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

Visceral adiposity index is associated with arterial stiffness in hypertensive adults with normal-weight: the china H-type hypertension registry study

Background

Limited information is available on arterial stiffness risk among hypertensive patients with metabolically abnormal but normal weight. Visceral adiposity index (VAI) is a novel indicator for visceral fat mass and metabolism, however, whether can be used to assessed arterial stiffness in a normal-weight population remains unclear. The goal of this study was to examine the independent association of VAI with arterial stiffness in normal-weight hypertensive patients.

Methods

3258 participants recruited from the China H-type Hypertension Registry Study. VAI value was calculated using sex-specific equations. High arterial stiffness was defined as baPWV ≥ 18 m/s. Multivariable regression analysis was used to identify the association of VAI with baPWV and high arterial stiffness.

Results

Of participants, 50.5% (1644) were males, the mean age was 65.5 (SD, 9.1) years. Mean VAI and baPWV were 2.0 (SD, 2.3) and 18.2 (SD, 3.9) m/s, respectively. For each unit increase of lg VAI in multivariable regression analysis, there was a 1.05 m/s increase in baPWV (95% CI 0.67, 1.43) and a 2.13-fold increase in the risk of high arterial stiffness (95% CI 1.59, 2.86). In all models, the VAI was consistently and significantly associated with baPWV after adjustment for different confounders. High VAI levels were stably associated with baPWV in all subgroups.

Conclusions

We found positive association of VAI with baPWV and high arterial stiffness in normal-weight adults with hypertension. The establishment of this association could help the arterial stiffness risk stratification in normal-weight hypertensive populations, who are frequently overlooked in preventing cardiovascular disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12986-021-00617-5.

PPARγ activation improves the microenvironment of perivascular adipose tissue and attenuates aortic stiffening in obesity

Background

Obesity-related cardiovascular risk, end points, and mortality are strongly related to arterial stiffening. Current therapeutic approaches for arterial stiffening are not focused on direct targeting within the vessel. Perivascular adipose tissue (PVAT) surrounding the artery has been shown to modulate vascular function and inflammation. Peroxisome proliferator-activated receptor γ (PPARγ) activation significantly decreases arterial stiffness and inflammation in diabetic patients with coronary artery disease. Thus, we hypothesized that PPARγ activation alters the PVAT microenvironment, thereby creating a favorable environment for the attenuation of arterial stiffening in obesity.

Methods

Obese ob/ob mice were used to investigate the effect of PPARγ activation on the attenuation of arterial stiffening. Various cell types, including macrophages, fibroblasts, adipocytes, and vascular smooth muscle cells, were used to test the inhibitory effect of pioglitazone, a PPARγ agonist, on the expression of elastolytic enzymes.

Results

PPARγ activation by pioglitazone effectively attenuated arterial stiffening in ob/ob mice. This beneficial effect was not associated with the repartitioning of fat from or changes in the browning of the PVAT depot but was strongly related to improvement of the PVAT microenvironment, as evidenced by reduction in the expression of pro-inflammatory and pro-oxidative factors. Pioglitazone treatment attenuated obesity-induced elastin fiber fragmentation and elastolytic activity and ameliorated the obesity-induced upregulation of cathepsin S and metalloproteinase 12, predominantly in the PVAT. In vitro, pioglitazone downregulated Ctss and Mmp12 in macrophages, fibroblasts, and adipocytes—cell types residing within the adventitia and PVAT. Ultimately, several PPARγ binding sites were found in Ctss and Mmp12 in Raw 264.7 and 3T3-L1 cells, suggesting a direct regulatory mechanism by which PPARγ activation repressed the expression of Ctss and Mmp-12 in macrophages and fibroblasts.

Conclusions

PPARγ activation attenuated obesity-induced arterial stiffening and reduced the inflammatory and oxidative status of PVAT. The improvement of the PVAT microenvironment further contributed to the amelioration of elastin fiber fragmentation, elastolytic activity, and upregulated expression of Ctss and Mmp12. Our data highlight the PVAT microenvironment as an important target against arterial stiffening in obesity and provide a novel strategy for the potential clinical use of PPARγ agonists as a therapeutic against arterial stiffness through modulation of PVAT function.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12929-021-00720-y.

Is Stiffness Parameter β Useful for the Evaluation of Atherosclerosis?~ Its Clinical Implications, Limitations, and Future Perspectives ~

Atherosclerosis comprises two components, atherosis and sclerosis, characterized by morphological wall thickening and functional stiffening, respectively, of the arterial wall. In recent years, much interest has been directed to the role of functional changes in large arteries, i.e., increased stiffness or decreased elasticity, on the development of cardiovascular diseases. In fact, the clinical evaluation of arterial stiffness is increasingly performed in patients with cardiovascular risk factors. Local arterial stiffness is measured using an ultrasound technique implemented with an echo-tracking system at the common carotid and femoral arteries. Several indices of local arterial stiffness are obtained by ultrasound, among which stiffness parameter β is unique because it is the least affected by blood pressure at the time of measurement. Evidence from cross-sectional studies indicates that increased stiffness parameter β is associated with a number of cardiovascular risk factors, such as older age, smoking, insufficient physical activity, hypertension, obesity, metabolic syndrome, insulin resistance, type 2 diabetes, chronic kidney disease, and comorbid cardiovascular disease. Results from several prospective observational studies also suggest that carotid stiffness parameter β is a useful surrogate marker of cardiovascular events and/or mortality, although the results differ depending on the characteristics of the study subjects. Furthermore, several interventional studies have shown that carotid stiffness parameter β improved after lifestyle modification or drug treatment. In this review, we summarize the current evidence of stiffness parameter β of the carotid artery and discuss its clinical implications as a marker of vascular health or as a predictor of cardiovascular outcomes.

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.

The Association Between Salivary Ghrelin Levels with Anthropometric Measures in Underweight, Normal, Overweight and Obese Healthy Adult Males

OBJECTIVES

The study aimed to measure salivary ghrelin levels in healthy adult males and investigate their association with age, weight, height, total as well as regional body fat and muscle mass. The study also aimed to investigate the relative contribution of body mass index (BMI), waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) in predicting salivary ghrelin levels in the studied groups.

METHODS

A sample of young adult males was divided into underweight, normal weight, overweight, and obese groups, according to their BMI. Standardised methods were used to measure height, WC and HC. Total body fat, visceral fat, subcutaneous fat, total and regional muscle mass were assessed by bioelectrical impedance technique utilising Karada scan. Salivary ghrelin concentrations were assessed using enzyme-linked immunosorbent assay.

RESULTS

A total of 90 adult males were included in the analysis (underweight n=9, normal weight n=41, overweight n=22, and obese n=18). One-way ANOVA test revealed significant differences among the groups in all of the variables except height and salivary ghrelin levels. Multiple linear regression revealed a significant association between salivary ghrelin levels with total fat, subcutaneous fat, visceral fat and muscle mass in the obese group. The analysis also revealed that BMI, WC, HC, WHR and WHtR were reliable predictors for salivary ghrelin levels in the obese group but not in other groups.

CONCLUSIONS

Anthropometric measures can be used as predictors for salivary ghrelin levels in healthy obese adults. However, they are poor predictors for salivary ghrelin levels in healthy lean, normal and overweight adults.

Visceral adiposity is associated with the discrepancy between glycated albumin and HbA1c in type 2 diabetes

Aim

We investigated the association of visceral adiposity with glycated albumin (GA) as well as GA/hemoglobin A1c (HbA1c) in type 2 diabetes.

Methods

One hundred twenty-three patients (68 males, 55 females) with type 2 diabetes were enrolled in this cross-sectional study. Visceral fat area (VFA) was determined using an abdominal dual bioelectrical impedance analysis (dual BIA) instrument. The relationship of VFA with GA and GA/HbA1c was analyzed.

Results

Simple regression analysis showed that BMI was inversely correlated with GA as well as GA/HbA1c, but not with HbA1c, while VFA had a significant correlation with GA and GA/HbA1c. Furthermore, multiple regression analysis revealed VFA as an independent contributor to GA/HbA1c. These results suggest that visceral adiposity is a primary factor associated with GA and HbA1c level discrepancy in patients with type 2 diabetes.

Conclusions

GA is a useful indicator for glycemic control, while visceral obesity should also be taken into consideration in type 2 diabetes cases.

Beneficial Effect of Bariatric Surgery on Abnormal MMP-9 and AMPK Activities: Potential Markers of Obesity-Related CV Risk

Bariatric surgery (BS) results in sustained weight loss and may reverse inflammation, metabolic alterations, extracellular matrix remodeling and arterial stiffness. We hypothesize that increased stiffening in omental arteries from obese patients might be associated with an increase in MMP activity and a decrease in p-AMPK, together with systemic oxidative stress and inflammation. Moreover, BS could contribute to reversing these alterations. This study was conducted with 38 patients of Caucasian origin: 31 adult patients with morbid obesity (9 men and 22 women; mean age 46 years and BMI = 42.7 ± 1.0 kg/m²) and 7 non-obese subjects (7 women; mean age 45 years and BMI = 22.7 ± 0.6 kg/m²). Seventeen obese patients were studied before and 12 months after BS. The stiffness index β, an index of intrinsic arterial stiffness, was determined in omental arteries and was significantly higher in obese patients. Levels of phosphorylated AMPK (p-AMPK^Thr-172) and SIRT-1 were significantly lower in peripheral blood mononuclear cells (PBMCs) from obese patients than those from non-obese patients (p < 0.05) and were normalized after BS. Total and active MMP-9 activities, LDH, protein carbonyls and uric acid were higher in obese patients and reduced by BS. Moreover, there was a correlation between plasmatic LDH levels and the stiffness index β. BS has a beneficial effect on abnormal MMP-9, LDH and AMPK activities that might be associated with the development of arterial stiffness in obese patients. Since these parameters are easily measured in blood samples, they could constitute potential biomarkers of cardiovascular risk in morbid obesity.

Visceral adiposity is significantly associated with type 2 diabetes in middle-aged and elderly Chinese women: A cross-sectional study

BACKGROUND

Previous studies suggest that visceral fat is associated with type 2 diabetes (T2D) independent of body mass index (BMI). However, epidemiological data about the relationship between visceral fat and T2D are rare in Chinese. The aim of the present study was to investigate whether visceral fat area (VFA) is associated with T2D beyond and above BMI in the Chinese population.

METHODS

The present community-based cross-sectional study was conducted in 2013 on 4126 individuals (2545 women, 1581 men) aged ≥ 40 years, with T2D diagnosed according to 1999 World Health Organization criteria. The VFA was measured by a fat area analyzer using bioelectrical impedance analysis.

RESULTS

Participants were categorized into normal weight and overweight/obese groups according to BMI. Within each group, compared with women with below-median VFA, women with above-median VFA had a significantly increased risk of diabetes (odds ratio [OR] 1.88, 95% confidence interval [CI] 1.31-2.69 in the normal weight group; OR 2.10, 95% CI 1.54-2.85 in the overweight/obese group), whereas among men the corresponding associations were not significant in either group. Among women, after multivariable adjustment including BMI, each one standard deviation increase in VFA was significantly associated with a 45% higher risk of having T2D (OR 1.45, 95% CI 1.26-1.67), whereas among men BMI, not VFA, was independently associated with T2D (OR 1.18, 95% CI 1.02-1.37).

CONCLUSIONS

Visceral fat was independently associated with T2D in women regardless of obesity status, whereas in men BMI may have a more important effect on T2D than visceral fat.

Adiposity measures and arterial stiffness in primary care: the MARK prospective observational study

BACKGROUND

The cardiovascular risk of obesity is potentially increased by arterial stiffness.

OBJECTIVE

To assess the relationship of adiposity measures with arterial stiffness in Caucasian adults with intermediate cardiovascular risk.

SETTING

Six Spanish health centres.

PARTICIPANTS

We enrolled 2354 adults (age range, 35-74 years; mean age, 61.4±7.7 years, 61.9% male).

METHODS

This is a cross-sectional study that analyses data from the baseline visit of the improving interMediAte RisK management (MARK) study. The main outcome variables were body mass index (BMI), waist-to-height ratio (WHtR), Clínica Universidad de Navarra-body adiposity estimation (CUN-BAE) body fat percentage and body roundness index (BRI). Vascular function was assessed by the cardio-ankle vascular index (CAVI) with the VaSera device; brachial-ankle pulse wave velocity (baPWV) was determined using a validated equation.

RESULTS

The mean adiposity measures were a BMI of 29.2±4.4, WHtR of 0.61±0.07, CUN-BAE of 35.7±1.7 and BRI of 5.8±1.7. The mean stiffness measures were a CAVI of 8.8±1.2 and baPWV of 14.9±2.5. In multiple linear regression analyses, all adiposity measures were negatively associated with CAVI and baPWV (p<0.01 for all) after adjustment for possible factors of confusion. The proportion of CAVI variability via the adiposity measures were 5.5% for BMI, 5.8% for CUN-BAE, 3.8% for WHtR and 3.7% for BRI. These were higher among diabetic, obese, younger (≤62 years) and non-hypertensive subjects who had similar activity and sedentary profiles.

CONCLUSIONS

Adiposity measures are negatively associated with arterial stiffness measures. The percentage of variation in CAVI explained by its relation to the different measures of adiposity ranges from 5.8% (CUN-BAE) to 3.7% (BRI). In the case of baPWV, it oscillates between 0.7% (CUN-BAE and BMI) and 0.1% (WHtR).

TRIAL REGISTRATION NUMBER

NCT01428934.

CIDE Family-Mediated Unique Lipid Droplet Morphology in White Adipose Tissue and Brown Adipose Tissue Determines the Adipocyte Energy Metabolism

White adipose tissue (WAT) stores energy as triacylglycerol in preparation for fasting state. In contrast, brown adipose tissue (BAT) consumes energy and produces heat in a cold environment. One of the major differences between these two adipose tissues is the morphology of the intracellular lipid droplet (LD), which is large and unilocular in WAT and small and multilocular in BAT. Although the fat-specific protein 27 alpha (FSP27α), belonging to the cell death-inducing DNA fragmentation factor A (DFFA)-like effector (Cide) family, was known to be indispensable for large unilocular LD formation in WAT, the mechanism that regulated small multilocular LD formation in BAT remained unknown. We recently uncovered that FSP27β, a novel isoform of FSP27 abundantly expressed in BAT, plays a crucial role in small multilocular LD formation by inhibiting the homodimerization of CideA in BAT. We speculate that unilocular LD formation is ideal for efficient lipid storage in WAT because lipolysis from the LD surface is restricted due to the minimum LD surface area. In addition, hydrolyzed free fatty acid (FFA) and glycerol can efficiently flow out into the circulation from the cell surface. In contrast, small multilocular LD formation is ideal for efficient intracellular lipolysis from the LD surface and the subsequent facilitation of FFA transport to mitochondria that are adjacent to LDs for β-oxidation in BAT. Thus, intracellular LD morphology is closely related to the functions and characteristics of adipose tissues. Given that the browning of adipose tissue leads to enhanced energy expenditure and the prevention of obesity, clarification of the mechanism with respect to intracellular LD formation is very meaningful.

Central Hemodynamics for Management of Arteriosclerotic Diseases

Arteriosclerosis, particularly aortosclerosis, is the most critical risk factor associated with cardiovascular, cerebrovascular, and renal diseases. The pulsatile hemodynamics in the central aorta consists of blood pressure, flow, and stiffness and substantially differs from the peripheral hemodynamics in muscular arteries. Arteriosclerotic changes with age appear earlier in the elastic aorta, and age-dependent increases in central pulse pressure are more marked than those apparent from brachial pressure measurement. Central pressure can be affected by lifestyle habits, metabolic disorders, and endocrine and inflammatory diseases in a manner different from brachial pressure. Central pulse pressure widening due to aortic stiffening increases left ventricular afterload in systole and reduces coronary artery flow in diastole, predisposing aortosclerotic patients to myocardial hypertrophy and ischemia. The widened pulse pressure is also transmitted deep into low-impedance organs such as the brain and kidney, causing microvascular damage responsible for lacunar stroke and albuminuria. In addition, aortic stiffening increases aortic blood flow reversal, which can lead to retrograde embolic stroke and renal function deterioration. Central pressure has been shown to predict cardiovascular events in most previous studies and potentially serves as a surrogate marker for intervention. Quantitative and comprehensive evaluation of central hemodynamics is now available through various noninvasive pressure/flow measurement modalities. This review will focus on the clinical usefulness and mechanistic rationale of central hemodynamic measurements for cardiovascular risk management.

Lipopolysaccharide-binding protein is associated with arterial stiffness in patients with type 2 diabetes: a cross-sectional study

BACKGROUND

Lipopolysaccharide (LPS)-binding protein (LBP) is an acute-phase reactant that mediates immune responses triggered by LPS. Recent evidence indicates the association of circulating LBP levels with obesity, diabetes, and cardiovascular diseases. In this study, we aimed to investigate the relationship between serum LBP levels and arterial stiffness in patients with type 2 diabetes.

METHODS

A total of 196 patients with type 2 diabetes, including 101 men and 95 women, were enrolled in this cross-sectional study. Fasting serum LBP levels were determined by enzyme-linked immunosorbent assay. Arterial stiffness was assessed by measuring the aortic pulse wave velocity (PWV).

RESULTS

The mean values of serum LBP and aortic PWV were 18.2 μg/mL and 1194 cm/s, respectively. Serum LBP levels were positively correlated with body mass index, triglycerides, high-sensitivity C-reactive protein, and insulin resistance index and were negatively correlated with high-density lipoprotein cholesterol. They were, however, not significantly correlated with aortic PWV in univariate analyses. Multivariate analysis revealed that serum LBP levels were independently and positively associated with aortic PWV (β = 0.135, p = 0.026) after adjusting for age, sex, body mass index, albumin, high-sensitivity C-reactive protein, and other cardiovascular risk factors. Further analyses revealed that the impact of serum LBP levels on aortic PWV was modified by sex, and the association between serum LBP levels and aortic PWV was found to be significant only in men.

CONCLUSIONS

Serum LBP levels are associated with arterial stiffness, independent of obesity and traditional cardiovascular risk factors, especially in men with type 2 diabetes. This study indicates a potential role of the LPS/LBP-induced innate immunity in the development and progression of arterial stiffness in type 2 diabetes.

Plasma C1q/TNF-Related Protein-9 Levels Are Associated with Atherosclerosis in Patients with Type 2 Diabetes without Renal Dysfunction

Aim. C1q/tumor necrosis factor-related protein-9 (CTRP9), a paralog of adiponectin, is expressed in adipose tissue. CTRP9 exerts protective effects against obesity and atherosclerosis in rodents. We investigated the association between plasma CTRP9 levels and atherosclerosis in patients with type 2 diabetes. Methods. We included 419 patients with type 2 diabetes, 161 of whom had chronic kidney disease (CKD). Fasting plasma CTRP9 and total adiponectin levels were measured with enzyme-linked immunosorbent assay. The intima-media thickness (IMT) of the common carotid artery was measured with ultrasonography. Results. Plasma CTRP9 levels were higher in the CKD group than in the non-CKD group. Plasma CTRP9 levels were positively correlated with carotid IMT in the non-CKD group. Multivariate analyses revealed that plasma CTRP9 levels were positively associated with carotid IMT in the non-CKD group, independent of age, sex, body mass index, adiponectin, and other cardiovascular risk factors. However, plasma CTRP9 levels were not associated with carotid IMT in the CKD group. Conclusion. Plasma CTRP9 levels are associated with atherosclerosis in diabetic patients without CKD, independently of obesity, adiponectin, and traditional cardiovascular risk factors. This study indicates a potential role of CTRP9 in atherosclerosis progression in human type 2 diabetes.