Different Impacts of Cardiovascular Risk Factors on Arterial Stiffness versus Arterial Wall Thickness in Japanese Patients with Type 2 Diabetes Mellitus

Arterial stiffening is a heritable trait associated with arterial dilation but not wall thickening: a longitudinal study in the twins UK cohort

Aims

Vascular ageing is characterized by arterial stiffening, dilation, and arterial wall thickening. We investigated the extent to which these changes are related and their heritability during 5 year follow-up in the Twins UK cohort.

Methods and results

Carotid-femoral pulse wave velocity (PWVcf), carotid diameter, carotid distensibility, and carotid intima-media thickness (IMT) were measured in 762 female twins (mean age 57.9 ± 8.6 years) at two time-points over an average follow-up of 4.9 ± 1.5 years. Magnetic resonance imaging (MRI) was performed in a sub-sample of 38 women to measure aortic pulse wave velocity (PWVaorta), diameter, and wall thickness. Heritability of changes in arterial wall properties was estimated using structural equation modelling. Annual increases in PWVcf, carotid diameter, distensibility, and IMT were 0.139 m/s, 0.028 mm, -0.4 kPa-1, and 0.011 mm per year, respectively. In regression analysis, predictors of progression in PWVcf included age, mean arterial pressure (MAP), and heart rate (HR) at baseline, and progression in MAP, HR, and body mass index (BMI). Predictors of progression in IMT included progression in MAP, BMI, and triglyceride levels. Progression of PWV and distensibility correlated with progression in carotid diameter but not with IMT. Heritability of progression of PWVcf, diameter, and IMT was 55%, 21%, and 8%, respectively. In a sub-sample of women that underwent MRI, aortic wall thickness increased by 0.19 mm/year, but aortic wall thickening was not correlated with an increase in lumen diameter or PWVaorta.

Conclusion

Arterial stiffening, as measured by PWVcf, and dilation are heritable but independent of arterial wall thickening. Genetic and cardiovascular risk factors contribute differently to progression of PWV and IMT.

Effect of physical activity on pulse wave velocity in elderly subjects with normal glucose, prediabetes or Type 2 Diabetes

Carotid-femoral pulse wave velocity ((cf)PWV) is a measure of arterial stiffness, predicting cardiovascular disease. We hypothesized that the amount of physical activity (PA) is correlated with reduced arterial stiffness in Type 2 diabetic (T2D) subjects. 570 subjects from the 1945 Oulu birth cohort were included in the analysis. (cf)PWV was determined by a non-invasive applanation tonometry. Oral glucose tolerance test was performed and LDL and HDL cholesterol analyzed. PA was registered daily with a wrist-worn acceleration meter for two weeks. (cf)PWV values in subjects with impaired glucose metabolism (IGM) and T2D were higher than in normal glycemic subjects (P < 0.001). PA, fasting and 2 h glucose and HbA1c correlated significantly with (cf)PWV, but HDL or LDL cholesterol did not. The 2 h glucose, heart rate and alcohol consumption in T2D subjects had independent effects on (cf)PWV in multiple regression analysis. T2D and IGM were significantly associated to (cf)PWV. Interestingly, lipids did not have an additional effect on (cf)PWV. Subjects walking more than 10 000 steps/day had 0.2 m/s lower (cf)PWV than those walking less than 6000 steps/day. Presence of T2D, elevated heart rate and alcohol consumption in males were associated with increased aortic stiffening in elderly subjects.

[Impact of sickle cell trait on arterial stiffness in African subjects]

Sickle cell trait (SCT) is the benign condition of sickle cell disease. Often asymptomatic, the carriers of the sickle cell trait have hemorheological disturbances with increased oxidative stress compared to healthy subjects. These disturbances can lead to structural and functional changes in large vessels. The aim of the study was to measure arterial stiffness, an independent marker of subclinical atherosclerosis, SCT carriers compared to sickle cell anemia (SCA) subjects. Nine SCT carriers aged 32±9 years (7 men) were compared to 14 SCA subjects aged 29±9 years (2 men) and 22 control subjects aged 34±9 years (11 men) recruited by the National blood transfusion center (CNTS) in Dakar (Senegal). Arterial stiffness was assessed by measurement of the finger-toe pulse wave velocity (PWVft) using pOpmètre^® (Axelife SAS-France). The cardiovascular risk (CVR) was assessed according to the Framingham Laurier score. The SCT carriers had a higher PWVft (m/s) than SCA subjects (8.2±2.2 vs 6.1±0.9m/s, P=0.004) but not different from that of healthy controls (8.2±2.2 vs 7.4±1.8m/s, P=0.33). Linear regression showed a positive relationship between PWVft and the pulse pressure (PP) (P˂0.001; r²=0.39; F=13.20). The results show that the SCT carriers have stiffer arteries than SCA subjects. Linear regressions adjusted for age, mean arterial pressure (MAP) and PP, showed that only age and PP were independently correlated with arterial stiffness in the entire population.

Oxidative Stress is Closely Associated with Increased Arterial Stiffness, Especially in Aged Male Smokers without Previous Cardiovascular Events: A Cross-Sectional Study

Aim: Cigarette smoking is one of the major risk factors for cardiovascular diseases and induces deleterious vascular damage. Oxidative stress is involved in vascular inflammation, the process of atherosclerosis. The purpose of the present study was to investigate whether the effects of oxidative stress on the arterial wall differ between smokers and non-smokers.

Methods: Male smokers and non-smokers without physical deconditioning who visited Enshu hospital for an annual physical check-up were enrolled in the study. To assess oxidative stress, serum levels of derivative reactive oxygen metabolites (d-ROM) were measured. The radial augmentation index (RAI) was measured using an automated device and was used as an index for arterial stiffness.

Results: Univariate and multivariate linear regression analysis showed that RAI was independently associated with d-ROM levels only in smokers. Moreover, RAI was significantly higher in smokers than in non-smokers. Logistic regression analysis with the endpoint of a higher RAI than the mean revealed that older age (> 65 years), hypertension, and smoking were independently associated with higher RAI. Similarly, logistic regression analysis with the endpoint of higher d-ROM levels than the mean showed that older age and smoking were independently associated with higher d-ROM levels.

Conclusions: Increased RAI is significantly associated with smoking and, in smokers, with increased d-ROM levels. These results suggest that the effects of oxidative stress on arterial properties differ between smokers and non-smokers and that oxidative stress is closely associated with arterial stiffness, especially in smokers.

Current views on neuropeptide Y and diabetes-related atherosclerosis

Diabetes-induced atherosclerotic cardiovascular disease is the leading cause of death of diabetic patients. Neuronal regulation plays a critical role in glucose metabolism and cardiovascular function under physiological and pathological conditions, among which, neurotransmitter neuropeptide Y has been shown to be closely involved in these two processes. Elevated central neuropeptide Y level promotes food intake and reduces energy expenditure, thereby increasing adiposity. Neuropeptide Y is co-localized with noradrenaline in central and sympathetic nervous systems. As a major peripheral vascular contractive neurotransmitter, through interactions with its receptors, neuropeptide Y has been implicated in the pathology and progression of diabetes, by promoting the proliferation of endothelial cells and vascular fibrosis, which may contribute to diabetes-induced cardiovascular disease. Neuropeptide Y also participates in the pathogenesis of atherosclerosis, the major form of cardiovascular disease, via aggravating endothelial dysfunction, growth of vascular smooth muscle cells, formation of foam cells and platelets aggregation. This review highlights the causal role of neuropeptide Y and its receptor system in the development of diabetes mellitus and one of its complications: atherosclerotic cardiovascular disease. The information from this review provides both critical insights onto the mechanisms underlying the pathogenesis of atherosclerosis and evidence for the development of therapeutic strategies.

Impact of cardiovascular risk factors on carotid intima-media thickness: sex differences

Background and purpose

There has been growing interest in the sex-related differences in the impact of cardiovascular (CV) risk factors on carotid intima–media thickness (CIMT). Therefore, we aimed at examining the influence of CV risk factors on CIMT in men and women and identifying differences between males and females in the risk profiles affecting CIMT.

Patients and methods

The study group consisted of 256 patients (mean age 54.7 years), including 134 females (52%), with the following CV risk factors: arterial hypertension, type 2 diabetes mellitus, dyslipidemia, nicotine addiction, overweight, and obesity. Subjects with the history of any overt CV disease were excluded. CIMT was measured through B-mode ultrasound examination of the right common carotid artery. In the analysis of CIMT values at different ages, the patients were divided into three age groups: 1) <45 years, 2) 45–60 years, and 3) >60 years. Regression analysis was used to examine the influence of CV risk factors on CIMT in men and women.

Results

CIMT increased with age in both men and women. Women had lower values of CIMT than men (0.54 mm vs 0.60 mm, P=0.011). The analysis in three age subgroups revealed that CIMT values were comparable in men and women in group 1 (0.48 mm vs 0.48 mm, P=0.861), but over the age of 45 years, CIMT values became significantly lower in women compared to men (group 2: 0.51 mm vs 0.63 mm, P=0.005; group 3: 0.63 mm vs 0.72 mm, P=0.020). Significant differences were observed between the sexes in terms of risk factor impact on CIMT. In men, only three factors significantly affected CIMT: age (b=+0.009, P<0.0001), hypertension (b=+0.067, P<0.05), and type 2 diabetes (b=+0.073, P<0.05). In women, apart from age (b=+0.008, P<0.0001) and type 2 diabetes (b=+0.111, P<0.01), significant factors were pulse pressure (PP; b=+0.005, P<0.0001), body mass index (b=+0.007, P<0.05), increased waist circumference (b=+0.092, P<0.01), and metabolic syndrome (b=+0.071, P<0.05). In the multiple regression analysis, independent CIMT determinants for the entire group were age (β=0.497, P<0.001) and body mass index (β=0.195, P=0.006). For males, age was the only independent determinant of CIMT (β=0.669, P<0.001). For females, these were PP (β=0.317, P=0.014), age (β=0.242, P=0.03), and increased waist circumference (β=0.207, P=0.048).

Conclusion

CIMT values are lower in women than in men, which is most pronounced over the age of 45 years. There are sex-related differences in the profile of CV risk factors affecting CIMT: in males, CIMT is mostly determined by age, while in females, by age, PP, and increased waist circumference.

The relationship between cholesterol concentration and carotid intima media thickness differs according to gender and menopausal status in Korean type 2 diabetic patients

BACKGROUND

We investigated the associations between cardiometabolic factors and carotid intima media thickness (IMT) in Korea type 2 diabetes (T2DM) patients, and assessed the possible difference with respect to gender and menopausal status.

METHODS

We conducted a cross-sectional study with 1288 T2DM patients from the Department of Endocrinology and Metabolism at Gangnam Severance Hospital. Carotid IMT and various biochemical parameters were measured, and the postmenopausal status was assessed.

RESULTS

In partial correlation analysis, total cholesterol (TC) and LDL cholesterol (LDL-C) were positively correlated with right maximum IMT in men. For postmenopausal women, TC and LDL-C were positively correlated with IMT (all p<0.05) while no such correlation was observed in premenopausal women. In regression analysis, age was the most predominant factor for IMT in all 3 groups. For men, insulin and TC were predictive factors for maximum IMT (all p<0.05), and for postmenopausal women, TC and LDL-C were significant factors for mean and maximum IMT (all p<0.01). However, cholesterol concentrations were not related to all types of IMT in premenopausal women.

CONCLUSION

The association between LDL-C and carotid IMT seems to differ according to gender and menopausal status in T2DM patients.

Visceral Adiposity is Preferentially Associated with Vascular Stiffness Rather than Thickness in Men with Type 2 Diabetes

Aim: Visceral fat accumulation is known to underlie the clustering of cardiovascular risk factors. However, it is not completely understood how visceral fat accumulation influences the development of cardiovascular disease. In this study, we investigated the clinical impact of visceral adiposity on vascular stiffness and thickness in patients with type 2 diabetes (T2D).

Methods: One hundred and sixty-one patients with T2D, including 92 men and 69 women, were included in this cross-sectional study. Visceral fat area (VFA) and subcutaneous fat area (SFA) were measured by dual bioelectrical impedance analysis. Stiffness parameter β and intima-media thickness (IMT) of the common carotid artery were measured by ultrasonography.

Results: The mean age and duration of diabetes in the study population were 61 years and 13.9 years, respectively. In men, VFA and waist circumference (WC) were positively correlated with stiffness parameter β, whereas body mass index (BMI), WC, and SFA were negatively correlated with IMT. In contrast, in women, none of the obesity-related indices were significantly correlated with stiffness parameter β or IMT. In multiple regression analyses, VFA as well as WC, BMI, and SFA were independently associated with stiffness parameter β after adjustment for age and other potential confounders in men but not in women. None of the obesity-related indices were independently associated with IMT for either sex.

Conclusion: In men with T2D, visceral adiposity is associated with carotid arterial stiffness but not thickness.