Can increased visceral adiposity without body weight changes accelerate carotid atherosclerosis in South Korean participants with type 2 diabetes?

Carotid artery intima-media thickness in adults receiving long-term home parenteral nutrition

BACKGROUND AND AIMS

Nutrition regimen in parenteral nutrition (PN) patients allows for a control of diet components. This may affect the process of lipid deposition in the vascular wall and change the risk of atherosclerosis. This study aims to examine the effect of long-term PN in adults on carotid intima-media thickness.

METHODS AND RESULTS

Thirty long-term PN patients (15 men and 15 women, mean age 64.7 ± 8.5 years) and thirty healthy volunteers (HV) (15 men and 15 women, mean age 64.9 ± 8.77 years) entered the study. Total amino acid and lipid formulation intake as well as duration of PN were calculated for PN patients. The common carotid artery intima-media thickness (CCA IMT) was examined in both groups. A lower CCA IMT (right/left mean: PN - 776 ± 121 vs HV - 848 ± 121 μm, p < 0.05; right/left maximum CCA IMT: PN - 935 ± 139 vs HV - 1024 ± 135 μm, p < 0.05) in PN patients was observed. A lower serum level of total (PN - 131.43 ± 43.12 vs HV - 209.2 ± 48.01 mg/dl, p < 0.05) and HDL (PN- 44.16 ± 12.45 vs HV - 72.57 ± 25.04 mg/dl, p < 0.05) cholesterol was reported in the PN patients. A correlation between patients' age and CCA IMT was observed in the control group, but not in the PN patients (right/left mean CCA IMT - PN: r = 0.48, p-0.007 vs HV: p-0.073; right/left maximum CCA IMT - PN: r = 0.48, p-0.008, vs HV: p-0.073).

CONCLUSIONS

Long term PN in adults is associated with lower CCA IMT. Long-term PN patients are a unique group in which carotid intima-media thickness does not correlate with the age.

Visceral adiposity index and cervical arterial atherosclerosis in northeast China: a population based cross-sectional survey

BACKGROUND AND PURPOSE

The burden of cervical arterial atherosclerosis, which is an important risk factor of stroke, is huge in China. The visceral adiposity index (VAI) is a convenient index that is related to a series of metabolic abnormalities and a variety of diseases, including cerebrovascular diseases. This study aimed to explore the relationship between VAI and cervical arterial atherosclerosis.

METHODS

This cross-sectional study used the multistage stratified random cluster sampling method to acquire a representative sample of residents aged ≥40 in the general population of northeast China. All participants completed a detailed questionnaire and provided blood samples. Cervical vascular ultrasound was performed by experienced ultrasound doctors. VAI was calculated by a well-established formula and analyzed by quartiles (Q1-Q4).

RESULTS

A total of 3688 people aged ≥40 years who underwent cervical arterial ultrasound were finally included, amongst whom 3.2% had increased intima-media thickness (IMT), 48.6% had carotid plaque and 4.0% had cervical artery stenosis (CAS). After adjusting for several parameters, little statistical significance was found between VAI and increased IMT; compared with the VAI-Q1 group, the VAI-Q2, VAI-Q3 and VAI-Q4 groups were more likely to have CAS [odds ratio (OR) 2.01, 95% confidence interval (CI) 1.17-3.43; OR 1.82, 95% CI 1.05-3.15; OR 1.79, 95% CI 1.03-3.12] and the VAI-Q3 and VAI-Q4 groups were at greater risk of carotid plaque (OR 1.30, 95% CI 1.05-1.62; OR 1.34, 95% CI 1.07-1.67).

CONCLUSIONS

The VAI was related to carotid plaque and CAS in the general population that is older than 40 years.

Oral ethinylestradiol-levonorgestrel attenuates cardiac glycogen and triglyceride accumulation in high fructose female rats by suppressing pyruvate dehydrogenase kinase-4

Fructose (FRU) intake has increased dramatically in recent decades with a corresponding increased incidence of insulin resistance (IR), particularly in young adults. The use of oral ethinylestradiol-levonorgestrel (EEL) formulation is also common among young women worldwide. The present study aimed at determining the effect of EEL on high fructose-induced cardiac triglyceride (TG) and glycogen accumulation. The study also investigated the possible involvement of pyruvate dehydrogenase kinase-4 (PDK-4) in EEL and/or high fructose metabolic effects on the heart. Ten-week-old female Wistar rats were allotted into four groups. The control, EEL, FRU, and EEL + FRU rats received distilled water (vehicle, p.o.), 1.0 μg ethinylestradiol plus 5.0 μg levonorgestrel (p.o.), 10% fructose (w/v), and 1.0 μg ethinylestradiol plus 5.0 μg levonorgestrel and 10% fructose, respectively, daily for 8 weeks. Data showed that EEL or high fructose caused IR' impaired glucose tolerance' hyperlipidemia' increased plasma lactate, lactate dehydrogenase, PDK-4, uric acid, xanthine oxidase (XO), adenosine deaminase (ADA), malondialdehyde (MDA), cardiac uric acid, TG, TG/HDL- cholesterol, glycogen synthesis, MDA, and visceral fat content and reduced glutathione. High fructose also resulted in impaired pancreatic β-cell function, hyperglycemia, and increased cardiac PDK-4, lactate synthesis, and mass. Nonetheless, these alterations were ameliorated in EEL plus high fructose rats. This study demonstrates that high fructose-induced myocardial TG and glycogen accumulation is attributable to increased PDK-4. Besides, EEL could be a useful pharmacological utility for protection against cardiac dysmetabolism by inhibiting PDK-4.

Chronic hyperglycemia mediated physiological alteration and metabolic distortion leads to organ dysfunction, infection, cancer progression and other pathophysiological consequences: An update on glucose toxicity

Chronic exposure of glucose rich environment creates several physiological and pathophysiological changes. There are several pathways by which hyperglycemia exacerbate its toxic effect on cells, tissues and organ systems. Hyperglycemia can induce oxidative stress, upsurge polyol pathway, activate protein kinase C (PKC), enhance hexosamine biosynthetic pathway (HBP), promote the formation of advanced glycation end-products (AGEs) and finally alters gene expressions. Prolonged hyperglycemic condition leads to severe diabetic condition by damaging the pancreatic β-cell and inducing insulin resistance. Numerous complications have been associated with diabetes, thus it has become a major health issue in the 21st century and has received serious attention. Dysregulation in the cardiovascular and reproductive systems along with nephropathy, retinopathy, neuropathy, diabetic foot ulcer may arise in the advanced stages of diabetes. High glucose level also encourages proliferation of cancer cells, development of osteoarthritis and potentiates a suitable environment for infections. This review culminates how elevated glucose level carries out its toxicity in cells, metabolic distortion along with organ dysfunction and elucidates the complications associated with chronic hyperglycemia.

Melanocortin overexpression limits diet-induced inflammation and atherosclerosis in LDLR-/- mice

Atherosclerosis is a chronic inflammatory disease of the arteries. The disease is initiated by endothelial dysfunction that allows the transport of leukocytes and low-density lipoprotein into the vessel wall forming atherosclerotic plaques. The melanocortin system is an endogenous peptide system that regulates, for example, energy homeostasis and cardiovascular function. Melanocortin treatment with endogenous or synthetic melanocortin peptides reduces body weight, protects the endothelium and alleviates vascular inflammation, but the long-term effects of melanocortin system activation on atheroprogression remain largely unknown. In this study, we evaluated the effects of transgenic melanocortin overexpression in a mouse model of atherosclerosis. Low-density lipoprotein receptor-deficient mice overexpressing alpha- and gamma₃-MSH (MSH-OE) and their wild-type littermates were fed either a regular chow or Western-style diet for 16 weeks. During this time, their metabolic parameters were monitored. The aortae were collected for functional analysis, and the plaques in the aortic root and arch were characterised by histological and immunohistochemical stainings. The aortic expression of inflammatory mediators was determined by quantitative PCR. We found that transgenic MSH-OE improved glucose tolerance and limited atherosclerotic plaque formation particularly in Western diet-fed mice. In terms of aortic vasoreactivity, MSH-OE blunted alpha₁-adrenoceptor-mediated vasoconstriction and enhanced relaxation response to acetylcholine, indicating improved endothelial function. In addition, MSH-OE markedly attenuated Western diet-induced upregulation of proinflammatory cytokines (Ccl2, Ccl5 and Il6) that contribute to the pathogenesis of atherosclerosis. These results show that the activation of the melanocortin system improves glucose homeostasis and limits diet-induced vascular inflammation and atherosclerotic plaque formation.

The Effects of Folate Supplementation on Carotid Intima-Media Thickness and Metabolic Status in Patients with Metabolic Syndrome

BACKGROUND

This study was carried out to evaluate the effects of folate supplementation on carotid intima-media thickness (CIMT) and metabolic status among patients with metabolic syndrome (MetS).

METHODS

This randomized, double-blind, placebo-controlled trial was conducted among 60 patients with type 2 diabetes mellitus and coronary heart disease. They were all overweight in the age range 40-85 years. Participants were randomly divided into 2 groups: group A (n = 30) received 5 mg folate supplements and group B (n = 30) received placebo for 12 weeks.

RESULTS

Folate supplementation resulted in a significant reduction in maximum levels of left CIMT (-0.05 ± 0.13 vs. +0.02 ± 0.11 mm, p = 0.01) compared with the placebo. Changes in fasting plasma glucose (-2.2 ± 37.5 vs. +30.2 ± 65.8 mg/dl, p = 0.02), serum insulin concentration (-2.0 ± 10.7 vs. +3.0 ± 7.6 µIU/ml, p = 0.04) and homeostasis of assessment-estimated insulin resistance (-0.6 ± 2.3 vs. +0.9 ± 2.3, p = 0.01) in supplemented patients were significantly different from those of patients in the placebo group. Changes in serum triglycerides (p = 0.04), high-density lipoprotein-cholesterol (p = 0.001), high sensitivity C-reactive protein (p = 0.01) and plasma nitric oxide concentrations (p < 0.001) were significantly different between the supplemented patients and placebo group.

CONCLUSIONS

Overall, 5 mg/day folate supplementation for 12 weeks among patients with MetS had beneficial effects on CIMT and the metabolic status.

Causes of changes in carotid intima-media thickness: a literature review

Atherosclerosis causes significant morbidity and mortality. Carotid intima-media thickness (CIMT) predicts future cardiovascular and ischaemic stroke incidence. CIMT, a measure of atherosclerotic disease, can be reliably determined in vivo by carotid ultrasound. In this review, we determined that CIMT is associated with traditional cardiovascular risk factors such as age, sex, race, smoking, alcohol consumption, habitual endurance exercise, blood pressure, dyslipidemia, dietary patterns, risk-lowering drug therapy, glycemia, hyperuricemia, obesity-related anthropometric parameters, obesity and obesity-related diseases. We also found that CIMT is associated with novel risk factors, including heredity, certain genotypic indices, anthropometric cardiovascular parameters, rheumatoid arthritis, immunological diseases, inflammatory cytokines, lipid peroxidation, anthropometric hemocyte parameters, infectious diseases, vitamin D, matrix metalloproteinases, and other novel factors and diseases. However, the conclusions are inconsonant; the underlying causes of these associations remain to be further explored.