Serum concentration of asprosin in new-onset type 2 diabetes

Circulating asprosin concentrations in individuals with new-onset type 2 diabetes and prediabetes

AIMS

This research aimed to clarify the relationship between serum asprosin levels and the occurrence of type 2 diabetes mellitus (T2DM) in light of mixed findings about the role of asprosin in T2DM and the lack of studies on its effects on prediabetic conditions.

METHODS

In this observational analysis the cohort included 252 adults aged22-69 recruitedfromJinan Central Hospital were categorized into three groups, normal glucose tolerance (NGT), impaired glucose regulation (IGR) and T2DM groups. Serum asprosin levels were measured using enzyme linked immunosorbent assay (ELISA). Additionally, all participants underwent assessments of various anthropometric and biochemical markers.

RESULTS

Analysis revealed a notable increase in serum asprosin levels among individuals with newly diagnosed T2DM, with IGR subjects also demonstrating slightly elevated asprosin levels compared to the healthy group. Further stratification by quartiles of asprosin levels revealed a progressive increase in the proportions of IGR + T2DM patients, highlighting a potential association between elevated asprosin and increased T2DM risk. The Receiver Operating Characteristic (ROC) curve analysis for the efficacy of asprosin in identifying IGR + T2DM yielded an area under curve (AUC) of 0.853 (95 % CI: 0.808-0.899), pointing a threshold value of 4.95 ng/ml for asprosin.

CONCLUSIONS

This investigation revealed that individuals with prediabetes and those newly diagnosed with T2DM exhibit increased serum asprosin levels, suggesting that elevated asprosin concentrations are linked to early disturbances in glucose homeostasis.

Asprosin aggravates nonalcoholic fatty liver disease via inflammation and lipid metabolic disturbance mediated by reactive oxygen species

Asprosin (ASP) is a newly-identified adipokine and plays important roles in energy metabolism homeostasis. However, there is no report on whether and how ASP is involved in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Therefore, in the study, we investigated the protective effects of ASP-deficiency on the liver in the NAFLD model mice and the detrimental effects of ASP treatment on the human normal hepatocytes (LO2 cell line). More important, we explored the underlying mechanism from the perspective of lipid metabolism and inflammation. In the in vivo experiments, our data showed that the ASP-deficiency significantly alleviated the high-fat diet-induced inflammation and NAFLD, inhibited the hepatic fat deposition and downregulated the expressions of fat acid synthase (FASN), peroxisome proliferator-activated receptor γ (PPARγ) and forkhead box protein O1 (FOXO1); moreover, the ASP-deficiency attenuated the inflammatory state and inhibited the activation of the IKK/NF-κBp65 inflammation pathway. In the in vitro experiments, our results revealed that ASP treatment caused and even exacerbated the injury of LO2 cells induced by FFA; In contrast, the ASP treatment upregulated the expressions of PPARγ, FOXO1, FASN, ACC and acyl-CoA oxidase 1 (ACOX1) and elevated the reactive oxygen species (ROS) levels. Accordingly, these results demonstrate that ASP causes NAFLD through disrupting lipid metabolism and promoting the inflammation mediated by ROS.

Comparison of HIIT and MICT and further detraining on metabolic syndrome and asprosin signaling pathway in metabolic syndrome model of rats

Physical activity promotes various metabolic benefits by balancing pro and anti-inflammatory adipokines. Recent studies suggest that asprosin might be involved in progression of metabolic syndrome (MetS), however, the underlying mechanisms have not been understood yet. This study aimed to evaluate the effects of high-intensity interval training (HIIT), moderate-intensity continuous training (MICT), and further detraining on MetS indices, insulin resistance, serum and the liver levels of asprosin, and AMP-activated protein kinase (AMPK) pathway in menopause-induced MetS model of rats. A total of 64 Wistar rats were used in this study and divided into eight groups: Sham1, OVX1 (ovariectomized), Sham2, OVX2, OVX + HIIT, OVX + MICT, OVX + HIIT + Det (detraining), and OVX + MICT + Det. Animals performed the protocols, and then serum concentrations of asprosin, TNF-α, insulin, fasting blood glucose, and lipid profiles (TC, LDL, TG, and HDL) were assessed. Additionally, the liver expression of asprosin, AMPK, and P-AMPK was measured by western blotting. Both HIIT and MICT caused a significant decrease in weight, waist circumference, BMI (P = 0.001), and serum levels of glucose, insulin, asprosin (P = 0.001), triglyceride, total cholesterol, low-density lipoprotein (LDL), and TNF-α (P = 0.001), but an increase in the liver AMPK, P-AMPK, and P-AMPK/AMPK (P = 0.001), compared with OVX2 noexercised group. MICT was superior to HIIT in reducing serum asprosin, TNF-a, TG, LDL (P = 0.001), insulin, fasting blood glucose, HOMA-IR, and QUEKI index (P = 0.001), but an increase in the liver AMPK, and p-AMPK (P = 0.001). Although after two months of de-training almost all indices returned to the pre exercise values (P < 0.05). The findings suggest that MICT effectively alleviates MetS induced by menopause, at least partly through the activation of liver signaling of P-AMPK and the reduction of asprosin and TNF-α. These results have practical implications for the development of exercise interventions targeting MetS in menopausal individuals, emphasizing the potential benefits of MICT in mitigating MetS-related complications.

The mediation effect of asprosin on the association between ambient air pollution and diabetes mellitus in the elderly population in Taiyuan, China

Evidence around the relationship between air pollution and the development of diabetes mellitus (DM) remains limited and inconsistent. To investigate the potential mediation effect of asprosin on the association between fine particulate matter (PM2.5), tropospheric ozone (O3) and blood glucose homeostasis. A case-control study was conducted on a total of 320 individuals aged over 60 years, including both diabetic and non-diabetic individuals, from six communities in Taiyuan, China, from July to September 2021. Generalized linear models (GLMs) suggested that short-term exposure to PM2.5 was associated with elevated fasting blood glucose (FBG), insulin resistance index (HOMA-IR), as well as reduced pancreatic β-cell function index (HOMA-β), and short-term exposure to O3 was associated with increased FBG and decreased HOMA-β in the total population and elderly diabetic patients. Mediation analysis showed that asprosin played a mediating role in the relationship of PM2.5 and O3 with FBG, with mediating ratios of 10.2% and 18.4%, respectively. Our study provides emerging evidence supporting that asprosin mediates the short-term effects of exposure to PM2.5 and O3 on elevated FBG levels in an elderly population. Additionally, the elderly who are diabetic, over 70 years, and BMI over 24 kg/m2 are more vulnerable to air pollutants and need additional protection to reduce their exposure to air pollution.

Inter-organ crosstalk during development and progression of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is characterized by tissue-specific insulin resistance and pancreatic β-cell dysfunction, which result from the interplay of local abnormalities within different tissues and systemic dysregulation of tissue crosstalk. The main local mechanisms comprise metabolic (lipid) signalling, altered mitochondrial metabolism with oxidative stress, endoplasmic reticulum stress and local inflammation. While the role of endocrine dysregulation in T2DM pathogenesis is well established, other forms of inter-organ crosstalk deserve closer investigation to better understand the multifactorial transition from normoglycaemia to hyperglycaemia. This narrative Review addresses the impact of certain tissue-specific messenger systems, such as metabolites, peptides and proteins and microRNAs, their secretion patterns and possible alternative transport mechanisms, such as extracellular vesicles (exosomes). The focus is on the effects of these messengers on distant organs during the development of T2DM and progression to its complications. Starting from the adipose tissue as a major organ relevant to T2DM pathophysiology, the discussion is expanded to other key tissues, such as skeletal muscle, liver, the endocrine pancreas and the intestine. Subsequently, this Review also sheds light on the potential of multimarker panels derived from these biomarkers and related multi-omics for the prediction of risk and progression of T2DM, novel diabetes mellitus subtypes and/or endotypes and T2DM-related complications.

Association of serum Asprosin concentrations with heart failure

BACKGROUND

To analyze the association of serum Asprosin concentrations with heart failure (HF).

METHODS

A total of 103 patients with HF were included in the HF group, and 103 patients with health checkups were included in the non-HF group. The serum Asprosin levels of the two groups were measured, and relevant clinical data were collected for statistical analysis.

RESULTS

Compared with the non-HF group, the serum Asprosin concentration was significantly higher in the HF group, and the difference was statistically significant (P < 0.001). According to the serum Asprosin levels, we divided all the subjects into three quartiles. We found that the prevalence of HF increased with increasing serum Asprosin levels in the three groups (P < 0.001). Serum Asprosin levels were positively correlated with NT-ProBNP (P < 0.05) and negatively correlated with LVEF (P < 0.001). Dichotomous logistic regression analysis found Asprosin and age to be independent risk factors for HF (OR = 1.010, 95% CI: 1.003-1.018; OR = 1.058, 95% CI:1.004-1.665, respectively). Combining Asprosin and NT-proBNP indicators to draw ROC curves can improve the specificity and sensitivity of HF diagnosis.

CONCLUSIONS

Serum Asprosin levels were significantly elevated in HF patients. The serum Asprosin level is an independent risk factor for HF, and the combined detection of Asprosin and NT-proBNP levels can improve the accuracy of HF diagnosis.

Meteorin-like Protein and Asprosin Levels in Children and Adolescents with Obesity and Their Relationship with Insulin Resistance and Metabolic Syndrome

OBJECTIVE

Two newly discovered adipokines, including Meteorin-like protein (Metrnl) and asprosin, have been implicated in glucose and insulin metabolism. This study aimed to investigate the associations of these adipokines with obesity in children and adolescents.

METHODS

This study was performed on 35 normal-weight children and 35 children with obesity. Anthropometric and biochemical parameters were determined. Serum concentrations of Metrnl, asprosin, and insulin were measured using enzyme-linked immunosorbent assay.

RESULTS

Metrnl level was significantly lower in obese children than normal-weight children. Additionally, Metrnl was negatively correlated with body mass index (BMI), insulin, waist-to-hip ratio, and homeostatic model assessment of insulin resistance (HOMA-IR). Our results also revealed that circulating asprosin levels were significantly increased in obese children compared to the control subjects and were positively correlated with BMI, insulin, HOMA-IR, cholesterol, and LDL-C.

CONCLUSION

Obesity is accompanied by significant alterations in Metrnl and asprosin and therefore these adipokines, especially Metrnl, are suggested as new promising therapeutic targets for obesity and its associated metabolic imbalances.

Can the new adipokine asprosin be a metabolic troublemaker for cardiovascular diseases? A state-of-the-art review

Adipokines play a significant role in cardiometabolic diseases. Asprosin, a newly discovered adipokine, was first identified as a glucose-raising protein hormone. Asprosin also stimulates appetite and regulates glucose and lipid metabolism. Its identified receptors so far include Olfr734 and Ptprd. Clinical studies have found that asprosin may be associated with cardiometabolic diseases. Asprosin may have diagnostic and therapeutic potential in obesity, diabetes, metabolic syndrome and atherosclerotic cardiovascular diseases. Herein, the structure, receptors, and functions of asprosin and its relationship with cardiometabolic diseases are summarized based on recent findings.

Serum Asprosin Correlates with Indirect Insulin Resistance Indices

BACKGROUND AND OBJECTIVES

Insulin resistance is a major contributor to the development of type 2 diabetes and can be assessed using indirect indicators calculated from non-invasive tests. Asprosin is a recently discovered adipokine with a postulated effect on glycemic regulation. This study aimed to investigate the correlation between serum asprosin levels and insulin resistance indices. The correlation between circulating asprosin and obesity indices was also investigated.

MATERIALS AND METHODS

A total of 50 non-diabetic patients with obesity and 50 healthy volunteers were studied. Laboratory data, including circulating asprosin and anthropometric data, were collected. The following insulin resistance indices were calculated: triglyceride-glucose index (TyG), TyG-neck circumference (TyG-NC), TyG-neck circumference to height ratio (TyG-NHtR), TyG-waist circumference (TyG-WC), TyG-waist to height ratio (TyG-WHtR), TyG-body mass index (TyG-BMI), and the ratio between triglycerides and high-density cholesterol (TG/HDLc). The obtained data were analyzed separately for males and females.

RESULTS

Asprosin concentrations were significantly higher in obese patients (p < 0.001). Asprosin concentrations positively correlated with body mass index (p < 0.001, r = 0.8 in females and r = 0.8 in males), waist circumference (p < 0.001, r = 0.73 in females and r = 0.81 in males), and all tested indices of insulin resistance. The strongest correlation was observed for TyG-BMI (p < 0.001, r = 0.78 in females and r = 0.81 in males). Circulating asprosin was higher in females (p < 0.001).

CONCLUSIONS

Asprosin can be considered a marker of obesity and insulin resistance.

Betatrophin, elabela, asprosin, glucagon and subfatin peptides in breast tissue, blood and milk in gestational diabetes

We investigated the presence of asprosin (ASP), betatrophin, elabela (ELA), glucagon and subfatin (SUB) in the milk of mothers with gestational diabetes mellitus (GDM) and compared their levels with blood levels. We also investigated whether these peptides are synthesized by the breast. We investigated 12 volunteer mothers with GDM and 14 pregnant non-GDM control mothers. The peptides were measured using ELISA and their tissue localization was determined using immunohistochemistry. Breast milk contains ASP, betatrophin, ELA, glucagon and SUB. The amount of the peptides ranged from highest to the lowest in colostrum, transitional milk and mature milk. The amount of peptides in the milk was greater than for blood. The peptides, except for ELA, were increased in milk and blood by GDM. Betatrophin and ELA are synthesized in the connective tissue of the breast. ASP, glucagon and SUB are synthesized in the alveolar tissue of the breast. These peptides in breast milk may contribute to the development of the gastrointestinal tract of newborns and infants.

Asprosin Enhances Cytokine Production by a Co-Culture of Fully Differentiated Mature Adipocytes and Macrophages Leading to the Exacerbation of the Condition Typical of Obesity-Related Inflammation

Asprosin, a fasting-induced, glucogenic, and orexigenic adipokine, has gained popularity in recent years as a potential target in the fight against obesity and its complications. However, the contribution of asprosin to the development of moderate obesity-related inflammation remains still unknown. The present study aimed to evaluate the effect of asprosin on the inflammatory activation of adipocyte–macrophage co-cultures at various stages of differentiation. The study was performed on co-cultures of the murine 3T3L1 adipocyte and the RAW264.7 macrophage cell lines treated with asprosin before, during, and after 3T3L1 cell differentiation, with or without lipopolysaccharide (LPS) stimulation. Cell viability, overall cell activity, and the expression and release of key inflammatory cytokines were analyzed. In the concentration range of 50–100 nM, asprosin increased the pro-inflammatory activity in the mature co-culture and enhanced the expression and release of tumor necrosis factor α (TNF-α), high-mobility group box protein 1 (HMGB1), and interleukin 6 (IL-6). Macrophage migration was also increased, which could be related to the upregulated expression and release of monocyte chemoattractant protein-1 (MCP-1) by the adipocytes. In summary, asprosin exerted a pro-inflammatory effect on the mature adipocyte–macrophage co-culture and may contribute to the spread of moderate obesity-associated inflammation. Nevertheless, further research is needed to fully elucidate this process.

Correlation of asprosin and Nrg-4 with type 2 diabetes Mellitus Complicated with Coronary Heart Disease and the Diagnostic Value

PURPOSE

Asprosin is a newly discovered adipose factor secreted by white fat, which is involved in glucose metabolism and inflammation. Neuregulin-4 (Nrg-4) is a new adipose factor released from brown adipose tissue and is considered to play an important role in metabolism. This study aims to explore the association between serum Asprosin, Nrg-4 level and coronary heart disease(CHD) in patients with type 2 diabetes mellitus(T2DM) and the diagnostic value.

PATIENTS AND METHODS

157 patients with T2DM were enrolled from Affiliated Hospital of Chengde Medical University between December 2020 to July 2021. These patients were divided into T2DM without CHD group (T2DM-0, n = 80) and T2DM with CHD (T2DM-CHD, n = 77). Serum Asprosin and Nrg-4 expression was detected by enzyme-linked immunosorbent assay, and the correlations between Asprosin or Nrg-4 and clinical and biochemical indicators were analyzed. A receiver operating characteristics curve analysis and area under the curve (AUC) were used to evaluate diagnostic accuracy.

RESULTS

Serum Asprosin level of the T2DM-CHD group were significantly higher and Nrg-4 level significantly lower than those of the T2DM-0 group.Spearman correlation analysis showed that serum Asprosin levels were significantly positively correlated with diabetes course,history of hypertension, fasting plasma glucose(FPG), glycosylated hemoglobin A1c(HbA1C), triglycerides(TG),triglyceride glucose index(TyG index) and urea, and negatively correlated with ALT (all p < 0.05). Nrg-4 was negatively correlated with history of hypertension, body mass index(BMI), FPG, HbA1C, TG, and TyG indexes (all p < 0.05), and positively correlated with high-density lipoprotein cholesterol(HDL-C)(p < 0.05).Logistic regression analysis showed that after adjusting potential confounders, Asprosin was a risk factor for diabetes mellitus, Nrg-4 was a protective factor.The AUC of Asprosin for diagnosing T2DM-CHD was 0.671 (95% confidence interval [CI] 0.584-0.759), and the AUC of the Nrg4 index for diagnosing T2DM-CHD was 0.772 (95% CI 0.700-0.844). The AUC of Asprosin and Nrg-4 for the combined diagnosis of T2DM-CHD was 0.796 (95% CI 0.726-0.864).

CONCLUSION

Asprosin and Nrg-4 may be novel diagnostic biomarkers for T2DM with CHD, as they effectively improved the diagnostic accuracy for T2DM-CHD.

Effect of D-β-hydroxybutyrate-(R)-1,3 butanediol on plasma levels of asprosin and leptin: results from a randomised controlled trial

Background: D-β-Hydroxybutyrate-(R)-1,3 butanediol - a non-racemic ketone monoester for ingestion - has emerged as an effective way to achieve acute nutritional ketosis. Whether white adipose tissue plays a role in effects of acute nutritional ketosis is largely unknown. Objective: To investigate the effects of acute nutritional ketosis on plasma levels of asprosin and leptin and if they are affected by abdominal fat phenotypes. Methods: The design was a randomised crossover trial. Participants received either the D-β-hydroxybutyrate-(R)-1,3 butanediol monoester (KEβHB) drink or placebo drink. Blood samples were collected at baseline, 30, 60, 90, 120, and 150 minutes. 3.0 Tesla magnetic resonance imaging was used to measure visceral and subcutaneous fat volumes (VFV and SFV, respectively), intra-hepatic fat deposition (IHFD), and intra-pancreatic fat deposition (IPFD). Results: A total of 18 adults were randomised, with no drop-outs. There were no significant differences in plasma levels of asprosin and leptin (p = 0.808 and p = 0.907, respectively) between the KEβHB and placebo drinks. There was no effect of time, treatment, or interaction between time and treatment on asprosin and leptin. After stratification by the VFV/SFV ratio, IHFD, and IPFD, there were no differences in asprosin and leptin between the KEβHB and placebo drinks. Conclusion: Plasma levels of asprosin and leptin were not significantly affected by acute nutritional ketosis. Abdominal fat phenotypes did not significantly affect circulating levels of the two hormones. White adipose tissue does not appear to play a role in altering hormone levels during acute nutritional ketosis. The clinical trial registry number is NCT03889210 (https://clinicaltrials.gov).

Asprosin in health and disease, a new glucose sensor with central and peripheral metabolic effects

Adipose tissue malfunction leads to altered adipokine secretion which might consequently contribute to an array of metabolic diseases spectrum including obesity, diabetes mellitus, and cardiovascular disorders. Asprosin is a novel diabetogenic adipokine classified as a caudamin hormone protein. This adipokine is released from white adipose tissue during fasting and elicits glucogenic and orexigenic effects. Although white adipose tissue is the dominant source for this multitask adipokine, other tissues also may produce asprosin such as salivary glands, pancreatic B-cells, and cartilage. Significantly, plasma asprosin levels link to glucose metabolism, lipid profile, insulin resistance (IR), and β-cell function. Indeed, asprosin exhibits a potent role in the metabolic process, induces hepatic glucose production, and influences appetite behavior. Clinical and preclinical research showed dysregulated levels of circulating asprosin in several metabolic diseases including obesity, type 2 diabetes mellitus (T2DM), polycystic ovarian syndrome (PCOS), non-alcoholic fatty liver (NAFLD), and several types of cancer. This review provides a comprehensive overview of the asprosin role in the etiology and pathophysiological manifestations of these conditions. Asprosin could be a promising candidate for both novel pharmacological treatment strategies and diagnostic tools, although developing a better understanding of its function and signaling pathways is still needed.

Fibrillin-1 and asprosin, novel players in metabolic syndrome

Fibrillin-1 is a major component of the extracellular microfibrils, where it interacts with other extracellular matrix proteins to provide elasticity to connective tissues, and regulates the bioavailability of TGFβ family members. A peptide consisting of the C-terminal 140 amino acids of fibrillin-1 has recently been identified as a glucogenic hormone, secreted from adipose tissue during fasting and targeting the liver to release glucose. This fragment, called asprosin, also signals in the hypothalamus to stimulate appetite. Asprosin levels are correlated with many of the pathologies indicative of metabolic syndrome, including insulin resistance and obesity. Previous studies and reviews have addressed the therapeutic potential of asprosin as a target in obesity, diabetes and related conditions without considering mechanisms underlying the relationship between generation of asprosin and expression of the much larger fibrillin-1 protein. Profibrillin-1 undergoes obligatory cleavage at the cell surface as part of its assembly into microfibrils, producing the asprosin peptide as well as mature fibrillin-1. Patterns of FBN1 mRNA expression are inconsistent with the necessity for regulated release of asprosin. The asprosin peptide may be protected from degradation in adipose tissue. We present evidence for an alternative possibility, that asprosin mRNA is generated independently from an internal promoter within the 3' end of the FBN1 gene, which would allow for regulation independent of fibrillin-synthesis and is more economical of cellular resources. The discovery of asprosin opened exciting possibilities for treatment of metabolic syndrome related conditions, but there is much to be understood before such therapies could be introduced into the clinic.

Association of ambient air pollution exposure with low birth weight

Increasing evidence has shown that exposure to air pollution is linked to adverse birth outcomes, but the results are not consistent. This study was performed on a subset of participants from the UK Biobank between 2006 and 2010. The land use regression (LUR) model was constructed to calculate the concentrations of particulate matter (PM2.5, PM2.5-10 and PM10), nitrogen oxides (NOx), and nitrogen dioxide (NO2). Binary logistic/multivariate linear regression models were applied to explore the potential linear relationships between air pollution exposure and newborn low birth weight (LBW) or BW. The Cochran-Armitage trend test was used to explore the possible association between the air pollution level and LBW. A restricted cubic spline (RCS) transformation of exposure variables was applied to visualize the relation of air pollutants to BW. Exposure to air pollutants, especially PM2.5 and PM10, was positively associated with LBW, and the odds ratios (ORs) and 95% confidence intervals (CIs) for each 10-μg/m3 increase in PM2.5 and PM10 were 1.25 ([1.03, 1.51], P = 0.025) and 1.12 ([1.02, 1.24], P = 0.021), respectively. A negative correlation was observed between the BW and PM2.5 (-0.05 [-0.08, -0.02], P = 0.001), PM10 (-0.03 [-0.05, -0.02], P < 0.001), PM2.5-10 (-0.04 [-0.07, -0.01], P < 0.001) and NOx (0.00 [0.00, 0.00], P = 0.021). Additionally, the BW changed dramatically up to a specific point (PM2.5 for 10.74 μg/m3, Pnonlinearity = 0.004; PM10 for 16.06 μg/m3, Pnonlinearity = 0.004; NO2 for 25.58 μg/m3, Pnonlinearity <0.001; and NOx for 39.88 μg/m3, Pnonlinearity <0.001), subsequently becoming relatively stable. PM2.5 and PM10 exposure were positively associated with LBW, and a negative correlation was observed between PM2.5, PM2.5-10, PM10 and NOx and BW.

Effects of GLP-1 receptor agonists on asprosin levels in normal weight or overweight/obesity patients with type 2 diabetes mellitus

Asprosin is a newly identified adipokine with glucose-raising and appetite-enhancing effects which acts differently from the known hepatic glucose utilization pathway. This study investigated changes in serum asprosin levels in normal weight or overweight/obese liraglutide-treated patients with type 2 diabetes (T2DM). This study is a non-randomized, prospective observational study. The metabolic parameters and asprosin levels were compared between 90 people with T2DM and 66 people who had normal glucose tolerance (NGT). During the treatment phase, only T2DM patients were given liraglutide at doses of 0.6 mg/d for the first 2 weeks, 1.2 mg/d for the subsequent 4 weeks, and 1.8 mg/d for the following 16 weeks. T2DM patients were separated into a normal weight group and an overweight/obesity group to compare changes in asprosin and parameters pre- and post-treatment. The T2DM group had significantly higher fasting asprosin and 2h-postprandial asprosin levels than the NGT group (all P < .001). Fasting asprosin and postprandial asprosin positively correlated with BMI, 2hPG, HbA1c, TG, and HOMA-IR, and negatively correlated with HDL-C in both the T2DM and NGT groups. Asprosin levels decreased after liraglutide treatment in both normal and overweight/obesity T2DM groups (all P < .001), with significantly reduced body weight and BMI in overweight/obese T2DM patients (all P < .001). Fasting and postprandial serum asprosin concentrations are higher in T2DM patients compared to normal glucose controls. Fasting and postprandial asprosin positively correlated with BMI, 2hPG, HbA1c, TG, and HOMA-IR and negatively correlated with HDL-C in all participants. Liraglutide lowers asprosin levels in T2DM patients and can reduce weight and BMI in overweight or obese type 2 diabetics.

Association between circulating asprosin levels and carotid atherosclerotic plaque in patients with type 2 diabetes

BACKGROUND

Carotid plaque is one of the typical manifestations and precursors of diabetic cardiovascular complications. As a new adipokine, asprosin participates in the development of diabetes and cardiovascular diseases, and is considered to be closely related to insulin resistance and glucolipid metabolism. This study aimed to analyze the relationship between serum asprosin level and carotid plaque in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 180 patients with T2DM were selected. The basic parameters and biochemical indexes of the subjects were measured, and the serum asprosin concentration of the subjects was detected by ELISA. The carotid plaque was evaluated by color Doppler ultrasound.

RESULTS

The level of serum asprosin in the T2DM with carotid plaque group was significantly higher than that in T2DM without carotid plaque group [2.53(1.73-3.21) vs 1.72(1.23-2.34) ng/mL, P < 0.05]. The incidence of carotid plaque in the low, middle and high quartiles was 31.7 %, 48.3 % and 70 % respectively. Correlation analysis showed that serum asprosin was positively correlated with BMI, WHR, SBP, DBP, FIns, LDL-C, HOMA-IR, and HOMA-β (P < 0.05). Linear regression analysis showed that WHR, DBP, FIns, and LDL-C were independent influencing factors of asprosin. Logistic regression analysis showed that serum asprosin was still significantly correlated with carotid plaque in T2DM patients after adjusting for multiple confounding factors. The area under receiver-operating curve (ROC) of asprosin predicting carotid plaque was 0.701 (0.625-0.777) in T2DM.

CONCLUSION

The level of serum asprosin in T2DM patients with carotid plaques is significantly higher, suggesting that asprosin may play a role in the occurrence and development of carotid plaques in T2DM. Detection of this index can provide new clinical evidence for the prevention and treatment of diabetic cardiovascular disease.

The Effects of Asprosin on Exercise-Intervention in Metabolic Diseases

Fibrillin is the major constituent of extracellular microfibrils, which are distributed throughout connective tissues. Asprosin is derived from the C-terminal region of the FBN1 gene, which encodes profibrillin that undergoes cleavage by furin protein. In response to fasting with low dietary glucose, asprosin is released as a secreted factor from white adipose tissue, and is transported to the liver for the mediation of glucose release into the blood circulation. Through binding to OLFR734, an olfactory G-protein-coupled receptor in liver cells, asprosin induces a glucogenic effect to regulate glucose homeostasis. Bioinformatics analyses revealed that the FBN1 gene is abundantly expressed in human skeletal muscle-derived mesoangioblasts, osteoblast-like cells, and mesenchymal stem cells, indicating that the musculoskeletal system might play a role in the regulation of asprosin expression. Interestingly, recent studies suggest that asprosin is regulated by exercise. This timely review discusses the role of asprosin in metabolism, its receptor signalling, as well as the exercise regulation of asprosin. Collectively, asprosin may have a vital regulatory effect on the improvement of metabolic disorders such as diabetes mellitus and obesity via exercise.

Asprosin, a C-Terminal Cleavage Product of Fibrillin 1 Encoded by the FBN1 Gene, in Health and Disease

BACKGROUND

Asprosin is a novel fasting-induced, glucogenic, and orexigenic protein hormone that is discovered with the help of genetic studies in patients with neonatal progeroid syndrome. Asprosin is encoded by the penultimate 2 exons (65 and 66) of the fibrillin 1 (FBN1) gene. Profibrillin 1 is the unprocessed protein product of FBN1 and undergoes a proteolytic cleavage by furin enzyme to produce mature fibrillin 1 and asprosin. The main organ responsible for the asprosin production seems to be white adipose tissue.

SUMMARY

Asprosin promotes hepatic glucose release in the liver and appetite stimulation in the hypothalamus through activation of the cAMP signaling circuitry through interacting with its G protein-coupled receptor, called OR4M1. Increasing mass of evidence suggests that asprosin is involved in the development and progression of various clinical conditions including diabetes, obesity, cardiomyopathy, cancer, and polycystic ovarian syndrome. It regulates various cellular and physiological processes such as appetite stimulation, glucose release, insulin secretion, apoptotic cell death, and inflammatory response. In this review, we discuss the current literature on asprosin and try to shed light on the yet undiscovered functions of asprosin.

KEY MESSAGE

Asprosin is a key regulatory factor for preserving the homeostasis of energy metabolism.

Ameliorative Effect of Oxytocin on FBN1 and PEPCK Gene Expression, and Behavioral Patterns in Rats' Obesity-Induced Diabetes

Amelioration of hyperinsulinemia and insulin resistance associated with obesity is a cardinal target for therapeutics. Therefore, we investigated the relation of Fibrilln-1 (FBN1) mRNA expression and hepatic phosphoenolpyruvate caboxykinase (PEPCK) enzyme to the ameliorative impact of oxytocin on obesity-induced diabetes, suggesting glycogenolysis markers in diabetic models. Four groups of forty male Wistar rats were formed (n = 10): a control group fed basal diet and intraperitoneal injections of saline; an oxytocin-injected group; a diet-induced obese group fed a high-fat/high-sugar diet and injected with saline; a diet-induced obese group injected with oxytocin. Depending on blood glucose levels, obese groups were further sub-grouped into prediabetic, and diabetic rats, with 5 rats each, at the ninth and the 16th week of the feeding period, respectively. FBN1 expression and PEPCK activity were determined using the qPCR technique and some biochemical parameters (glycemic, lipid profile, kidney, and liver functions) were determined using kits. Obese groups showed an elevation of brain FBN1 expression, high serum lipid profile, high glucose level, and a deleterious impact on liver and kidney functions. Obese groups showed the stimulator effect of the PEPCK enzyme and time-dependent pathological changes in renal and hepatic tissues. The motor activities were negatively correlated with FBN1 gene expression in prediabetic and diabetic rats. In addition to our previous review of the crucial role of asprosin, here we showed that oxytocin could ameliorate obesity-induced diabetes and decrease FBN1 gene expression centrally to block appetite. Oxytocin caused decreases in PEPCK enzyme activity as well as glycogenolysis in the liver. Therefore, oxytocin has a potential effect on FBN1 expression and PEPCK enzyme activity in the obesity-induced diabetic-rat model.

A cross-sectional comparative study on the effects of body mass index and exercise/sedentary on serum asprosin in male college students

Adipocytes regulate the body’s metabolism by secreting adipokines to maintain energy homeostasis. Asprosin is a new type of adipokine, and its relationship with obesity remains controversial. There are a few reports on the effect of long-term exercise on serum asprosin level. This study aimed to investigate the effects of body mass index (BMI) and exercise/sedentary habit on serum asprosin in male college students as well as the relationship between serum asprosin and body composition and related metabolic indicators and provided a basis for further exploration of the biological function of asprosin. Ninety-six male college students were classified into the sedentary habit group (SD; 48) and the special training experience group (ET; 48). Both groups included three subgroups of normal BMI, overweight, and obesity, with 16 people in each subgroup. One-way analysis of variance, analysis of covariance, and Pearson correlation analysis were performed. The results showed that serum asprosin levels in the obesity subgroup were significantly higher than those in the normal and overweight subgroups. Excluding BMI interference, there were no significant differences in serum asprosin between the SD and ET groups; however, there were significant differences in body composition, tumor necrosis factor-α, interleukin-6, and interleukin-10. Asprosin was positively correlated with BMI, body fat percentage, visceral fat area, fasting insulin, insulin resistance homeostasis model, total cholesterol, low-density lipoprotein, tumor necrosis factor-α, interleukin-6, and leptin levels and was negatively correlated with relative lean body mass, relative skeletal muscle mass, high-density lipoprotein, and interleukin-10, and adiponectin levels. In conclusion, serum asprosin is closely related to body weight, body composition, glucose and lipid metabolism, inflammatory response, and fat hormones. Long-term exercise training cannot prevent BMI increase from increasing serum asprosin level. If the influence of BMI is excluded, long-term exercise training does not affect serum asprosin.

Bioaccumulation and health risk assessment of exposure to potentially toxic elements by consuming agricultural products irrigated with wastewater effluents

Potentially toxic elements (PTEs) have many adverse health effects due to bioaccumulation capability and their long persistence in the environment. As a renewable water source, the effluents of municipal wastewater treatment systems have been used to irrigate agricultural products widely. However, the evidence on the bioaccumulation of PTEs in crops irrigated with these effluents is still scarce, with no available study in low and middle-income countries. Therefore, this study aimed to assess the PTEs concentration in the soil and crops irrigated with effluents of Sabzevar wastewater treatment plant and the related health risk by that. The clustered method was used to determine the soil and craps samples. Seventy cumulative samples were randomly prepared in summer and autumn 2016 and 2017 from crops, soil and effluent. Inductively coupled plasma mass spectrometry (ICP-MS) was used to measure PTEs. The health risk of exposure to PTEs was assessed using Monte Carlo simulation technique. Kruskal Wallis test and Posthoc Tukey HSD test were used to assess the mean difference of PTEs between soil, effluent and crops as well as between crops together. The bioaccumulation factor (BAF) magnitude order in different crop samples was Cd > Sr > Cu > Pb > Zn > Co > As > Cr > Ni, respectively. The Cd accumulation in Sugar beet plant was significantly higher than in other samples. The highest hazard quotient (HQ) based on single PTEs was observed for As (mineral) (mean: 5.62 × 10^-1 and percentile 95th: 2.13) in Okra. Regarding total HQ (THQ), the highest and lowest mean (percentile 95th) values were 1.50 (3.22) and 2.40 × 10^-1 (4.01 × 10^-1) for Okra and Watermelon, respectively. The mean concentrations of Co, Cr, Ni and Zn were significantly higher in crops compared to soil and influent samples. Posthoc tests indicated that the concentration of PTEs between investigated crop samples were not statistically significant different (p > 0.05). Overall, our study suggested that irrigation with the effluent of stabilization pond wastewater treatment system exerts a potential health risk due to bioaccumulation of PTEs in crops.

Association of traffic-related air pollution with Newborn's anthropometric indexes at birth

An emerging body of evidence has associated exposure to traffic-related air pollution (TRAP) during pregnancy with birth outcomes. However, the evidence on the association of TRAP exposure and neonatal anthropometric measurements (NAPM) in low and middle-income countries is very scarce yet. Therefore, we investigate the association of prenatal exposure to indicators of traffic and ambient particulate matter (PM) with NAPM. This cross-sectional study was based on hospital medical records of 4053 mother-neonate pairs between May 16, 2016, and December 5, 2018. PMs were estimated at residential addresses based on validated spatiotemporal models. Moreover, total street length in 100, 300 and 500m buffers around the home, residential distance to the ring road, major roads, heavy-traffic lights, gas station, motorway junction, bank, square, bus terminal, public parking and industrial land-use were calculated as indicators of traffic. The head circumference (HC), birth weight (BW) and birth length (BL) of neonates were collected as NAPM. Multivariate regression models were applied to evaluate the relationship between PMs and indicators of traffic with NAPM, controlled for relevant covariates. The median (IQR) of BW, BL, and HC of newborns were 3250 (592) gr, 51.0 (3.5) cm, 35 (2) cm, respectively. The adjusted models revealed that higher exposure to PM_2.5 and PM₁₀ was significantly related with lower BW and BL. Similar results were observed for total street length in a 100 m buffer around maternal home with BW and BL. Moreover, higher distance to heavy traffic lights was significantly associated with higher BW and BL. An IQR increase in PM₁₀ was significantly related to lower HC (95% CI: 0.11, -0.01, P-value = 0.03). An increase in distance from residential address to heavy traffic lights, ring roads, bus terminal, and transportation land-use was associated with higher HC. Overall, our findings suggested that higher prenatal exposure to TRAP was related with lower BW, BL and HC.

Asprosin induces vascular endothelial-to-mesenchymal transition in diabetic lower extremity peripheral artery disease

Background

Altered adipokine secretion in dysfunctional adipose tissue facilitates the development of atherosclerotic diseases including lower extremity peripheral artery disease (PAD). Asprosin is a recently identified adipokine and displays potent regulatory role in metabolism, but the relationship between asprosin and lower extremity PAD remains uninvestigated.

Methods

33 type 2 diabetes mellitus (T2DM) patients (DM), 51 T2DM patients with PAD (DM + PAD) and 30 healthy normal control (NC) volunteers were recruited and the blood samples were collected for detecting the circulatory asprosin level and metabolomic screening. RNA sequencing was performed using the aorta tissues from the type 2 diabetic db/db mice and human umbilical vein endothelial cells (HUVECs) were treated with asprosin to determine its impact on the endothelial-to-mesenchymal transition (EndMT).

Results

The circulating levels of asprosin in DM + PAD group were significantly higher than that of NC group and the DM group. Circulating asprosin level was remarkably negatively correlated with ankle-brachial index (ABI), even after adjusting for age, sex, body mass index (BMI) and other traditional risk factors of PAD. Logistic regression analysis revealed that asprosin is an independent risk factor for PAD and receiver-operator characteristic (ROC) curve determined a good sensitivity (74.5%) and specificity (74.6%) of asprosin to distinguish PAD. Data from metabolomics displayed a typical characteristics of de novo amino acid synthesis in collagen protein production by myofibroblasts in patients with PAD and activation of TGF-β signaling pathway appeared in the aortic tissue of db/db mice. Asprosin directly induces EndMT in HUVECs in a TGF-β-dependent manner as TGF-β signaling pathway inhibitor SB431542 erased the promotional effect of asprosin on EndMT.

Conclusions

Elevated circulatory asprosin level is an independent risk factor of lower extremity PAD and might serve as a diagnostic marker. Mechanistically, asprosin directly induces EndMT that participates in vascular injury via activation of TGF-β signaling pathway.

Trial registration This trial was registered at clinicaltrials.gov as NCT05068895

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01457-0.

Sensitive asprosin detection in clinical samples reveals serum/saliva correlation and indicates cartilage as source for serum asprosin

The C-terminal pro-fibrillin-1 propeptide asprosin is described as white adipose tissue derived hormone that stimulates rapid hepatic glucose release and activates hunger-promoting hypothalamic neurons. Numerous studies proposed correlations of asprosin levels with clinical parameters. However, the enormous variability of reported serum and plasma asprosin levels illustrates the need for sensitive and reliable detection methods in clinical samples. Here we report on newly developed biochemical methods for asprosin concentration and detection in several body fluids including serum, plasma, saliva, breast milk, and urine. Since we found that glycosylation impacts human asprosin detection we analyzed its glycosylation profile. Employing a new sandwich ELISA revealed that serum and saliva asprosin correlate strongly, depend on biological sex, and feeding status. To investigate the contribution of connective tissue-derived asprosin to serum levels we screened two cohorts with described cartilage turnover. Serum asprosin correlated with COMP, a marker for cartilage degradation upon running exercise and after total hip replacement surgery. This together with our finding that asprosin is produced by primary human chondrocytes and expressed in human cartilage suggests a contribution of cartilage to serum asprosin. Furthermore, we determined asprosin levels in breast milk, and urine, for the first time, and propose saliva asprosin as an accessible clinical marker for future studies.

New Discovered Adipokines Associated with the Pathogenesis of Obesity and Type 2 Diabetes

Obesity is defined as abnormal or excessive accumulation of adipose tissue, closely associated with the increased risk of various comorbidities, especially type 2 diabetes mellitus (T2DM). Adipose tissue is a complex structure responsible for not only fat storage but also releasing adipokines which may play roles in the pathogenesis and could be developed into biomarkers for diagnosis, treatment and prognosis of obesity-related metabolic diseases. This review aims to summarize several adipokines discovered recently that have promising functions in obesity and T2DM. Among them, the levels of FSTL1, WISP1 and Asprosin in subjects with obesity or diabetes are commonly higher than in normal controls, suggesting that they may be pathogenic. Inversely, SFRP5, Metrnl, NRG4 and FAM19A5 may serve as the protective factors.

Formation of Self-Assembled Liquid Crystalline Nanoparticles and Absorption Enhancement of Ω-3s by Phospholipids and Oleic Acids

This study aimed to optimize and evaluate self-assembled liquid crystalline nanoparticles (SALCs) prepared from phospholipids and oleic acid for enhancing the absorption of Ω-3s. We explored the structure and optimal formulation of SALCs, which are composed of Ω-3 ethyl ester (Ω-3 EE), phospholipids, and oleic acid, using a ternary diagram and evaluated the improvement in Ω-3 dissolution, permeation, and oral bioavailability. The in vitro dissolution and pharmacokinetics of Ω-3 SALCs were compared with those of Omacor soft capsules (as the reference). The shape of the liquid crystal was determined according to the composition of phospholipids, oleic acids, and Ω-3s and was found to be in cubic, lamellar, and hexagonal forms. The dissolution rates of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) obtained from Ω-3 SALCs were 1.7 to 2.3-fold higher than those of the Omacor soft capsules. Furthermore, a pharmacokinetic study in male beagle dogs revealed that Ω-3 SALCs increased the oral bioavailability of Ω-3 EE by 2.5-fold for EPA and 3.1-fold for DHA compared with the reference. We found an optimal formulation that spontaneously forms liquid crystal-based nanoparticles, improving the bioavailability of EPA and DHA, not found in the existing literature. Our findings offer insight into the impact of nanoparticle phase on the oral delivery of oil-soluble drugs and provide a novel Ω-3 EE formulation that improves the bioavailability of EPA and DHA.

A Serum Marker for Early Pancreatic Cancer with a Possible Link to Diabetes

BACKGROUND

Pancreatic cancer (PC) has a grim prognosis, and an early diagnostic biomarker has been highly desired. The molecular link between diabetes and PC has not been well-established.

METHODS

Bioinformatics screening was performed for a serum PC marker. Experiments in cell lines (5 PC and 1 normal cell lines), mouse models, and human tissue staining (37 PC and 10 normal cases) were performed to test asprosin production from PC. Asprosin's diagnostic performance was tested with serums from multi-center cohorts (347 PC, 209 normal, and 55 additional diabetic subjects) and evaluated according to PC status, stages, and diabetic status, which was compared with that of CA19-9.

RESULTS

Asprosin, a diabetes-related hormone, was found from the bioinformatics screening, and its production from PC was confirmed. Serum asprosin levels from multi-center cohorts yielded an age-adjusted diagnostic AUC of 0.987 (95% confidence interval [CI] = 0.961 to 0.997), superior to that of CA19-9 (AUC = 0.876, 95% CI = 0.847 to 0.905), and a cut-off of 7.18 ng/mL, at which the validation set exhibited a sensitivity of 0.957 and a specificity of 0.924. Importantly, the performance was maintained in early-stage and non-metastatic PC, consistent with the tissue staining. A slightly lower performance against additional diabetic patients (n = 55) was restored by combining asprosin and CA19-9 (AUC = 0.985, 95% CI = 0.975 to 0.995).

CONCLUSION

Asprosin is presented as an early-stage PC serum marker that may provide clues for PC-induced diabetes. Larger prospective clinical studies are warranted to solidify its utility.

Serum levels of Asprosin in patients diagnosed with coronary artery disease (CAD): a case-control study

Background

Coronary artery disease (CAD) is considered as a multi-faceted chronic inflammatory disease involving reduced blood supply to the myocardium as a result of accumulating lipids in the atrial walls. Visceral adiposity with disrupted release of adipokines play a key role in its pathogenesis. Asprosin is a newly identified fasting-induced glucogenic adipokine that has been related with metabolic disorders such as type II diabetes mellitus and polycystic ovary syndrome. The preset study sought to assess circulating asprosin in context of CAD.

Methods

In this study, serum levels of asprosin were determined in 88 CAD patients and 88 non-CAD healthy controls. Serum IL-6, TNF-α, asprosin and adiponectin were assessed using ELISA kits.

Results: Serum asprosin was found to be higher in CAD patients when compared to non-CAD subjects (7.84 ± 2.08 versus 5.02 ± 1.29 μg/mL, p <  0.001). Similarly, serum TNF-α, and IL-6 elevated in CAD group significantly (p <  0.001). However, circulating adiponectin diminished in CAD group when compared with non-CAD subjects (p < 0.001). Moreover, serum asprosin levels directly correlated with BMI, FBG, HOMA-IR, TG and TC. Logistic regression analyses showed that asprosin levels were associated with increased risk of developing CAD (odds ratio: 3.01, 95% CI: 2.16, 4.20 and p < 0.001), after adjusting for potential confounders (age, sex and BMI).

Conclusions

The present study findings suggested a possible relation of serum asprosin with the pathogenesis of CAD, in particular through insulin resistance and dyslipidemia.

Increased asprosin is associated with non-alcoholic fatty liver disease in children with obesity

BACKGROUND

Obesity is a common disease among children, often accompanied by a lot of metabolic disease. Non-alcoholic fatty liver disease (NAFLD) is one of the most common complications of obesity among children and adolescents. Asprosin has been identified as a new adipokine that is closely associated with hepatic glucose metabolism. However, few data on asprosin in obese children with NAFLD are available. The present study focuses on the relationship between serum asprosin level and NAFLD in children with obesity.

METHODS

A total of 110 subjects (71 boys and 39 girls aged 6-18 years) were recruited from the Second Affiliated Hospital of Xi'an Jiaotong University: 36 obese children with NAFLD, 39 obese children without NAFLD and 35 lean controls. Anthropometric parameters and biochemical data were measured, and the concentrations of asprosin were detected by ELISA.

RESULTS

The levels of serum asprosin were significantly higher in obese children, particularly those with NAFLD and were positively correlated with body mass index, waist to height ratio, fasting blood glucose, alanine aminotransferase and tumor necrosis factor-alpha. Furthermore, asprosin was independently associated with NAFLD in binary logistic regression analysis.

CONCLUSION

Serum asprosin levels were elevated in obese children, especially in those with NAFLD, and were involved in the pathogenesis of NAFLD in children with obesity.

Asprosin, a novel pleiotropic adipokine implicated in fasting and obesity-related cardio-metabolic disease: Comprehensive review of preclinical and clinical evidence

White adipose tissue is a dynamic endocrine organ that releases an array of adipokines, which play a key role in regulating metabolic homeostasis and multiple other physiological processes. An altered adipokine secretion profile from adipose tissue depots frequently characterizes obesity and related cardio-metabolic diseases. Asprosin is a recently discovered adipokine that is released in response to fasting. Following secretion, asprosin acts - via an olfactory G-protein coupled receptor and potentially via other unknown receptor(s) - on hepatocytes and agouti-related peptide-expressing neurons in the central nervous system to stimulate glucose secretion and promote appetite, respectively. A growing body of both in vitro and in vivo studies have shown asprosin to exert a number of effects on different metabolic tissues. Indeed, asprosin can attenuate insulin signalling and promote insulin resistance in skeletal muscle by increasing inflammation and endoplasmic reticulum stress. Interestingly, asprosin may also play a protective role in cardiomyocytes that are exposed to hypoxic conditions. Moreover, clinical studies have reported elevated circulating asprosin levels in obesity, type 2 diabetes and other obesity-related cardio-metabolic diseases, with significant associations to clinically relevant parameters. Understanding the spectrum of the effects of this novel adipokine is essential in order to determine its physiologic role and its significance as a potential therapeutic target and/or a biomarker of cardio-metabolic disease. The present review offers a comprehensive overview of the published literature on asprosin, including both clinical and preclinical studies, focusing on its role in metabolism and cardio-metabolic disease.

Asprosin-A Fasting-Induced, Glucogenic, and Orexigenic Adipokine as a New Promising Player. Will It Be a New Factor in the Treatment of Obesity, Diabetes, or Infertility? A Review of the Literature

Asprosin is a recently discovered protein released during fasting conditions mainly by adipocytes from white adipose tissue. As a glucogenic peptide, it stimulates the release of glucose from hepatic cells by binding to the OLFR734 receptor and leading to the activation of the G protein-cAMP-PKA pathway. As it crosses the blood–brain barrier, it also acts as an orexigenic peptide that stimulates food intake through activation of AgRP neurons in the hypothalamus; thus, asprosin participates in maintaining the body’s energy homeostasis. Moreover, studies have shown that asprosin levels are pathologically elevated in obesity and related diseases. However, the administration of anti-asprosin antibodies can both normalize its concentration and reduce food intake in obese mice, which makes it an interesting factor to combat obesity and related diseases. Current research also draws attention to the relationship between asprosin and fertility, especially in men. Asprosin improves age- and obesity-related decrease in fertility potential by improving sperm motility. It should also be mentioned that plasma asprosin levels can be differentially modulated by physical activity; intense anaerobic exercise increases asprosin level, while aerobic exercise decreases it. However, further research is necessary to confirm the exact mechanisms of asprosin activity and its potential as a therapeutic target.

High Serum Asprosin Levels Are Associated with Presence of Metabolic Syndrome

OBJECTIVE

Asprosin, a new adipocytokine, has reportedly been associated with glucose release, dyslipidemia, and insulin resistance (IR). However, the relationship of asprosin with metabolic syndrome (MetS) remains unknown. This study aimed to investigate serum asprosin levels in MetS as well as their association with various metabolic parameters in humans.

METHODS

A total of 131 consecutive patients with MetS, and 162 age-matched, healthy subjects were recruited for this study. Serum asprosin concentrations were determined using the enzyme-linked immunosorbent assay. Lipid profile, glucose, insulin, and inflammatory markers were also measured.

RESULTS

Serum asprosin levels were higher in subjects with MetS (23.52 [16.70, 32.05] ng/mL) than in controls (16.70 [12.87, 22.38] ng/mL; P < 0.01), and they showed an increasing trend with increasing numbers of metabolic components (P for trend < 0.01). In all studied subjects, serum asprosin levels were positively correlated with body mass index, waist circumference, triglycerides, fasting plasma glucose, 2-hour plasma glucose, fasting insulin, homeostatic model assessment of insulin resistance (HOMA-IR) index, interleukin-6, and monocyte chemoattractant protein-1 and negatively correlated with high-density lipoprotein cholesterol (P < 0.05). In multiple linear regression, asprosin was independently and positively correlated with triglyceride and HOMA-IR (P < 0.05). Binary logistic regression revealed that asprosin was independently and positively correlated with the occurrence of MetS and IR, even after controlling for anthropometric variables, lipid profiles, and inflammatory markers.

CONCLUSION

Asprosin is a potential metabolic-related adipokine and may be related to IR and MetS. This trial was registered with ChiCTR, ChiCTR1800018347.

Meal-Related Asprosin Serum Levels Are Affected by Insulin Resistance and Impaired Fasting Glucose in Children With Obesity

Asprosin physiologically increases in fasting conditions and decreases with refeeding and has been implicated in glucose homeostasis. An alteration of meal-related circadian oscillation of asprosin has been suggested in adults affected by type 2 diabetes mellitus. Aims of this study were to test the hypothesis of an alteration in the meal-related variation of asprosin levels in non-diabetic children and adolescents with obesity and to assess which metabolic variables condition this variation in non-diabetic children and adolescents with obesity. This is a cross-sectional study which included 79 children and adolescents with obesity. Children underwent clinical and biochemical assessments, including oral glucose tolerance test (OGTT), and liver ultrasound evaluation. Asprosin serum levels were measured by an enzyme-linked immunosorbent assay at a fasting state and at the 120-minute OGTT timepoint (2h-postprandial asprosin). Fasting and 2h-postprandial asprosin serum levels did not significantly differ in the entire study population (374.28 ± 77.23 vs 375.27 ± 81.26;p=0.837). 55.7% of patients had a significant increase in 2h-postprandial asprosin compared with fasting levels. The asprosin level increase condition was significantly associated with HOMA-IR (OR,1.41; 95%CI,1.005-1.977; p=0.047), fasting glycaemia (OR,1.073; 95%CI,1.009-1.141;p=0.024) and HOMA-B (OR,0.99; 95%CI,0.984-0.999; p=0.035). Moreover, the IFG condition was associated with the increase in asprosin levels (OR, 3.040; 95%CI, 1.095-8.436; p=0.033), even after adjustment for HOMA-IR, BMI SDS, sex and pubertal stage. Insulin resistance and IFG influence meal-related changes of asprosin serum levels in our study population of obese, non-diabetic, children. Alteration of asprosin circadian secretion might be an early biomarker of impaired glucose regulation in obese children with insulin resistance.