A possible connection between tumor necrosis factor alpha and adropin levels in polycystic ovary syndrome

Hepatokines: the missing link in the development of insulin resistance and hyperandrogenism in PCOS?

The liver plays a critical role in several metabolic pathways, including the regulation of glucose and lipid metabolism. Non-alcoholic fatty liver disease (NAFLD), the most common chronic liver disease worldwide, is closely associated with insulin resistance (IR) and metabolic syndrome (MetS). Hepatokines, newly discovered proteins secreted by hepatocytes, have been linked to the induction of these metabolic dysregulations. Polycystic ovary syndrome (PCOS), the most common endocrine disorder in women of reproductive age, has been associated with NAFLD and IR, while hyperandrogenism additionally appears to be implicated in the pathogenesis of the latter. However, the potential role of hepatokines in the development of metabolic disorders in PCOS has not been fully investigated. Therefore, the aim of this review is to critically appraise the current evidence regarding the interplay of hepatokines with NAFLD, hyperandrogenism, and IR in PCOS.

Circulating levels of adropin and diabetes: a systematic review and meta-analysis of observational studies

OBJECTIVE

Adropin, a newly identified regulatory protein has garnered attention given its potential role in metabolism regulation, especially glucose metabolism and insulin resistance. However, studies on the association between adropin and type 2 diabetes mellitus (T2DM) are equivocal. The aim of this study is to assess the association between serum adropin levels and T2DM using a systematic review and meta-analysis of observational studies.

METHODS

PubMed, Scopus, ISI Web of science, and Google Scholar were searched, up to August 2022, for studies that reported the association between serum levels of adropin in adults with T2DM compared to a control group without diabetes. A random-effect model was used to compute the pooled weighted mean difference (WMD) with 95% confidence intervals (CI).

RESULTS

Meta-analysis of 15 studies (n = 2813 participants) revealed that the serum adropin concentrations were significantly lower in patients with T2DM compared with the control group (WMD= -0.60 ng/mL, 95% CI: -0.70 to -0.49; I² = 99.5%). Subgroup analysis also found lower concentration of adropin in patients with T2DM who were otherwise healthy compared to a control group (n = 9; WMD=-0.04 ng/ml, 95% CI= -0.06 to -0.01, p = 0.002; I² = 96.4).

CONCLUSIONS

Our study showed adropin levels are lower in patients with diabetes compared to a control group without diabetes. However, the limitations of observational studies challenge the validity of the results, and further investigations are needed to confirm the veracity of these findings and additionally explore possible mechanisms.

Regulation of Adropin by Sitagliptin monotherapy in participants with newly diagnosed type 2 Diabetes

BACKGROUND

Adropin is a potent metabolic regulator of insulin sensitivity and glycolipid metabolism. The present study investigated the effects of sitagliptin on adropin and metabolic parameters in participants with newly diagnosed type 2 diabetes (T2D).

METHODS

Thirty-five participants newly-diagnosed with T2D were prescribed sitagliptin 100 mg once daily for 17 weeks. Twenty-eight age-, sex-, and BMI-matched healthy subjects were included as the control group. Adropin and clinical parameters were assessed at baseline and after treatment.

RESULTS

At baseline, serum adropin levels were lower in T2D participants than in the healthy individuals (3.12 ± 0.73 vs. 5.90 ± 1.22 ng/ml, P <  0.01). Serum adropin levels were significantly higher in T2D patients after sitagliptin treatment (4.97 ± 1.01 vs. 3.12 ± 0.73 ng/ml, P <  0.01). The changes in serum adropin levels after sitagliptin treatment were associated with the improvements of fasting blood glucose (FBG) (β = - 0.71, P <  0.01), glycosylated hemoglobin (HbA1c) (β = - 0.44, P <  0.01) and homeostatic model assessment of β-cell function (HOMA-β) (β = 9.02, P <  0.01).

CONCLUSIONS

Sitagliptin treatment could significantly increase serum adropin levels in participants with newly diagnosed T2D. The increase in serum adropin levels could be associated with the amelioration of glucose metabolism, which might be involved in beneficial glucose-lowering mechanisms of sitagliptin.

TRIAL REGISTRATION

Clinicaltrials.gov , NCT04495881 . Retrospectively registered on 03/08/2020.

Correlation Between Circulating Adropin Levels and Patients with PCOS: An Updated Systematic Review and Meta-analysis

An increasing number of young women suffer from polycystic ovary syndrome (PCOS). Reasonable diagnosis and monitoring are important steps in the treatment of PCOS. Therefore, we performed an updated meta-analysis between adropin levels and PCOS to identify their relationship. We searched 8 databases (Pubmed, EMBASE, Cochrane Library, CNKI, Wanfang, CBM, clinicaltrials.gov, OpenGrey) for relevant studies using the following search items: 'PCOS or polycystic ovary syndrome or Stein-Leventhal syndrome' AND 'adropin'. Standardized mean difference (SMD) and 95% confidence intervals(CIs) were used as the outcomes. Data were analyzed using Revman 5.3, Stata 16, and MetaXL. Nineteen articles were include in this meta-analysis. The PCOS group had significantly lower adropin levels than the healthy groups (SMD = -2.79 ng/ml, 95%CI (-3.42, -2.16), p < 0.00001). Significant publication bias (p < 0.05) was observed; additionally, the results were robust based on metatrim and fail-safe number (Nfs). Meta-regression analysis showed that age, glucose ratio and luteinizing hormone (LH) may be sources of heterogeneity (univariate meta-regression analysis: P = 0.058 vs P = 0.026 vs P = 0.091). Furthermore, BMI, insulin, glucose, HOMA-IR, total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), and low-density lipoprotein (LDL) may be closely related to adropin levels (p < 0.05) owing to meta-analysis of correlation coefficient. We found there was a correlation between adropin levels and PCOS: circulating adropin levels were significantly lower in patients with PCOS than healthy controls, which may be helpful for clinical diagnosis and detection of PCOS.

Exploration of hub genes involved in PCOS using biological informatics methods

BACKGROUND

The aim of this study was to find underlying genes and their interaction mechanism crucial to the polycystic ovarian syndrome (PCOS) by analyzing differentially expressed genes (DEGs) between PCOS and non-PCOS subjects.

METHODS

Gene expression data of PCOS and non-PCOS subjects were collected from gene expression omnibus (GEO) database. GEO2R were used to calculating P value and logFC. The screening threshold of DEGs was P < .05 and | FC | ≥ 1.2. GO annotation and Kyoto encyclopedia of genes and genomes (KEGG) signaling pathway enrichment analysis was performed by using DAVID (2021 Update). The protein-protein interaction (PPI) network of DEGs was constructed by using the STRING database, and the hub genes were recognized through Hubba plugin of Cytoscape software.

RESULTS

PCOS and non-PCOS subjects shared a total of 174 DGEs, including 14 upregulated and 160 downregulated genes. The GO biological processes enriched by DEGs mainly involved actin cytoskeleton organization, positive regulation of NF-κB signaling pathway, and positive regulation of canonical Wnt signaling pathway. The DEGs were significantly enriched in cytoplasm, nucleus and cytosol. Their molecular functions mainly focused on protein binding, calmodulin binding and glycerol-3-phosphate dehydrogenase activity. The PI3K/Akt signaling pathway and glycosaminoglycan biosynthesis were highlighted as critical pathways enriched by DEGs. 10 hub genes were screened from the constructed PPI network, of which EGF, FN1 and TLR4 were mainly enriched in the PI3K/Akt signaling pathway.

CONCLUSION

In this study, a total of 174 DEGs and 10 hub genes were identified as new candidate targets for insulin resistance (IR) in PCOS individuals, which may provide a new direction for developing novel treatment strategies for PCOS.

Inflammation Markers in Infants of Mothers with Gestational Diabetes

AimPentraxin-3, high sensitive CRP (HsCRP) and adropin were investigated in cord blood of infants of mothers with gestational diabetes mellitus (IDM) to evaluate the exposure of fetus to inflammation and whether there is any correlation with clinical findings.MethodsForty IDM and forty three infants whose mother did not have diabetes were included in this prospective study. Adropin, pentraxin-3 and HsCRP levels were measured in the cord blood samples. Echocardiographic measurements were performed in the first three days of life.ResultsAdropin and pentraxine-3 levels were significantly lower and HsCRP levels were significantly higher in IDM group. Echocardiographic measurements of myocardial hypertrophy were negatively correlated with adropin.ConclusionAlterations in these markers in IDM supports the hypothesis of in utero fetal exposure to inflammation caused by gestational diabetes mellitus. Potentially, cord blood adropin might be used as a predictor for complications of diabetes.

Adropin levels and its associations as a fat-burning hormone in patients with polycystic ovary syndrome: a correlational meta-analysis

AIMS

Adropin is a peptide hormone with potential implications in patients with polycystic ovary syndrome (PCOS). The aim of this meta-analysis was to compare the circulating (serum/plasma) and follicular fluid adropin levels between human PCOS patients and non-PCOS controls.

METHODS

Relevant studies were retrieved by online database and manual searching. The standardized mean differences (SMDs) with 95% confidence intervals (CIs) were obtained by a random-effects meta-analysis. Meta-analysis of correlations was performed for the associations of adropin with anthropometric, lipid, insulin resistance and hormonal covariates. The funnel plot analysis with Begg's and Egger's tests was used for publication bias.

RESULTS

A total of 9 studies were included in this meta-analysis. The results indicated that the adropin levels were significantly decreased in PCOS patients as compared to non-PCOS controls (SMD = -1.87, 95% CI = -2.55 to -1.18, p < .0001). This decrease was more evident in overweight PCOS patients than their normoweight counterparts (SMD = -0.55, 95% CI = -0.80 to -0.30, p < .0001). A one-study leave-out sensitivity analysis indicated that no single study had a significant influence on the overall outcome, suggesting the robustness of this meta-analysis. There were significant associations of decreased adropin levels with the body mass index, dyslipidemia and insulin resistance in PCOS.

CONCLUSION

Adropin levels are significantly reduced in PCOS patients compared to controls, and this decrease was more evident in overweight PCOS patients.

The Role of Chronic Inflammation in Polycystic Ovarian Syndrome-A Systematic Review and Meta-Analysis

Although the current literature associates polycystic ovarian syndrome (PCOS) with chronic inflammation, the evidence for this link remains inconclusive and its causal nature remains unclear. The purpose of this systematic review was to assess the inflammatory status in PCOS women and to determine whether it is related to PCOS or to its associated adiposity. We searched electronic databases including PUBMED, EMBASE and MEDLINE, SCOPUS, DynaMed plus, TRIP, ScienceDirect and Cochrane Library, for studies investigating C-reactive protein (CRP) and other inflammatory makers in PCOS women versus healthy controls. Quality and risk of bias for selected studies were assessed using the modified Newcastle-Ottawa scale. CRP data were extracted and pooled using RevMan for calculation of the standardized mean difference (SMD) and 95% confidence interval (CI). Eighty-five eligible studies were included in the systematic review, of which 63 were included in the meta-analysis. Pooled analysis of the 63 studies revealed significantly higher circulating CRP in PCOS women (n = 4086) versus controls (n = 3120) (SMD 1.26, 95%CI, 0.99, 1.53). Sensitivity meta-analysis of 35 high quality studies including non-obese women showed significantly higher circulating CRP in PCOS women versus controls (SMD 1.80, 95%CI, 1.36, 2.25). In conclusion, circulating CRP is moderately elevated in PCOS women independent of obesity, which is indicative of low-grade chronic inflammation.

Potential effects of adropin on systemic metabolic and hormonal abnormalities in polycystic ovary syndrome

RESEARCH QUESTION

The study aimed to explore the effects of adropin on hormone concentrations and glucolipid and amino acid metabolism in patients with polycystic ovary syndrome (PCOS).

DESIGN

A total of 220 PCOS patients and 67 controls were recruited and basal state plasma was collected for adropin measurement. Follicular fluids from 50 PCOS patients and 30 controls were also collected for adropin analysis.

RESULTS

Plasma and follicular fluid adropin concentrations were lower in PCOS patients than controls (P < 0.001; P = 0.017). Adropin concentrations were negatively correlated with body mass index (BMI), free androgen index, Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), androstenedione and triglycerides, and positively correlated with sex hormone-binding globulin (SHBG) and high-density lipoprotein (HDL) (all P < 0.05). PCOS patients who were either obese or glucose intolerant had lower adropin concentrations (P < 0.001). Follicular fluid adropin concentrations were negatively correlated with HOMA-IR, isoleucine and valine in the PCOS group (all P < 0.05). After adjusting for age, BMI, HOMA-IR and HDL, SHBG still significantly impacted the concentration of plasma adropin (P = 0.022). After adjusting for age and BMI, the odds of subjects with reduced adropin concentrations having PCOS still remained significant (P = 0.045). The association between plasma adropin and PCOS disappeared following SHBG adjustment.

CONCLUSIONS

The concentrations of adropin in plasma and follicular fluid were lower in PCOS patients, which might affect the development of insulin resistance. The association between adropin concentrations and hyperandrogenaemia in PCOS might be mediated through SHBG. The decreased adropin concentrations are associated with abnormal branched-chain amino acid metabolism in PCOS.

Adropin as a potential mediator of the metabolic system-autonomic nervous system-chronobiology axis: Implementing a personalized signature-based platform for chronotherapy

Adropin is a peptide hormone, which plays a role in energy homeostasis and controls glucose and fatty acid metabolism. Its levels correlate with changes in carbohydrate-lipid metabolism, metabolic diseases, central nervous system function, endothelial function and cardiovascular disease. Both metabolic pathways and adropin are regulated by the circadian clocks. Here, we review the roles of the autonomic nervous system and circadian rhythms in regulating metabolic pathways and energy homeostasis. The beneficial effects of chronotherapy in various systems are discussed. We suggest a potential role for adropin as a mediator of the metabolic system-autonomic nervous system axis. We discuss the possibility of establishing an individualized adropin and circadian rhythm-based platform for implementing chronotherapy, and variability signatures for improving the efficacy of adropin-based therapies are discussed.

Serum adropin levels are reduced in patients with inflammatory bowel diseases.Sci Rep. 2020;10:9264. [PMID: 32518265 DOI: 10.1038/s41598-020-66254-9]

Adropin is a novel peptide mostly associated with energy homeostasis and vascular protection. To our knowledge, there are no studies that investigated its relationship with inflammatory bowel diseases (IBD). The aim of this study was to compare serum adropin levels between 55 patients with IBD (30 Ulcerative colitis (UC) patients, 25 Crohn’s disease (CD) patients) and 50 age/gender matched controls. Furthermore, we explored adropin correlations with IBD severity scores, hsCRP, fecal calprotectin, fasting glucose and insulin levels. Serum adropin levels were significantly lower in patients with IBD in comparison with the control group (2.89 ± 0.94 vs 3.37 ± 0.60 ng/mL, P = 0.002), while there was no significant difference in comparison of UC patients with CD patients (P = 0.585). Furthermore, there was a negative correlation between adropin and fecal calprotectin (r = −0.303, P = 0.025), whereas in the total study population, we found a significant negative correlation with fasting glucose levels (r = −0.222, P = 0.023). A multivariable logistic regression showed that serum adropin was a significant predictor of positive IBD status when enumerated along with baseline characteristics (OR 0.455, 95% CI 0.251–0.823, P = 0.009). Our findings imply that adropin could be involved in complex pathophysiology of IBD, but further larger scale studies are needed to address these findings.

A Review of Adropin as the Medium of Dialogue between Energy Regulation and Immune Regulation

Adropin is a secretory protein encoded by the energy balance gene and is closely associated with regulation of energy metabolism and insulin resistance. The clinical findings demonstrated its decreased expression in various inflammatory diseases, its negative correlation with the expression levels of inflammatory cytokines, and its potential anti-inflammatory effects. We speculate that adropin plays a pivotal regulatory role in immune cells and inflammatory factors. In this study, we reviewed the advances in researches concentrated on immunological effects of adropin.

Adropin as A Fat-Burning Hormone with Multiple Functions-Review of a Decade of Research

Adropin is a unique hormone encoded by the energy homeostasis-associated (Enho) gene. Adropin is produced in the liver and brain, and also in peripheral tissues such as in the heart and gastrointestinal tract. Furthermore, adropin is present in the circulatory system. A decade after its discovery, there is evidence that adropin may contribute to body weight regulation, glucose and lipid homeostasis, and cardiovascular system functions. In this review, we summarize and discuss the physiological, metabolic, and pathophysiological factors regulating Enho as well as adropin. Furthermore, we review the literature addressing the role of adropin in adiposity and type 2 diabetes. Finally, we elaborate on the role of adropin in the context of the cardiovascular system, liver diseases, and cancer.

Assessment of Serum Concentrations of Adropin, Afamin, and Neudesin in Children with Type 1 Diabetes

Introduction

The increasing knowledge of adropin, afamin, and neudesin and the regulation of glucose metabolism and insulin resistance allows for the assessment of the differences in their concentrations between the groups with varied duration of diabetes mellitus (DM).

Aim of the Study

Assessment of serum levels of adropin, afamin, and neudesin in children with type 1 diabetes, with respect to the disease duration.

Materials and Methods

The study consisted of 138 patients aged 5–18 years (M 40.58%). Children with type 1 diabetes (n = 68) were compared to the control group (n = 70). The diabetic group was divided into 4 subgroups: (I) newly diagnosed patients, after an episode of ketoacidosis (n = 14), (II) duration no longer than 5 years (n = 18), (III) 5 to 10 years (n = 27), and (IV) longer than 10 years (n = 9). Serum concentrations of adropin, afamin, and neudesin were assessed and compared between the groups of patients. The criterion for statistical significance was p < 0.05.

Results

The concentrations of adropin and afamin across all subgroups were lower than that in the control group, while neudesin levels were higher in diabetic patients compared to the control group. The differences were statistically significant.

Conclusions

Adropin, afamin, and neudesin may play a major role in the regulation of glucose metabolism and have a significant potential as novel biomarkers to predict future metabolic disorders. However, further multicentre studies on a larger cohort of patients are necessary to specify the role of these substances in the course and treatment of type 1 diabetes.

Fractalkine: an inflammatory chemokine elevated in subjects with polycystic ovary syndrome

PURPOSE

Fractalkine (FKN) is an inflammatory chemokine related to reproductive system and glucose metabolism. There is a link between FKN and steroidogenesis as FKN induces progesterone synthesis. Polycystic ovary syndrome (PCOS) is a common reproductive and metabolic disorder associated with low progesterone production and insulin resistance. We aimed to explore whether women with PCOS have any difference in FKN levels compared to women without PCOS. We also focused on determination of any association between FKN levels and hormonal-metabolic parameters in women with PCOS.

METHODS

The current research was designed as a case-control study. Eighty subjects with PCOS and 80 age- and body mass index (BMI)-matched subjects with normal menstrual cycle were taken into the study. We measured circulating FKN levels via ELISA methods.

RESULTS

Circulating FKN levels were higher in women with PCOS than controls (1.93 ± 0.61 vs. 1.22 ± 0.33 ng/ml, P< 0.001). FKN levels showed a positive correlation with body mass index (BMI), insulin resistance, inflammatory marker hs-CRP, total testosterone, and free-androgen index (FAI), whereas it showed a negative correlation with sex hormone-binding protein in women with PCOS. Linear regression analyses revealed that the link of FKN with BMI, insulin resistance, hs-CRP, and FAI was independent. Binary logistic regression analysis showed that the risk of having PCOS was associated with high levels of FKN.

CONCLUSIONS

Increased FKN levels related to insulin resistance, inflammation and androgens in women with PCOS. FKN may have an inter-related role in different pathophysiologic pathways of PCOS.

The association of serum and vitreous adropin concentrations with diabetic retinopathy

Objective

Adropin, a newly identified regulatory protein encoded by Enho gene, is correlated with insulin sensitivity and diabetes. The aim of this study is to determine whether serum and vitreous adropin concentrations are correlated with the presence of diabetic retinopathy.

Methods

A population of 165 patients with type 2 diabetes mellitus (52 without diabetic retinopathy, 69 with non-proliferative diabetic retinopathy and 44 patients with proliferative diabetic retinopathy) was enrolled in this study. The control group enrolled 68 healthy subjects who had underwent vitrectomy for retinal detachment. Serum and vitreous adropin concentrations were examined using enzyme-linked immunosorbent assay method.

Results

Control subjects had significantly higher serum and vitreous adropin concentrations compared with diabetic patients. Serum and vitreous adropin concentrations in proliferative diabetic retinopathy patients were significantly reduced compared with those in non-proliferative diabetic retinopathy patients and type 2 diabetes mellitus patients without diabetic retinopathy. In addition, there were lower serum and vitreous adropin concentrations in non-proliferative diabetic retinopathy patients compared with type 2 diabetes mellitus patients without diabetic retinopathy. Logistic regression analysis revealed that serum and vitreous adropin were associated with a decreased risk of type 2 diabetes mellitus and diabetic retinopathy.

Conclusion

Serum and vitreous adropin concentrations are negatively associated with the presence of diabetic retinopathy.

Serum Adropin Levels Are Reduced in Adult Patients with Nonalcoholic Fatty Liver Disease

OBJECTIVES

Adropin is a novel marker of metabolic syndrome and insulin resistance. The aim of this study was to explore the association of serum adropin levels with hepatosteatosis among adult patients.

MATERIALS AND METHODS

Serum biochemical parameters including liver and renal function tests, insulin levels, and serum adropin levels were compared between adult patients with nonalcoholic fatty liver disease (NAFLD) and healthy control cases.

RESULTS

A total of 51 patients with a mean age of 37.9 ± 9.96 years diagnosed with grade 2-3 hepatosteatosis and 30 healthy control cases with a mean age of 34.8 ± 9.5 years were included in the study. Serum adropin levels in the NAFLD group were statistically significantly lower than in the control cases (588.4 ± 261.0 vs. 894.2 ± 301.2, respectively; p < 0.001). The study participants were further subdivided into 2 groups as patients with (n = 35) or without (n = 46) insulin resistance using the serum homeostatic model of assessment-insulin resistance (HOMA-IR). Serum adropin levels were statistically significantly lower in patients with insulin resistance (p < 0.01). There was a negative correlation between adropin levels and serum insulin, HOMA-IR, urea, gamma-glutamyl transferase, total cholesterol, and triglyceride levels.

CONCLUSION

We observed a decrease in serum adropin levels among adult patients with NAFLD. We also found lower levels of serum adropin in patients with insulin resistance, supporting previous data in the literature. Studies investigating the association of adropin levels with other inflammatory parameters are warranted to define its exact role in the pathogenesis of hepatosteatosis.

Plasma Adropin as a Potential Marker Predicting Obesity and Obesity-associated Cancer in Korean Patients With Type 2 Diabetes Mellitus

Background

Type 2 diabetes mellitus (T2DM) and cancer are serious health problems worldwide, and their prevalences have been on the rise in recent years. It has been reported that adropin plays an important role in the development of T2DM, oxidative stress, inflammation, and obesity. However, there is limited information available on T2DM from human studies, especially for the Korean population. In this study, we aimed to investigate the correlation between adropin levels and obesity of Korean T2DM patients.

Methods

Thirty-six T2DM patients were recruited for this study. The participants were further classified into female (n = 12) and male (n = 24). Their body composition, metabolic parameters, inflammatory factors, and oxidative stress were measured.

Results

The severity of obesity is more manifested in male than in female. Plasma triglyceride (TG) and high-sensitivity C-reactive protein (hs-CRP) levels of male were significantly higher than female. The plasma adropin and adiponectin level of female was significantly higher than male. The body weight, body mass index (BMI), body fat mass were negatively correlated with the plasma adropin level in female, whereas adropin has positive correlation with adiponectin in female. The hs-CRP was negatively correlated with the plasma adropin level in female and male. malondialdehyde, reactive oxidative species, and TNF-α was not significantly correlated with adropin in patients with T2DM.

Conclusions

These findings suggest that adropin may be more used as a biomarker for predicting the risk of obesity and inflammation in Korean patients with T2DM, especially women.

UPLC/Q‑TOF‑MS based plasma metabolomics and clinical characteristics of polycystic ovarian syndrome

The present study aimed to develop novel diagnostic methods for polycystic ovarian syndrome (PCOS) by screening and identifying specific PCOS‑associated metabolic markers using plasma metabolomics. Ultra‑performance liquid chromatography/quadrapole‑time of flight‑mass spectrometry was adopted to establish the plasma metabolic fingerprint of 49 patients and 50 normal controls, in order to screen the potential metabolic markers. In addition, these markers were integrated with the clinical indexes, followed by focused analysis to obtain diagnostic markers. The present results demonstrated that not only was the concentration of palmitoyl sphingomyelin in plasma of patients with PCOS significantly increased; however, a statistically significant difference between the two PCOS subgroups was additionally demonstrated. At the same time, the concentrations of cyclic guanosine monophosphate (cGMP) and dehydroepiandrosterone sulphate in the plasma of patients of the subgroup 1 were significantly elevated. These markers were additionally integrated with the clinical index number of follicles in the left ovary and high‑density lipoprotein (HDL‑C), followed by receiver operating characteristic curve analysis, which demonstrated a diagnostic accuracy of ~90% in the control and the two subgroups. The integrated marker system consisting of palmitoyl sphingomyelin, cGMP and androsterone sulfate, as well as the number of left follicles and HDL‑C may be used for the accurate diagnosis and classification of PCOS. These results confirmed that the abnormalities in hormone metabolism and lipid metabolism disorder were primarily involved in the onset of PCOS.

Serum adropin levels are decreased in Chinese type 2 diabetic patients and negatively correlated with body mass index

Adropin has been identified as potent regulatory hormone implicated in insulin sensitivity and the maintenance of energy homeostasis. The aim of current study was to investigate serum adropin concentrations of type 2 diabetes mellitus (T2DM) patients in the fasting status, especially those overweight/obese and evaluate the relationships between adropin levels and metabolic parameters. A total of 116 T2DM patients and 60 controls with normal glucose tolerance (NGT) were recruited to the study. Adropin concentration was determined using commercial ELISA kits. Anthropometric characteristics were collected and biochemistry, glycosylated hemoglobin A₁c (HbA₁c) and fasting insulin (FIns) were detected by clinical laboratory. Insulin resistance was estimated by homeostasis model 2 assessment of insulin resistance (HOMA2-IR). Serum adropin levels in Chinese T2DM patients were decreased compared with the controls [3.8 (3.0-5.5) vs. 5.5 (3.7-7.9) ng/mL, p < 0.01]. Meanwhile, overweight/obese patients had more considerably reduced levels of adropin. Adropin level was negatively correlated with body mass index (BMI), high-sensitive C reactive protein (hs-CRP), triglycerides (TG), fasting plasma glucose (FPG), FIns, HOMA2-IR and HbA₁c, while positively with high-density lipoprotein cholesterol (HDL-C) in study participants (p < 0.01). The correlations of adropin with glucolipid variables (TG, HDL-C, FPG, FIns, HOMA2-IR, HbA₁c) still existed after adjusting the effect of BMI. Besides, HOMA2-IR and HbA₁c were independent factors associated with serum adropin levels. Binary logistic regression analyses showed that adropin was significantly associated with T2DM after removing confounding factors (p < 0.01). Receiver operating characteristic (ROC) curve demonstrated adropin concentration of 5.8 ng/mL could be used as a possible optimal cut-off value to identify T2DM from non-T2DM with sensitivity of 81.9% and specificity of 46.7%. Serum adropin concentrations are decreased in Chinese T2DM patients, especially those overweight/obese. Adropin, associated with glucolipid homeostasis and insulin sensitivity, may implicate in the pathogenesis of T2DM.

Adropin and Inflammation Biomarker Levels in Male Patients With Obstructive Sleep Apnea: A Link With Glucose Metabolism and Sleep Parameters

STUDY OBJECTIVES

The main objectives of the study were to determine plasma adropin, systemic inflammation biomarker levels, and glucose metabolism parameters in patients with moderate and severe obstructive sleep apnea (OSA) compared to healthy controls.

METHODS

In this study, we included 50 male patients with OSA (25 moderate and 25 severe) and 25 age- and sex-matched control subjects. All subjects underwent fasting sampling of peripheral blood for laboratory analyses.

RESULTS

Adropin plasma levels were significantly lower in the severe OSA group in comparison with the moderate and control groups (4.50 ± 1.45 versus 6.55 ± 1.68 versus 8.15 ± 1.79 ng/mL, P < .001). Plasma biomarkers of systemic inflammation were significantly increased in patients with moderate OSA (interleukin [IL]-6 and tumor necrosis factor alpha [TNF-α]) and severe OSA (IL-6, TNF-α, high-sensitivity C-reactive protein) when compared with controls (P < .001). Adropin levels showed a significant negative correlation with IL-6 (r = -.419, P < .001), TNF-α (r = -.540, P < .001), fasting glucose (r = -.331, P = .004), hemoglobin A1c (r = -.438, P < .001), homeostatic model assessment insulin resistance index (r = -.213, P = .046), and polysomnographic parameters including apnea-hypopnea index (r = -.615, P < .001) and oxygen desaturation index (r = -.573, P < .001). A multivariate regression analysis showed that plasma adropin remained as a significant negative predictor of severe OSA status, when adjusted for age and body mass index and computed along with other inflammatory biomarkers in the regression model (odds ratio 0.069, 95% confidence interval 0.009-0.517, P = .009).

CONCLUSIONS

Plasma adropin concentrations significantly correlate with indices of disease severity in patients with OSA, suggesting that adropin potentially plays an important role in the complex pathophysiology of the disease.

Adropin levels in women with polycystic ovaries undergoing ovarian stimulation: correlation with lipoprotein lipid profiles

This study aimed to investigate serum and follicular fluid (FF) adropin levels in polycystic ovary syndrome (PCOS) and normal women undergoing controlled ovarian stimulation and correlate them with the lipid and lipoprotein levels. We included 60 women (30 lean and 30 overweight) with diagnosed PCOS, and 60 age and weight-matched non-PCOS controls (30 lean and 30 overweight), under in vitro fertilization (IVF) treatment. Serum lipid and lipoprotein levels were assessed by the Abbott Architect c8000 autoanalyzer while adropin levels were determined by enzyme immunoassay. Serum and FF adropin levels were significantly lower in PCOS women compared with controls and FF adropin levels were lower than serum levels. Significantly higher serum levels of total cholesterol, LDL-C, triglycerides, apolipoprotein B, lipoprotein(a) and homocysteine were encountered in PCOS subjects, while HDL-C and apolipoprotein A1 were significantly lower compared with controls. According to univariate and multivariate analysis, serum and FF adropin levels were positively correlated with BMI and HDL-C levels and negatively correlated with LDL-C levels. Women with polycystic ovaries exhibit lipid lipoprotein alterations increasing the risk of cardiovascular diseases later in life. Our findings suggest a probable involvement of adropin both in human metabolism and in the pathophysiology of PCOS.

Association of Serum Adropin Concentrations with Diabetic Nephropathy

Objective. Adropin is a newly identified regulatory protein encoded by the Enho gene and is critically involved in energy homeostasis and insulin sensitivity. This study aims to determine the correlation of serum adropin concentrations with diabetic nephropathy (DN). Methods. This study consisted of 245 patients with type 2 diabetes mellitus (T2DM) and 81 healthy subjects. Then T2DM patients were divided into normoalbuminuria, microalbuminuria, and macroalbuminuria subgroups based on urine albumin to creatinine ratio (ACR). Results. T2DM patients showed significantly lower serum adropin concentrations than those in the controls. T2DM patients with macroalbuminuria had significantly decreased serum adropin concentrations compared with the other three groups. In addition, T2DM patients with microalbuminuria showed lower serum adropin concentrations than those in patients with normoalbuminuria. Logistic regression analysis showed that serum adropin was correlated with decreased risk of developing T2DM and DN. Pearson correlation analysis indicated that serum adropin was negatively correlated with body mass index (BMI), blood urea nitrogen, creatinine, and ACR and positively correlated with glomerular filtration rate. Furthermore, multiple linear regression analysis showed that BMI and ACR were negatively correlated with serum adropin levels. Conclusion. Serum adropin concentrations are negatively associated with renal function. Adropin may be implicated in the pathogenesis of DN development.