designed to investigate the relationship between DN and the serum levels of triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL), and low-density lipoprotein cholesterol (LDL). Candidate studies were comprehensively identified by searching PubMed, Embase, Cochrane Library and Web of Science databases up to May 2020. Observational methodological meta-analysis was conducted to assess the relationships of TG, TC, HDL, and LDL levels with DN. Changes in blood lipids were used to estimate the effect size. The results were pooled using a random-effects or fixed-effects model. Potential sources of heterogeneity were explored by subgroup analysis. Various outcomes were included, and statistical analyses were performed using STATA (Version 12.0). Mean differences (MDs) and odds ratios (ORs) with 95% confidence intervals (CIs) were estimated. The Newcastle–Ottawa Scale (NOS) was applied to assess the methodological quality. I2 statistics were calculated to evaluate statistical heterogeneity. Funnel plots were utilized to test for publication bias. A sensitivity analysis was performed by omitting each study one by one. Thirty-nine clinical trials containing 32,668 patients were included in the meta-analysis. The results demonstrated that DN patients showed higher TG and lower HDL levels (MD = 0.34, 95% CI: 0.20–0.48 for TG; MD = -0.05, 95% CI: -0.08–-0.02, I² = 81.3% for HDL) than controls. Subgroup analysis showed that patients with type 1 diabetes mellitus (T1DM) neuropathy had elevated TG levels in their serum (MD = 0.25, 95% CI: 0.16–0.35,I² = 64.4% for T1DM). However, only patients with T1DM neuropathy had reduced serum HDL levels, and there was no significant difference in serum HDL levels between patients with T2DM neuropathy and controls (MD = -0.07, 95% CI: -0.10–-0.03, I² = 12.4% for T1DM; MD = -0.02, 95% CI: -0.07–0.03, I² = 80.2% for T2DM). TC and LDL levels were not significantly different between DN patients and controls (MD = -0.03, 95% CI: -0.14–0.09, I² = 82.9% for TC; MD = -0.00, 95% CI: -0.08–0.08, I² = 78.9% for LDL). In addition, compared with mild or painless DN patients, those with moderate or severe pain DN pain had significantly reduced serum TC and LDL levels (MD = -0.31, 95% CI: -0.49–-0.13, I² = 0% for TC; MD = -0.19, 95% CI: -0.32–-0.08, I² = 0% for LDL). TG levels and HDL levels did not vary considerably between patients with mild or painless DN and those with moderate or severe DN pain patients (MD = 0.12, 95% CI: -0.28–0.51, I² = 83.2% for TG; MD = -0.07, 95% CI:-0.14–0.01, I² = 58.8% for HDL). Furthermore, people with higher TG and LDL levels had higher risk of DN (OR = 1.36, 95% CI: 1.20–1.54, I² = 86.1% for TG and OR = 1.10, 95% CI: 1.02–1.19, I² = 17.8% for LDL). Conversely, high serum HDL levels reduced the risk of DN (OR = 0.85, 95% CI: 0.75–0.96, I² = 72.6%), while TC levels made no significant difference with the risk of DN (OR = 1.02, 95% CI: 1.00–1.04, I² = 84.7%). This meta-analysis indicated that serum lipid profile changes are among the biological characteristics of DN. Lipid levels should be explored as routine laboratory markers for predicting the risk of DN, as they will help clinicians choose appropriate therapies, and thus optimize the use of available resources.

Cardio-metabolic profile of subjects with early stages of glucose intolerance and cardiovascular autonomic dysfunction

AIMS

The present study evaluates the cardio-metabolic profile of subjects with early stages of glucose intolerance and presence of cardiovascular autonomic dysfunction (CAD).

MATERIALS AND METHODS

478 subjects, of mean age 49.3±13.7years and mean BMI 31.0±6.2kg/m², divided according to glucose tolerance: 130 with normal glucose tolerance, 227 with prediabetes, and 121 with newly-diagnosed type 2 diabetes, were enrolled. Glucose tolerance was studied during OGTT applying 2006 WHO criteria. Anthropometric indices, blood pressure, HbA1c, serum lipids, hsCRP, and albumin-to-creatinine ratio (ACR) were measured. Body fat distribution was estimated by a bioimpedance method (InBody720, BioSpace). Tissue AGEs accumulation was assessed by skin autofluorescence (AGE-Reader-DiagnOptics™). CAD was assessed by ANX-3.0 method.

RESULTS

CAD was found in 24.1% of subjects with any disorder of glucose tolerance in comparison to 12.3% in NGT, OR 2.0 (95% CI: 1.2-3.2), p=0.005. Sympathetic and parasympathetic tone declined with the progression of glucose intolerance. Age, waist circumference, visceral fat area, fasting and 120-min plasma glucose, HbA1c, AGEs, ACR and QTc interval were higher in subjects with CAD, p<0.05. In a logistic regression analysis the panel of age >53years (76% sensitivity, 61% specificity), HbA1c >6.0% (66% sensitivity, 60% specificity), QTc interval >423ms (65% sensitivity, 61% specificity) and presence of arterial hypertension (83% sensitivity, 55% specificity) was related to the presence of CAD - AUC 0.778 (95% CI: 0.73-0.83), p<0.001.

CONCLUSION

Our results demonstrate a high prevalence of CAD in early stages of glucose dysmetabolism. Age, HbA1c, QTc interval and presence of arterial hypertension are related to the presence of CAD in this population.