Role of serum adropin measurement in the assessment of insulin resistance in obesity

Predictive biomarkers for cardiometabolic risk in postmenopausal women: insights into visfatin, adropin, and adiponectin

Background

Visfatin, adropin, and adiponectin are involved in many changes associated with obesity and metabolic disorders, and may be related to metabolic syndrome and cardiovascular disease. The selection of visfatin, adropin, and adiponectin as biomarkers is based on their significant roles in metabolic regulation and inflammation, which are critical factors in cardiometabolic risk. Visfatin is known for its pro-inflammatory properties and its ability to modulate insulin resistance. Adropin is involved in energy homeostasis and metabolic health, while adiponectin has anti-inflammatory and insulin-sensitizing effects. During the perimenopausal period, the risk of obesity, and consequently cardiometabolic diseases increases. Therefore, the aim of this study was to assess the relationship between cardiometabolic parameters and circulating levels of visfatin, adropin, and adiponectin in perimenopausal women with regard to their obesity status.

Materials and methods

This study of 168 perimenopausal women utilized a cross-sectional design with non-random sampling. It involved the use of questionnaires, as well as anthropometric and blood pressure measurements. Blood samples were collected to determine the levels of visfatin, adropin, and adiponectin. Statistical analyses, including correlation coefficients, were performed to evaluate the relationship between these biomarkers and cardiometabolic risk factors, such as insulin resistance, lipid profiles, and inflammatory markers.

Results

In our study, visceral adiposity index and lipid accumulation product negatively correlated with adiponectin levels. Preliminary multivariate linear regression analysis revealed a positive correlation between circulating visfatin and IL-6 levels. Circulating adropin negatively correlated with HbA1C, fasting blood glucose, and insulin. Adiponectin negatively correlated with HbA1C, fasting blood glucose, insulin, and triglycerides. Furthermore, circulating adiponectin positively correlated with HDL, and negatively with HOMA-IR.

Conclusions

Adiponectin is a promising biomarker for predicting cardiometabolic risk in postmenopausal women.

Adropin: a key player in immune cell homeostasis and regulation of inflammation in several diseases

Adropin is a secreted peptide encoded by the energy homeostasis-associated gene (ENHO), located chromosome 9p13.3, with a conserved amino acid sequence across humans and mice. Its expression is regulated by various factors, including fat, LXRα, ERα, ROR, and STAT3. Adropin plays a critical role in glucose and lipid metabolism, as well as insulin resistance, by modulating multiple signaling pathways that contribute to the reduction of obesity and the improvement of blood lipid and glucose homeostasis. Additionally, it influences immune cells and inflammation, exerting anti-inflammatory effects across various diseases. While extensive research has summarized the regulation of cellular energy metabolism by adropin, limited studies have explored its role in immune regulation and inflammation. To enhance the understanding of adropin's immune-modulating and anti-inflammatory mechanisms, this review synthesizes recent findings on its effects in conditions such as atherosclerosis, diabetes, fatty liver, non-alcoholic hepatitis, and inflammation. Furthermore, the review discusses the current research limitations and outlines potential future directions for adropin-related investigations. It is hoped that ongoing research into adropin will contribute significantly to the advancement of medical treatments for various diseases.

Role of the Unique Secreted Peptide Adropin in Various Physiological and Disease States

Adropin, a secreted peptide hormone identified in 2008, plays a significant role in regulating energy homeostasis, glucose metabolism, and lipid metabolism. Its expression is linked to dietary macronutrient intake and is influenced by metabolic syndrome, obesity, diabetes, and cardiovascular diseases. Emerging evidence suggests that adropin might be a biomarker for various conditions, including metabolic syndrome, coronary artery disease, and hypertensive disorders complicating pregnancy. In cerebrovascular diseases, adropin demonstrates protective effects by reducing blood-brain barrier permeability, brain edema, and infarct size while improving cognitive and sensorimotor functions in ischemic stroke models. The protective effects of adropin extend to preventing endothelial damage, promoting angiogenesis, and mitigating inflammation, making it a promising therapeutic target for cardiovascular and neurodegenerative diseases. This review provides a comprehensive overview of adropin's multifaceted roles in physiological and pathological conditions, as well as our recent work demonstrating adropin's role in subarachnoid hemorrhage-mediated neural injury and delayed cerebral infarction.

Adropin regulates macrophage phenotype via PPARγ signalling: A preliminary study of adropin and Crohn's disease

Macrophage polarization is increasingly recognized as a vital pathogenetic factor in Crohn's disease (CD). Adropin is a secreted protein implicated in energy homeostasis, chiefly linked to glucose and lipid metabolism. However, the significance of adropin in CD is not clear. The objective of this study was to detect the expression of adropin in CD patients and investigate the effect of adropin on macrophage polarization induced by lipopolysaccharide (LPS) and its potential mechanism. Our study showed that serum adropin levels were markedly lower in patients with CD in active (CDA) than patients with CD in remission (CDR) and control groups (p < 0.01), however, there was no significant difference between in remission CD and healthy controls (p > 0.05). The colon mucous adropin levels in CDA were distinctly higher than CDR and controls (p < 0.01), while a significant difference between in remission CD and in healthy controls was not observed (p > 0.05). Exploration of the specific mechanism of action indicated that adropin promoted LPS-induced RAW264.7 macrophage polarization to M2 phenotype by modulating the expression and nuclear translocation of peroxisome proliferator receptor gamma (PPARγ), which may help weaken the intestinal inflammatory response. PPARγ inhibitor GW9662 reversed adropin-induced M2 macrophage polarization. Knockdown of GPR19, an adropin receptor, abrogated the M2 macrophage polarization caused by PPARγ. These findings suggest that adropin in colonic mucosa is a protective response in patients with active Crohn's disease.

Serum adropin level in wet-type age-related macular degeneration

PURPOSE

Our objective was to compare the serum Adropin levels between patients with wet-type Age-Related Macular Degeneration (AMD) and otherwise healthy individuals.

METHOD

The study included 45 patients with wet-type AMD and 45 individuals without age-related macular degeneration. Patients with co-morbidities such as diabetes, hypertension, autoimmune diseases, and a previous history of visual impairment; were excluded. FBS, Hemoglobin A1C (HbA1C), lipid profile, and serum Adropin level were checked.

RESULTS

The mean serum Adropin level of patients with wet-type AMD was significantly lower than the control group (P-value < 0.001). Also, the mean High-sensitivity C-reactive protein ( hsCRP) level and High Density Lipoprotein (HDL) were significantly higher in wet-type AMD patients (P-value = 0.031 and < 0.001 respectively).

CONCLUSIONS

In our study, wet-type AMD was associated with a lower level of serum Adropin. Because of Adropin involvement in glucose metabolism and age-related changes, it may have a role in the pathogenesis of AMD, but it requires more investigations at the molecular level to elucidate its function.

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.

Adropin’s Role in Energy Homeostasis and Metabolic Disorders

Adropin is a novel 76-amino acid-peptide that is expressed in different tissues and cells including the liver, pancreas, heart and vascular tissues, kidney, milk, serum, plasma and many parts of the brain. Adropin, encoded by the Enho gene, plays a crucial role in energy homeostasis. The literature review indicates that adropin alleviates the degree of insulin resistance by reducing endogenous hepatic glucose production. Adropin improves glucose metabolism by enhancing glucose utilization in mice, including the sensitization of insulin signaling pathways such as Akt phosphorylation and the activation of the glucose transporter 4 receptor. Several studies have also demonstrated that adropin improves cardiac function, cardiac efficiency and coronary blood flow in mice. Adropin can also reduce the levels of serum triglycerides, total cholesterol and low-density lipoprotein cholesterol. In contrast, it increases the level of high-density lipoprotein cholesterol, often referred to as the beneficial cholesterol. Adropin inhibits inflammation by reducing the tissue level of pro-inflammatory cytokines such as tumor necrosis factor alpha and interleukin-6. The protective effect of adropin on the vascular endothelium is through an increase in the expression of endothelial nitric oxide synthase. This article provides an overview of the existing literature about the role of adropin in different pathological conditions.

Association between weight change and risk of metabolic abnormalities in non-overweight/obese and overweight/obese population: A retrospective cohort study among Chinese adults

OBJECTIVES

To explore the effects of weight change on the risk of metabolic abnormalities in the Chinese population.

METHODS

A total of 1895 metabolically healthy adults aged 21-78 years completed anthropometric and biological measurements at baseline (2012) and at an eight year follow-up (2020). Based on absolute weight change and relative weight change, the participants were split into five classes. A Cox proportional hazards regression model was used to estimate the relative risk (RR) and 95% confidence intervals (95% CI) for the risk of metabolic abnormalities using stable weight as the reference group. Stratified analysis was used to explore this relationship in participants with different baseline body mass index (BMI) levels.

RESULTS

During the follow-up period, 35.41% of the participants retained a stable weight, and 10.71% had metabolic abnormalities. After covariate adjustment, for every kilogram gained over eight years, the risk of developing metabolic abnormalities increased by 22% (RR: 1.094; 95% CI: 1.063-1.127). Compared with stable weight participants, weight gain of 2-4 Kg and weight gain ≥ 4 Kg exhibited significantly higher risks of metabolic abnormalities, with RR of 1.700 (95% CI 1.150-2.513) and 1.981 (95% CI 1.372-2.859), respectively. A weight gain of ≥ 4 Kg had an opposite effect on the overweight/obesity and non-overweight/obesity groups, with an increased risk of metabolic abnormalities only in the non-overweight/obesity group (RR, 2.291; 95% CI, 1.331-3.942). Moreover, weight loss ≥ 4 Kg significantly reduced the risk of metabolic abnormalities only among overweight/obese adults (RR 0.373; 95% CI 0.154-0.906). Similar results were observed in relative body weight change analyses.

CONCLUSIONS

Long-term excessive body weight gain is positively associated with an increased risk of metabolic abnormalities among adults with non-overweight/obesity, whereas long-term body weight loss is a protective factor for metabolic health among adults with overweight/obesity.