Association of serum omentin levels with cardiac autonomic neuropathy in patients with type 2 diabetes mellitus: a hospital-based study

Association of baseline and trajectory of triglyceride-glucose index with the incidence of cardiovascular autonomic neuropathy in type 2 diabetes mellitus

BACKGROUND

Cardiovascular autonomic neuropathy (CAN), characterized by disrupted autonomic regulation of the cardiovascular system, is a frequent complication associated with diabetes. The triglyceride-glucose (TyG) index represents a precise insulin resistance indicator. However, the influence of baseline and prolonged TyG index patterns on CAN risk in type 2 diabetes remains unclear.

METHODS

Based on the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial, multivariate logistic regression models and restricted cubic splines (RCS) were deployed for elucidating the relation between baseline TyG index and the incidence of CAN. The area under the curve (AUC) of receiver operating characteristic (ROC) curve was used to assess the diagnostic value of the TyG index in predicting the risk of CAN. The relationship between TyG trajectory and the occurrence of CAN in individuals with diabetes was examined using Kaplan-Meier curve and a multivariable Cox proportional hazards regression model. Subgroup analysis was used to assess the robustness of the results. Additionally, we explored the impact of intensive glycemia treatment on the relationship between trajectory of TyG index and CAN risk.

RESULTS

In this study, these in the top quartile of the TyG index had a greater likelihood of developing CAN (TyG index Q4 vs. Q1 in Model II, OR = 1.29, 95% CI 1.03-1.62, P = 0.027). RCS indicated a rising trend in the TyG index in relation to the incidence of CAN. The AUC of the TyG index for predicting the occurrence of CAN was 0.636 (95% CI 0.620-0.651; P < 0.001), with the cut-off value of 0.208. During a 7-year follow-up period, three unique TyG trajectories were recognized: class 1 (n = 431, 23.26%), class 2 (n = 798, 27.57%), and class 3 (n = 293, 31.71%). Notable discrepancies in CAN risk across various trajectories were identified in Kaplan-Meier curve (P < 0.001). Cox regression analysis indicated that individuals in class 3 experienced a greater incidence of CAN in comparison to those in class 1 after adjusting for all covariates. Subgroup analysis found no significant effect modification in this relationship. Additionally, in the intensive glycemia group, class 2 had a reduced risk of CAN, while class 3 had an increased risk when compared to standard glycemia group.

CONCLUSION

Increased baseline levels and long-term trajectory of TyG index are associated with an increased incidence of CAN. Intensive glycemic therapy might influence the association between the trajectory of TyG index and the chance of developing CAN.

Omentin-1 and diabetes: more evidence but far from enough

AIMS AND BACKGROUND

Omentin-1 (oment-1) is a type of adipokines that is mainly expressed in visceral fat tissue. Based on accumulating evidence, oment-1 is closely related to diabetes and its complications. However, so far data about oment-1 and diabetes is fragmented. In this review, we focus on the role of oment-1 on diabetes, including its possible signalling pathways, the correlation of circulating omens-1 levels with diabetes and its complications.

METHODS

The web of PubMed was searched for articles of relevant studies published until February, 2023.

RESULTS AND CONCLUSIONS

Oment-1 might exert its effects by inhibiting the NF-κB pathway and activating the Akt and AMPK-dependent pathways. The level of circulating oment-1 is negatively correlated with the occurrence of type 2 diabetes and some complications, including diabetic vascular disease, cardiomyopathy, and retinopathy, which can be affected by anti-diabetic therapies. Oment-1 could be a promising marker for screening and targeted therapy for diabetes and its complications; however, more studies are still needed.

Remodeling of the Intracardiac Ganglia During the Development of Cardiovascular Autonomic Dysfunction in Type 2 Diabetes: Molecular Mechanisms and Therapeutics

Type 2 diabetes mellitus (T2DM) is one of the most significant health issues worldwide, with associated healthcare costs estimated to surpass USD 1054 billion by 2045. The leading cause of death in T2DM patients is the development of cardiovascular disease (CVD). In the early stages of T2DM, patients develop cardiovascular autonomic dysfunction due to the withdrawal of cardiac parasympathetic activity. Diminished cardiac parasympathetic tone can lead to cardiac arrhythmia-related sudden cardiac death, which accounts for 50% of CVD-related deaths in T2DM patients. Regulation of cardiovascular parasympathetic activity is integrated by neural circuitry at multiple levels including afferent, central, and efferent components. Efferent control of cardiac parasympathetic autonomic tone is mediated through the activity of preganglionic parasympathetic neurons located in the cardiac extensions of the vagus nerve that signals to postganglionic parasympathetic neurons located in the intracardiac ganglia (ICG) on the heart. Postganglionic parasympathetic neurons exert local control on the heart, independent of higher brain centers, through the release of neurotransmitters, such as acetylcholine. Structural and functional alterations in cardiac parasympathetic postganglionic neurons contribute to the withdrawal of cardiac parasympathetic tone, resulting in arrhythmogenesis and sudden cardiac death. This review provides an overview of the remodeling of parasympathetic postganglionic neurons in the ICG, and potential mechanisms contributing to the withdrawal of cardiac parasympathetic tone, ventricular arrhythmogenesis, and sudden cardiac death in T2DM. Improving cardiac parasympathetic tone could be a therapeutic avenue to reduce malignant ventricular arrhythmia and sudden cardiac death, increasing both the lifespan and improving quality of life of T2DM patients.

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

Background and aims

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.

Methods

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.

Results

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%).

Conclusion

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.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01359-2.

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.

Association of Plasma Omentin-1 Levels With Diabetes and Its Complications

Introduction: Plasma omentin-1 is a relatively new biomarker that has anti-diabetogenic and its level is inversely related with insulin resistance and diabetes mellitus, thus, increasing the risk of diabetic complications. In this study, we will determine the association between serum plasma omentin-1 levels and diabetes and its complications.

Methods: This case control study was conducted from July 2020 to August 2021 in the internal medicine unit of a tertiary care hospital in Pakistan. There was a total of three groups, each comprising 250 patients. One group was type 2 diabetic patients with complications, the second group was type 2 diabetic patients without complications, and the third group was the control group, i.e. participants without type 2 diabetes. Their plasma omentin-1 levels were compared.

Results: Patients with diabetic complications had significantly lower serum omentin levels than patients without complications (59.01 ± 9.21 ug/dL vs. 75.72 ± 14.11 ug/L; p-value: <0.0001). Patients with diabetes had significantly lower serum omentin levels in comparison to patients without diabetes (75.72 ± 14.11 ug/dL vs. 90.12 ± 17.89 ug/L; p-value: <0.0001).

Conclusion: Based on our study, plasma omentin-1 is negatively associated with diabetes and its complications. Therefore, adequate levels of omentin-1 are needed in order to prevent diabetic complications.

Association of serum CTRP9 levels with cardiac autonomic neuropathy in patients with type 2 diabetes mellitus

AIMS

Cardiac autonomic neuropathy (CAN) is a serious complication of diabetes and is associated with adipokines. The C1q tumor necrosis factor-related protein 9 (CTRP9) is a newly discovered adipokine. This study aimed to evaluate the association of serum CTRP9 levels with the prevalence and severity of CAN in patients with type 2 diabetes mellitus.

MATERIALS AND METHODS

We enrolled 262 patients (aged ≥18 years) with type 2 diabetes mellitus into this study. Standard cardiovascular autonomic reflex tests (CARTs) were used to assess CAN and patients were divided into three groups accordingly: a non-CAN group, an early CAN group, and a definite CAN group. Serum CTRP9 levels were measured by enzyme-linked immunosorbent assay, and the tertiles were calculated.

RESULTS

Serum CTRP9 levels decreased significantly in the early CAN and definite CAN groups (P < 0.05). The percentage of definite CAN was the highest at the minimum tertile of serum CTRP9 level (T1; P < 0.05). Additionally, serum CTRP9 levels were negatively correlated with age, DM duration, hemoglobin A1c (HbA1c), and fasting plasma glucose (FPG) while positively correlated with high-density lipoprotein cholesterol (HDL; P < 0.05). The level of CTRP9 was also significantly associated with the four indexes of CARTs (P < 0.05). Furthermore, CTRP9 was a protective factor for definite CAN (P < 0.05). Compared with the maximum tertile (T3) of the serum CTRP9 levels, a decreased level of serum CTRP9 in T1 significantly increased the prevalence ratio of definite CAN in patients with type 2 diabetes mellitus (P < 0.05).

CONCLUSION

Serum CTRP9 levels were independently associated with definite CAN. CTRP9 represents a reliable biomarker for exploring CAN in patients with type 2 diabetes mellitus.

Association of Circulating Omentin-1 with Osteoporosis in a Chinese Type 2 Diabetic Population

Aims

Omentin-1, a newly identified adipokine, has been demonstrated to be associated with bone metabolism, but the results have been inconsistent. Moreover, the potential relationship of circulating omentin-1 with diabetic osteoporosis has never been reported. This study is intended for studying the association between circulating omentin-1, bone mineral density (BMD), prior fragility fractures, and other bone metabolic-related parameters.

Methods

Circulating omentin-1 levels were measured in 172 patients with type 2 diabetes mellitus (T2DM), and participants were divided into the normal BMD group (n = 52), the osteopenia group (n = 66), and the osteoporosis group (n = 54). The relationship between circulating omentin-1 and diabetic osteoporosis and other parameters was analyzed.

Results

Circulating omentin-1 was significantly higher in the osteoporosis group than in the normal group and in the osteopenia group (both P < 0.05). Circulating omentin-1 levels were correlated significantly and positively with sex; high-density lipoprotein cholesterol; apolipoprotein A; and prevalence of prior fragility fractures, diabetic nephropathy, and retinopathy; they were correlated negatively with diastolic blood pressure, triglyceride, hemoglobin, atherogenic index of plasma, osteoporosis self-assessment tool for Asians, BMD at different skeletal sites, and corresponding T scores, irrespective of age, sex, and body mass index (P < 0.01 or P < 0.05). Moreover, circulating omentin-1 was an independent decisive factor for the presence of osteoporosis only in women after multivariate adjustment (odds ratio: 1.069; 95% confidence interval: 1.003-1.139; P < 0.05). Lastly, the analysis of receiver operating characteristic curves revealed that the best cutoff value for circulating omentin-1 to predict diabetic osteoporosis was 15.37 ng/mL (sensitivity: 71.7%; specificity: 58.5%) in female subjects.

Conclusions

High levels of circulating omentin-1 may be associated with the development of osteoporosis in female diabetic subjects and may be a potential biomarker for diabetic osteoporosis in women.

Association between Omentin-1 and Coronary Artery Disease: Pathogenesis and Clinical Research

Like other adipokines, omentin-1 is secreted from visceral adipose tissue and plays a vital role in the development of chronic inflammatory diseases, including cardiovascular events. Recent studies have shown that circulating omentin-1 levels are associated with various metabolic risk factors, such as high blood pressure, increased waist circumference, dyslipidemia, and glucose intolerance. The decrease in serum omentin level is an independent predictor of Coronary Artery Disease (CAD) and is associated with the severity of this disease. Since there is no relevant review in the literature, we aimed to summarize the studies on the relationship between omentin-1 and CAD.

Cardiovascular autonomic neuropathy in patients with type 2 diabetes mellitus and its association with serum omentin and leptin

Cardiovascular autonomic neuropathy (CAN) is a major cause of morbidity and mortality in patients with diabetes as it is associated with a high risk of cardiac arrhythmias.

Newly Discovered Adipokines: Pathophysiological Link Between Obesity and Cardiometabolic Disorders

With the increasing prevalence of obesity, obesity-related problems such as cardiometabolic disorders (CMD), are also rapidly increasing. To prevent and alleviate the progressive course of CMD, it is important to discover the pathophysiological mechanisms between obesity and CMD. Adipose tissue is now recognized as an active endocrine organ that releases adipokines. Adipokines play a pivotal role in chronic low-grade inflammation, oxidative stress, and impaired insulin signaling, contributing to metabolic derangement and leading to CMD. Recent studies have provided substantial evidence supporting the association between adipokines and CMD. In this review, we highlight the pathophysiological action of adipokines in CMD that includes metabolic syndrome, type 2 diabetes, non-alcoholic fatty liver disease, and cardiovascular diseases. We focused on translational and clinical research of novel adipokines associated with metabolic and cardiovascular regulation. Exploration of the role of these adipokines connecting obesity and CMD may provide a perspective on adipokine-based therapeutic implications for CMD.

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.

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.

The Association of Serum hsCRP and Urinary Alpha1-Microglobulin in Patients with Type 2 Diabetes Mellitus

This study aimed to investigate the association of serum hsCRP and urinary A1MG in patients with T2DM. Numerous investigations have proven that serum hypersensitive C-reactive protein (hsCRP) concentration in patients with type 2 diabetes mellitus (T2DM) is increased. Also, increased urinary alpha-1 microglobulin (A1MG) can be an early sign of renal damage, primarily on the proximal tubules in T2DM. Little information is available with respect to the associations of serum hsCRP levels and urinary A1MG in T2DM. A total of 520 patients with T2DM were recruited to participate in this study. Serum hsCRP and UA1MG (urinary alpha1-microglobulin to creatinine ratio), UACR (urinary microalbumin to creatinine ratio), UIGG (urinary immunoglobulin G to creatinine ratio), and UTRF (urinary transferrin to creatinine ratio) were obtained. The association of serum hsCRP level and each urinary protein parameter was analyzed by using the regression analysis, respectively. LnhsCRP was positively associated with the lnUA1MG in all three linear regression models (adjusted β in model 3=0.122, SE=0.027, P<0.001). Furthermore, the high hsCRP group (hsCRP > 3mg/L) was associated with increasing risk of high UA1MG (adjusted OR in model 3=1.610, 95% CI 1.037-2.499, P=0.034) by logistic regression. This study suggests that serum hsCRP levels independently associate with UA1MG in patients with T2DM. Further research is warranted to elucidate these interactions.

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.

Peripheral Sensory Neuropathy and associated factors among adult diabetes mellitus patients in Bahr Dar, Ethiopia

Background

Diabetic sensory neuropathy is a common form of microvascular complication among diabetic patients. The swiftly growing population of people living with diabetes in Ethiopia and lack of elaborated scientific data on peripheral sensory neuropathy among diabetic population in Ethiopia prompted this work. This study was set out to assess the enormity and associated factors of peripheral sensory neuropathy among diabetes patients attending chronic illness clinic of Felege Hiwot Regional Referral Hospital, Bahr Dar, Northwest Ethiopia.

Methods

An institution based cross-sectional study was conducted at Felege Hiwot Referral Hospital chronic illness clinic using Michigan neuropathy screening instrument tool for diabetic peripheral sensory neuropathy on 408 diabetic patients during 2016. Data were collected using interview, patient record review, anthropometric measurements and physical examination. Both bivariate and multivariate binary logistic regression was employed to identify factors associated with peripheral sensory neuropathy. Odds ratios with their 95% CI and P value less than 0.05 used to determine statistically significant associations.

Results

A total of 368 patients were included with the mean age of 49 ± 14.3 years. The overall prevalence of Peripheral Sensory Neuropathy was found to be 52.2%. The major associated factors identified by multivariate analysis were age >50 years: AOR: 3.0 CI [1.11, 7.89]; overweight and obese: AOR: 7.3 CI [3.57, 14.99]; duration of DM: AOR: 3.4 CI [1.75, 6.60]; not involved in physical exercise: AOR: 4.8 CI [1.90, 7.89]; male gender: AOR: 2.4 CI [1.18, 5.05].

Conclusion

Almost half of the diabetic patients who attended Felege Hiwot regional referral hospital during study period were found to present with peripheral sensory neuropathy. Socio-demographic and bio characteristics like patients age, Body Mass Index, level of physical activity and marital status were significantly associated with diabetic peripheral sensory neuropathy.

Association between omentin-1 expression in human epicardial adipose tissue and coronary atherosclerosis

BACKGROUND

Omentin-1, a novel adipocytokine mainly expressed in visceral adipose tissue, has been found to inhibit the inflammatory response and improve insulin resistance as well as other obesity-related disorders. This study investigated the association between omentin-1 expression in human epicardial adipose tissue (EAT) and coronary atherosclerosis.

METHODS

Serum samples, and paired biopsies from EAT and subcutaneous adipose tissue (SAT), were obtained from patients with and without coronary artery disease (CAD, n = 28 and NCAD, n = 12, respectively) during elective cardiac surgery. Coronary angiography was performed to identify CAD presence. Serum omentin-1 and adiponectin levels were measured by ELISA. mRNA expression of omentin-1 and adiponectin was detected in adipose tissue by quantitative real-time PCR, and omentin-1 protein expression was evaluated by immunohistochemistry. Correlation and multivariate linear regression analyses were performed to determine the association between omentin-1 expression and clinical risk factors.

RESULTS

mRNA and protein expression of omentin-1 were higher in EAT than paired SAT in patients with CAD and NCAD. Compared with NCAD patients, CAD patients had lower omentin-1 and adiponectin mRNA levels in EAT and serum levels as well as lower omentin-1 protein levels. Among patients with CAD, omentin-1 expression was lower in EAT surrounding coronary segments with stenosis than those without stenosis, in terms of mRNA and protein, whereas adiponectin mRNA level in EAT did not seem to differ between stenotic and non-stenotic coronary segments in CAD patients. In multivariate linear regression analysis, CAD was an independent predictor of EAT omentin-1 mRNA expression (beta = -0.57, 95 % CI -0.89 to -0.24; P = 0.001) and serum omentin-1 levels (beta = -0.35, 95 % CI -0.67 to -0.03; P = 0.036).

CONCLUSIONS

Circulating and EAT-derived omentin-1 levels were reduced in patients with CAD. Omentin-1 expression in patients with CAD was lower in EAT adjacent to coronary stenotic segments than non-stenotic segments.