Additive effects of postchallenge hyperglycemia and low-density lipoprotein particles on the risk of arterial stiffness in healthy adults

Serum Malondialdehyde-Modified Low-Density Lipoprotein as a Risk Marker for Peripheral Arterial Stiffness in Maintenance Hemodialysis Patients

Background and Objectives: Peripheral arterial stiffness (PAS), assessed by brachial-ankle pulse wave velocity (baPWV), is an independent biomarker of cardiovascular diseases (CVD) in patients on maintenance hemodialysis (HD). Malondialdehyde-modified low-density lipoprotein (MDA-LDL), an oxidative stress marker, has been linked to atherosclerosis and CVD. However, the association between serum MDA-LDL and PAS among HD patients has not been fully elucidated. This study aimed to examine the association of serum MDA-LDL with PAS in HD patients and to identify the optimal cutoff value of serum MDA-LDL for predicting PAS. Materials and Methods: A cross-sectional study was conducted in 100 HD patients. Serum MDA-LDL was quantified using an enzyme-linked immunosorbent assay (ELISA), and baPWV was measured using a volume plethysmographic device. Patients were divided into the PAS group (baPWV > 18.0 m/s) and the non-PAS group (baPWV ≤ 18.0 m/s). The associations of baPWV and other clinical and biochemical parameters with serum MDA-LDL were assessed by multivariable logistic regression analyses. A receiver operating characteristic (ROC) curve analysis was performed to determine the optimal cutoff value of serum MDA-LDL for predicting PAS. Results: In multivariable logistic regression analysis, higher serum MDA-LDL, older age, and higher serum C-reactive protein [odds ratios (ORs) and 95% confidence intervals: 1.014 (1.004-1.025), 1.044 (1.004-1.085) and 3.697 (1.149-11.893)] were significantly associated with PAS. In the ROC curve analysis, the optimal cutoff value of MDA-LDL for predicting PAS was 80.91 mg/dL, with a sensitivity of 79.25% and a specificity of 59.57%. Conclusions: Greater serum MDA-LDL levels, particularly ≥80.91 mg/dL, were independently associated with PAS in HD patients. The findings suggest that oxidative stress plays a crucial role in the pathogenesis of PAS, and targeting MDA-LDL may be a potential therapeutic strategy for reducing cardiovascular risk in HD patients.

Measurement of aortofemoral volume wave velocity during the routine 12-channel ECG: relation to age, physiological hemoglobin A 1C, triglycerides and SBP in healthy individuals

OBJECTIVE

Measurements of pulse wave velocity are generally thought to be too impractical for clinical routine. This study aimed to develop a method that can be performed during routine 12-channel ECG.

METHODS

A 12-channel ECG simultaneously supplies arterial impedance plethysmographic signals from the extremities beside segmental multifrequency impedance measurements for obtaining body composition. The origin of the plethysmographic signal (volume wave) at the arms and legs was determined at the level of the elbows and the knees. The volume wave velocity (VWV) at the aorta and femoral arteries was calculated from the time difference of the plethysmographic signals between arms and legs.

RESULTS

Automated measurement of VWV was highly reproducible (r = 0.96). In 107 participants in perfect health, VWV in different models was positively related to age, physiological hemoglobin A 1C, triglycerides, normal standardized unattended blood pressure, but not to physiological low-density lipoprotein-cholesterol and high-density lipoprotein-cholesterol. Aortofemoral VWV was significantly higher in patients with established coronary artery disease than in healthy controls of the same age group (18.1 ± 5.8 vs. 11.9 ± 1.7 m/s, P < 0.001). VWV in study participants was higher than tonometrically determined pulse wave velocity as muscular arteries are included (13.2 ± 5.81 vs. 8.8 ± 2.98 m/s, n = 115, P < 0.001).

CONCLUSION

These background arterial impedance plethysmographic measurements for the measurement of VWV made simultaneously during 12-channel ECG show promise for large-scale, routine clinical assessment of large artery function.

Lipoprotein Particle Predictors of Arterial Stiffness after 17 Years of Follow Up: The Malmö Diet and Cancer Study

BACKGROUND

Central arterial stiffness is a surrogate of cardiovascular risk and predicts cardiovascular mortality. Apolipoprotein B lipoproteins are also established cardiovascular risk factors. It is not known whether specific lipoprotein subclasses measured in the Malmö Diet and Cancer Study and previously shown to be associated with coronary heart disease also predict arterial stiffening after a mean period of 17 years.

METHODS

Lipoprotein particle analysis was performed on 2,505 men and women from Malmö, Sweden, from 1991 to 1994, and arterial stiffness was assessed by carotid-femoral pulse wave velocity (c-fPWV) on this same cohort from 2007 to 2012. Associations between c-fPWV and lipoprotein particles were determined with multiple linear regression, controlling for sex, presence of diabetes, waist-to-hip circumference, and smoking status at baseline, as well as heart rate (measured at the carotid artery), mean arterial pressure, antihypertensive and lipid-lowering medications, C-reactive protein (CRP), and age at the time of c-fPWV measurement.

RESULTS

The results confirm that triglycerides (TG) and high-density lipoprotein cholesterol (HDL-c) but not low-density lipoprotein cholesterol (LDL-c) predict c-fPWV. We identify a positive predictive association for very small, small, and medium (high risk), but not large LDL particles. There was a negative association for large HDL particles. The relationships between c-fPWV and high-risk LDL particles were unaffected by adjusting for LDL-c or CRP and were only mildly attenuated by adjusting for the homeostatic model for insulin resistance (HOMA-IR). Due to the collinearity of very small, small, and medium LDL particles and dyslipidemia (elevated TG and decreased HDL-c), the observed relationship between c-fPWV and high-risk LDL particles became insignificant after controlling for the concentration of HDL-c, large cholesterol-rich HDL particles, and TG.

CONCLUSIONS

The development of central arterial stiffness previously associated with combined dyslipidemia may be mediated in part by LDL particles, particularly the very small-, small-, and medium-sized LDL particles.

Positive Association Between Small Dense Low-Density Lipoprotein Cholesterol Concentration and Biomarkers of Inflammation, Thrombosis, and Prediabetes in Non-Diabetic Adults

Aims: Recent studies suggest elevated levels of small dense low-density lipoprotein cholesterol (sdLDL-C) can predict the risk of incident coronary heart disease (CHD), even in individuals considered to be at low risk for cardiovascular disease(CVD) based on their LDL-C levels. This study aims to prospectively investigate the association between sdLDL-C concentration and traditional and nontraditional CHD risk markers to explore the underlying roles of sdLDL-C in atherogenic processes.

Methods: Between 2009 and 2011, 594 healthy volunteers aged 35–65 years were recruited as control subjects in a study of work-related risk factors and acute CHD. All participants fasted for 12–14 h, and venous blood samples were collected in the morning to measure serum lipid profiles and other CHD-related markers. A standard oral glucose tolerance test was performed on all participants to assess their subclinical diabetes and prediabetes status.

Results: There were significantly positive associations between sdLDL-C concentration and traditional (age, smoking and alcohol drinking habit, blood pressure, body mass index (BMI), serum lipid profiles, and diabetes status) and nontraditional risk factors (complete blood counts, (CBC), fibrinogen, high-sensitivity C-reactive protein, and subclinical diabetes status) for CVD. After adjusting for confounding variables which include age, gender, BMI, hypertension, household income, and smoking and alcohol drinking habits, all atherosclerotic risk markers except D-dimer were significantly and positively associated with sdLDL-C.

Conclusions: Our data indicated sdLDL-C is strongly associated with atherosclerotic risk markers, such as inflammation, thrombosis, hematological markers, and prediabetes. This study supports the hypothesis that sdLDL-C is a promising CVD risk biomarker.

Association of lipoprotein subfractions with endothelial function and arterial stiffness in acute ischemic stroke

Hypercholesterolemia represents a risk factor for the development of atherosclerosis. Lipoprotein research has recently been focused on the phenomenon of atherogenic and non-atherogenic lipoproteins. The aim of this study was to explore the association of lipoprotein subfractions with a measure for endothelial function (represented by reactive hyperemia index [RHI]) and arterial stiffness (represented by augmentation index [AI]) in patients with acute ischemic stroke. We enrolled 51 patients with acute ischemic stroke. Blood samples were obtained within 24 h after the stroke onset in a fasting condition. Electrophoresis method on polyacrylamide gel was used for the analysis of plasma lipoproteins. RHI and AI was measured by peripheral arterial tonometry (EndoPAT2000 device). We failed to find any significant correlation between RHI and baseline characteristics of the population. Significant correlation was found between AI and age, hypertension, low density lipoprotein cholesterol (LDL) 1, LDL 3-7, score for anti-atherogenic risk and atherogenic profile. Age (beta = .362, p = .006) and LDL1 (beta = -0.283, p = .031) were the only independent variables significantly associated with AI in regression analysis. Significantly higher AI was found in an atherogenic lipoprotein profile compared to a non-atherogenic profile population (median 25% vs. median 11.5%, p = .043). In conclusion, our results suggest significant inverse correlation between levels of LDL 1 subfraction and measures of AI in patients with acute ischemic stroke. Significantly higher values of AI were observed in the population with an atherogenic lipoprotein profile.

A Randomized, Double-Blind, Placebo-Controlled Clinical Trial to Assess the Efficacy and Safety of Ethyl-Ester Omega-3 Fatty Acid in Taiwanese Hypertriglyceridemic Patients

Aim: Information regarding the effects of omega-3 fatty acid on hypertriglyceridemic patients in Chinese is still limited. This study aimed to investigate the efficacy and safety of Omacor^®, a prescription ethyl-ester omega-3 fatty acid for the treatment of hypertriglyceridemia, administered at doses of 2 g/day and 4 g/day to Taiwanese hypertriglyceridemic patients.

Methods: A multicenter, randomized, double-blind, placebo-controlled, parallel study in adults with hypertriglyceridemia was conducted. After a five-week diet lead in period patients with triglycerides = 200–1000 mg/dL were randomized to receive Omacor^®, a concentrated preparation of omega-3 eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) in a dose of 1 g twice daily (2 g Omacor ^®), 2 g twice daily (4 g Omacor^®) or placebo, for eight weeks. The primary endpoint was the percentage change in triglyceride serum levels from baseline to the end of treatment.

Results: A total of 253 Taiwanese patients were randomized, of which 65.6% (166) were men. At the end of the treatment, the percentage change in triglyceride serum levels in both the Omacor^® 4 g/day (−32.1%) and 2 g/day (−29.7%) groups was larger than in the placebo group (−5.4%) (p < 0.001). The incidence of drug-related adverse events was as follows: 0.0%, 1.2%, and 0.0% in Omacor ^® 4 g/day, Omacor^® 2 g/day, and placebo groups, respectively. No drug-related serious adverse events were reported during the study.

Conclusions: Omacor^® may be a feasible option to treat hypertriglyceridemia in Taiwanese patients.

Serum perfluorinated chemicals, glucose homeostasis and the risk of diabetes in working-aged Taiwanese adults

BACKGROUND

The link among perfluoroalkyl and polyfluoroalkyl substances (PFASs), abnormal glucose homeostasis and the risk of diabetes has been intensively debated with conflicting evidence.

OBJECTIVES

We evaluated the associations among PFASs, oral glucose tolerance testing (OGTT) curves and diabetes prevalence in 571 working-aged Taiwanese participants.

METHODS

Exposure measures included serum perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorononanoic acid (PFNA), and perfluoroundecanoic acid (PFUA). Outcomes were OGTT curves and prevalent diabetes defined by fasting blood glucose (FBG) ≥126mg/dL, 2-h glucose ≥200mg/dL, or glycated hemoglobin ≥6.5%. Analyses were performed with multiple logistic regression and functional data analysis.

RESULTS

A total of 39 participants (6.8%) had diabetes in this study. After full adjustment, the increase in the geometric means of FBG, 2-h glucose concentrations, and area under the OGTT curve (AUC120) with a doubling increase in PFOS was 3% (95% CI 1-4), 8% (5-12), and 6% (4-9), respectively. Compared to the lowest-quartile of PFOS concentrations (<2.4ng/ml), the OGTT trajectories were significantly steeper in participants of the highest-quartile PFOS exposure (>4.8ng/ml) and the vertical shifting of the mean curve for each PFOS quartile showed a dose-response pattern. The adjusted odds ratio for diabetes comparing the highest to lowest quartile was 3.37 (95% CI 1.18-9.65). For PFOA, PFNA, and PFUA, the opposite pattern of OGTT trajectory and the opposite risk profile for diabetes were observed.

CONCLUSIONS

Chronic PFOS exposure was associated with impaired glucose homeostasis and the increased prevalence of diabetes. However, PFOA, PFNA, and PFUA showed a potential protective effect against glucose intolerance and the risk of diabetes. Future research focusing on clarifying possible differential effects of different species of PFASs on glucose homeostasis and establishing the prospective associations between PFASs and diabetes is needed.

Serum Mimecan Is Associated With Arterial Stiffness in Hypertensive Patients

Background

Mimecan plays an important role in endothelial and vascular smooth muscle cell integrity and may be involved the pathology of arterial stiffness. However, the role of mimecan in arterial stiffness in patients with hypertension is not well defined.

Methods and Results

A total of 116 hypertension patients and 54 healthy controls were enrolled in the investigation. Hypertensive patients were divided into 2 groups: the with arterial stiffness group (brachial-ankle pulse wave velocity [baPWV] ≥1400 cm/s; n=83) and the without arterial stiffness group (baPWV <1400 cm/s; n=33). A noninvasive measure of vascular stiffness was performed using pulse wave velocity (PWV) measurement of baPWV. Hypertensive patients had higher baPWV, mimecan, and endothelin 1 (ET-1) than healthy controls. The arterial stiffness group had higher mimecan and endothelin 1 (ET-1) and lower ankle-brachial pressure index (ABI) than those without stiffness. In hypertensive patients, mimecan was inversely correlated with ABI (P<0.05) and positively correlated with baPWV, ET-1, and total cholesterol. On multivariable logistic regression analysis, diastolic blood pressure, mimecan, ET-1, and creatinine were independent predictors of arterial stiffness in hypertensive patients (P<0.05).

Conclusions

Mimecan levels are higher in hypertensive patients than in healthy controls. Increased plasma mimecan levels are independently associated with increased arterial stiffness as assessed by baPWV.