Omentin-1 Levels Research Articles

The Role of Adipokines between Genders in the Pathogenesis of Osteoarthritis

Osteoarthritis (OA) is a chronic, progressive, degenerative joint disease characterized by joint pain, stiffness, and limited movement. It presents significant intra- and inter-individual variability—in particular, between genders. Recent research has increasingly focused on the role of adipokines—especially leptin, adiponectin, and resistin—in the development of OA. Adipokines, peptide hormones primarily secreted by adipose tissue, are involved in crucial physiological processes related to metabolism and immunity. They can also impact bone and cartilage turnover by interacting with joint cells such as osteoblasts, osteoclasts, chondrocytes, and mesenchymal stem cells, thereby linking inflammation with bone cartilage homeostasis. This review aims to elucidate the structure and functions of various adipokines, their serum and synovial levels, and their association with clinical presentation and radiographic progression in OA patients, with a focus on differences between sexes. A narrative literature review was conducted using three databases specifically analyzing sex differences. OA patients generally show elevated serum and synovial levels of leptin, chemerin, and visfatin, as well as high plasma levels of resistin and visfatin. In contrast, synovial levels of adiponectin and omentin are reduced in OA patients compared to healthy individuals, with an inverse relationship to disease severity, suggesting a potential protective role. Resistin and leptin were positively correlated with pain severity and radiographic progression, while adiponectin’s role in OA remains controversial. Regarding sex differences, male OA patients exhibited higher serum levels of leptin, chemerin, and omentin compared to healthy controls, with a positive correlation to the BMI and estrogen levels, potentially explaining the sexual dimorphism observed in this condition. Studies on visfatin and lipocalin did not reveal significant differences in synovial or serum levels between the sexes. The role of resistin remains controversial. Adipokines influence the joint microenvironment and contribute to the progression of osteoarthritis (OA). However, the precise biological mechanisms are not yet fully understood due to the complex interactions between the metabolic, mechanical, and immune systems. Further research is needed to clarify their roles in OA and to identify targeted therapies for managing this degenerative disease.

Evaluation of Serum Adipokine Levels in Girls With Central Precocious Puberty.

Adipose tissue has an important endocrine function by secreting a variety of hormones known as adipokines, such as Visfatin, Omentin-1 and Chemerin. On the other hand, these hormones are also secreted from places other than fatty tissues in the girl's genital system. The goal of this study was to demonstrate the secretory status of adipokines in patients with central precocious puberty (CPP) and their utility in the diagnosis of precocious puberty. A total of 105 patients were included in the study (53 in the CPP group and 52 in the control group). The following were used as the CPP diagnostic criteria; breast development, basal LH measurement higher than 0.3 IU/L, peak LH level ≥ 5 IU/L, peak LH/FSH ratio ≥ 0.66 (after 0.1 mg GnRH stimulation test) and a difference of at least 1 year between bone and chronological age. A statistically significant difference was detected between the groups in serum Omentin-1 and Chemerin levels, and no significant differences were detected between the groups in Visfatin values. The cut-off values for the diagnosis of CPP were calculated as ≤ 48.9 with 81% sensitivity and 54% specificity for Omentin-1, and as ≥ 417 with 85% sensitivity and 60% specificity for Chemerin. In our study, we found that Omentin-1 level decreased and Chemerin level increased in lean girls with CPP. More studies are needed to elucidate how adipokines play roles in explaining the onset of CPP, and whether they may be used as a reliable marker for the diagnosis of CPP.

Effects of Febuxostat Therapy on Circulating Adipokine Profiles in Patients with Overweight or Obesity and Asymptomatic Hyperuricemia: A Randomized Controlled Study

Introduction: Elevated levels of serum uric acid (SUA) are strongly associated with several components of the metabolic syndrome, particularly obesity. Previous studies have reported the correlation between SUA levels, xanthine oxidoreductase (XOR) activity, and the imbalanced adipokine levels that are characteristic of obesity. In this study, we explored the effect of febuxostat on circulating adipokine profiles in patients with overweight or obesity and asymptomatic hyperuricemia. Methods: This study was a single-center, randomized, and controlled clinical trial that enrolled 130 participants with asymptomatic hyperuricemia and obesity. One hundred seventeen participants were included in the final analysis, with 60 participants in the febuxostat group and 57 in the control group. We compared the circulating adipokine levels at 3 and 6 months, including high molecular weight (HMW) adiponectin, chemerin, omentin, monocyte chemotactic protein-1, asprosin, fibroblast growth factor 21, neuregulin-4, leptin, resistin, vaspin, visfatin, adipsin, and assessed the correlation between changes in adipokine levels (Δadipokines) and changes in XOR activity (ΔXOR) after febuxostat treatment. Results: The results showed that an increase in HMW adiponectin and omentin levels and a decrease in chemerin and asprosin levels at 3 or 6 months compared to the control group. Additionally, a positive correlation was observed between ΔXOR activity and Δasprosin. Furthermore, after adjusting for triglyceride (ΔTG) and serum uric acid (ΔSUA) in multiple linear regression analyses, we found that ΔXOR activity was independently correlated with Δasprosin. Conclusion: This study may provide important evidence that febuxostat could alleviate the imbalance in circulating adipokine levels in patients with overweight or obesity and asymptomatic hyperuricemia. Furthermore, we observed a positive correlation between changes in asprosin levels and changes in XOR activity after febuxostat treatment.

Level of omentin in chronic inflammatory rheumative diseases

At the moment, a number of studies have been carried out that have proven that omentin has a sensitizing effect on insulin, has anti-inflammatory and anti-atherosclerotic effects. Plasma levels of omentin are known to be significantly reduced in obese patients with insulin resistance. Decreased levels of omentin have also been reported to be associated with inflammatory and autoimmune diseases, including atherosclerosis and psoriasis. The article presents research data that allow to identify changes in the level of omentin in chronic inflammatory rheumatic diseases, as well as to suggest its effect on the risk of development and course of cardiovascular complications.

Assessment of Serum Omentin-1 and Interleukin-6 in the Diagnosis of Early Stages of Diabetic Nephropathy: A Cross-Sectional Observational Study.

Introduction The pathogenesis of diabetic nephropathy highlights the progression of inflammation and fibrosis from tubular to glomerular damage during the early stages of kidney involvement in diabetic individuals. As urine albumin serves as a marker for glomerular function, its detection indicates a stage of diabetic nephropathy where the glomerulus is already compromised. Consequently, relying solely on urine albumin for diagnosis becomes questionable. In our pursuit of identifying innovative biomarkers for the early detection of diabetic nephropathy, this study was crafted to explore the relationship between chemokines, omentin-1, interleukin-6, and microalbuminuria. Materials and methods Our study cohort comprised 116 patients diagnosed with diabetes mellitus. In our study, participants were stratified into two groups based on their urine albumin levels: Group 1, characterized by urine albumin creatinine ratio <30 mg/gm and estimated glomerular filtration rate >90 ml/min, and Group 2, with urine albumin creatinine ratio ≥30 mg/gm and <300 mg/gm, and estimated glomerular filtration rate >60 ml/min and <90 ml/min.Serum creatinine, glycated hemoglobin (HbA1c), fasting blood sugar and post-prandial blood sugar, lipid profile, total protein, albumin, fasting insulin, omentin-1, and interleukin-6 were estimated. Result There was a significant difference in the medians of serum urea, creatinine, omentin-1, interleukin-6, urine albumin creatinine ratio, and estimated glomerular filtration rate levels in the two groups. There was no difference in fasting blood sugar, post-prandial blood sugar,HbA1c, serum lipids, fasting insulin, and homeostatic model assessment for insulin resistance. The receiver operating characteristic curve plotted for the newer biomarkers of diabetic nephropathy showed that there was a significant diagnostic utility in diabetic nephropathy detection of serum omentin (p=0.000), interleukin-6 (p=0.002), and interleukin-6: omentin-1 ratio (p=0.000), which correlated well with the routine test that is urine microalbumin estimation. Risk assessment demonstrated that type 2 diabetes mellitus patients with an interleukin-6: omentin-1 ratio ≥0.26 had significantly higher odds, with an odds ratio of 3.97, for developing diabetic nephropathy, which was statistically significant. Conversely, a ratio of ≤0.26 was associated with kidney protection among patients with type 2 diabetes mellitus. Conclusion Our findings revealed decreased levels of omentin-1 and increased levels of interleukin-6 in the group with diabetic nephropathy compared to those without diabetic nephropathy among patients with type 2 diabetes mellitus. Interleukin-6: omentin-1ratio of ≤0.26 was associated with kidney protection among patients with type 2 diabetes mellitus. Based on the results obtained from this study, we propose that measuring the serum interleukin-6: omentin-1 ratio in patients with type 2 diabetes mellitus may assist in identifying the early stages of diabetic nephropathy before the onset of microalbuminuria. Timely intervention in these patients predisposed to diabetic nephropathy can aid in better treatment outcomes in type 2 diabetes mellitus.

Efficacy of tibial cortex transverse transport in treating diabetic foot ulcer and its effect on serum omentin-1 and irisin levels

ObjectiveDiabetic foot ulcer (DFU) is a common and debilitating complication of diabetes that is associated with an increased risk of lower-limb amputation and a reduced life expectancy. Tibial cortex transverse transport (TTT) has become a newly alternative surgical method to facilitate ulcer healing and prevent lower limb amputation. Herein, we investigated the efficacy of TTT in treating DFU and changes of serum omentin-1 and irisin levels.MethodsThis study prospectively recruited 52 consecutive patients with DFU who were treated with TTT. The follow-up was performed weekly during the first 12 weeks postoperatively and every 3 months until 1 year after TTT. The serum levels of vascular endothelial growth factor (VEGF), omentin-1, and irisin in DFU patients undergoing TTT were determined by ELISA methods on the preoperative 1st day, postoperative 2nd week and 4th week.ResultsThe wound healing rate was 92.3% (48/52) at the 1-year follow-up. The visual analog scale (VAS) pain scores of patients showed a significant reduction at the 4th week after TTT (p < 0.001). The dorsal foot skin temperature, ankle brachial index, and dorsal foot blood flow of patients were significantly increased at the 4th week after TTT (p < 0.001). Results of ELISA methods showed the serum levels of VEGF, omentin-1, and irisin on the 2nd week and 4th week after TTT were notably elevated compared to the levels determined on the preoperative 1st day (p < 0.001). The serum levels of VEGF, omentin-1, and irisin on the 4th week after TTT were also significantly higher than the levels determined on the 2nd week after TTT (p < 0.001).ConclusionTTT could promote the wound healing and reduce the risk of lower limb amputation, demonstrating promising clinical benefits in the treatment of DFU. Increased expressions of serum proangiogenic factors including VEGF, omentin-1, and irisin were noted in the early stage after TTT, which may provide a new mechanism of TTT promoting wound heal.

The contribution of hormonal disorders in the pathogenesis of metabolic-associated steatotic liver disease

The analysis has been performed for the contribution of hormones to the pathogenetic mechanisms of metabolic‑associated steatotic liver disease (MASLD). The role of adipose tissue hormones in the development of metabolic disorders and systemic inflammatory reactions is well investigated and proved. With progression of metabolic‑associated steatohepatitis (MASH), the leptin levels increase, and adiponectin and omentin levels decrease, associating with the proinflammatory and profibrotic state of the liver and impaired glucose metabolism. The liver also produces hormone‑like proteins, hepatokines, which actively affect the extrahepatic regulation of metabolism, namely, contribute to the development of insulin resistance and dyslipidemia. Medications, affecting the endocrinological component of MASLD/MASH pathogenesis, are considered one the of the most promising approaches for the treatment of these diseases. It should be noted that only pioglitazone and glucagon‑like peptide (GLP)‑1 receptor agonists are the two antihyperglycemic drugs with proven efficacy and safety at MASH. Thus, the use of GLP‑1 agonists results in the reduction of food intake, body weight, improvement of glucose control in patients with MASH, they reduce steatosis and insulin resistance, and the level of inflammation in the liver. The data are available indicating the prospect of using dual agonists of GLP‑1/glucagon and GLP‑1 and glucose‑dependent insulinotropic peptide for the treatment of MASLD/MASH. According to preliminary data, such combinations resulted in the decrease in steatosis and improvement in liver fibrosis indicators, though additional proof is required to confirm changes in the histological liver characteristics. Another group of hormones with significant importance in MASLD pathogenesis, are hormones of the adrenal glands (aldosterone, cortisol and androgens), as they take an active part in the regulation of the response to stress and lipolysis. In this aspect, androgens attract special attention, because firstly, both their deficiency and excess will contribute to the development of hepatic steatosis, obesity, insulin resistance and other signs of metabolic syndrome, and secondly, their deficiency will contribute to the development of sarcopenia, which is very important in the aspect of MASLD. A lack of estrogen in women will also contribute to liver steatosis, insulin resistance, dyslipidemia, and obesity. One of the factors affecting the development of liver steatosis can be growth hormone, decrease in its level will contribute to the intrahepatic accumulation of fat, which will increase the risk of MASHP. Thyroid hormones can also play a role in the development of MASLD, the severity of hypothyroidism has a direct correlation with the severity of MASLD, and the levels of thyroid‑stimulating hormone and free thyroxine have an association with liver fibrosis.

Attenuated adiponectin, omentin, increased interleukin-6 and tumor necrosis factor-alpha levels with altered cognition and depression in non-Hodgkin lymphoma patients: A case-control study

Background and purposeImmune dysfunction is one of the risk factors which plays an important role in the development of non-Hodgkin lymphoma (NHL), and inflammation may be involved in its etiology. Minimal data is available on the effect of cytokine levels on neurobehavioral function in lymphoma before the initiation of chemotherapy. Therefore, we aimed to explore the risk of NHL by assessment of cytokine and adipokine levels and their correlation with neurobehavioral changes. MethodsThis case-control study enrolled 62 subjects (age-sex matched: 31 cases and 31 controls). Neurobehavioral assessment was done using Montreal Cognitive Assessment questionnaire (MoCA) and Patient Health Questionnaire (PHQ-9). EORTC Core Quality of Life questionnaire (EORTC QLQ-C30) was used to assess quality of life. Questionnaire assessment and sample collection were done after the patient enrolment and before first cycle of chemotherapy. ResultsMean age of NHL patients and healthy controls was 51.9 ± 11.8 and 50 ± 10.9 years, respectively. NHL patients showed significantly higher levels of IL-6 (0.77 ± 0.11) and TNF- α (1.47 ± 1.31) than controls (0.55 ± 0.4 and 0.66 ± 0.89, respectively) with p-value<0.005. Also, NHL patients showed significantly lower levels of adiponectin (0.31 ± 0.24) and omentin (0.46 ± 0.1) than controls (0.42 ± 0.13 and 0.53 ± 0.11, respectively) with p-value<0.005. Lower MoCA and EORTC QLQ C-30 scores and higher PHQ-9 scores were observed in NHL patients in comparison to healthy control. ConclusionOur results showed that adiponectin, omentin IL-6 and TNF-α may be used as pre-diagnostic markers of NHL risk. Neurobehavioral changes observed in NHL patients may alter the quality of life.

Omentin reduces venous neointimal hyperplasia in arteriovenous fistula through hypoxia-inducible factor-1 alpha inhibition

Arteriovenous fistula (AVF) failure often involves venous neointimal hyperplasia (VNH) driven by elevated hypoxia-inducible factor-1 alpha (HIF-1α) in the venous wall. Omentin, known for its anti-inflammatory and anti-hyperplasia properties, has an uncertain role in early AVF failure. This study investigates omentin's impact on VNH using a chronic renal failure (CRF) rabbit model. The CRF rabbit model of AVF received omentin-expressing adenoviral vector or control β-gal vector to assess omentin's effects on VNH. Human vascular smooth muscle cells (HVSMCs), stimulated with tumor necrosis factor-α (TNF-α), were exposed to recombinant human omentin (Rh-OMT) to study its influence on cell proliferation and migration. The AMP-activated protein kinase (AMPK) inhibitor compound C and the mammalian target of rapamycin (mTOR) activator MHY1485 were employed to explore omentin's mechanisms in VNH reduction through HIF-1α inhibition. Omentin treatment reduced VNH in CRF rabbits, concomitant with HIF-1α down-regulation and the suppression of downstream factors, including vascular endothelial growth factor and matrix metalloproteinases. Rh-OMT inhibited TNF-α-induced HVSMC proliferation and migration by modulating both cell cycle and cell adhesion proteins. Additionally, omentin reduced HIF-1α expression through the AMPK/mTOR pathway activation. Notably, the blockade of AMPK/mTOR signaling reversed omentin-mediated inhibition of VNH, cell proliferation, and migration, both in vivo and in vitro. In conclusion, omentin mitigates VNH post-AVF creation by restraining HIF-1α via AMPK/mTOR signaling. Strategies boosting circulating omentin levels may offer promise in averting AVF failure.

Association of Apelin, Chemerin and Omentin Levels with Oxidative Stress Markers in Non-Diabetic and Induced Diabetic Rats

Abstract &#x0D; Oxidative stress has a significant impact on the etiology of type 1 diabetes mellitus (T1DM). However, associations of adipokines with oxidative stress biomarkers have yet to be investigated. Therefore, the present study aimed to investigate the estimation of serum apelin, chemerin, and omentin levels in induced TIDM and their correlations with oxidative stress markers. The study included sixty male albino rats divided into two groups. The first group (n = 30) was diabetic (TIDM induced with an intraperitoneal injection of 40mg/kg STZ). The non-diabetic control group was the second (n: 30). The enzyme-linked immunosorbent (ELISA) test was used to quantify the serum levels of apelin, chemerin, omentin and asymmetric dimethylarginine (ADMA). Furthermore, blood glucose, lipid profile triglyceride (TG), cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), very low-density lipoprotein (VLDL), liver enzymes (alanine aminotransferase (ALT) and aspartate transaminase (AST)), malondialdehyde (MDA) and nitric oxide (NO) parameters were evaluated. Rats with induced TIDM had significantly higher serum levels of apelin, chemerin, omentin, malondialdehyde MDA, ADMA, and NO compared to non-diabetics. According to the coefficient of correlation analysis, the results revealed a positive association between apelin and LDL, ALT, and MDA and a negative correlation between apelin and AST: ALT. In addition, no correlation was found between apelin and serum levels of glucose, cholesterol, HDL, LDL: HDL TG, TG: HDL, VLDL, AST, creatinine, uric acid, albumin, NO, and ADMA. LDL, ALT, and MDA. Serum chemerin level correlated positively with LD: HDL and ADMA. Also, the plasma level of omentin showed a significant and positive correlation with both TG: HDL and MDA values. In conclusion, the results of this study introduced apelin and chemerin as potential biomarkers for the early detection of diabetes. Elevated serum apelin levels in induced T1DM could provide compensatory action for low insulin levels. While, apelin, chemerin and omentin’s positive correlations with MDA level suggest the potential roles of these adipokines in diabetes-induced complications caused by oxidative stress.

Omentin associates with serum metabolite profiles indicating lower diabetes risk: KORA F4 Study

IntroductionCirculating omentin levels have been positively associated with insulin sensitivity. Although a role for adiponectin in this relationship has been suggested, underlying mechanisms remain elusive. In order to reveal the...

Expression of TNF-α, omentin-1, and IL-6 before and after adjunctive treatment with a bioactive antimicrobial peptide periodontal gel.

The objective of this study was to evaluate and compare the expression levels of TNF-α, omentin-1, and IL-6 in periodontitis patients before and after treatment with biological antimicrobial peptide (AMP) periodontal gel. There involved 86 periodontitis patients admitted to our hospital from January 2020 to March 2021. They were equally and randomly distributed into the study group and the control group. The efficacy and adverse reactions were compared between the two groups after treatment, Additionally, the sulcus bleeding index (SBI), plaque index (PLI), gingival index (GI), periodontal probing depth (PD), and levels of TNF-α, omentin-1, and IL-6 were measured before and after treatment. After treatment, the total effective rate of the study group was significantly higher than that of the control group (p < 0.05), while the scores of four indicators (SBI, PLI, GI, and PD) and the levels of TNF-α, omentin-1, and IL-6 in the study group were evidently lower than the control group (p < 0.05). The study group had 1 case of mild irritant reaction, with an adverse reaction rate of 2.33% (1/43). And the control group had 1 case of nausea and 1 case of allergy, with an adverse reaction rate of 4.65% (2/43). The adverse reactions demonstrated no statistical difference between the two groups (χ2 = 0.345, p = 0.557). The levels of TNF-α and IL-6 were highly expressed before the auxiliary therapy of biological AMP periodontal gel for periodontitis, alongside low expression of omentin-1. Subsequently, the biological antibacterial polypeptide periodontal gel demonstrated efficacy in the treatment of periodontitis.

The Relationship between Omentin Gene (ITLN1) Variant rs190234680 and Serum Omentin levels in patients with Diabetic Foot

Diabetic foot is a common and serious complication of diabetes, characterized by neuropathy, ischemia, and infections which can lead to amputation of the affected limb. Omentin is a protein that is predominantly expressed in adipose tissue and has been implicated in insulin sensitivity and glucose metabolism. Low plasma omentin levels have been associated with several metabolic disorders, including T2DM. Objectives: Study objective were to assess the pattern of omentin-1 [ITLN1] single nucleotide gene polymorphism in diabetic foot patients compared to uncomplicated T2DM. It also sought to compare the serum omentin-1 levels between diabetic foot patients and those with uncomplicated Type 2 diabetes mellitus and determine the association between omentin levels and the clinical staging of diabetic foot patients. Methodology: In this cross-sectional analytical study, 130 participants of DF and T2DM were enrolled. Omentin (ITLN1) gene polymorphism(rs190234680) was determined by sequencing and serum omentin levels were estimated by ELISA. Result: A significant association was observed between the GG genotype (wild type) of the omentin (ITLN1) gene and diabetic foot, while no significant difference was found in serum omentin levels between cases and controls. The analysis did not provide clear evidence of a significant relationship between omentin levels in different grades of diabetic foot Conclusion:The study suggested that the GG genotype of omentin 1 gene may be an important risk factor in development of diabetic foot in patients with type 2 diabetes. However, there was no significant difference in serum omentin levels between different stages of diabetic foot.

The effect of aerobic and resistance training on Omentin-1 and Nesfatin-1 levels in adults: A systematic review and meta -Analysis

The effect of aerobic and resistance training on Omentin-1 and Nesfatin-1 levels in adults: A systematic review and meta -Analysis

Association between serum omentin-1 and mucosal disease activity in patients with ulcerative colitis.

Mucosal inflammation is a key feature of ulcerative colitis (UC), a chronic relapsing and remitting form of inflammatory bowel disease. Omentin-1, a newly discovered adipokine, is reported to have anti-inflammatory effects and has been found to be decreased in patients with inflammatory bowel disease. The aim of our study was to investigate the association between serum omentin-1 levels and mucosal disease activity in patients with UC. A total of 126 patients with UC and 77 healthy volunteers were enrolled in the study. Serum omentin-1 expression levels were measured using enzyme-linked immunosorbent assay to evaluate its potential for monitoring disease activity, including clinical and endoscopic activity. Serum omentin-1 levels were significantly lower in patients with UC compared to healthy controls (HC) (UC, 61.7 interquartile range: 51.5-72.6 versus healthy controls, 103.5 interquartile range: 48.3-156.2ng/ml; P < .001). Furthermore, serum omentin-1 levels were associated with both clinical and endoscopic activity in patients with UC. Notably, omentin-1 levels were significantly lower in patients who achieved mucosal healing. Receiver operating characteristic curves indicated that serum omentin-1 levels could potentially serve as an activity index for evaluating UC. These findings provide further insight into the association between omentin-1 and UC, suggesting that omentin-1 may be a useful biomarker for monitoring mucosal disease activity in patients with UC.

Omentin: A Key Player in Glucose Homeostasis, Atheroprotection, and Anti-Inflammatory Potential for Cardiovascular Health in Obesity and Diabetes.

Omentin is an adipokine mainly produced by visceral fat tissue. It has two isoforms, omentin-1 and omentin-2. Omentin-1 is predominantly secreted by visceral adipose tissue, derived specifically from the stromal vascular fraction cells of white adipose tissue (WAT). Levels of omentin-1 are also expressed in other WAT depots, such as epicardial adipose tissue. Omentin-1 exerts several beneficial effects in glucose homeostasis in obesity and diabetes. In addition, research has suggested that omentin-1 may have atheroprotective (protective against the development of atherosclerosis) and anti-inflammatory effects, potentially contributing to cardiovascular health. This review highlights the potential therapeutic targets of omentin-1 in metabolic disorders.

Оментин-1 и ишемическая болезнь сердца

Aim. The purpose of the review is to summarize the results of studies on the relationship between the level of omentin-1 and coronary artery disease (CAD). Key points. Adipose tissue is currently considered as an endocrine organ synthesizing biologically active factors known as adipocytokines, which may be involved in the pathogenesis of obesity-related metabolic and cardiovascular diseases, in particular, CAD. Omentin-1 is an adipocytokine that is predominantly secreted by visceral adipose tissue and plays an important role in the development of chronic inflammatory diseases, including CAD. Two isoforms of omentin are known: omentin-1 and omentin-2. Omentin-1 is the main circulating form of omentin. Its blood level in healthy people, according to different authors, varies from 1.61 to 815.3 ng/ml. A number of studies have found that the concentration of omentin-1 in the blood of women is higher than that of men, which may be due to sexual dimorphism of adipose tissue. The results of the studies indicate that the levels of omentin-1 circulating in the blood are associated with various metabolic risk factors. The review describes the main molecular mechanisms that determine these effects of omentin-1. A decrease in serum omentin-1 levels can be considered as an independent predictor of CAD and correlates with the severity and prognosis of this disease. A number of studies have established an association between the carriage of various variants of the omentin-1 (ITLN1) gene, CAD and obesity. The article analyzes the available data on the role of the level of omentin-1 in CAD, determined not only in the blood, but also in subcutaneous and visceral adipose tissue. The possible prospects for the use of various molecules capable of increasing the level of omentin-1 in the blood are analyzed. Conclusion. A decrease in the level of omentin-1 may be an independent predictor of CAD and is associated with the severity and progression of the disease. It is likely that omentin-1 can act as an alternative diagnostic tool to ensure optimal management of patients with CAD. Studies of the effect of omentin-1 on the prognosis in patients with various forms of CAD are largely ambiguous and therefore further, more comprehensive studies are needed. Keywords: coronary artery disease, acute coronary syndrome, omentin-1, adipokines, subcutaneous and visceral adipose tissue, omentin-1 gene (ITLN1).

Serum omentin-1 is correlated with the severity of liver disease in patients with chronic hepatitis C.

Patients with chronic hepatitis C virus (HCV) infection have increased serum omentin-1. Omentin-1 is an anti-inflammatory adipokine, and higher levels may be a direct effect of HCV infection. Successful elimination of HCV by direct acting antivirals almost normalized circulating levels of various molecules with a role in inflammation. To evaluate the effect of HCV infection on serum omentin-1, serum omentin-1 levels of HCV patients were measured before therapy and at 12 wk after therapy end. Associations of serum omentin-1 with parameters of inflammation and liver function were explored at both time points. Serum omentin-1 levels of patients with and without liver cirrhosis, which was defined by ultrasound or the fibrosis-4 (FIB-4) score, were compared. Serum omentin-1 levels were measured by enzyme-linked immunosorbent assay in 84 chronic HCV patients before therapy and at 12 wk after therapy end where sustained virological response 12 (SVR12) was achieved in all patients. Serum omentin-1 of 14 non-infected controls was measured in parallel. In patients with chronic HCV, serum omentin-1 levels were not related to viral load or viral genotype. HCV patients with liver steatosis and HCV patients with diabetes had serum omentin-1 levels comparable to patients not suffering from these conditions. Serum omentin-1 levels at SVR12 were similar in comparison to pretreatment levels. In addition, serum levels did not differ between HCV-infected patients and non-infected controls. Serum omentin-1 levels did not correlate with leukocyte count or C-reactive protein. Positive correlations of serum omentin-1 with bilirubin and the model for end-stage liver disease score (MELD) were detected before therapy and at SVR12 in the whole cohort. Bilirubin and the MELD score also positively correlated with serum omentin-1 levels in the subgroup of patients with ultrasound diagnosed liver cirrhosis before therapy. At SVR12, serum omentin-1 levels of patients with liver cirrhosis negatively correlated with albumin. Before therapy start, patients with high FIB-4 scores had increased serum omentin-1 in comparison to patients with a low score. Serum omentin-1 levels of patients with liver cirrhosis defined by ultrasound were increased at baseline and at SVR12. Present study showed that liver cirrhosis, but not HCV infection per se, is related to elevated serum omentin-1 levels.

The potential role of omentin-1 in obesity-related metabolic dysfunction-associated steatotic liver disease: evidence from translational studies

BackgroundObesity, characterized by visceral adipose tissue (VAT) expansion, is closely associated with metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH). Recent research has highlighted the crucial role of the adipose tissue—liver axis in the development of MASLD. In this study, we investigated the potential role of omentin-1, a novel adipokine expressed by VAT, in obesity-related MASLD pathogenesis.MethodsThrough in silico analysis of differentially expressed genes in VAT from obese patients with and without MASH, we identified omentin-1 as a significant candidate. To validate our findings, we measured omentin-1 levels in VAT and plasma of lean controls and obese patients with biopsy-proven MASLD. Additionally, we assessed omentin-1 expression in the VAT of diet-induced mice MASLD model. In vitro and ex vivo studies were conducted to investigate the effects of omentin-1 on MASLD-related mechanisms, including steatosis, inflammation, endoplasmic reticulum (ER) stress, and oxidative stress. We also analyzed the impact of d-glucose and insulin on VAT omentin-1 levels ex vivo.ResultsCompared to the lean group, the obese groups exhibited significantly lower VAT and plasma levels of omentin-1. Interestingly, within the obese groups, omentin-1 is further decreased in MASH groups, independent of fibrosis. Likewise, VAT of mice fed with high-fat diet, showing histological signs of MASH showed decreased omentin-1 levels as compared to their control diet counterpart. In vitro experiments on fat-laden human hepatocytes revealed that omentin-1 did not affect steatosis but significantly reduced TNF-α levels, ER stress, and oxidative stress. Similar results were obtained using ex vivo VAT explants from obese patients upon omentin-1 supplementation. Furthermore, omentin-1 decreased the mRNA expression of NF-κB and mitogen-activated protein kinases (ERK and JNK). Ex vivo VAT explants showed that d-glucose and insulin significantly reduced omentin-1 mRNA expression and protein levels.ConclusionsCollectively, our findings suggest that reduced omentin-1 levels contribute to the development of MASLD. Omentin-1 supplementation likely exerts its beneficial effects through the inhibition of the NF-κB and MAPK signaling pathways, and it may additionally play a role in the regulation of glucose and insulin metabolism. Further research is warranted to explore omentin-1 as a potential therapeutic target and/or biomarker for MASLD.Graphical

Association of serum omentin levels with microvascular complications of type 2 diabetes mellitus: a systematic review and meta-analysis.

Type 2 diabetes mellitus (T2DM) is a chronic condition associated with various microvascular complications, including neuropathy, retinopathy, and nephropathy. Recent studies have suggested a potential association between serum omentin levels and the risk of developing microvascular complications in patients with T2DM. However, the existing evidence remains inconclusive. Therefore, we conducted a systematic review and meta-analysis to examine the association between serum omentin levels and microvascular complications in T2DM patients. A comprehensive search was conducted in PubMed, Scopus, and Google Scholar databases to retrieve relevant articles published up to May 2023. Observational studies investigating omentin levels association with microvascular complications in T2DM patients were included. Data was extracted and hence analyzed. A total of seven cross-sectional articles met the inclusion criteria, with a total population of 1587 participants. The meta-analysis revealed a significant association between serum omentin levels and microvascular complications in patients with T2DM. Serum omentin levels were lower in patients with microvascular complications than in those without complications (Mean difference, 95% confidence interval: -1.31 [-2.50, -0.13], I2 = 99.62%). This systematic review and meta-analysis provides evidence supporting an association between serum omentin levels and microvascular complications in patients with T2DM. The findings suggest that Omentin may be lower in T2DM patients with microvascular complications. Further research is warranted to elucidate the underlying mechanisms and explore the clinical implications of these findings. The online version contains supplementary material available at 10.1007/s40200-023-01359-2.