Changes of serum omentin-1 levels in normal subjects, type 2 diabetes and type 2 diabetes with overweight and obesity in Chinese adults

Comparative Effects of Gymnema sylvestre and Berberine on Adipokines, Body Composition, and Metabolic Parameters in Obese Patients: A Randomized Study

Gymnema sylvestre (GS) and berberine (BBR) are natural products that have demonstrated therapeutic potential for the management of obesity and its comorbidities, as effective and safe alternatives to synthetic drugs. Although their anti-obesogenic and antidiabetic properties have been widely studied, comparative research on their impact on the gene expression of adipokines, such as resistin (Res), omentin (Ome), visfatin (Vis) and apelin (Ap), has not been reported.

METHODOLOGY

We performed a comparative study in 50 adult Mexican patients with obesity treated with GS or BBR for 3 months. The baseline and final biochemical parameters, body composition, blood pressure, gene expression of Res, Ome, Vis, and Ap, and safety parameters were evaluated.

RESULTS

BBR significantly decreased (p < 0.05) body weight, blood pressure and Vis and Ap gene expression and increased Ome, while GS decreased fasting glucose and Res gene expression (p < 0.05). A comparative analysis of the final measurements revealed a lower gene expression of Ap and Vis (p < 0.05) in patients treated with BBR than in those treated with GS. The most frequent adverse effects in both groups were gastrointestinal symptoms, which attenuated during the first month of treatment.

CONCLUSION

In patients with obesity, BBR has a better effect on body composition, blood pressure, and the gene expression of adipokines related to metabolic risk, while GS has a better effect on fasting glucose and adipokines related to insulin resistance, with minimal side effects.

Controlling Nutritional Status (CONUT) score is a novel marker of type 2 diabetes mellitus and diabetic microvascular complications

OBJECTIVES

Type 2 diabetes mellitus (T2DM) and its microvascular complications are characterized by chronic inflammation. The Controlling Nutritional Status (CONUT) score is a tool used to assess nutritional status and is often associated indirectly with inflammatory processes. We aimed to compare the CONUT scores of T2DM patients with those of healthy volunteers and to compare T2DM patients with and without microvascular complications.

METHODS

Patients diagnosed with T2DM and healthy volunteers (as controls) were included in the study. The CONUT score is calculated using the following formula: serum albumin score + total cholesterol score + total lymphocyte count score. CONUT scores of T2DM patients and healthy controls, as well as those of diabetics with and without microvascular complications, were compared.

RESULTS

The CONUT scores of the T2DM and control groups were (1 [0-7]) and (0 [0-2]), respectively (p < 0.001). The sensitivity and specificity of the CONUT score (<1.5 threshold) in detecting T2DM were 43% and 90%, respectively (AUC: 0.67, p < 0.001, 95% CI: 0.64-0.71). Moreover, the CONUT score was an independent risk factor for T2DM (OR: 0.34, p < 0.001, 95% CI: 0.22-0.52). The CONUT score of T2DM patients with microvascular complications (2 [0-7]) was significantly higher than that of T2DM patients without microvascular complications (0 [0-4]) and control subjects (0 [0-2]) (p < 0.001). A CONUT score higher than 1.5 had 83% sensitivity and 92% specificity in detecting T2DM with microvascular complications (AUC: 0.91, p < 0.001, 95% CI: 0.89-0.93).

CONCLUSION

The CONUT score could be useful in detecting diabetic microvascular complications in clinical practice, as it is an inexpensive and easy-to-assess marker.

Determination of serum and gingival crevicular fluid levels of omentin in healthy and rheumatoid arthritis subjects with and without periodontitis

OBJECTIVE

The aim of this study was to assess and correlate the serum and GCF levels of omentin with the periodontal status of rheumatoid arthritis (RA) patients with and without periodontitis.

METHODS

Forty-four patients were divided into four groups: group H: 11 systemically and periodontally healthy subjects; group P: 11 systemically healthy subjects with periodontitis; group RA: 11 periodontally healthy subjects with rheumatoid arthritis and group RA + P: 11 rheumatoid arthritis subjects with periodontitis. Periodontal parameters (plaque index, modified gingival index, probing depth, and clinical attachment level) were recorded and serum and GCF samples were collected for the estimation of omentin using ELISA.

RESULTS

The mean value of plaque index, modified gingival index, probing depth, and clinical attachment level were significantly higher whereas serum and GCF omentin levels were found to be decreased in group IV when compared to the other groups. The significant correlation was found between the serum and GCF omentin levels with all the periodontal parameters.

CONCLUSION

The omentin level in serum and GCF was found to be lower in RA patients with periodontitis. It is also inversely correlated with the periodontal parameters. Thus, omentin can serve as a significant diagnostic and therapeutic tool in both periodontal and rheumatoid disease.

Omentin-1 drives cardiomyocyte cell cycle arrest and metabolic maturation by interacting with BMP7

Mammalian cardiomyocytes (CMs) undergo maturation during postnatal heart development to meet the increased demands of growth. Here, we found that omentin-1, an adipokine, facilitates CM cell cycle arrest and metabolic maturation. Deletion of omentin-1 causes mouse heart enlargement and dysfunction in adulthood and CM maturation retardation in juveniles, including delayed cell cycle arrest and reduced fatty acid oxidation. Through RNA sequencing, molecular docking analysis, and proximity ligation assays, we found that omentin-1 regulates CM maturation by interacting directly with bone morphogenetic protein 7 (BMP7). Omentin-1 prevents BMP7 from binding to activin type II receptor B (ActRIIB), subsequently decreasing the downstream pathways mothers against DPP homolog 1 (SMAD1)/Yes-associated protein (YAP) and p38 mitogen-activated protein kinase (p38 MAPK). In addition, omentin-1 is required and sufficient for the maturation of human embryonic stem cell-derived CMs. Together, our findings reveal that omentin-1 is a pro-maturation factor for CMs that is essential for postnatal heart development and cardiac function maintenance.

Evaluation of serum adipokines (omentin-1 and visfatin) in coronary artery disease at a North Indian hospital

Objective. Adipose tissue is considered to be an endocrine organ that secretes bioactive substances known as adipokines that contribute to the pathophysiology of metabolic and coronary diseases related to obesity. In this study, various novel biomarkers, such as inflammatory markers that are pro-inflammatory (visfatin) and anti-inflammatory (omentin-1), as prognostic indicators for people with coronary artery disease (CAD) were investigated. Methods. In this study, 30 diabetic patients with CAD, 30 diabetic patients without CAD, and 30 healthy control counterparts were included. Serum omentin and visfatin concentrations were evaluated by solid-phase enzyme linked immunosorbent assay (ELISA) kit. Patients with established diagnosis of CAD based on angiography, ECG, and elevated cardiac marker level were included into the study. Patients with cardioembolic stroke, cerebral venous sinus thrombosis, CNS vasculitis, and hemorrhage due to trauma, tumor, vascular malformation, and coagulopathy were excluded. Results. The serum omentin-1 levels were significantly higher in the healthy controls in comparison with the diabetic group (p<0.0001) and serum visfatin levels were significantly higher in the diabetic group in comparison with the healthy controls (p<0.0001). The serum omentin levels were significantly higher in the diabetic group in comparison with the cardio-diabetic group (p<0.0001) and serum visfatin levels were significantly higher in the cardio-diabetic group in comparison with the diabetic group (p<0.0001). The serum omentin-1 showed negative correlation with the serum visfatin in the cardio-diabetic group. Conclusion. The adipokines, such as omentin and visfatin, may be good therapeutic candidates in preventing or ameliorating CAD.

The immune system's role in PCOS

Polycystic ovary syndrome (PCOS) is a common disorder of the endocrine system. Its main manifestations include oligo-ovulation, hyperandrogenism, and polycystic ovary morphology (PCOM), affecting women of childbearing age. Although the exact pathogenesis of this disease is still unknown, many factors, including genetic, endocrine, and metabolism disorders, play critical roles in its development. The immunopathogenesis of PCOS has not yet been studied in-depth, but it is hypothesized that immune system abnormalities may play a key role in it. Recent research has shown inflammation's effect on ovulation and ovarian follicular dynamics. Thus, it is suggested that there is a close association between PCOS and low-grade chronic systemic inflammation. As a result, chronic low-grade inflammation is identified as a significant factor in the pathogenesis and development of PCOS, which in turn leads to infertility. As a result, this article reviews PCOS immunopathology, evaluates long-standing hypotheses about the immune system's role in PCOS, and assesses the association between inflammatory factors and PCOS.

Effects of High-Intensity Interval Training on Selected Adipokines and Cardiometabolic Risk Markers in Normal-Weight and Overweight/Obese Young Males-A Pre-Post Test Trial

The study aimed to assess effects of high-intensity interval training (HIIT) on plasma adipokines and cardiometabolic markers in normal and excess weight youth. Eighteen healthy young males (18.2 ± 1.06 yrs.) were divided in normal-weight group (NWG; body mass index (BMI), 20.5 ± 1.51 kg/m2; n = 9) and excess-weight group (EWG; BMI, 30.8 ± 4.56 kg/m2; n = 9). Participants performed an eight-week HIIT program without caloric restriction. Body composition, plasma leptin, adiponectin, chemerin, omentin-1, lipids, C-reactive protein (CRP), and the homeostasis model assessment index for insulin resistance (HOMA-IR) were assessed before and after the HIIT program. The program resulted in significant increases in omentin levels (p < 0.01) in EWG (27%) and NWG (22%), but no changes in leptin, adiponectin, and chemerin in both groups. BMI (−1.62%; p = 0.015), body fat (−1.59%; p = 0.021), total cholesterol (−11.8%; p = 0.026), triglycerides (−21.3%; p = 0.023), and HOMA-IR (−31.5%; p = 0.043) decreased in EWG only. Repeated measures detected significant interaction “Time x Group” for body mass and BMI only. Eight-week HIIT program improved body composition, lipid profile, and insulin sensitivity in excess-weight individuals. It resulted in an increase in omentin levels in both normal- and excess-weight groups, but no changes in leptin, adiponectin, and chemerin. Body composition has not influenced the response of the four adipokines to HIIT.

Correlation of Serum Vaspin, Omentin-1, and adiponectin with metabolic phenotypes in Type-2 diabetes mellitus patients

Objectives:

To investigate adipocytokines’ (vaspin, omentin-1, and adiponectin) correlation with metabolic phenotypes in type 2 diabetes mellitus (T2DM) patients.

Methods:

This case-control research was done at the Diabetic Clinic in Jeddah, Kingdom of Saudi Arabia (KSA), from November 2018 to March 2019. Seventy-five T2DM patients and 75 gender, age, and BMI-matched healthy subjects were recruited for this research.

Results:

In DM patients, the concentrations of serum vaspin and omentin-1 were substantially lower (p<0.001) than in the control group. A significant positive relationship between vaspin concentration and DBP (p<0.001), BMI (p<0.001), and waist circumference (p<0.001) was found in patients and control subjects, while FPG (p<0.016), serum insulin (p<0.001), HOMA-IR (p<0.001), TC (p<0.001), TG (p<0.001), and LDLc (p<0.001) were significantly interrelated among patients. Serum concentrations of omentin-1 and ADN were significantly negatively correlated with serum insulin, HOMA-IR, and TG among the DM group. Serum vaspin and ADN levels were significantly higher in the cases and control groups with BMI>25, and no gender-wise variance was observed in adipocytokines levels. Binary logistic regression analysis showed a significantly negative predictive relationship of vaspin and omentin-1 with DM.

Conclusion:

The DM group displayed substantially lower serum vaspin and omentin-1 levels. However, there was no consistent relationship observed between these adipocytokines and metabolic phenotypes.

The Role of Anti-Inflammatory Adipokines in Cardiometabolic Disorders: Moving beyond Adiponectin

The global burden of obesity has multiplied owing to its rapidly growing prevalence and obesity-related morbidity and mortality. In addition to the classic role of depositing extra energy, adipose tissue actively interferes with the metabolic balance by means of secreting bioactive compounds called adipokines. While most adipokines give rise to inflammatory conditions, the others with anti-inflammatory properties have been the novel focus of attention for the amelioration of cardiometabolic complications. This review compiles the current evidence on the roles of anti-inflammatory adipokines, namely, adiponectin, vaspin, the C1q/TNF-related protein (CTRP) family, secreted frizzled-related protein 5 (SFRP5), and omentin-1 on cardiometabolic health. Further investigations on the mechanism of action and prospective human trials may pave the way to their clinical application as innovative biomarkers and therapeutic targets for cardiovascular and metabolic disorders.

Relationship between circulating serum omentin-1 levels and nascent metabolic syndrome in patients with hypertension

The prevalence of metabolic syndrome (MetS) is more common in patients with hypertension and is associated with an increased risk of target organ damage and/or cardiovascular disease (CVD). Omentin-1 is a beneficial adipokine considered to play a role in MetS and MetS-related states such as obesity, diabetes, and coronary artery disease. The aim of this study was to determine the relationship between circulating omentin-1 levels and MetS uncomplicated by diabetes or CVD (nascent MetS) in patients with hypertension. In this study, 110 patients (54 men, 49%; average age: 49.72±11.32 years) treated for hypertension but without overt diabetes and/or CVD were enrolled. 66 patients were stratified into MetS (+) (group 1) and 44 patients into MetS (-) (group 2) according to the American Heart Association/National Heart, Lung, and Blood Institute criteria. The triglyceride glucose (TyG) index was used to assess insulin resistance. Circulating omentin-1 levels in venous blood samples were measured by an ELISA kit. Circulating omentin-1 levels in patients with MetS were significantly lower than in patients without MetS (46.35 ng/mL (42.70-57.70 ng/mL) vs 130.95 ng/mL (62.83-236.48 ng/mL), p<0.001). Omentin-1 was inversely correlated with TyG index (r=-0.204, p=0.033). In a multivariate logistic regression analysis, omentin-1, TyG index, and body mass index were independent predictors of MetS. A receiver operating characteristic curve analysis determined that the best cut-off value for omentin-1 in predicting MetS was 62.20 ng/mL and the area under the curve was 0.880 (95% CI 0.817 to 0.942, p<0.001). The findings of this study suggest that circulating omentin-1 levels are inversely related to the presence of MetS and may be a reliable marker to predict the development of MetS in patients with hypertension.

Omentin-1: a biomarker in large artery ischaemic stroke patients

Background

Omentin-1 is a novel adipocytokine that is related to atherosclerosis-based ischaemic cardiovascular disease and stroke. Previous studies have linked its lower levels with poor stroke outcomes. We aimed to assess the level of serum omentin-1 as a prognostic marker in patients with large artery ischaemic stroke.

Methods

Fifty ischaemic stroke patients suffering large artery ischaemic stroke and another 50 subjects without a prior history of strokes were recruited. All participants were subjected to neurological examinations, echocardiography and laboratory investigations including a lipid profile and HBA1c. Carotid intima-media thickness (IMT) was measured for all participants. Stroke patients were evaluated by the National Institute of Health Stroke Scale (NIHSS) and the modified Rankin Scale (mRS). Infarction volume was measured by magnetic resonance image (MRI) and serum level of omentin-1 was gauged for all participants.

Results

Carotid IMT significantly increased in stroke patients compared to control subjects. While serum omentin-1 levels were higher in control non-diabetic subjects, they were lower in diabetic patients with ischaemic stroke. Serum omentin-1 levels were inversely correlated with NIHSS, carotid IMT, infarction volume and mRS scores in all stroke patients. Serum omentin-1 level less than 24.5 ng/ml showed 93.7%sensitivity and 44.4% specificity in prediction of poor stroke outcome while values less than 27.8 ng/ml in non-diabetic stroke patients had sensitivity and specificity with 87.5% and 55.6% respectively.

Conclusion

Lower levels of serum omentin-1 are associated with increased ischaemic stroke severity and poor functional outcome.

Metabolic syndrome and hidradenitis suppurativa: epidemiological, molecular, and therapeutic aspects

Hidradenitis suppurativa (HS) is a chronic, suppurative condition of the pilosebaceous unit. Patients suffering from HS demonstrate a molecular profile in keeping with a state of systemic inflammation and are often found to fit the criteria for a diagnosis of metabolic syndrome (MetS). In this paper, we review the literature with regards to established data on the prevalence of MetS in HS patients and revise the odds ratio of comorbid disease. Furthermore, we attempt to draw parallels between inflammatory pathways in HS and MetS and evaluate how convergences may explain the risk of comorbid disease, necessitating the need for multidisciplinary care.

Relationships between serum omentin-1 concentration, body composition and physical activity levels in older women

This study aimed to investigate the relationships between omentin-1, body composition and physical activity (PA) levels in older women.Eighty-one older women (age = 64 ± 6years; body mass index = 24.2 ± 3.2 kg/m2; body fat percentage = 36.1 ± 5.7%) participated in this study. We divided the subjects into overweight/obesity and normal weight group. Body composition was measured by dual energy X-ray absorptiometry. Serum omentin-1 concentration was measured using enzyme linked immunosorbent assay. PA levels were obtained by using accelerometers. In addition, anthropometric and insulin resistance values were determined.Omentin-1 level in overweight/obesity group was significantly lower than in the normal weight group (P < .01). Analysis of all subjects showed that serum omentin-1 was negatively correlated with body weight, BMI (body mass index), waist circumference (WC), WHR (waist-to-hip ratio), percentage of body fat, total body fat mass (FM), fat-free mass (FFM) (r = -.571, -0.569, -0.546, -0.382, -0.394, -0.484, -0.524, all P < .01), respectively. We also found a negative correlation between moderate-to-vigorous physical activity (MVPA) and total body FM (r = -.233, P < .05). However, no significant correlation was found between omentin-1 and sedentary behavior and MVPA (both P > .05). Moreover, the relationship between omentin-1, body composition and PA was analyzed by using multiple linear stepwise regressions. The results showed that serum omentin-1 concentration was inversely correlated with total body FM (β = -0.334, P = .004) in multiple linear stepwise regression analysis.We found that total body FM was inversely related to serum omentin-1 concentration and PA levels, but there was no correlation between omentin-1 and PA levels. These results showed that PA may participate in the regulation of body composition, which may be also affected by serum omentin-1. However, the mechanism by which PA affects body composition may not be through omentin-1 and was more likely through other metabolic pathways.

Omentin-1: Protective impact on ischemic stroke via ameliorating atherosclerosis

Omentin-1, a newly identified adipokine, has recently been revealed as a novel biomarker for ischemic stroke (IS). Low circulating omentin-1 levels could indicate a high risk of IS, and elevated omentin-1 levels exert a favorable impact on cerebral ischemia. Furthermore, omentin-1 has anti-atherosclerotic, anti-inflammatory, and cardiovascular protective capabilities through the intracellular Akt/AMP-activated protein kinase (AMPK)/ nuclear factor-κB (NF-κB) and certain protein kinase (ERK, JNK, and p38) signaling pathways. Omentin-1 also alleviates endothelial cell dysfunction, improves revascularization via the Akt-endothelial nitric-oxide synthase (eNOS) regulatory axis, promotes endothelium-dependent vasodilation through endothelium-derived NO in an eNOS fashion, and inhibits VSMC proliferation by means of AMPK/ERK signaling pathways, VSMC migration via inactivation of the NADPH oxidase (NOX)/ROS/p38/HSP27 pathways and artery calcification via the PI3K-Akt pathway. These findings indicate that omentin-1 may be a negative mediator of IS. Pharmacologically, several lines of clinical evidence indicate that metformin and statins could elevate omentin-1 levels, although the specific mechanism has not been precisely delineated until now. This study is the first to summarize the comprehensive mechanisms between omentin-1 and atherosclerosis and to review the shielding effect of omentin-1 on IS. We shed light on omentin-1 as a novel therapeutic target for combating IS.

The association between serum omentin level and bodyweight: A systematic review and meta-analysis of observational studies

BACKGROUND AND AIMS

A number of studies have examined the association between omentin and body weight, but the findings have been inconclusive. Here in, we systematically reviewed available observational studies to elucidate the overall relationship between omentin and body weight, by comparison of serum omentin level in overweight/obese and normal weight subjects.

METHODS

PubMed, Science direct, Scopus and ISI web of science databases were searched for all available literature until January 2020 for studies assessing the association between omentin and body weight. The Newcastle-Ottawa Quality Assessment Scale was used to assess the quality of each study.

RESULTS

A total of 27 articles met the inclusion criteria and were included in our systematic review and meta-analysis. There was a significant association between omentin serum level and body weight (Standard Mean Difference (SMD) -0.43; 95% CI, -0.70 to -0.15; P = 0.002; I² = 93.2%). In order to find the probable source of heterogeneity subgroup analysis based on the participants' age (adolescent, adult), gender (male, female, both gender), health status (healthy, unhealthy), geographical location (Asian, non-Asian countries), study quality (low, medium, high), study design (case-control, cross-sectional), participants' health status (healthy, unhealthy) and BMI (obese, overweight) was carried out.

CONCLUSION

According to what was discussed, we found that serum omentin level is significantly lower in overweight subjects but not obese ones. This finding should be interpreted cautiously because of significant heterogeneity among included studies.

Omentin: a biomarker of cardiovascular risk in individuals with axial spondyloarthritis

Cardiovascular (CV) disease is the main cause of mortality in axial spondyloarthritis (axSpA). CV risk is enhanced by dysregulation of adipokines. Low omentin levels were associated with metabolic dysfunction and CV disease in conditions different from axSpA. Accordingly, we evaluated the genetic and functional implication of omentin in CV risk and subclinical atherosclerosis in a cohort of 385 axSpA patients. Subclinical atherosclerosis was evaluated by carotid ultrasound. Omentin rs12409609, in linkage disequilibrium with a polymorphism associated with CV risk, was genotyped in 385 patients and 84 controls. Serum omentin levels were also determined. omentin mRNA expression was assessed in a subgroup of individuals. Serum and mRNA omentin levels were lower in axSpA compared to controls. Low serum omentin levels were related to male sex, obesity, inflammatory bowel disease (IBD) and high atherogenic index. rs12409609 minor allele was associated with low omentin mRNA expression in axSpA. No association was observed with subclinical atherosclerosis at the genetic or functional level. In conclusion, in our study low omentin serum levels were associated with CV risk factors in axSpA. Furthermore, rs12409609 minor allele may be downregulating the expression of omentin. These data support a role of omentin as a CV risk biomarker in axSpA.

Association of serum omentin concentration with anthropometric, physiological, and biochemical parameters in obese individuals

OBJECTIVE

Omentin is a secretory protein produced in visceral adipose tissue. The potential protective action of omentin in metabolic disorders is not yet fully understood. The aim of this study was to determine the association of omentin with anthropometric, physiologic, and biochemical parameters in obese individuals.

METHODS

Sixty obese individuals and 40 normal weight controls were enrolled in the study. Anthropometric measurements were taken, systolic (SBP) and diastolic blood pressures (DBP) were recorded. Serum fasting glucose, insulin, homeostatic model assessment of insulin resistance (HOMA-IR), lipid profile, and serum omentin concentrations were determined.

RESULTS

The concentration of omentin in obese individuals was significantly lower than in controls (145.5 ± 33.3 versus 383.6 ± 92.9; P < 0.001). Omentin correlated negatively with waist circumference (P < 0.01), hip circumference (P < 0.05), percent of adipose tissue (P < 0.001), fasting insulin (P < 0.001), HOMA-IR (P < 0.001), and SBP (P < 0.001) in the patients who were obese. A positive relationship was documented with high-density lipoprotein in both the obese patients (P < 0.01) and the overall population (P < 0.001). Multiple negative omentin correlations with body weight, body mass index, waist and hip circumference and its ratio, percent of adipose tissue, SBP, triacylglycerols, glucose, fasting insulin, and HOMA-IR were demonstrated in the entire population. In the multivariate linear regression model, insulin concentration (β = -0.49; P < 0.001), percent of adipose tissue (β = -0.31; P < 0.001), and waist circumference (β = -0.21; P < 0.01) were independent predictors of omentin concentration in individuals who were obese.

CONCLUSIONS

A concentration of omentin is associated with cardiometabolic risk-related factors in obesity. Fasting insulin, adipose tissue percentage, and waist circumference can be considered candidates for markers of omentin concentration in obese individuals.

Serum omentin-1 level in patients with benign prostatic hyperplasia

Backgroud

To evaluate the relationship between omentin-1 and benign prostatic hyperplasia (BPH). BPH is the most common urological disease in elderly men worldwide. Lower serum omentin-1 levels were reported to be negatively associated with the incidence of inflammation, diabetes, obesity and metabolic syndrome, which all play a role in the development of BPH. To the best of our knowledge, the relationship between omentin-1 and BPH has not been investigated previously.

Methods

A total of 70 males participated in this study, including forty patients diagnosed with BPH and thirty healthy males. The anthropometric measurements and the biochemical parameters were measured in this study. We evaluated serum omentin-1 levels and the correlation with those data. We also test the gene expression of IL-8, IL-18 in BPH group using the TURP tissues.

Results

The serum omentin-1 levels were lower in the BPH patients than in the control group (27.95 ± 4.18 versus 32.03 ± 5.46, p < 0.001). The general characteristics and biochemical parameters were investigated, and a negative correlation was found between serum omentin-1 levels and BMI in the BPH group (r = − 0.391, p = 0.013) as well as the whole group (r = − 0.457, p < 0.001). Multiple-factor binary regression analysis revealed that serum omentin-1was a protective factor of BPH development. Furthermore, lower serum omentin-1 levels were associated with higher mRNA expression of IL-8 or IL-18 in the BPH group.

Conclusion

Omentin-1 may suppress the development of BPH and Lower serum omentin-1 levels in BPH patients might associated with higher prostate volume and higher IL-8 and IL-18 expression levels in their prostatic cells.

Higher circulating omentin is associated with increased risk of primary cardiovascular events in individuals with diabetes

AIMS/HYPOTHESIS

Higher concentrations of the adipokine omentin are associated with lower levels of cardiometabolic risk factors in experimental and cross-sectional studies, but with higher risk of type 2 diabetes and cardiovascular diseases in population-based cohort studies. However, it is unknown whether high omentin concentrations are associated with increased risk of cardiovascular events in people with established diabetes. Therefore, the present study investigated the association between serum omentin concentrations and the risk of cardiovascular events in individuals with diabetes.

METHODS

This prospective study was based on participants of the German ESTHER cohort with diabetes and without previous cardiovascular event. The ESTHER cohort consists of individuals aged 50-75 years at baseline who were recruited by their general practitioners. After exclusion of individuals with serum C-reactive protein ≥10 mg/l (≥95.24 nmol/l), the final analysis population consisted of 933 individuals. At baseline, serum omentin concentrations were measured by ELISA. Cox regression models were fitted to estimate HRs and their corresponding 95% CIs for associations of omentin tertiles with a composite endpoint of cardiovascular events and separately with incident myocardial infarction, stroke and cardiovascular death.

RESULTS

During 14 years of follow-up, 228 individuals experienced a primary cardiovascular event (myocardial infarction, stroke or cardiovascular death). After comprehensive adjustment for age, sex, BMI, metabolic and lifestyle factors and medication use, HRs (95% CIs) for the 2nd and 3rd tertile of omentin compared with the 1st tertile were: 1.24 (95% CI 0.86, 1.79) and 1.63 (1.15, 2.32) (p_trend = 0.005) for the composite cardiovascular endpoint; 1.39 (0.78, 2.47) and 1.71 (0.98, 2.99) (p_trend = 0.065) for incident myocardial infarction; 1.40 (0.78, 2.53) and 2.05 (1.17, 3.58) (p_trend = 0.010) for incident stroke; and 1.43 (0.85, 2.40) and 1.72 (1.04, 2.83) (p_trend = 0.040) for cardiovascular death. Effect estimates and p values were almost unaltered after additional adjustment for adiponectin.

CONCLUSIONS/INTERPRETATION

Higher omentin concentrations are associated with an increased risk for cardiovascular events in individuals with diabetes after adjustment for multiple cardiovascular risk factors. Given data from preclinical studies, it appears possible that this association reflects a compensatory, but insufficient upregulation of omentin concentrations as a response to stimuli that increase cardiovascular risk.

Increased Release of Proinflammatory Proteins in Primary Human Adipocytes and Activation of the Inflammatory NFĸB, p38, and ERK Pathways upon Omentin Treatment

OBJECTIVES

To investigate the impact of omentin on the release of inflammation-related biomarkers and inflammatory pathways in primary human adipocytes.

METHODS

Adipocytes were treated with or without omentin (500 and 2,000 ng/mL), and the supernatants were analyzed for inflammation-related biomarkers using proximity extension assay technology. Potential upstream regulators of the omentin-stimulated proteins were identified using Ingenuity Pathway Analysis. Protein levels of components of inflammatory pathways were measured using Western blotting.

RESULTS

2,000 ng/mL omentin induced the release of 30 biomarkers 97.1 ± 31.1-fold in the supernatants (all p < 0.05). Most biomarkers were proin-flammatory chemokines and cytokines. We identified the transcription factor nuclear factor "kappa-light-chain-enhancer" of activated B cells (NFĸB) and the kinases p38 and extracellular signal-regulated kinase (ERK)1/2 as potential upstream regulators in silico. On the cellular level, treatment with 2,000 ng/mL omentin for 24 h enhanced the phosphorylation levels of NFĸB 2.1 ± 0.3-fold (p < 0.05), of p38 2.6 ± 0.4-fold (p < 0.05), and of ERK1/2 1.8 ± 0.2-fold (p < 0.05).

CONCLUSIONS

These data argue that omentin exerts proinflammatory effects through the activation of the inflammatory NFĸB, p38, and ERK1/2 pathways in cultured primary adipocytes.

New Insights into Adipokines as Potential Biomarkers for Type-2 Diabetes Mellitus

A large number of studies have been focused on investigating serum biomarkers associated with risk or diagnosis of type-2 diabetes mellitus. In the last decade, promising studies have shown that circulating levels of adipokines could be used as a relevant biomarker for diabetes mellitus progression as well as therapeutic future targets. Here, we discuss the possible use of recently described adipokines, including apelin, omentin-1, resistin, FGF-21, neuregulin-4 and visfatin, as early biomarkers for diabetes. In addition, we also include recent findings of other well known adipokines such as leptin and adiponectin. In conclusion, further studies are needed to clarify the pathophysiological significance and clinical value of these biological factors as potential biomarkers in type-2 diabetes and related dysfunctions.

The association between omentin and diabetes: a systematic review and meta-analysis of observational studies

AIMS

A number of studies have examined the association between the serum levels of omentin and diabetes, but the findings have been inconclusive. Herein, we systematically reviewed available observational studies to elucidate the overall relationship between omentin and diabetes, including type 1 diabetes mellitus (T1DM), type 2 diabetes mellitus (T2DM), and impaired glucose tolerance (IGT) among adolescent and adult population.

METHODS

PubMed, Cochrane's Library, Science Direct, Scopus, Google Scholar, and ISI Web of Science databases were searched for all available literature until January 2019 for studies assessing the association between omentin and diabetes. The Newcastle-Ottawa Quality Assessment Scale was used to assess the quality of each study.

RESULTS

A total of 28 articles met the inclusion criteria and were included in our systematic review and meta-analysis. There was a significant association between serum omentin and diabetes (WMD-1.68; 95% CI, -2.17 to -1.19; P<0.001). The result of our sub-group analysis based on participants' health status revealed that omentin was significantly lower in T2DM and IGT subjects but not in T1DM ones compared to healthy controls.

CONCLUSION

We found that serum omentin level is significantly lower in T2DM and IGT patients but not in T1DM ones. These data could be used by clinicians for early diagnosis and management of diabetes. Furthermore, we need more clinical trials to investigate new agents which could influence omentin levels.

Association between plasma omentin-1 levels in type 2 diabetic patients and peripheral artery disease

Background

Type-2 diabetes mellitus is one of the major risk factors of atherosclerosis, particularly in peripheral artery disease (PAD). Several studies have documented a correlation between omentin-1 serum levels, atherosclerosis, and cardiovascular diseases. However, a clear link between circulating omentin-1 and PAD in diabetic patients has yet to be established. The aim of this study was to investigate the potential role of omentin-1 in PAD in type-2 diabetic patients.

Methods

In this cross-sectional study, we analyzed omentin-1 serum levels by ELISA in 600 type-2 diabetic patients with (n = 300) and without (n = 300) PAD at Fontaine’s stage II, III, or IV.

Results

We found that omentin-1 serum levels were significantly lower in diabetic patients with PAD than in diabetic controls (29.46 vs 49.24 ng/mL, P < 0.001) and that the levels gradually decreased in proportion to disease severity (P < 0.05). The association between omentin-1 levels and PAD remained significant after adjusting for major risk factors in a multivariate analysis.

Conclusions

Our results suggest that omentin-1 is reduced in type 2 diabetic patients with PAD and that omentin-1 levels are related to disease severity.

Adiponectin, Omentin, Ghrelin, and Visfatin Levels in Obese Patients with Severe Obstructive Sleep Apnea

Objectives

Obstructive sleep apnea (OSA) is closely associated with obesity, insulin resistance, and inflammation. Adiponectin, omentin, ghrelin, and visfatin are adipokines involved in insulin sensitivity or regulation of inflammatory disease. This study aims to clarify the relationship between OSA and associated adipokines.

Patients and Methods

Thirty overweight male patients with severe OSA and twenty controls underwent standard diagnostic polysomnography (PSG), and 10 patients underwent overnight continuous positive airway pressure (CPAP) treatment. Blood samples were collected in the morning after PSG or CPAP procedures.

Results

Among the investigated adipokines, only plasma omentin levels of patients with OSA were significantly lower than those of control subjects (442.94 ± 191.89 ng/ml versus 573.52±228.67 ng/ml, p=0.034) and levels did not change after CPAP treatment. In patients with OSA, omentin levels were positively correlated with high-density lipoprotein cholesterol (HDL) levels (r=0.378, p=0.007), adiponectin levels (r=0.709, p<0.001), percentage of sleep at the rapid eye movement (REM) stage (r=0.307, p=0.003), and average and minimum SpO₂ (p=0.041, 0.046, respectively) and negatively with hypersensitive C-reactive protein (hsCRP, r=-0.379, p=0.007) and apnea-hypopnea index (AHI, r=-0.315, p=0.026). However, plasma concentrations of adiponectin, ghrelin, and visfatin in patients with OSA did not significantly differ from those of the control or correlate with sleep parameters and CPAP treatment.

Conclusions

Patients with OSA have decreased omentin levels, which are associated with sleep parameters, including AHI, SpO₂, percentage of REM sleep, hsCRP, HDL, and adiponectin levels.

Independent and opposite associations of serum levels of omentin-1 and adiponectin with increases of glycaemia and incident type 2 diabetes in an older population: KORA F4/FF4 study

OBJECTIVE

Cross-sectional studies found that higher levels of the novel adipokine omentin-1 were associated with higher adiponectin and lower levels of risk factors for type 2 diabetes, but its relevance for incident type 2 diabetes is currently not understood. Therefore this study investigated whether serum omentin-1 was associated with changes in glycaemia and incident type 2 diabetes independently of adiponectin.

DESIGN AND METHODS

The study was based on participants aged 62-81 years from the population-based Cooperative Health Research in the Region of Augsburg (KORA) F4/FF4 cohort. Associations of baseline serum levels of omentin-1 and adiponectin with changes in glycaemia were assessed in 471 non-diabetic participants, and associations between both adipokines and incident type 2 diabetes were assessed in 76 cases and 430 non-cases (follow-up time 6.5 years). Multivariable linear and logistic regression models were adjusted for multiple potential confounders.

RESULTS

Higher serum levels of omentin-1 were associated with increases in fasting glucose, 2-h glucose and HbA1c (all P < 0.001) and with incident type 2 diabetes (adjusted odds ratio (OR) (95% CI): 1.40 (1.03; 1.90) per s.d. of log₂-transformed omentin-1; P = 0.032). These associations were independent from adiponectin levels, which showed associations with changes in glycaemia and risk of type 2 diabetes in the opposite direction. We found no statistically significant interactions of omentin-1 with adiponectin or sex in the association with incident type 2 diabetes (all P > 0.1).

CONCLUSIONS

Systemic levels of omentin-1 were positively associated with increases in glycaemia and incident type 2 diabetes in this older population. These associations were independent of potential confounders including adiponectin.

Adipose Tissue-Derived Omentin-1 Function and Regulation

Omentin-1, also known as intelectin-1, is a recently identified novel adipocytokine of 313 amino acids, which is expressed in visceral (omental and epicardial) fat as well as mesothelial cells, vascular cells, airway goblet cells, small intestine, colon, ovary, and plasma. The level of omentin-1 expression in (pre)adipocytes is decreased by glucose/insulin and stimulated by fibroblast growth factor-21 and dexamethasone. Several lines of experimental evidence have shown that omentin-1 plays crucial roles in the maintenance of body metabolism and insulin sensitivity, and has anti-inflammatory, anti-atherosclerotic, and cardiovascular protective effects via AMP-activated protein kinase/Akt/nuclear factor-κB/mitogen-activated protein kinase (ERK, JNK, and p38) signaling. Clinical studies have indicated the usage of circulating omentin-1 as a biomarker of obesity, metabolic disorders including insulin resistance, diabetes, and metabolic syndrome, and atherosclerotic cardiovascular diseases. It is also possible to use circulating omentin-1 as a biomarker of bone metabolism, inflammatory diseases, cancers, sleep apnea syndrome, preeclampsia, and polycystic ovary syndrome. Decreased omentin-1 levels are generally associated with these diseases. However, omentin-1 increases to counteract the acute phase after onset of these diseases. These findings indicate that omentin-1 may be a negative risk factor for these diseases, and also act as an acute-phase reactant by its anti-inflammatory and atheroprotective effects. Therapeutic strategies to restore omentin-1 levels may be valuable for the prevention or treatment of these diseases. Weight loss, olive oil-rich diet, aerobic training, and treatment with atorvastatin and antidiabetic drugs (metformin, pioglitazone, and exenatide) are effective means of increasing circulating omentin-1 levels. This review provides insights into the potential use of omentin-1 as a biomarker and therapeutic target for these diseases. © 2017 American Physiological Society. Compr Physiol 7:765-781, 2017.

Serum omentin-1, vaspin, and apelin levels and central obesity in patients with nonalcoholic fatty liver disease

Background:

Omentin-1, vaspin, and apelin are novel adipokines which closely associate with obesity, nonalcoholic fatty liver disease (NAFLD), and inflammation. The aim of this study was to investigate the circulating levels of omentin-1, vaspin, and apelin in NAFLD patients and to clarify their relationship with biochemical parameters, abdominal obesity, and high sensitive C-reactive protein.

Materials and Methods:

In a case–control study, serum levels of omentin-1, vaspin, and apelin were measured in 41 NAFLD patients and 41 healthy volunteers. The study was performed in the outpatients’ clinic of Imam-Ali Hospital in Zahedan, Iran, during February to July 2015. Fatty liver was confirmed by ultrasonography. The association of the adipokines with lipid profile and anthropometric parameters was assessed using multivariable linear regression models. In this model, those variables that showed P < 0.05 were included in the study.

Results:

NAFLD patients presented a significantly higher apelin levels compared to the controls (P < 0.01), whereas serum omentin-1 and vaspin levels did not differ between two groups (both P > 0.05). Multiple regression analysis showed that the serum levels of apelin and vaspin correlated positively with waist circumference (WC) (P < 0.01 and P < 0.05, respectively) and low-density lipoprotein (P < 0.05 and P < 0.01, respectively) while serum omentin-1 was inversely correlated with WC (P < 0.01) and positively corrected with high-density lipoprotein (P < 0.05).

Conclusion:

The findings showed that among the analyzed adipokines only apelin was different in patients with NAFLD when compared to controls. Considering the multivariate regression analysis, apelin seems be more suitable diagnostic marker in predicting of NAFLD and omentin might be considered as a protective factor in occurrence of NAFLD, particularly in those with central obesity.

Effect of High-Intensity Interval Training on Plasma Omentin-1 Concentration in Overweight/Obese and Normal-Weight Youth

OBJECTIVES

Omentin-1 is a recently discovered adipokine, mainly produced by visceral adipose tissue, which is thought to improve insulin sensitivity. The study aimed to assess the association of plasma omentin-1 with cardiometabolic traits and physical performance and to test its response to high-intensity interval training (HIIT) in obese and normal-weight subjects.

METHODS

Nine overweight/obese (OG) and 9 normal-weight (NWG) young men performed an 8-week HIIT program. Body composition, physical performance, homeostasis model assessment index for insulin resistance (HOMA-IR) as well as plasma omentin-1and lipid levels were assessed before and after the HIIT program.

RESULTS

Baseline plasma omentin-1 was lower in OG than NWG men (359 ± 138 vs. 470 ± 114 ng/ml; p = 0.052). Plasma omentin-1 was related to body fat (r = -0.57; p = 0.03) and LDL-cholesterol (r = -0.49; p = 0.04). There was a trend towards significant association of omentin-1 with BMI (r = -0.47; p = 0.06) and VO2max (r = 0.41; p = 0.09). However, no association was observed with HOMA-IR. Following the HIIT program, omentin-1 concentrations have significantly (p < 0.01) increased in OG (359 ± 138 to 455 ± 126 ng/ml) and NWG men (470 ± 114 to 572 ± 115 ng/ml). In parallel, the cardiometabolic profile has improved with a significant decrease of HOMA-IR in OG.

CONCLUSIONS

HIIT resulted in a plasma omentin-1 increase and an improvement with regard to cardiometabolic traits in the OG men, which may contribute to modulate insulin sensitivity.

Association of circulating adipokines with metabolic dyslipidemia in obese versus non-obese individuals

AIM

Previous studies have shown that circulating adipokines may play an important role in the pathogenesis of some obesity related chronic disease such as dyslipidemia and type2 diabetes mellitus. The aim of the present study was to investigate the association between vaspin, omentin-1 and retinol binding protein-4 levels with metabolic dyslipidemia (MD) criteria in obese and non-obese individuals.

METHOD

The study was conducted on 170 obese and 81 non-obese individuals. After collecting the blood samples, serum levels metabolic parameters as well as three circulating adipokines and body composition were measured.

RESULTS

No significant difference was noted regarding the mean serum levels of omentin-1 and vaspin between the obese and non-obese groups, while, serum level of RBP4 was significantly higher in the non-obese group. We found the 0.22 increased risk of MD in obese individuals with higher RBP4 concentration. After the adjustment for confounding factors, this association was still significant. No significant association was noted between MD and its components relative risks with omentin-1 and vaspin levels.

CONCLUSION

Our study demonstrated that circulating RBP4 was significantly higher in the obese individuals which may increase the risk of MD in them. Further researches are needed to address this association.

The protective functions of omentin in cardiovascular diseases

Adipose tissue is considered as a large gland that can produce paracrine and endocrine hormones. Growing evidence suggests that adipocytes may link obesity to cardiovascular diseases (CVD). Adipose tissue produces a large number of mediators, which affect metabolism, inflammation and coagulation. Omentin, a novel adipocytokine, has come into the center of interest due to its favorable effects on inflammation, glucose homeostasis and CVD. The present review provides a concise and general overview on the roles of omentin in CVD. The knowledge of these concepts may provide a new strategy to reduce disease risks on CVD in the future.

Effectiveness and safety of laparoscopic Roux-en-Y gastric bypass in treating type 2 diabetes mellitus

AIM: To explore the effectiveness and safety of laparoscopic Roux-en-Y gastric bypass (LRYGB) for treating type 2 diabetes mellitus (T2DM).

METHODS: Forty patients with T2DM who underwent LRYGB between February 2011 and May 2012 at Tianjin Nankai Hospital were analyzed, and clinical records including preoperative and postoperative body mass index (BMI), fasting plasma glucose (FPG), 2 h plasma glucose (2-h PG) after oral glucose challenge, hemoglobin A1c levels (HbA1c), fasting C-peptide (C-P), blood lipid levels, and prognostic factors were analyzed.

RESULTS: LRYGB procedures were successfully performed in all the 40 patients with no conversion to open surgery. All the patients were followed for 24 months. Two (5.0%) patients developed abdominal distension. After 24 mo, 27 (67.5%) patients showed complete remission, 7 (17.5%) showed partial remission and 6 (15%) showed improvement. The overall effective rate was 100%. The group achieving complete remission had a shorter disease duration (P = 0.002) and higher BMI (P = 0.002) compared with the partial remission and improvement groups.

CONCLUSION: LYRGB is efficient and safe in treating T2DM patients. Early intervention in patients who had a shorter disease duration and higher BMI may yield better outcomes.