Serum apolipoprotein A-1 concentrations and the prevalence of cardiovascular autonomic neuropathy in individuals with type 2 diabetes

Quantification of lipoproteins by proton nuclear magnetic resonance spectroscopy (1H-NMRS) improves the prediction of cardiac autonomic dysfunction in patients with type 1 diabetes

AIMS

To assess if advanced characterization of serum glycoprotein and lipoprotein profile, measured by proton nuclear magnetic resonance spectroscopy (1H-NMRS) improves a predictive clinical model of cardioautonomic neuropathy (CAN) in subjects with type 1 diabetes (T1D).

METHODS

Cross-sectional study (ClinicalTrials.gov Identifier: NCT04950634). CAN was diagnosed using Ewing's score. Advanced characterization of macromolecular complexes including glycoprotein and lipoprotein profiles in serum samples were measured by 1H-NMRS. We addressed the relationships between these biomarkers and CAN using correlation and regression analyses. Diagnostic performance was assessed by analyzing their areas under the receiver operating characteristic curves (AUCROC).

RESULTS

Three hundred and twenty-three patients were included (46% female, mean age and duration of diabetes of 41 ± 13 years and 19 ± 11 years, respectively). The overall prevalence of CAN was 28% [95% confidence interval (95%CI): 23; 33]. Glycoproteins such as N-acetylglucosamine/galactosamine and sialic acid showed strong correlations with inflammatory markers such as high-sensitive C-reactive protein, fibrinogen, IL-10, IL-6, and TNF-α. On the contrary, we did not find any association between the former and CAN. A stepwise binary logistic regression model (R2 = 0.078; P = 0.003) retained intermediate-density lipoprotein-triglycerides (IDL-TG) [β:0.082 (95%CI: 0.005; 0.160); P = 0.039], high-density lipoprotein-triglycerides (HDL-TGL)/HDL-Cholesterol [β:3.633 (95%CI: 0.873; 6.394); P = 0.010], and large-HDL particle number [β: 3.710 (95%CI: 0.677; 6.744); P = 0.001] as statistically significant determinants of CAN. Adding these lipoprotein particles to a clinical prediction model of CAN that included age, duration of diabetes, and A1c enhanced its diagnostic performance, improving AUCROC from 0.546 (95%CI: 0.404; 0.688) to 0.728 (95%CI: 0.616; 0.840).

CONCLUSIONS

When added to clinical variables, 1H-NMRS-lipoprotein particle profiles may be helpful to identify those patients with T1D at risk of CAN.

A review of the anti-diabetic potential of saffron

Diabetes mellitus is one of the most prevalent metabolic disorders that affect people of all genders, ages, and races. Medicinal herbs have gained attention from researchers and have been widely investigated for their antidiabetic potential. Saffron (Crocus sativus L.) and its main constituents, that is, crocin and crocetin, are natural carotenoid compounds, widely known to possess a wide spectrum of properties and induce pleiotropic anti-inflammatory, anti-oxidative, and neuro-protective effects. An increasing number of experimental, animal and human studies have investigated the effects and mechanism of action of these compounds and their potential therapeutic use in the treatment of diabetes. This narrative review presents the key findings of published clinical studies that examined the effects of saffron and/or its constituents in the context of diabetes mellitus. Moreover, an overview of the proposed underlying mechanisms mediating these effects, the medicinal applications of saffron, and the new findings regarding its effect on diabetes and various cellular and molecular mechanisms of action will be debated.

Serum apolipoprotein A1 rather than apolipoprotein B is associated with hypertension prevalence in Chinese people with coronary artery disease

OBJECTIVE

Studies on the association of apolipoprotein A1 (ApoA1) and apolipoprotein B (ApoB) with hypertension (HTN) prevalence in patients with coronary artery disease (CAD) are limited. This cross-sectional study aimed to investigate this association in Chinese people in Wuhan, China.

METHODS

Serum ApoA1 and ApoB levels were measured by immunoturbidimetry assay. Logistic regression analysis was used to estimate the associations of ApoA1 and ApoB level and ApoB/A1 ratio with HTN prevalence.

RESULTS

We included 5192 individuals (3060 men, mean age 61 years; 4412 HTN cases) in this study. After adjusting for covariates, serum ApoA1 but not ApoB level or ApoB/A1 ratio was inversely associated with HTN prevalence. HTN prevalence was reduced with the fifth versus first quintile of ApoA1 level [odds ratio = 0.78 (95% confidence interval 0.62-0.98)]. In stratified analyses based on sex, the probability of HTN with the fifth versus first ApoA1 level was 0.71 (0.53-0.96) for men. The probability of HTN with the fifth versus first quintile of ApoB/A1 ratio was 1.54 (1.11-2.13) after adjustment. With quintiles 2-5 versus of ApoB level, the probability of HTN did not differ in both men and women. On path analyses, the association of ApoA1 level and ApoB/A1 ratio with HTN was mediated by BMI (β coefficients: -0.179 to 0.133).

CONCLUSION

In general, high serum ApoA1 level may be associated with a reduced probability of HTN prevalence in patients with CAD in China, and this association may be mediated by BMI.

Decreased Physiological Serum Total Bile Acid Concentrations in Patients with Type 2 Diabetic Peripheral Neuropathy

PURPOSE

Bile acids, amphipathic cholesterol metabolites, have been reported to have cytoprotective and neuroprotective effects in humans and animal models. The relationship of physiological serum total bile acid (TBA) levels with diabetic peripheral neuropathy (DPN), however, has not been determined. The purpose of this study was to investigate the relationship between physiological serum TBA and DPN.

PATIENTS AND METHODS

In total, 856 patients with type 2 diabetes mellitus (T2DM) aged 20-89 years were enrolled in this cross-sectional study. Serum TBA was measured, and its relationship with DPN and other parameters was analyzed.

RESULTS

T2DM patients with DPN had significantly lower serum TBA compared with those without (P<0.01). Serum TBA was negatively associated with glycated hemoglobin A1C, plateletcrit, fibrinogen, urine albumin-to-creatinine ratio, vibration perception thresholds, and prevalence of DPN, peripheral arterial disease, and diabetic foot ulceration after adjustment for age, sex, and body mass index (P<0.01 or P<0.05). A graded association with prevalence of DPN and increase in serum TBA quartiles was observed (P for trend <0.01), and there was an 48.2% decreased risk of DPN in the highest quartile of serum TBA versus the lowest quartile (95% CI 0.299-0.617; P=0.000) after multivariate adjustment. Receiver-operating characteristic analysis revealed that the optimal cutoff point of serum TBA to indicate DPN was 2.85 μmol/L (sensitivity 77.6% and specificity 45.6%).

CONCLUSION

These findings suggest that lower physiological serum TBA level may be associated with the prevalence of DPN in T2DM patients and may be a potential biomarker for DPN.

Vitamin C ameliorated cardiac autonomic neuropathy in type 2 diabetic rats

BACKGROUND

Vitamin C (VC) is a common antioxidant with cell protection potentials. However, its possible protective effect on cardiac autonomic nerves from diabetic induced insults is yet to be explored.

AIM

To investigate the effects of VC on diabetic cardiac autonomic neuropathy.

METHODS

Thirty male Wistar rats were equally grouped into control, diabetic and diabetic + VC. Type 2 diabetes was induced with fructose diet and alloxan. VC (1 g/kg) was administered for 4 wk via oral canula. Blood pressure and heart rate were measured non-invasively using tail flick blood pressure monitor. Spectral analysis of heart rate variability (HRV) was used to assess cardiac autonomic neuropathy. Blood was collected from the ocular sinus for biochemical analysis. Urethane (1 g/kg-ip) was used for anaesthesia prior to HRV and cervical dislocation to harvest hearts. Intracardiac autonomic nerve was assessed using tyrosine hydroxylase immunohistochemistry on fixed heart sections.

RESULTS

Results were analysed using ANOVA at α_0.05. Unlike VC and control groups, diabetic rats showed significantly (P < 0.0001) reduced HRV, increased heart-rate and blood pressure, initial increase in cardiac tyrosine hydroxylase activities at week-2 and sparse activity at week-4 of diabetes. Furthermore, apolipoprotein B, Oxidative stress and inflammatory markers were significantly (P < 0.01) reduced in VC treated rats.

CONCLUSION

VC possesses cardio-autonomic nerve protective potential and ameliorates the symptoms of cardiac autonomic neuropathy in type 2 diabetes. The possible mechanisms via which VC exert these effects may be via downregulation of oxidative stress, inflammation and apolipoprotein B.

Progression of cardiovascular autonomic neuropathy and cardiovascular disease in type 2 diabetes

BACKGROUND

To examine whether the progression rate of cardiovascular autonomic neuropathy (CAN) stage is an independent predictive factor for cardiovascular disease (CVD) in type 2 diabetes.

METHODS

Standardized cardiovascular autonomic reflex tests (CARTs) using traditional Ewing method were performed at baseline. The follow-up CARTs was recommended once every two years. We estimated the primary CVD endpoint, defined as coronary artery disease and ischemic stroke. The association between the progression rate of CAN stage and CVD was examined using time-dependent Cox proportional hazard models.

RESULTS

At baseline, 578 patients completed follow-up CARTs; the cohort comprised 329 women (56.9%) with a mean age of 58.3 ± 10.3 years and a mean diabetes duration of 10.1 ± 6.2 years. One hundred and seventy-six patients (30.4%) developed CAN progression between baseline and follow-up CARTs. In the multivariable Cox proportional hazards regression analysis, patients with CAN progression demonstrated a 3.32 times higher risk (95% confidence interval, CI 1.81-6.14, P < 0.001) of CVD than those without CAN progression. Patients who experienced CAN progression from the normal to definite stage had the greatest risk of CVD compared to other patients (hazard ratio 4.91, 95% CI 2.05-11.77, P for trend = 0.001).

CONCLUSIONS

CAN stage progression was associated with an increased risk of CVD in this type 2 diabetes cohort. Patients with rapid CAN progression had the greatest risk of CVD. Thus, regular screening and risk management of CAN progression is necessary to prevent CVD.