Contribution of visceral fat accumulation to carotid intima-media thickness in a Chinese population

The Interconnection between Carotid Intima-Media Thickness and Obesity: Anthropometric, Clinical and Biochemical Correlations

Background and Objectives: Carotid intima-media thickness (CIMT) and obesity are considered independent determinants of cardio- and cerebrovascular events. The aim of our study was to investigate the effect of obesity on CIMT and to define which traditional cardiovascular risk factors correlate the most with CIMT values in patients with obesity. Materials and Methods: Anthropometric measurements were collected for the whole study group, as well as body composition and blood pressure data, and biochemical blood analyses were also performed. Results: Although our study group was significantly older according to vascular compared with chronological age, the mean CIMT values were lower when compared with the reference values. We found a statistically significant correlation of CIMT with chronological and vascular age, systolic blood pressure, fasting glucose, total cholesterol and triglyceride levels, waist-to-hip ratio, waist circumference, body muscle mass and skeletal muscle mass index. Atherosclerotic Cardiovascular Disease (ASCVD) risk assessment and SCORE (Systematic COronary Risk Evaluation) showed significant positive correlations, but there was only a weak correlation of ASCVD with CIMT. Conclusions: To deduce, since no diagnostic tool currently includes body weight as an individual risk factor, further trials are highly needed to determine if SCORE, SCORE2, ASCVD risk assessment or CIMT would be the most accurate and relevant diagnostic tool for prediction of risk for future CV events in patients with obesity.

Gut Microbiome Alterations in Patients With Visceral Obesity Based on Quantitative Computed Tomography

The gut microbiota is crucial in the pathogenesis of obesity. Abdominal obesity is known to significantly increase the risk of metabolic syndrome and cardiovascular disease, so further study is needed to investigate the changes of intestinal microorganisms in patients with excessive visceral fat. In our study, 41 people (n = 41) with normal body mass index (BMI) (18.5 ≤ BMI < 23.9) were included and divided into the low visceral fat area (L-VFA) group (n = 23, VFA < 100 cm²) and the high visceral fat area (H-VFA) group (n = 18, VFA ≥ 100 cm²). Several clinical indicators of the H-VFA group were significantly higher than those of the L-VFA group, including the waist circumference (WC), the fasting blood glucose (FBG), the triglyceride (TG), the total cholesterol (TC), the low-density lipoprotein cholesterol (LDL), the serum uric acid (SUA), the white blood cell count (WBC), the blood neutrophil count (NEC), and the blood lymphocyte count (LYC). Using whole-genome shotgun sequencing, we found that the types of the intestinal microbiota of H-VFA patients were different from those of the L-VFA patients, with 18 bacteria enriched in the H-VFA group and nine bacteria in the L-VFA group. A total of 16 species of gut microbes showed a strong correlation with VFA, and Escherichia coli has the strongest correlation, followed by Mitsuokella unclassified, Bifidobacterium longum, Escherichia unclassified, Ruminococcus torques, Dialister succinatiphilus, Eubacterium hallii, and Ruminococcus gnavus. Compared to the VFA, only two species show a strong correlation with BMI and WC. Further functional genetic studies suggested that the degradation of short-chain fatty acids (SCFAs) and the generation of lipopolysaccharide (LPS) might be related to visceral fat accumulation. Together, visceral fat was more closely correlated with the gut microbiome compared with BMI and WC. It suggested an intrinsic connection between the gut microbiome and visceral fat and its related metabolic disorders. Specific microbial species and pathways associated with visceral fat accumulation might contribute to new targeted therapies for visceral fat and its metabolic disorders.

Epidemiology and determinants of obesity in China

Obesity has become a major public health issue in China. Overweight and obesity have increased rapidly in the past four decades, and the latest national prevalence estimates for 2015-19, based on Chinese criteria, were 6·8% for overweight and 3·6% for obesity in children younger than 6 years, 11·1% for overweight and 7·9% for obesity in children and adolescents aged 6-17 years, and 34·3% for overweight and 16·4% for obesity in adults (≥18 years). Prevalence differed by sex, age group, and geographical location, but was substantial in all subpopulations. Strong evidence from prospective cohort studies has linked overweight and obesity to increased risks of major non-communicable diseases and premature mortality in Chinese populations. The growing burden of overweight and obesity could be driven by economic developments, sociocultural norms, and policies that have shaped individual-level risk factors for obesity through urbanisation, urban planning and built environments, and food systems and environments. Substantial changes in dietary patterns have occurred in China, with increased consumption of animal-source foods, refined grains, and highly processed, high-sugar, and high-fat foods, while physical activity levels in all major domains have decreased with increasing sedentary behaviours. The effects of dietary factors and physical inactivity intersect with other individual-level risk factors such as genetic susceptibility, psychosocial factors, obesogens, and in-utero and early-life exposures. In view of the scarcity of research around the individual and collective roles of these upstream and downstream factors, multidisciplinary and transdisciplinary studies are urgently needed to identify systemic approaches that target both the population-level determinants and individual-level risk factors for obesity in China.

Exenatide improves cardiovascular risk factors in obese patients with type 2 diabetes mellitus: a prospective study

Background/aim

The aim of this study was to evaluate the effects of a 6-month treatment regimen with exenatide on the lipid profile, high-sensitivity C-reactive protein (hsCRP), carotid intima media thickness (CIMT), visceral adiposity, and nonalcoholic fatty liver disease (NAFLD), all of which are important cardiovascular risk factors.

Materials and methods

This study included 45 obese patients with type 2 diabetes mellitus (T2DM). Baseline clinical findings, laboratory parameters, and ultrasonography findings were recorded. An exenatide recipe was given twice daily to the patients and, after 6 months of therapy, the same variables were compared. The compared parameters were lipid profiles, hsCRP, aspartat aminotransferase, alanine aminotransferase, gamma-glutamyl transferase, liver craniocaudal diameter, visceral fat volume, subcutaneous fat thickness, and CIMT. Liver diameter, visceral fat volume, subcutaneous fat thickness, and CIMT were measured by ultrasonography.

Results

After therapy, statistically significant improvements were achieved in lipid profile, hsCRP, liver enzymes, body mass index, and waist and hip circumferences. Also, statistically significant decreases were obtained in liver craniocaudal diameter, subcutaneous fat thickness, visceral fat volume, and CIMT. The reduction of CIMT and liver diameter were not correlated with BMI and HbA_1c reduction.

Conclusion

This study showed improvement in lipid profile and hsCRP levels with exenatide treatment. We also showed decrease in both visceral fat volume and subcutaneous fat thickness. We demonstrated significant decrease in liver enzymes with significant decrease in liver diameter. These findings support the use of exenatide in patients with NAFLD and T2DM. Additionally, this study showed that exenatide treatment given twice daily reduces CIMT in obese T2DM patients.

Optimal Cut-Off Values of Visceral Fat Area for Predicting Metabolic Syndrome Among Type 2 Diabetes Patients in Ningbo, China

OBJECTIVE

To examine the optimal cut-off values of visceral fat area (VFA) for predicting metabolic syndrome (MetS) among type 2 diabetes (T2D) patients in Ningbo China.

METHODS

A total of 1017 subjects were selected from T2D patients who accepted standardized management by the National Standardized Metabolic Disease Management Center at Ningbo First Hospital from March 2018 to January 2020. Demography and medical information were collected through questionnaires. Regional adiposity was examined by a visceral fat analyzer using the dual bioelectrical impedance method.

RESULTS

Overall, 769 (75.6%) T2D patients were defined to have MetS. Patients with MetS had higher anthropometric values and biomarkers, compared to those without MetS. VFA was significantly correlated with risk factors of MetS. Further logistic regression models showed that VFA was significantly associated with MetS in men (OR=1.02) and in women (OR=1.03) (P<0.001 for both genders) after controlling for related factors. Receiver-operating characteristic curve analysis demonstrated that the optimal cut-off values of VFA were 84.7 cm² for men and 81.1 cm² for women to predict MetS in T2D patients.

CONCLUSION

VFA was associated with MetS and could be an independent predictor of MetS in T2D patients.

CLINICAL TRIAL REGISTRATION

www.ClinicalTrials.gov, number: NCT03811470.

A metagenome-wide association study of gut microbiome and visceral fat accumulation

Purpose

Visceral fat is an independent risk factor for metabolic and cardiovascular disease. The study aimed to investigate the associations between gut microbiome and visceral fat.

Methods

We recruited 32 obese adults and 30 healthy controls at baseline. Among the obese subjects, 14 subjects underwent laparoscopic sleeve gastrectomy (LSG) and were followed 6 months after surgery. Abdominal visceral fat area (VFA) and subcutaneous fat area (SFA) were measured by magnetic resonance imaging. Waist, hipline, waist-to-hip ratio (WHR) and body mass index (BMI) were included as simple obese parameters. Gut microbiome was analyzed by metagenomic sequencing.

Results

Among the obese parameters, VFA had the largest number of correlations with the species that were differentially enriched between obese and healthy subjects, following by waist, WHR, BMI, hipline, and SFA. Within the species negatively correlated with VFA, Eubacterium eligens had the strongest correlation, following by Clostridium citroniae, C. symbiosum, Bacteroides uniformis, E. ventriosum, Ruminococcaceae bacterium D16, C. hathewayi, etc. C. hathewayi and C. citroniae were increased after LSG. Functional analyses showed that among all the obese parameters, VFA had strongest correlation coefficients with the obesity-related microbial pathways. Microbial pathways involved in carbohydrate fermentation and biosynthesis of L-glutamate and L-glutamine might contribute to visceral fat accumulation.

Conclusions

Visceral fat was more closely correlated with gut microbiome compared with subcutaneous fat, suggesting an intrinsic connection between gut microbiome and metabolic cardiovascular diseases. Specific microbial species and pathways which were closely associated with visceral fat accumulation might contribute to new targeted therapies for metabolic disorders.

Are Obesity Indices Useful for Detecting Subclinical Atheromatosis in a Middle-Aged Population?

OBJECTIVE

There is a close relationship between excess adiposity and cardiovascular disease. Although body mass index (BMI) is the most used approach to estimate excess weight, other anthropometric indices have been developed to measure total body and abdominal adiposity. Here, our objective was to assess the usefulness of these anthropometric indices to detect subclinical atheromatous disease.

METHODS

A cross-sectional study with 6,809 middle-aged subjects (mean age, 57 [53-63] years) with low to moderate cardiovascular risk from the ILERVAS project. Measures of total body fat (BMI, Clínica Universidad de Navarra - Body Adiposity Estimator [CUN-BAE], and Deurenberg's formula) and central adiposity (waist and neck circumferences, conicity index, waist-to-height ratio, Bonora's equation, the A body adiposity index, and body roundness index) were performed in all participants. Bilateral carotid and femoral ultrasound vascular studies allowed the identification of subjects with plaque. -Results: All measured indices were significantly higher in males with subclinical carotid or femoral plaques (p ≤ 0.021 for all). Also, a positive and significant correlation between all indices and the number of affected territories was found (p ≤ 0.013 for all). From the ROC analysis, all measurements identified patients with asymptomatic atheromatosis but none of them helped make clinical decisions. Regarding females, the results were less conclusive.

CONCLUSION

Obesity indices are related to subclinical atheromatosis, especially in men, in a large cohort of middle-aged subjects. However, the indices could not detect the presence of arterial plaque, so, when used in isolation, are unlikely to be decisive.

Analysis of risk factors for carotid intima-media thickness in patients with type 2 diabetes mellitus in Western China assessed by logistic regression combined with a decision tree model

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in patients with type 2 diabetes (T2DM). Carotid intima-media thickness (CIMT) is considered a preclinical stage of atherosclerosis. Therefore, it is necessary to identify the related risk factors for CIMT to facilitate the early prevention of CVD. Previous studies have shown that visceral fat area (VFA) is a risk factor for T2DM and CVD. However, few studies have focused on the effects of VFA on CIMT associated with T2DM. Moreover, considering that the body fat distribution shows regional and racial heterogeneity, the purpose of this study was to investigate the predictive value of VFA and other risk factors for CIMT associated with T2DM in Western China.

METHODS

In a cross-sectional study, a total of 1372 patients with T2DM were divided into the CIMT (-) group (n = 965) and the CIMT (+) group (n = 407) based on CIMT values. In addition to the univariate analyses, logistic regression analysis and a decision tree model were simultaneously performed to establish a correlation factor model for CIMT.

RESULTS

Univariate analyses showed that sex, smoking status, age, heart rate, systolic blood pressure (SBP), diastolic blood pressure (DBP), height, weight, body mass index (BMI), waist circumference, hip circumference, waist-hip ratio, VFA, subcutaneous fat area, and the levels of 2-h C-peptide, serum creatinine, urea nitrogen and uric acid were significantly different between the two groups (all p < 0.05). Smoking, increased VFA, female sex and increased BMI were risk factors in the logistic regression analyses (OR = 5.759, OR = 1.364, OR = 2.239, OR = 1.186, respectively). In the decision tree model, smoking was the root node, followed by sex, waist circumference, VFA and chronic kidney disease (CKD) in order of importance.

CONCLUSIONS

In addition to smoking, sex and BMI, VFA has a significant effect on CIMT associated with T2DM in the Chinese Han population in Western China. In addition, the decision tree model could help clinicians make more effective decisions, with its simplicity and intuitiveness, making it worth promoting in future medical research.Trial registration ChiCTR, ChiCTR1900027739. Registered 24 November 2019-Retrospectively registered, http://www.chictr.org.cn/index.aspx.

Effects of Exenatide and Humalog Mix25 on Fat Distribution, Insulin Sensitivity, and β-Cell Function in Normal BMI Patients with Type 2 Diabetes and Visceral Adiposity

In China, most normal BMI (body mass index of ≥18.5 to <25 kg/m²) adults with type 2 diabetes (T2DM) exhibit visceral adiposity. This study compared the effects of exenatide and humalog Mix25 on normal BMI patients with T2DM and visceral adiposity. A total of 95 patients were randomized to receive either exenatide or humalog Mix25 treatment for 24 weeks. Subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) were quantified by magnetic resonance imaging (MRI) and liver fat content (LFC) by liver proton magnetic resonance spectroscopy (¹H MRS). Each patient's weight, waist circumference, BMI, blood glucose, insulin sensitivity, pancreatic β-cell function, and fibroblast growth factor 21 (FGF-21) levels were measured. Data from 81 patients who completed the study (40 and 41 in the exenatide and humalog Mix25 groups, respectively) were analysed. The change in 2 h plasma blood glucose was greater in the exenatide group (P = 0.039). HOMA-IR and MBCI improved significantly after exenatide therapy (P < 0.01, P = 0.045). VAT and LFC decreased in both groups (P < 0.01 for all) but to a greater extent in the exenatide group, while SAT only decreased with exenatide therapy (P < 0.01). FGF-21 levels declined more in the exenatide group (P < 0.01), but were positively correlated with VAT in the entire cohort before (r = 0.244, P = 0.043) and after (r = 0.290, P = 0.016) the intervention. The effects of exenatide on glycaemic metabolism, insulin resistance, pancreatic β-cell function, and fat deposition support its administration to normal BMI patients with T2DM and visceral adiposity.

Osteocalcin value to identify subclinical atherosclerosis over atherosclerotic cardiovascular disease (ASCVD) risk score in middle-aged and elderly Chinese asymptomatic men

BACKGROUND

Our study examined whether osteocalcin contributed to identifying carotid intima-media thickness (C-IMT) over the atherosclerotic cardiovascular disease (ASCVD) risk score.

METHODS

We recruited 618 middle-aged and elderly men from communities in Shanghai. Serum osteocalcin levels were determined using an electrochemiluminescence immunoassay. C-IMT was measured by ultrasonography.

RESULTS

The study included 245 men with low ASCVD risk and 373 men with moderate-to-high ASCVD risk. Serum osteocalcin levels were lower in the moderate-to-high risk vs. low risk men (p=0.042). Multivariate stepwise regression analysis showed that body mass index (BMI) and glycated hemoglobin were predictors for reduced osteocalcin levels (both p<0.001). Among all subjects, the proportion with an elevated C-IMT was higher in the low-osteocalcin group than in the high-osteocalcin group (p=0.042), and the significance of this result was greater when considering only subjects with a moderate-to-high ASCVD risk (p=0.011). The recognition rate of elevated C-IMT was superior with both low osteocalcin and moderate-to-high ASCVD risk vs. either parameter alone (p<0.001 and p=0.015, respectively). Osteocalcin was independently and inversely associated with elevated C-IMT after adjusting for the 10-year ASCVD risk score (p=0.004). The negative relationship remained statistically significant in subjects with a moderate-to-high ASCVD risk in particular (standardized β=-0.104, p=0.044).

CONCLUSIONS

In middle-aged and elderly men, serum osteocalcin levels strengthen identifying subclinical atherosclerosis over ASCVD risk score, especially among subjects with a moderate-to-high ASCVD risk.

Anthropometric Obesity Indices were Stronger than CT-Based Indices in Associations with Carotid Intima-Media Thickness in Japanese Men

AIM

Computed tomography (CT) can directly provide information on body compositions and distributions, compared to anthropometric indices. It has been shown that various obesity indices are associated with carotid intima-media thickness (IMT). However, whether CT-based obesity indices are stronger than anthropometric indices in association with atherosclerosis remains to be determined in a general population.

METHODS

We cross-sectionally assessed carotid IMT using ultrasound in 944 community-dwelling Japanese men free of stroke and myocardial infarction. CT image at the L4-L5 level was obtained to compute areas of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). Anthropometric measures assessed included body mass index (BMI), waist circumference, and waist-to-hip ratio. Using multivariable linear regression, slopes of IMT per 20^th to 80^th percentile of each index were compared. We also compared the slope of index with simultaneous adjustment for BMI in the same model.

RESULTS

Areas of VAT and SAT were positively associated with IMT, but not stronger than those of anthropometric indices in point estimates. Among all obesity indices, BMI was strongest in association with IMT after adjusting for age and lifestyle factors or further adjusting for metabolic factors. In simultaneous adjustment models, BMI, but not CT-based indices, remained significant and showed the strongest association.

CONCLUSIONS

In community-dwelling Japanese men, anthropometric obesity indices, BMI in particular, were more strongly associated with carotid atherosclerosis than CT-based obesity indices. The association of general obesity with carotid atherosclerosis was strong and adding CT-based obesity measure did not considerably influence in the association.

Neck circumference as an effective measure for identifying cardio-metabolic syndrome: a comparison with waist circumference

Neck circumference is a new anthropometric index for estimating obesity. We aimed to determine the relationship between neck circumference and body fat content and distribution as well as the efficacy of neck circumference for identifying visceral adiposity and metabolic disorders. A total of 1943 subjects (783 men, 1160 women) with a mean age of 58 ± 7 years were enrolled in this cross-sectional study. Metabolic syndrome was defined according to the standard in the 2013 China Guideline. Analyses were conducted to determine optimal neck circumference cutoff points for visceral adiposity quantified by magnetic resonance imaging, and to compare the performance of neck circumference with that of waist circumference in identifying abdominal obesity and metabolic disorders. Visceral fat content was independently correlated with neck circumference. Receiver operating characteristic curves showed that the area under the curve for the ability of neck circumference to determine visceral adiposity was 0.781 for men and 0.777 for women. Moreover, in men a neck circumference value of 38.5 cm had a sensitivity of 56.1 % and specificity of 83.5 %, and in women, a neck circumference value of 34.5 cm had a sensitivity of 58.1 % and specificity of 82.5 %. These values were the optimal cutoffs for identifying visceral obesity. There were no statistically significant differences between the proportions of metabolic syndrome and its components identified by an increased neck circumference and waist circumference. Neck circumference has the same power as waist circumference for identifying metabolic disorders in a Chinese population.

Contribution of fibroblast growth factor 23 to Framingham risk score for identifying subclinical atherosclerosis in Chinese men

BACKGROUND AND AIMS

Fibroblast growth factor 23 (FGF23) was demonstrated to be involved in the occurrence and development of cardiovascular disease (CVD). The goal of the present study was to investigate the relationship between serum FGF23 levels and carotid intima-media thickness (C-IMT) in men with a low-to-moderate CVD risk.

METHODS AND RESULTS

Subjects with normal kidney function were selected from the Shanghai Obesity Study. Serum FGF23 levels were determined by sandwich enzyme-linked immunosorbent assay. C-IMT was measured by ultrasonography. The Framingham risk score (FRS) was used to assess CVD risk. A total of 392 men with low CVD risk and 372 men with moderate CVD risk were enrolled. The recognition rate of an elevated C-IMT was 85.66% with the combination of a moderate CVD risk and high serum FGF23 levels, which was greater than that with either parameter alone (65.44% and 61.03%, respectively). Subjects with high serum FGF23 levels, and either low or moderate CVD risk, were more likely to have elevated C-IMT than those with low serum FGF23 levels and low CVD risk (P = 0.014 and 0.001, respectively). The serum FGF23 levels were independently and positively associated with C-IMT in subjects with low or moderate CVD risk (both P = 0.007).

CONCLUSION

In men with low-to-moderate CVD risk, serum FGF23 levels were associated independently and positively with C-IMT. As a complementary index, serum FGF23 levels strengthen the capacity of the FRS to identify subclinical atherosclerosis.

Elevation in fibroblast growth factor 23 and its value for identifying subclinical atherosclerosis in first-degree relatives of patients with diabetes

Accumulating evidence supported an association between diabetes and fibroblast growth factor 23 (FGF23). The goal of the present study was to explore alteration in serum FGF23 levels and to assess its value for identifying subclinical atherosclerosis in normoglycemic individuals with a first-degree family history of diabetes (FHD). The study enrolled 312 subjects with a first-degree FHD and 1407 subjects without an FHD. Serum FGF23 levels were detected by a sandwich enzyme-linked immunosorbent assay. Serum FGF23 levels were much higher in subjects with a first-degree FHD than in those without an FHD (P = 0.006). A first-degree FHD was positively associated with serum FGF23 levels, independent of C-IMT and cardiovascular factors (both P < 0.05). In subjects with a first-degree FHD, only those with serum FGF23 levels in the upper quartile were more likely to have an increased C-IMT (odds ratio = 2.263, P < 0.05). As conclusions, a first-degree FHD contributes to the increased serum FGF23 levels independently. Subjects with a first-degree FHD need higher serum FGF23 levels to indicate subclinical atherosclerosis. The influence of a first-degree FHD on serum FGF23 levels should be considered to avoid overestimating the risk of cardiovascular disease in normoglycemic individuals with a first-degree FHD.

Serum lipocalin-2 levels are positively associated with not only total body fat but also visceral fat area in Chinese men

Serum lipocalin-2 (LCN2) plays an important role in the regulation of the obesity-associated dysmetabolic state and cardiovascular disease. However, relatively little is known about the relationship between serum LCN2 levels and body fat content and distribution. We examined the associations of total body fat content and abdominal fat distribution with serum LCN2 levels in Chinese men.The study was based on a cross-sectional analysis of data for 1203 Chinese men aged 22 to 78 years from the Shanghai Obesity Study. Body fat percentage (fat%) was assessed by bioelectrical impedance analysis, and magnetic resonance imaging was adopted to quantify the visceral fat area (VFA) and subcutaneous fat area (SFA). Serum levels of LCN2 were measured with a standard enzyme-linked immunosorbent assay method.Subjects with a high fat% had higher serum LCN2 levels than those with a normal fat% regardless of their body mass index category (<25 and ≥25 kg/m). The frequency of isolated high VFA was increased with increasing quintiles of serum LCN2 levels (P < 0.001), but the frequency of isolated high SFA did not differ between quintiles of serum LCN2 levels. A trend of increasing VFA was observed with increasing serum LCN2 levels (P < 0.001). Multiple stepwise regression analysis showed that VFA was positively associated with serum LCN2 levels, independent of overall obesity and other confounding factors (standardized β = 0.082, P = 0.008).Serum LCN2 levels are positively correlated with body fat content and independently associated with VFA in Chinese men.

Reappraisal of waist circumference cutoff value according to general obesity

BACKGROUND

Current criterion of waist circumference (WC) for abdominal obesity is not enough to demonstrate characteristics of obese and non-obese populations defined by BMI. The aim of this study was to redefine the cutoff values of WC according to general obesity (BMI ≥ 25 kg/m(2)).

METHODS

The receiver operating characteristic curve analysis was performed to determine cutoff values of WC for predicting atherosclerosis according to BMI in 1,063 non-diabetic subjects. To validate this new criterion, diabetic patients (n = 3,690) were divided into three groups based on the current (WC of 90/80 cm for men/women) and new cutoff values of WC: 1) group with WC below the lowest value of two criteria; 2) intermediate group defined as having a WC between them; and 3) group with WC more than the highest value of them.

RESULTS

The new cutoff values of WC for predicting atherosclerosis in non-diabetic subjects were 84/76 cm for non-obese men/women, and 93/87 cm for obese men/women, respectively. Of non-obese diabetic patients, the intermediate group (WC 84 ~ 90/76 ~ 80 cm for men/women) was more insulin resistant and showed elevated odds ratio (OR) for having 2 or more metabolic risk factors compared to group with WC below 84/76 cm for men/women [OR 2.48 (95 % CI 1.89-3.25) in men, 2.01 (95% CI 1.45-2.78) in women]. In contrast, among obese diabetic patients, insulin resistance and the likelihood of having 2 or more metabolic risk factors were not different from the intermediate group (WC 90 ~ 93/80 ~ 87 cm for men/women) and group with WC below 90/80 cm for men/women.

CONCLUSIONS

The current universal cutoff values of WC may under- or over-estimate the metabolic risks of intermediate groups. Therefore, the WC criteria for abdominal obesity should be applied differently depending on the BMI.

Serum vitamin D levels are inversely related with non-alcoholic fatty liver disease independent of visceral obesity in Chinese postmenopausal women

The aim of the present study was to investigate the association between serum vitamin D levels and both visceral adipose and with non-alcoholic fatty liver disease (NAFLD) in Chinese postmenopausal women. Four hundred and fifty-one postmenopausal women between 45 and 74 years of age (mean (± SD) age 57.3 ± 4.6 years) were enrolled in the study. All subjects participated in the Shanghai Obesity Study between June and August 2011 and underwent abdominal magnetic resonance imaging and an abdominal ultrasonography. Patients with a visceral fat area (VFA) ≥ 80 cm(2) were classified as abdominally obese. Serum 25-hydroxyvitamin D3 (25(OH)D3 ) levels were measured with an electrochemiluminescence immunoassay. The prevalence of NAFLD in the study population was 34.8% (n = 157). Women with abdominal obesity had significantly lower serum 25(OH)D3 levels than those without abdominal obesity (median (interquartile range) 11.23 (8.64-14.12) vs 12.56 (9.41-15.98) ng/mL, respectively; P < 0.01). Regardless of abdominal obesity status, serum 25(OH)D3 levels in patients with NAFLD were lower than those without non-NAFLD (11.14 (8.63-13.81) vs 12.92 (9.48-16.37) ng/mL (P < 0.05) for those without abdominal obesity; 10.86 (8.61-13.56) vs 11.55 (8.82-16.38) ng/mL (P < 0.05) for those with abdominal obesity). Partial correlation analyses demonstrated a negative correlation between serum 25(OH)D3 levels and VFA (P < 0.05). Logistic regression analysis revealed that high serum 25(OH)D3 levels were a protective factor against NAFLD after adjusting for risk factors such as VFA. In conclusion, independent of visceral obesity, vitamin D is inversely correlated with NAFLD in Chinese postmenopausal women.

Association between serum osteocalcin level and visceral obesity in Chinese postmenopausal women

BACKGROUND

A low serum osteocalcin level, visceral obesity and postmenopausal status are recognized risk factors for cardiovascular disease.

OBJECTIVE

We investigated the relationship between the serum osteocalcin level and visceral fat content in a population of Chinese postmenopausal women.

DESIGN AND PATIENTS

In total, 1481 postmenopausal women (mean age ± standard deviation, 57·1 ± 4·8 years) were selected from the Shanghai Obesity Study.

MEASUREMENTS

Abdominal fat accumulation was quantified using magnetic resonance imaging. Subjects with a visceral fat area (VFA) of ≥80 cm(2) were classified as abdominally obese. The total serum osteocalcin level was measured by electrochemiluminescence immunoassay.

RESULTS

The median serum osteocalcin level was 20·66 μg/l (interquartile range, 16·88-25·42 μg/l). The overall prevalence of abdominal obesity was 49·1% (n = 727). Abdominally obese subjects had lower serum osteocalcin levels than did nonabdominally obese subjects [19·14 (16·02-23·82) vs 21·97 (18·14-26·77) μg/l, respectively; P < 0·001]. Partial correlation analysis showed that the serum osteocalcin level was still negatively correlated with VFA after adjusting for age, years since menopause and body mass index (P < 0·01). Moreover, VFA was independently associated with the serum osteocalcin level after adjustment for confounding factors (P < 0·05). A low serum osteocalcin level was an independent risk factor for abdominal obesity (odds ratio, 0·972; 95% confidence interval, 0·953-0·991; P = 0·004).

CONCLUSION

The serum osteocalcin level was inversely correlated with the visceral fat content in these Chinese postmenopausal women.

Individual contributions of visceral fat and total body fat to subclinical atherosclerosis: The NEO study

BACKGROUND

Both overall and abdominal adiposity are established risk factors for cardiovascular disease. Visceral adipose tissue (VAT) and total body fat (TBF) are strongly correlated and previous studies did not make this distinction.

OBJECTIVE

We aimed to distinguish individual contributions of TBF, VAT, and the ratio of VAT to abdominal subcutaneous adipose tissue (VAT/SAT) to subclinical atherosclerosis in men and women.

METHODS

In this cross-sectional analysis of the Netherlands Epidemiology of Obesity (NEO) study, we assessed VAT and SAT with magnetic resonance imaging, TBF with bio-electrical impendence analysis, and carotid Intima-Media Thickness (cIMT) with ultrasound. We performed linear regression analyses of standardized values of TBF, VAT, VAT/SAT with cIMT. We adjusted the models for confounding factors (age, sex, ethnicity, education, smoking, alcohol, physical activity), and either for VAT or TBF.

RESULTS

This analysis included 2451 participants, 53% men with mean (SD) cIMT of 615 (91)μm. After adjustment for confounding factors, the difference in cIMT (95% CI) per SD in VAT was 14 (8,21)μm in men and 18 (13,24)μm in women. After adjustment for TBF, this attenuated to 5 (-3,13)μm in men and 13 (5,20)μm in women. In the full model, differences in cIMT (95% CI) per SD of TBF were 14 (6,22)μm in men and 8 (0,16)μm in women, and per SD of VAT/SAT were 7 (-1,15)μm and 9 (3,16)μm respectively.

CONCLUSIONS

In this population-based study, VAT contributed beyond overall adiposity to subclinical atherosclerosis, particularly in women. This implies a specific role of VAT in the early development of atherosclerosis.

Insulin action in muscle and adipose tissue in type 2 diabetes: The significance of blood flow

Under normal metabolic conditions insulin stimulates microvascular perfusion (capillary recruitment) of skeletal muscle and subcutaneous adipose tissue and thus increases blood flow mainly after meal ingestion or physical exercise. This helps the delivery of insulin itself but also that of substrates and of other signalling molecules to multiple tissues beds and facilitates glucose disposal and lipid kinetics. This effect is impaired in insulin resistance and type 2 diabetes early in the development of metabolic dysregulation and reflects early-onset endothelial dysfunction. Failure of insulin to increase muscle and adipose tissue blood flow results in decreased glucose handling. In fat depots, a blunted postprandial blood flow response will result in an insufficient suppression of lipolysis and an increased spill over of fatty acids in the circulation, leading to a more pronounced insulin resistant state in skeletal muscle. This defect in blood flow response is apparent even in the prediabetic state, implying that it is a facet of insulin resistance and exists long before overt hyperglycaemia develops. The following review intends to summarize the contribution of blood flow impairment to the development of the atherogenic dysglycemia and dyslipidaemia.

Inverse association of serum vitamin D in relation to carotid intima-media thickness in Chinese postmenopausal women

Objective

This study aimed to investigate the relationship between serum vitamin D level and carotid intima-media thickness (C-IMT) in Chinese postmenopausal women.

Methods

Nine hundred and twenty six Chinese postmenopausal women without carotid artery plaque or history of cardiovascular disease were selected for analysis. Measurements of serum 25 hydroxyvitamin D₃ (25(OH)D₃) concentration and C-IMT were made by electrochemiluminescence immunoassay and B-mode ultrasound, respectively. Trend analysis was conducted according to tertiles of C-IMT.

Results

The median serum 25(OH)D₃ level was 11.03 ng/mL, with an interquartile range of 8.22–14.70. A decreasing trend of serum 25(OH)D₃ level was accompanied by increased C-IMT tertiles (P for trend = 0.001). Correlation analysis found an inverse relationship between serum 25(OH)D₃ level and C-IMT (r = –0.113, P = 0.001). After adjustment for confounding factors, multiple regression analysis showed that serum 25(OH)D₃ level independently and negatively associated with C-IMT (Standard β = –0.112, P < 0.001). Moreover, the inverse correlation of serum 25(OH)D₃ with C-IMT was also found in a subgroup of women with normal glucose tolerance, blood pressure and body mass index, and without undergoing lipid-lowering therapy (standard β = –0.140, P = 0.018).

Conclusions

Serum 25(OH)D₃ level was inversely correlated with C-IMT in Chinese postmenopausal women.

Positive relationship between serum low-density lipoprotein cholesterol levels and visceral fat in a Chinese nondiabetic population

Background

It has been reported that obesity and serum low-density lipoprotein cholesterol (LDL-c) are important risk factors of cardiovascular disease (CVD). It is recognized that regionalized adiposity has different cardiovascular risk, visceral versus subcutaneous, is a better predictor of CVD. However, the relationship between regionalized adiposity and LDL-c is unclear. The present study was designed to investigate the relationship between visceral fat accumulation and serum LDL-c levels in a Chinese cohort.

Methods

A total of 1 538 subjects (539 men, 999 women; 20–75 years old) with normal glucose tolerance and blood pressure were recruited. All subjects underwent magnetic resonance imaging to quantify visceral fat area (VFA) and subcutaneous fat area. Serum LDL-c levels were detected by direct assay method.

Results

Overweight/obese subjects (body mass index (BMI) ≥25 kg/m²) had significantly higher serum LDL-c levels than the lean subjects (BMI <25 kg/m²) (P<0.01). An increasing trend in serum LDL-c levels was found to accompany the increase in VFA (P for trend <0.01). Within the same BMI category, subjects with abdominal obesity (VFA ≥80 cm²) had significantly higher LDL-c levels than those without abdominal obesity (VFA <80 cm²) (P<0.05). Multiple stepwise regression analysis showed that increased VFA was an independent risk factor for elevated LDL-c levels, not only in the entire study population (Standard β = 0.138; P<0.01), but also when the study population was subdivided into men, premenopausal and postmenopausal women (Standard β = 0.117, 0.145, 0.090 respectively for men, premenopausal women, postmenopausal women; all P<0.01).

Conclusions

VFA was positively correlated with serum LDL-c levels in a nondiabetic Chinese population with normal blood pressure.

Serum adipocyte fatty acid binding protein levels are positively associated with subclinical atherosclerosis in Chinese pre- and postmenopausal women with normal glucose tolerance

CONTEXT

Recent studies highlight a critical interaction between adipocyte fatty acid binding protein (A-FABP) and cardiovascular disorders. However, associations of A-FABP with subclinical atherosclerosis in a population with normal glucose tolerance remain unknown.

OBJECTIVE

The study aimed to evaluate the relationship between A-FABP and carotid intima-media thickness (C-IMT) in a Chinese population with normal glucose tolerance.

DESIGN AND SETTING

A cross-sectional analysis was conducted of 2253 cardiovascular disease-free normal glucose tolerance subjects (835 men, 1418 women; 20-78 years old) from the Shanghai Obesity Study.

MAIN OUTCOME AND MEASURES

C-IMT was measured by B-mode ultrasound and used to assess subclinical atherosclerosis. Serum A-FABP levels were quantified by a sandwich ELISA.

RESULTS

The median serum level for A-FABP was 4.0 ng/mL (interquartile range: 2.6-6.0 ng/mL), and significantly higher in women than men (P < .001). After adjusting for age and body mass index (BMI), a partial correlation analysis showed that A-FABP levels correlated with C-IMT in men, premenopausal, and postmenopausal women (P = .024, .006, and .016, respectively). Furthermore, C-IMT increased along with quartile A-FABP values (all P for trend <.001). Regression analyses demonstrated that A-FABP was associated with C-IMT only in women (P = .044 and .001 for pre- and postmenopausal, respectively). Moreover, A-FABP was identified as a risk factor for C-IMT in pre- and postmenopausal women with a normal BMI (P < .001 and P = .012, respectively).

CONCLUSIONS

Serum A-FABP levels independently and positively correlate with subclinical atherosclerosis in pre- and postmenopausal Chinese women with normal glucose tolerance after adjustments for the traditional risk factors.

Contribution of subcutaneous abdominal fat on ultrasonography to carotid atherosclerosis in patients with type 2 diabetes mellitus

BACKGROUND

Whereas visceral abdominal adipose tissue (VAT) is associated with cardiometabolic risk, there is debate regarding the role of subcutaneous abdominal adipose tissue (SAT). The aim of this study was to investigate the relationships of subcutaneous and visceral abdominal fat with carotid atherosclerosis in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 234 patients (men 131, women 103, mean age: 53 years) with T2DM were enrolled. Carotid intima-media thickness (CIMT), abdominal subcutaneous fat thickness (SFT) and visceral fat thickness (VFT) were assessed by high-resolution B-mode ultrasonography (US).

RESULTS

Compared to women, men had significantly higher VFT and lower SFT (p = 0.002, p = 0.04, respectively). In partial correlation coefficient analyses between CIMT and abdominal fat thickness after adjustment for body mass index (BMI), SFT showed a negative correlation with CIMT in men (r = -0.27, p = 0.03). VFT was not correlated with CIMT in either men or women. In women, SFT was not correlated with CIMT (r = -0.01, p = 0.93). VFT/SFT ratio was not correlated with CIMT in either men or women. In multivariate regression analyses adjusted for BMI and other CVD risk factors, SFT but not VFT was independently inversely associated with CIMT in men but not in women (p < 0.001).

CONCLUSIONS

SFT assessed by US was inversely associated with carotid atherosclerosis in patients with T2DM, particularly men. Further research into the different roles of the two types of abdominal adipose tissue in both men and women is warranted.

Associations of serum 25-hydroxyvitamin D3 levels with visceral adipose tissue in Chinese men with normal glucose tolerance

Objective

Decreased serum vitamin D level is a common observation in obese adults. Since no Chinese population-based study has yet evaluated the relationship between serum vitamin D levels and the accurate adiposity variables, this study investigated the association of serum vitamin D (assessed by 25-hydroxyvitamin D₃ [25(OH)D₃]) levels with precise body fat content and distribution in a cohort of Chinese men.

Methods

Serum samples were collected from a total of 567 men with normal glucose tolerance (NGT) for assessment by electrochemiluminescence immunoassay to measure 25(OH)D₃ levels. In addition, each participant underwent bioelectrical impedance analysis to quantify total body fat and magnetic resonance imaging to measure visceral fat area (VFA) and subcutaneous fat area (SFA).

Results

Overweight/obese (BMI ≥25 kg/m²) subjects had significantly lower serum 25(OH)D₃ levels than non-overweight/non-obese (BMI <25 kg/m²) subjects (P  = 0.029). Greater fat mass and VFA were accompanied by a downward trend in serum 25(OH)D₃ levels (P for trend <0.01). Among overweight/obese subjects, those with body fat percent ≥25% also had significantly lower serum 25(OH)D₃ levels (P <0.05). Moreover, participants with VFA ≥80 cm² had significantly lower serum 25(OH)D₃ (P <0.05), regardless of BMI value. VFA was independently correlated with serum 25(OH)D₃ levels (β  =  −0.023, P <0.001), even after adjustments for confounding factors. In addition, serum 25(OH)D₃ levels were found to decrease by 0.26 ng/mL per 10 cm² increment of VFA.

Conclusions

Serum 25(OH)D₃ levels were inversely associated with VFA in Chinese men with NGT.

Endothelial wall thickness, cardiorespiratory fitness and inflammatory markers in obese and non-obese adolescents

BACKGROUND

Increased carotid intima-media thickness (c-IMT) is considered a marker of early-onset atherosclerosis and it has been found in obese children and adolescents, but the risk factors associated with this population remain to be elucidated.

OBJECTIVE

To compare and verify the relationship between c-IMT, metabolic profile, inflammatory markers, and cardiorespiratory fitness in obese and non-obese children and adolescents.

METHOD

Thirty-five obese subjects (19 boys) and 18 non-obese subjects (9 boys), aged 10-16 years, were included. Anthropometry, body composition, blood pressure, maximal oxygen consumption (VO2max), and basal metabolic rate were evaluated. Serum glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), blood lipids, C-reactive protein (CRP), and adiponectin were assessed. c-IMT was measured by ultrasound.

RESULTS

The results showed that c-IMT, triglycerides, insulin, HOMA-IR, and CRP values were significantly higher in the obese group than in the non-obese group, and high-density lipoprotein cholesterol (HDL-c), adiponectin, and VO2max values were significantly lower in the obese group than in the non-obese group. The c-IMT was directly correlated with body weight, waist circumference, % body fat, and HOMA-IR and inversely correlated with % free fat mass, HDL-c, and VO2max.

CONCLUSIONS

Our findings show that c-IMT correlates not only with body composition, lipids, insulin resistance, and inflammation but also with low VO2max values in children and adolescents.

Serum glycated albumin is inversely influenced by fat mass and visceral adipose tissue in Chinese with normal glucose tolerance

Background

Recent studies have revealed that body mass index (BMI) inversely influenced serum glycated albumin (GA), which may cause an underestimation of GA-monitored short-term hyperglycemic control.

Objective

This study was to investigate the association between anthropometric variables (BMI and waist circumference (W)) and accurate adiposity variables (percentage of body fat (%fat), fat mass, free fat mass (FFM), subcutaneous fat area (SFA), and visceral fat area (VFA)) with serum GA.

Design

A total of 2563 subjects (1037 men, 593 premenopausal women, and 933 postmenopausal women) with normal glucose tolerance underwent bioelectrical impedance body fat content measurement and magnetic resonance imaging. Serum GA and absolute value of GA (aGA) were measured by enzymatic assay.

Results

Compared to the BMI <25.0 kg/m² group, the BMI ≥25.0 kg/m² group had significantly higher fasting plasma glucose, glycated hemoglobin A1c, and body fat parameters including W, %fat, fat mass, FFM, SFA, and VFA, but significantly lower aGA, and GA in all the three sex- and menopause-stratified groups (all P<0.05). GA decreased with the increment of fat mass for all three groups (all P for trend <0.001). In the same BMI category, men and postmenopausal women with elevated %fat (men, ≥25%; women, ≥35%) still had significantly lower GA than those with normal %fat (men, <25%; women, <35%) (all P<0.05). Multiple stepwise regression showed that %fat, fat mass, and VFA were independently associated with GA.

Conclusions

Serum GA was inversely influenced by fat mass and visceral adipose tissue in Chinese with normal glucose tolerance.