Metabolically healthy obesity and the risk for subclinical atherosclerosis

Obesity phenotypes and cardiovascular risk: From pathophysiology to clinical management

Obesity epidemic reached the dimensions of a real global health crisis with more than one billion people worldwide living with obesity. Multiple obesity-related mechanisms cause structural, functional, humoral, and hemodynamic alterations with cardiovascular (CV) deleterious effects. A correct assessment of the cardiovascular risk in people with obesity is critical for reducing mortality and preserving quality of life. The correct identification of the obesity status remains difficult as recent evidence suggest that different phenotypes of obesity exist, each one associated with different degrees of CV risk. Diagnosis of obesity cannot depend only on anthropometric parameters but should include a precise assessment of the metabolic status. Recently, the World Heart Federation and World Obesity Federation provided an action plan for management of obesity-related CV risk and mortality, stressing for the instauration of comprehensive structured programs encompassing multidisciplinary teams. In this review we aim at providing an updated summary regarding the different obesity phenotypes, their specific effects on CV risk and differences in clinical management.

miR-125a-3p regulates the expression of FSTL1, a pro-inflammatory factor, during adipogenic differentiation, and inhibits adipogenesis in mice

Adipogenesis is tightly regulated by various factors, including genes and microRNAs. Excessive fat deposition is the key feature of obesity, which is a low-grade chronic inflammatory disease. Follistatin-like 1 (FSTL1) has been reported to be an important mediator involved in various inflammatory diseases. However, the underlying mechanism of FSTL1 in preadipocyte differentiation and inflammatory response is still unclear. The current study was designed to explore the biological function and potential mechanism of FSTL1 in mouse subcutaneous preadipocyte differentiation. We found that FSTL1 was highly expressed in the early stage of differentiation and subsequently decreased sharply, suggesting that FSTL1 played a possible role in adipogenesis. Meanwhile, the gain- and loss-of-function assays showed that FSTL1 was not only involved in the inflammatory response by inducing the expression of pro-inflammatory factors IL-1β and CCL2 but also significantly attenuated preadipocyte differentiation, as evidenced by the reduction of lipid accumulation and the levels of adipogenic genes, including PPARγ and FABP4. In addition, the target gene prediction and luciferase reporter assay validated that miR-125a-3p targeted the 3' UTR region of FSTL1. These results demonstrated that miR-125a-3p negatively regulated the expression of FSTL1 at the mRNA and protein levels. Furthermore, overexpressing miR-125a-3p in preadipocytes dramatically accelerated adipogenic differentiation and downregulated the levels of IL-1β and CCL2, which were in accordance with the knockdown of FSTL1. On the contrary, treatment with miR-125a-3p inhibitors attenuated adipogenesis but induced the expression of inflammatory genes. In summary, this study suggests a positive function of FSTL1 in adipocyte-induced inflammation and negatively regulates preadipocyte differentiation. Further studies demonstrated that miR-125a-3p could reverse the effect by targeting FSTL1, which might provide a better understanding of treating obesity-related inflammatory diseases.

Obesity is associated with coronary artery stenosis independently of metabolic risk factors: The population-based SCAPIS study

BACKGROUND AND AIMS

Previous studies reported divergent results on whether metabolically healthy obesity is associated with increased coronary artery calcium and carotid plaques. We investigated this in a cross-sectional fashion in a large, well-defined, middle-aged population using coronary CT angiography (CCTA) and carotid ultrasound.

METHODS

In the SCAPIS study (50-65 years, 51% female), CCTA and carotid artery ultrasound were performed in 23,674 individuals without clinical atherosclerotic disease. These subjects were divided into six groups according to BMI (normal weight, overweight, obese) and the presence of metabolic syndrome (MetS) according to the NCEP consensus criteria.

RESULTS

The severity of coronary artery stenosis was increased in individuals with obesity without MetS compared to normal-weight individuals without MetS (OR 1.47, 95%CI 1.34-1.62; p < 0.0001), even after adjusting for non-HDL-cholesterol and several lifestyle factors. Such difference was not observed for the presence of carotid artery plaques (OR 0.94, 95%CI 0.87-1.02; p = 0.11). Obese or overweight individuals without any MetS criteria (except the waist criterion) showed significantly more pronounced stenosis in the coronary arteries as compared to the normal-weight individuals, while one criterion was needed to show increased plaque prevalence in the carotid arteries. High blood pressure was the most important single criterion for increased atherosclerosis in this respect.

CONCLUSIONS

Individuals with obesity without MetS showed increased severity of coronary artery stenosis, but no increased occurrence of carotid artery plaques compared to normal-weight individuals without MetS, further emphasizing that obesity is not a benign condition even in the absence of MetS.

Short-term Effects of Eating Behavior Modification on Metabolic Syndrome-Related Risks in Overweight and Obese Korean Adults

Background

We investigated whether eating behavior modification improves metabolic syndrome (MetS)-related risks in overweight/obese Korean adults, and identified dietary factors that improve metabolic status.

Methods

Among 159 volunteers, 71 with a body mass index ≥23 kg/m² and without other chronic diseases participated in the 8-week intervention, among which 54 participants who completed the intervention were included in the analyses. At baseline, patients were categorized either metabolically healthy obese (MHO; <3 MetS risk factors, n=42) or metabolically unhealthy obese (MUHO; ≥3 MetS risk factors, n=12), and then educated regarding how to choose healthy foods and meals.

Results

Lipid profiles and anthropometric and glycemic parameters were significantly improved among all participants after the intervention. Changes in waist circumference (P=0.025), and glycemic parameters (glucose, P=0.046, insulin, P=0.005, C-peptide, P=0.041) were positively correlated with changes in calorie intake from snacks. Changes in visceral fat area were negatively correlated with changes in total calorie intake (P=0.046), and positively correlated with those in calorie intake from dietary fats (P=0.039). In addition, changes in insulin (P=0.013) and C-peptide (P=0.008) concentrations were negatively correlated with changes in dietary fiber intake at dinner. After the intervention, 83.3% of initially MUHO participants became MHO and 16.7% of MHO participants became MUHO.

Conclusion

Eating behavior modification may be an important strategy to improve metabolic factors in overweight/obese people.

Natural histories of metabolite BMI phenotypes and their impacts on cardiovascular disease risk over a decade-long follow-up

PURPOSE

The prognostic significance of obesity phenotypes is under debate, and few studies have characterized their transition trajectories. This study examined the natural courses of different phenotypes and their associations with cardiovascular disease risks.

METHODS

A total of 1827 participants were followed for 14 years and re-evaluated every 4-5 years. Four metabolite BMI phenotypes were determined according to overweight or obesity (BMI ≥ 24 kg/m²) and metabolic health status (≤1 Adult Treatment Panel III criteria, excluding waist circumference). Cardiovascular risks were assessed by evaluating baPWV and hypertension, diabetes and chronic kidney disease (CKD) development.

RESULTS

More than 20% of participants changed their initial phenotypes within 5 years. One-third of healthy overweight/obese (MHO) individuals became unhealthy, and only 10.6% regressed to a healthy normal weight (MHN) at the end of follow-up. Compared with MHN participants, MHO participants had higher odds of increased baPWV (OR: 1.18, 95% CI, 0.42-3.33) and increased risks of incident hypertension (HR: 1.87, 95% CI, 1.18-2.98) and diabetes (HR: 2.61, 95% CI, 1.35-5.03). Metabolic deterioration during follow-up resulted in an increased risk of baPWV and clinical diseases.

CONCLUSIONS

The natural trajectory of metabolite BMI phenotypes is time-varying, and interventions for both healthy and unhealthy overweight/obese individuals should be widely recommended.

Transition from metabolically healthy to unhealth status associated with risk of carotid artery plaque in Chinese adults

Objective

We aimed to evaluate the association between the shift of metabolic status and future risk of carotid artery plaque (CAP) in community-based Chinese adults.

Methods

The current study included 9836 Chinese adults (4085 males and 5751 females, mean age 35.8 years) with metabolically healthy status at baseline (2013). Metabolically healthy status was defined as no self-reported history of metabolic diseases and cancer, and normal blood pressure, fasting blood glucose, glycated hemoglobin A1c level, and lipid profiles. Metabolically unhealthy status was defined if any of the following metabolic abnormalities were confirmed twice during follow up: high blood pressure, impaired glucose regulation, high triglycerides, high total cholesterol, high low-density lipoprotein cholesterols, or low high-density lipoprotein cholesterols. The transition was confirmed if participants’ metabolic status shifted from baseline healthy to unhealthy status during follow up (2014–2018).

Results

We have identified 133 incident cases of CAP during follow up. Compared to those who remained metabolically healthy, the transition to high blood pressure, high total cholesterol, and high low-density lipoprotein cholesterols, were associated with high risk of developing carotid artery plaque (Hazards ratios (HRs) ranged from 1.69 to 2.34; p < 0.05 for all). The transition to impaired glucose regulation, high total triglycerides, and low high-density lipoprotein cholesterols, were associated with high risk of carotid artery plaque only in participants with metabolically healthy overweight at baseline (HR ranged from 1.95 to 4.62; p < 0.05 for all).

Conclusion

The transition from baseline metabolically healthy status to unhealth status was associated with high risk of incident CAP.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02279-w.

Propionic Acid Rescues High-Fat Diet Enhanced Immunopathology in Autoimmunity via Effects on Th17 Responses

High-fat diets (HFD) are linked to obesity and associated comorbidities and induce pathogenic T helper (Th) 17 cells while decreasing regulatory T cells (Treg). This pro-inflammatory environment also aggravates immunopathology in experimental autoimmune encephalomyelitis (EAE) as a prototype model of T cell mediated autoimmunity. The strong association of HFD to obesity as well as the increasing risk of autoimmunity in the Western world stresses the importance to identify compounds that counteract this metabolically induced pro-inflammatory state in humans. One prominent candidate is the short-chain fatty acid propionate (PA) that was recently identified as potent therapy in the autoimmune disease multiple sclerosis by enhancing Treg cell frequencies and functionality. Mice were fed a HFD rich lauric acid (LA) and treated either with water or PA during MOG_35-55-EAE. We analyzed Treg and Th17 cell frequencies in different tissues, antigen-specific cell proliferation and cytokine secretion, investigated Treg cell functionality by suppression assays and IL-10 signaling blockade and employed Western blotting to investigate the involvement of p38-MAPK signaling. Finally, we performed an explorative study in obese and non-obese MS patients, investigating fecal PA concentrations as well as peripheral Th17 and Treg frequencies before and after 90 days of daily PA intake. As compared to controls, mice on a HFD displayed a more severe course of EAE with enhanced demyelination and immune cell infiltration in the spinal cord. PA treatment prevented this disease enhancing effect of HFD by inhibiting Th17 mediated inflammatory processes in the gut and the spleen. Blocking experiments and signaling studies revealed p38-MAPK and IL-10 signaling as important targets linking the beneficial effects of PA treatment and reduced inflammation due to enhanced Treg frequency and functionality. An explorative study in a small group of MS patients revealed reduced PA concentrations in fecal samples of obese MS patients compared to the non-obese group, coinciding with increased Th17 but decreased Treg cells in obese patients. Importantly, PA intake could restore the Treg-Th17 homeostasis. Our data thus identify Th17 responses as an important target for the beneficial effects of PA in HFD and obesity in addition to the recently identified potential of PA as a Treg inducing therapy in T cell mediated autoimmunity.

Asymptomatic Hyperuricemia and Metabolically Unhealthy Obesity: A Cross-Sectional Analysis in the Tianning Cohort

OBJECTIVE

The relationship between obesity and hyperuricemia has been demonstrated by many studies. However, whether or to what extent metabolic condition influents the association between obesity and hyperuricemia was not clear. Here, we aimed to examine the association between obese-metabolic phenotype and hyperuricemia in a large sample of Chinese adults.

METHODS

According to BMI and metabolic syndrome, obese-metabolic phenotype was defined as metabolically unhealthy obesity (MUO), metabolically healthy obesity (MHO), metabolically unhealthy non-obesity (MUNO) and metabolically healthy non-obesity (MHNO)in the Tianning cohort (N=5072). We conducted a cross-sectional analysis between obese-metabolic phenotype and hyperuricemia, followed by a Mendelian Randomization analysis using GWAS summary data to confirm the causality between uric acid and BMI.

RESULTS

The average level of serum UA showed 41.87-higher μmol/L in participants with MHO (β=41.87, P<0.001) and 63.18-higher μmol/L in participants with MUO (β=63.18, P<0.001), compared to those with MHNO. Compared to participants with MHNO, those with MUO had the highest likelihood to have hyperuricemia (OR=4.56, P<0.001), followed by those with MHO (OR=3.32, P<0.001). Mendelian randomization analysis indicated that uric acid was more likely to be a consequence of BMI (β=0.059, P=6.54×10^-154).

CONCLUSION

MUO, in comparison with MHO, was significantly associated with hyperuricemia in Chinese adults.

Long non-coding RNA LINC00299 knockdown inhibits ox-LDL-induced T/G HAVSMC injury by regulating miR-135a-5p/XBP1 axis in atherosclerosis

BACKGROUND

Atherosclerosis (AS) is a highly relevant social problem. Long noncoding RNA (lncRNA) long intergenic non-coding00299 (LINC00299) participates in the regulation of AS development. Therefore, this study was to explore the potential role and mechanism of LINC00299 in AS.

METHODS

Human aortic vascular smooth muscle cells (T/G HA-VSMCs) were treated with oxidized low-density lipoprotein (ox-LDL). Cell viability and migration were measured by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) and transwell assays, severally. The activities of SOD and MDA were detected by total superoxide dismutase assay kit and malondialdehyde assay kit. The protein levels of ki67, matrix metalloproteinase 9 (MMP9) and X-box binding protein 1 (XBP1) were detected by western blot assay. The expression levels of LINC00299, microRNA-135a-5p (miR-135a-5p) and XBP1 were detected by real-time quantitative polymerase chain reaction (RT-qPCR). The binding relationship between miR-135a-5p and LINC00299 or XBP1 was predicted by miRcode and Starbase3.0 then verified by the dual-luciferase reporter assay.

RESULTS

Ox-LDL induced cell viability, oxidative damage and migration of T/G HA-VSMCs. LINC00299 knockdown weakened ox-LDL-induced T/G HA-VSMCs injury. Mechanical analysis confirmed that LINC00299 improved XBP1 expression by interacting with miR-135a-5p. Furthermore, rescue assays showed that LINC00299 regulated ox-LDL-induced T/G HA-VSMCs injury through the miR-135a-5p/XBP1 axis.

CONCLUSIONS

Our studies revealed the regulatory function of LINC00299/miR-135a-5p/XBP1 axis in AS development, suggesting a potential therapeutic strategy for AS treatment.

Impact of metabolically healthy obesity on carotid intima-media thickness - The Brazilian Longitudinal Study of Adult Health

BACKGROUND AND AIMS

Obesity increases the risk of metabolic abnormalities, which contributes to elevated cardiovascular risk. However, the independent role of obesity in the development of cardiovascular disease is still debatable. There are individuals with an obesity phenotype without metabolic abnormalities: "metabolically healthy obesity" (MHO). This study evaluates the association between MHO and carotid intima-media thickness (CIMT), an early marker of subclinical atherosclerosis.

METHODS AND RESULTS

This is a cross-sectional analysis of the baseline data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). We used a strict definition to classify MHO: body mass index ≥30 kg/m² and meeting none of the four metabolic syndrome criteria. Data from 10,335 participants were analyzed. The obesity prevalence in our population was 21.2% (n = 2191). The prevalence of MHO was 5.6% (n = 124). When individuals were stratified according to metabolic health, we found the metabolically healthy individuals were younger, more likely to be women and never smokers. The mean CIMT of the sample was 0.81 mm (±0.20). The mean CIMT of the metabolically healthy subsample was 0.70 mm (±0.13) in individuals without obesity and 0.76 mm (±0.13) in individuals with obesity (p < 0.001). The mean CIMT of the metabolically unhealthy subsample was 0.81 mm (±0.20) in individuals without obesity and 0.88 mm (±0.20) in individuals with obesity (p < 0.001). These findings remained essentially unchanged after multivariate adjustment for confounding factors.

CONCLUSION

The concept of MHO, even with the strict definition, seems inadequate, as even in this population, obesity is associated with higher CIMT levels.

Metabolically Healthy Obesity and Bariatric Surgery

A peculiar category of persons with obesity lacking common metabolic disturbances has been depicted and termed as metabolically healthy obesity (MHO). Yet, although MHO patients are free of obesity-associated complications, they might not be entirely precluded from developing cardio-metabolic disorders. Among patients with morbid obesity (MO) who are referred to bariatric surgery, a subset of metabolically healthy MO (MHMO) has been identified and the question arises if these patients would benefit from surgery in terms of mitigating the peril of cardio-metabolic complications. We revisited the pathophysiological mechanisms that define MHO, the currently available data on the cardio-metabolic risk of these patients and finally we reviewed the benefits of bariatric surgery and the urge to better characterize MHMO before submission to surgery.

Metabolically Healthy Obesity and the Risk of Erosive Esophagitis: A Cohort Study

OBJECTIVES

Obesity is an established risk factor of erosive esophagitis, and metabolic unhealthiness has been implicated in the pathogenesis of erosive esophagitis. Yet, the risk of erosive esophagitis among obese individuals without obesity-related metabolic unhealthiness, a condition referred to as "metabolically healthy obese (MHO)", remains unclear. We examined the association between body mass index (BMI) categories and the development of erosive esophagitis in a cohort of metabolically healthy individuals.

METHODS

We conducted a cohort study of 14,725 asymptomatic adults free of erosive esophagitis and metabolic abnormalities, who underwent repeated health checkups including screening endoscopy. A metabolically healthy state was defined as having no metabolic syndrome components and a homeostasis model assessment of insulin resistance <2.5. The presence of erosive esophagitis was determined using endoscopy.

RESULTS

During 81,385.2 person-years of follow-up, 1,865 participants developed erosive esophagitis (incidence rate, 22.9 per 1,000 person-years). The multivariable adjusted hazard ratios (95% confidence intervals) for incident erosive esophagitis comparing overweight (BMI 23.0-24.9) and obese (≥25) with normal-weight participants (18.5-22.9) were 1.12 (1.00-1.25) and 1.29 (1.14-1.47), respectively. In dose-response analyses, increasing BMI also showed positive association with overall and LA-B grade or higher. The association persisted in MHO individuals without central obesity. The association between waist circumference categories and the development of erosive esophagitis was also evident.

DISCUSSION

In a large cohort of strictly defined metabolically healthy men and women, the MHO phenotype was associated with an increased incidence of erosive esophagitis, providing evidence that the MHO phenotype is not protective from gastroesophageal reflux disease.

Metformin Improves Fertility in Obese Males by Alleviating Oxidative Stress-Induced Blood-Testis Barrier Damage

Background/Aims

Obesity, which is related to increased oxidative stress in various tissues, is a risk factor for male infertility. Metformin is reported to have an antioxidant effect; however, the precise role of metformin in obesity-induced male infertility remains unknown. The current study is aimed at exploring the effects of metformin and characterizing its underlying mechanism in the fertility of obese males.

Methods

An obese male mouse model was generated by feeding mice with a high-fat diet; then, the mice were administered metformin in water for 8 weeks. Reproductive ability, metabolic parameters, and follicle-stimulating hormone (FSH) were assessed by cohabitation, enzymatic methods, and ELISA, respectively. Damage to the integrity of the blood-testis barrier (BTB), which ensures spermatogenesis, was assessed by transmission electron microscopy and immunofluorescence with a biotin tracer. Malondialdehyde (MDA), superoxide dismutase (SOD), and reactive oxygen species (ROS) were employed for the assessments of oxidative stress. BTB-related proteins were measured by immunoblotting. Nuclear factor κB (NF-κB) was assessed by immunofluorescence.

Results

High-fat-diet-fed mice presented evident lipid metabolic disturbances, disrupted BTB integrity, and decreased reproductive function. Metformin alleviated the decrease in male fertility, decreased ectopic lipid deposition in the testis, and increased serum FSH levels. A further mechanistic analysis revealed that metformin ameliorated the high-fat-diet-induced injury to the BTB structure and permeability and restored the disordered BTB-related proteins, which might be associated with an improvement in oxidative stress and a recovery of NF-κB activity in Sertoli cells (SCs).

Conclusion

Metformin improves obese male fertility by alleviating oxidative stress-induced BTB damage. These findings provide new insights into the effect of metformin on various diseases and suggest future possibilities in the treatment of male infertility.

Transition from metabolically benign to metabolically unhealthy obesity and 10-year cardiovascular disease incidence: The ATTICA cohort study

BACKGROUND/OBJECTIVES

Metabolically benign obesity remains a scientific field of considerable debate. The aim of the present work was to evaluate whether metabolically healthy obese (MHO) status is a transient condition which propagates 10-year cardiovascular disease (CVD) onset.

METHODS

A prospective longitudinal study was conducted during 2001-2012, the ATTICA study studying 1514 (49.8%) men and 1528 (50.2%) women (aged >18 years old) free of CVD and residing in the greater Athens area, Greece. Follow-up assessment of first combined CVD event (2011-2012) was achieved in n = 2020 participants; of them, 317 (15.7%) incident cases were identified. Obesity was defined as body mass index ≥30 kg/m² and healthy metabolic status as absence of all NCEP ATP III (2005) metabolic syndrome components (excluding waist circumference).

RESULTS

The MHO prevalence was 4.8% (n = 146) with 28.2% of obese participants presenting metabolically healthy status at baseline. Within this group, 52% developed unhealthy metabolic status during the 10-year follow up. MHO vs. metabolically healthy non-obese participants had a higher likelihood of presenting with 10-year CVD events, yet only the subset of them who lost their baseline status reached the level of significance (Hazard Ratio (HR) = 1.43, 95% Confidence Interval (95% CI) 1.02, 2.01). Sensitivity analyses revealed that MHO status was independently associated with elevated CVD risk in women and participants with low adherence to the Mediterranean diet, low grade inflammation, and insulin resistance.

CONCLUSIONS

MHO status is a transient condition where weight management is demanded to prevent the establishment of unhealthy cardiometabolic features. The existence of obese persons who remain "longitudinally" resilient to metabolic abnormalities is an emerging area of future research.

The long-term prognosis of heart diseases for different metabolic phenotypes: a systematic review and meta-analysis of prospective cohort studies

PURPOSE

This meta-analysis aimed to assess the association of different categories of weight and metabolic status with risk of heart diseases including myocardial infarction (MI), cardiovascular diseases (CVDs), and heart failure (HF).

METHODS

Data from relevant studies were identified systematically by searching PubMed and Scopus search engines up to 29 May 2018. Prospective studies were included in the analyses with metabolically healthy normal weight (MHNW) as the reference. Pooled RRs and 95% CI were calculated using random-effects or fixed-effect models when appropriate. Subgroup analysis was applied to define possible sources of heterogeneity.

RESULTS

Overall, 21 studies (n = 778,401 participants) were eligible for the present meta-analysis. Generally, the risk of CVDs for all metabolic phenotypes in metabolically unhealthy obese increased compared with the MHNW group. A significant positive association between all metabolic phenotypes and the risk of HF was also observed expect for MHOW (RR = 1.10, 95% CI: 0.60-2.00, P = 0.76) and MHO phenotypes (RR = 0.96, 95% CI: 0.25-3.77, P = 0.95). Moreover, MUHO phenotype was associated with greater risk of MI compared with the MHNW phenotype (RR = 1.82, 95% CI: 1.50-2.22, P < 0.001, respectively).

CONCLUSIONS

Our findings showed that all metabolically unhealthy phenotypes in different categories of weight were associated with increased incident of CVDs/HF and MI. Furthermore, healthy overweight and obese subjects had increased risk of CVDs.

Associations of metabolically healthy obesity with prevalence and progression of coronary artery calcification: Results from the Heinz Nixdorf Recall Cohort Study

BACKGROUND AND AIMS

There is controversy on the potentially benign nature of metabolically healthy obesity (MHO), i.e., obese persons with few or no metabolic abnormalities. So far, associations between MHO and coronary artery calcification (CAC), a measure of subclinical atherosclerosis, have mainly been studied cross-sectionally in Asian populations. We assessed cross-sectional and longitudinal MHO CAC associations in a Caucasian population.

METHODS AND RESULTS

In the Heinz Nixdorf Recall Study, a population-based cohort study in Germany, CAC was assessed by electron-beam tomography at baseline and at 5-year follow-up. For cross-sectional and longitudinal analyses, we included 1585 participants free of coronary heart disease at baseline, with CAC measurements at baseline and at follow-up, and with either normal weight (BMI 18.5-24.9 kg/m²) or obesity (BMI ≥30.0 kg/m²) at baseline. We used four definitions of MHO. In our main analysis, we defined obese persons as metabolically healthy if they met ≤1 of the NCEP ATP III criteria for the definition of the metabolic syndrome - waist circumference was not taken into account because of collinearity with BMI. Persons with MHO had a higher prevalence of CAC than metabolically healthy normal weight (MHNW) persons (prevalence ratio = 1.59 (95% confidence interval 1.38-1.84) for the main analysis). Persons with MHO had slightly larger odds of CAC progression than persons with MHNW (odds ratios ranged from 1.17 (0.69-1.99) to 1.48 (1.02-2.13) depending on MHO definition and statistical approach).

CONCLUSION

Our analyses on MHO CAC associations add to the evidence that MHO is not a purely benign health condition.

Prevalence and clinical characteristics of metabolically unhealthy obesity in an Iranian adult population

PURPOSE

The incidence of obesity is globally increasing and it is a predisposing factor for morbidity and mortality. This study assessed the prevalence of metabolically unhealthy (MU) individuals and its determinants according to body mass index (BMI).

MATERIALS AND METHOD

In our cross-sectional study, 891 persons aged 30 years or older participated. Participants were classified as obese (BMI ≥30 kg/m²), overweight (BMI 25-<30 kg/m² and normal weight (BMI <25 kg/m²). Metabolic health status was defined using four existing cardio-metabolic abnormalities (elevated blood pressure, elevated serum concentrations of triglyceride and fasting glucose and a low serum concentration of high density lipoprotein cholesterol). Then, two phenotypes were defined: healthy (existence of 0-1 cardio-metabolic abnormalities) and unhealthy (presence of 2 or more cardio-metabolic abnormalities).

RESULT

Overall, 10.9% (95% confidence interval (CI): 8.8-13.0) and 7.2% (95% CI: 5.5-8.9) of participants were MU obese and metabolically healthy obese, respectively. The prevalence of MU was higher in overweight (55.6%; 95% CI: 50.6-60.6, p<0.001) and obese (60.2%; 95% CI: 52.8-67.6, p=0.001) subjects than in individuals with a normal weight (37.5%; 95% CI: 29.4-42.6). Multiple logistic regression analysis showed an association of a MU state with age and dyslipidaemia in the BMI subgroups and with female sex in the normal weight individuals.

CONCLUSION

The prevalence of a MU state increased with increasing BMI. Ageing and dyslipidaemia were associated with an unhealthy metabolic state in normal weight, overweight and obese subjects and with the female sex in normal weight subjects.

The effects of metabolic status on non-alcoholic fatty liver disease-related outcomes, beyond the presence of obesity

BACKGROUND

Metabolically healthy obesity (MHO) shows a reduced risk compared with obese patients with adverse metabolic conditions. Lean people suffering some metabolic derangements also have non-alcoholic fatty liver disease (NAFLD)-related outcomes compared with non-obese subjects with a few metabolic risks.

AIM

To define the impact of the metabolic status on the NAFLD-related outcomes, beyond the presence of obesity.

METHODS

We designed a multicentre cross-sectional study, including 1058 biopsy-proven NAFLD patients. Metabolically healthy status was strictly defined by the lack of metabolic risk factors (diabetes mellitus, low HDL, hypertriglyceridemia, arterial hypertension). Non-alcoholic steatohepatitis (NASH) and significant fibrosis (F2-F4) were identified by liver biopsy. Chronic kidney disease epidemiology collaboration equation was calculated for kidney function and the atherogenic index of plasma (AIP) for cardiovascular risk.

RESULTS

Metabolically healthy (OR 1.88; P = 0.050) and unhealthy obesity (OR 3.47: P < 0.0001), and unhealthy non-obesity (OR 3.70; P < 0.0001) were independently associated with NASH together with homeostatic model assessment (HOMA), ALT, and platelets. Significant fibrosis was more frequently observed in the presence of adverse metabolic conditions in obese (OR 3.89; P = 0.003) and non-obese patients (OR 3.92; P = 0.002), and independently associated with platelets, albumin, ALT, HOMA, and age. The number of metabolic factors determined the risk of NASH and significant fibrosis. Glomerular filtration rate was lower in unhealthy (91.7 ± 18) than healthy metabolism (95.6 ± 17) (P = 0.007). AIP was higher in adverse metabolic conditions (P = 0.0001). Metabolically unhealthy non-obesity showed higher liver damage (NASH 55.8% vs 42.4%; P < 0.05; significant fibrosis 31.7% vs 11.4%; P < 0.0001) and cardiovascular risk (P < 0.0001) than healthy obesity.

CONCLUSIONS

Metabolic unhealthy status showed a greater impact on NASH, significant fibrosis, kidney dysfunction, and atherogenic profile than obesity. However, metabolically healthy obesity was not a full healthy condition. We should focus our messages especially on patients with adverse metabolic conditions.

LDL-C:HDL-C ratio and common carotid plaque in Xinjiang Uygur obese adults: a cross-sectional study

OBJECTIVE

The aim of this study was to explore the relationship between low-density lipoprotein cholesterol:high-density lipoprotein cholesterol (LDL-C:HDL-C) ratio and common carotid atherosclerotic plaque (CCAP) among obese adults of Uygur community in Xinjiang, China.

DESIGN

A hospital-based cross-sectional study.

SETTING

First Affiliated Hospital of Xinjiang Medical University.

PARTICIPANTS

A total of 1449 obese adults of Uygur population who were free of coronary artery disease were included in our study from 1 January 2014 to 31 December 2016.

METHODOLOGY

Lipid profiles, other routine laboratory parameters and intima-media thickness of the common carotid artery were measured in all participants. Multivariate logistic regression analysis was used to examine the association between LDL-C:HDL-C ratio and CCAP.

RESULTS

Four hundred and fifteen (28.64%) participants had CCAP. Participants with CCAP had significantly higher LDL-C:HDL-C ratio compared with those without CCAP (3.21 [2.50, 3.88] vs 2.33 [1.95, 2.97], p<0.001). Multivariate logistic regression analysis showed high LDL-C:HDL-C ratio as independent predictor of CCAP after adjusting for conventional cardiovascular risk factors. The top LDL-C:HDL-C ratio quartile (≥3.25) had an OR of 9.355 (95% CI 6.181 to 14.157) compared with the bottom quartile (<2.07) of LDL-C:HDL-C ratio (p<0.001) after adjustment for age, body mass index, smoking, diabetes mellitus and serum level of total cholesterol.

CONCLUSION

CCAP is highly prevalent in Uygur obese adults. A high LDL-C:HDL-C ratio is an independent predictor of CCAP. It may help identify obese individuals who are at high risk of CCAP and who may benefit from intensive LDL-lowering therapy.

Obesity impairs leukocyte-endothelium cell interactions and oxidative stress in humans

BACKGROUND

To evaluate the relationship between leukocyte-endothelial cell interactions and oxidative stress parameters in non-diabetic patients with different grades of obesity.

MATERIAL AND METHODS

For this cross-sectional study, 225 subjects were recruited from January 1, 2014 to December 31, 2016 and divided into groups according to BMI (<30 kg/m² , 30-40 kg/m² and >40 kg/m²). We determined clinical parameters, systemic inflammatory markers, soluble cellular adhesion molecules, leukocyte-endothelium cell interactions-rolling flux, velocity and adhesion-, oxidative stress parameters-total ROS, total superoxide, glutathione-and mitochondrial membrane potential in leukocytes.

RESULTS

We verified that HOMA-IR and hsCRP increased progressively as obesity developed, whereas A1c, IL6 and TNFα were augmented in the BMI > 40 kg/m² group. The cellular adhesion molecule sP-selectin was increased in patients with obesity, while sICAM, total ROS, total superoxide and mitochondrial membrane potential were selectively higher in the BMI > 40 kg/m² group. Obesity induced a progressive decrease in rolling velocity and an enhancement of rolling flux and leukocyte adhesion.

CONCLUSION

Our findings reveal that endothelial dysfunction markers are altered in human obesity and are associated with proinflammatory cytokines and increased oxidative stress parameters.

The relation between body fat distribution, plasma concentrations of adipokines and the metabolic syndrome in patients with clinically manifest vascular disease

Introduction

We evaluated the relationship between adipokine plasma concentrations and body fat distribution and the metabolic syndrome.

Methods

In a cohort of 1215 patients with clinically manifest vascular disease the relation between subcutaneous adipose tissue, visceral adipose tissue, waist circumference, body mass index and plasma concentrations of adipsin, chemerin, monocyte chemoattractant protein-1, migration inhibitory factor, nerve growth factor, resistin, plasma amyloid A1, adiponectin, leptin, plasminogen activator inhibitor-1 and hepatic growth factor were cross-sectionally assessed with linear regression and adjusted for age and gender. The relation between adipokines and the metabolic syndrome was cross-sectionally evaluated using logistic regression. An adipokine profile was developed to measure the effect of combined rather than single adipokines.

Results

Adiposity was related to higher nerve growth factor, hepatic growth factor, migration inhibitory factor, leptin and adipsin and with lower chemerin, plasminogen activator inhibitor-1, resistin, plasma amyloid A1 and adiponectin. The strongest positive relations were between body mass index and adipsin (β 0.247; 95% CI 0.137–0.356) and leptin (β 0.266; 95% CI 0.207–0.324); the strongest negative relations were between body mass index and plasma amyloid A1 (β –0.266; 95% CI –0.386 to –0.146) and visceral adipose tissue and adiponectin (β –0.168; 95% CI –0.226 to –0.111). There was no relation between subcutaneous adipose tissue and adipokines. Odds for the metabolic syndrome were higher with each 1 SD higher hepatic growth factor (OR 1.21; 95% CI 1.06–1.38) and leptin (OR 1.26; 95% CI 1.10–1.45) and lower with each 1 SD higher adiponectin (OR 0.73; 95% CI 0.64–0.83) and resistin (OR 0.85; 95% CI 0.74–0.97). The adipokine profile was related to the metabolic syndrome (OR 1.03; 95% CI 1.00–1.06).

Conclusion

Plasma concentrations of adipokines are related to obesity and body fat distribution. The relation between adipokine concentrations and the metabolic syndrome is independent of visceral adipose tissue.

Protective effect of KLF15 on vascular endothelial dysfunction induced by TNF‑α

Atherosclerosis (AS) is a cardiovascular disease with a relatively high incidence rate. Krüppel-like factor 15 (KLF15) has a role in numerous pathological processes, including nephropathy, abnormal glucose metabolism and myocardial injury. The aim of the present study was to investigate the function of KLF15 in vascular endothelial dysfunction. MTT analyses, nitric oxide (NO) detection and cell adhesion detection kits were used to investigate the viability and adhesion of, and quantity of NO released by Eahy926 cells induced by tumor necrosis factor (TNF)-α, respectively. Reverse transcription-quantitative polymerase chain reaction and western blot analyses were performed to determine the expression levels of KLF15, endothelial nitric oxide synthase, monocyte chemoattractant protein-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1), transforming growth factor-β1 (TGF-β1), phosphorylated (p-)transcription factor p65 (p65) and nuclear factor erythroid 2-related factor 2 (Nrf2). The results of the present study demonstrated that TNF-α was able to induce vascular endothelial dysfunction in Eahy926 cells at an optimum concentration of 10 ng/ml. Overexpression of KLF15 markedly enhanced cell viability in addition to the quantity of released NO of TNF-α-induced Eahy926 cells, and increased the expression levels of eNOS and Nrf2. Furthermore, overexpression of KLF15 markedly suppressed the rate of cellular adhesion, and downregulated levels of MCP-1, ICAM-1, TGF-β1 and p-p65 in TNF-α induced Eahy926 cells. In conclusion, the results of the present study suggested that overexpression of KLF15 in Eahy926 cells exhibited a protective effect against TNF-α induced dysfunction via activation of Nrf2 signaling and inhibition of nuclear factor κB signaling.

Obesity-Related Metabolomic Profiles and Discrimination of Metabolically Unhealthy Obesity

A particular subgroup of obese adults, considered as metabolically healthy obese (MHO), has a reduced risk of metabolic complications. However, the molecular basis contributing to this healthy phenotype remains unclear. The objective of this work was to identify obesity-related metabolite patterns differed between MHO and metabolically unhealthy obese (MUHO) groups and examine whether these patterns are associated with the development of cardiometabolic disorders in a sample of Iranian adult population aged 18-50 years. Valid metabolites were defined as metabolites that passed the quality control analysis of the study. In this case-control study, 104 valid metabolites of 107 MHO and 100 MUHO patients were separately compared to those of 78 normal-weight metabolically healthy (NWMH) adults. Multivariable linear regression was used to investigate all potential relations in the study. A targeted metabolomic approach using liquid chromatography coupled to triple quadrupole mass spectrometry was employed to profile plasma metabolites. The study revealed that, after Bonferroni correction, branched-chain amino-acids, tyrosine, glutamic acid, diacyl-phosphatidylcholines C32:1 and C38:3 were directly and acyl-carnitine C18:2, acyl-lysophosphatidylcholines C18:1 and C18:2, and alkyl-lysophosphatidylcholines C18.0 were inversely associated with MHO phenotype. The same patterns were observed in MUHO patients except for the acyl-carnitine and lysophosphatidylcholine profiles where acyl-carnitine C3:0 and acyl-lysophosphatidylcholine C16:1 were higher and acyl-lysophosphatidylcholines C18:1, C18:2 were lower in this phenotype. Furthermore, proline, and diacyl-phosphatidylcholines C32:2 and C34:2 were directly and serine, asparagines, and acyl-alkyl-phosphatidylcholine C34:3 were negatively linked to MUHO group. Factors composed of amino acids were directly and those containing lysophosphatidylcholines were inversely related to cardiometabolic biomarkers in both phenotypes. Interestingly, the diacyl-phosphatidylcholines-containing factor was directly associated with cardiometabolic disorders in the MUHO group. A particular pattern of amino acids and choline-containing phospholipids may aid in the identification of metabolic health among obese patients.

Exenatide with Metformin Ameliorated Visceral Adiposity and Insulin Resistance

BACKGROUND

To study the effectiveness of exenatide with metformin and sequential treatment with exenatide and glargine added to metformin and their influence on insulin sensitivity and adipose distribution.

METHODS

20 newly diagnosed obese type 2 diabetic patients were enrolled, and 2-month washout treatment of metformin, 6-month exenatide treatment, and 6-month glargine treatment were administrated sequentially accompanied with previous metformin. Glucolipid metabolic parameters were compared among groups. Adipose distribution was quantified with computerized tomography according to anatomy, dividing into visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT), adding up to total adipose tissue (TAT).

RESULTS

The 6-month exenatide treatment dramatically ameliorated the glucose and lipid profile, improved insulin sensitivity, and mainly decreased VAT and also the ratio of VAT/SAT (RVS). The following 6-month glargine treatment increased VAT. The whole 12-month sequential treatment with exenatide and glargine added to metformin basically improved the insulin sensitivity and glucolipid control though VAT rebounded at the end, however without deteriorating the other parameters.

CONCLUSION

Exenatide is an ideal treatment for obese type 2 diabetic patients in the aspect of adipose tissue distribution. Sequential treatment of exenatide and glargine could be an alternative for low-income patients who cannot afford GLP-1 agonist for long time. This trial is registered with ChiCTR-OOC-17013679.