Nordic Walking at Maximal Fat Oxidation Intensity Decreases Circulating Asprosin and Visceral Obesity in Women With Metabolic Disorders

Asprosin is a Reliable Predictor of Osteoporosis in Type 2 Diabetic Postmenopausal Women: A Case-Control Study

The study evaluates Asprosin's value in diabetic postmenopausal women, examining its reliability as a predictor for osteoporosis (OP) in the second type of diabetes (T2D) women. A case-control study recruited 255 postmenopausal women attending the geriatric department of the University Hospital. They were grouped into controls (non-OP non-T2D), and study cases. The latter were subdivided into: non-OP T2D, and OP T2D postmenopausal women (85/255) for each. Serum Asprosin level showed a significant increase in postmenopausal T2D women with OP (42.51 ± 2.97 ng/mL, P < 0.001) compared with postmenopausal T2D women without OP and controls. Additionally, there is a significant interrelationship between OP radiological indicators and bone-forming hormone in T2D women, osteocalcin. Moreover, bone resorption and glycemic markers in T2D women correlated significantly and positively with Asprosin. The Receiver operator characteristic curve discriminates OP T2D postmenopausal women from non-OP T2D postmenopausal women by estimating cutoff value (> 39.3 ng/mL) at 90% sensitivity, 63.3% specificity, and P < 0.001.

The association of plasma asprosin with anthropometric and metabolic parameters in Korean children and adolescents

Background

This study aimed to determine the correlation of plasma asprosin with anthropometric and metabolic parameters in Korean children and adolescents.

Methods

This single-center study included 109 Korean children and adolescents: 62 (56.9%) obese participants with a body mass index (BMI) ≥95th percentile and 47 (43.1%) healthy controls with BMI between the 15th and 85th percentile. Metabolic parameters were measured, including fasting blood glucose, fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), triglyceride and glucose (TyG) index, and lipid profiles.

Results

Plasma asprosin levels were higher in the obese group than in the control group (mean 87.0 vs. 69.3 ng/mL; p = 0.001) and in the IR group than in the non-IR group (mean 98.6 vs. 70.2 ng/mL; p < 0.001). Plasma asprosin levels were not associated with sex or pubertal stage. Plasma asprosin levels were positively correlated with BMI SDS (r = 0.34; p = 0.002), glycated hemoglobin (HbA1c) (r = 0.25; p = 0.02), glucose (r = 0.33; p = 0.002), insulin (r = 0.44; p < 0.001), HOMA-IR (r = 0.47; p < 0.001), triglyceride (TG) (r = 0.33; p = 0.003), high-density lipoprotein (HDL) cholesterol (r = -0.29; p = 0.008), and TyG index (r = 0.38; p < 0.001). Multiple linear regression analysis indicated that plasma asprosin levels were independently associated with HOMA-IR (p < 0.001) and TG/HDL cholesterol ratio (p < 0.001).

Conclusions

This study demonstrated an association between plasma asprosin levels and obesity and insulin resistance in Korean children and adolescents.

Relation of the intense physical exercise and asprosin concentrations in type 2 diabetic rats

AIM

Asprosin, a protein hormone, is released by unilocular adipocytes in reaction to low blood sugar. We aimed to examine how exercise affects asprosin hormone levels and associated organs, including the liver and pancreas, in diabetes.

METHODS

Twenty-one male Wistar albino rats were firstly allocated into two main groups: control (n = 7) and diabetes (n = 14). Then, the diabetes group was further separated into two subgroups: sedentary (n = 7) and exercise (n = 7). The exercise group participated in a swimming training regimen (30 min/daily, six weeks). Serum levels of asprosin and various other biochemical parameters were evaluated through commercial ELISA kits. The liver was analyzed histopathologically, and pancreatic islet cells were examined for Cas-3 immune expression.

RESULTS

Asprosin and total oxidant status decreased significantly in the exercise diabetic subgroup (p < 0.05). Glucose, insulin, creatinine, IL-6, and HomaIR concentrations decreased slightly with exercise (p > 0.05). Liver tissue injury scores and Cas-3 immune expression in pancreas islet cells decreased in exercise diabetic rats.

CONCLUSIONS

Reducing asprosin may lower glucose, insulin, and HOMA-IR. Physical activity decreases asprosin and total oxidative status, fostering anti-apoptosis and tissue healing in diabetes, potentially enhancing health. Monitoring asprosin levels offers insights into diabetes progression. Our findings imply that asprosin can be a therapeutic target for diabetes.

The Beneficial Effects of Nordic Walking Training Combined with Time-Restricted Eating 14/24 in Women with Abnormal Body Composition Depend on the Application Period

The aim of the study was to assess the impact of two lengths of Nordic walking (NW) training interventions combined with time-restricted eating (TRE) on improving body-composition parameters, lipid profiles, and levels of selected adipokines in women with elevated body mass. Overweight and obese women (n = 55, age: 21-85) were recruited. Four groups were selected: 6 weeks (SG6, n = 13) and 12 weeks intervention (SG12, n = 13); and two control groups: CON6 (n = 13) and CON12 (n = 13). The training sessions took place three times a week (60 min each) and were conducted outdoors under the supervision of a professional coach. The training intensity was determined individually. The extended NW program combined with TRE induced a significant weight reduction in SG12 by 1.96 kg (p = 0.010) and fat tissue by 1.64 kg (p = 0.05). The proposed interventions did not affect LBM, TBW [kg], VFA, and lipid profile. The LDL/HDL ratio changed with a small size effect. The leptin concentration differed between groups (p = 0.006), but not over time. For resistin, the differentiating factor was time (p = 0.019), with lower results observed after the intervention. The change in leptin concentration was negatively correlated with its baseline concentration (p = 0.025). Extended to 12 weeks, this intervention allows for an improvement in body composition. Neither 6 nor 12 weeks of training and fasting affected the lipoprotein profile. It is, therefore, indicated to recommend prolonged training protocols and to inform patients that beneficial effects will be seen only after prolonged use of training and time-restricted eating.

Exercise-induced effects on asprosin and indices of atherogenicity and insulin resistance in males with metabolic syndrome: a randomized controlled trial

Metabolic syndrome (MetS) development is associated with insulin resistance and obesity, with the progression of visceral adipose tissue playing a crucial role. Excessive adipose tissue is accompanied by an increase in the asprosin (ASP), which is responsible for carbohydrate metabolism and the regulation of hunger and satiety. Exercise affects the release of ASP, which may regulate metabolism accordingly. Due to the inconclusive results of the effect of exercise on ASP concentration in men with MetS, 12-week interventions were carried out in the following groups: EG1-aerobic training (n = 21, age: 34.21 ± 6.06, WC; waist circumference: 114.7 ± 10.93) and EG2-a combination of aerobic and resistance training (n = 21, age: 37.37 ± 7.08, WC: 114.8 ± 11.64) and compared with a control group (CG) of men with MetS without any intervention (n = 20, age: 38.26 ± 7.43, WC: 115.3 ± 10.54). Body composition, indicators of carbohydrate-lipid metabolism, and ASP were assessed four times: before the intervention, at 6 and 12 weeks of training, and 4 weeks after the training sessions. A comparison of the intervention influence on changes in the analyzed variables between the groups was performed using ANOVA test for dependent groups with post-hoc comparison. The effect size (ES) was also assessed using squared eta (η2). The implementation of aerobic training resulted in a decrease in ASP concentration (p = 0.03) within 6 weeks of the intervention, while in the CG a gradual increase in ASP was confirmed (p < 0.001). Aerobic-resistance training did not induce significant changes in ASP concentration but resulted in an increase in fat-free mass/fat mass (FFM/FM) ratio (p < 0.001), and a decrease (p = 0.04) in Homeostasis Model Assessment of Insulin Resistance (HOMA-IR). Changes in the visceral adipose tissue level indicate a gradual decrease in both the EG1 (p = 0.01) and EG2 (p = 0.04) groups. Both aerobic and aerobic-resistance exercises may have a regulatory effect, mainly by reducing visceral adipose tissue, on the improvement of metabolic disorders.

Toward Exercise Guidelines for Optimizing Fat Oxidation During Exercise in Obesity: A Systematic Review and Meta-Regression

BACKGROUND

Exercise training performed at maximal fat oxidation (FATmax) is an efficient non-pharmacological approach for the management of obesity and its related cardio-metabolic disorders.

OBJECTIVES

Therefore, this work aimed to provide exercise intensity guidelines and training volume recommendations for maximizing fat oxidation in patients with obesity.

METHODS

A systematic review of original articles published in English, Spanish or French languages was carried out in EBSCOhost, PubMed and Scopus by strictly following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement. Those studies that analyzed maximal fat oxidation (MFO) and FATmax in patients with obesity (body fat > 25% for men; > 35% for women) by calculating substrate oxidation rates through indirect calorimetry during a graded exercise test with short-duration stages (< 10 min) were selected for quantitative analysis. The accuracy of relative oxygen uptake (% peak oxygen uptake [%[Formula: see text]O2peak]) and relative heart rate (% peak heart rate [%HRpeak]) for establishing FATmax reference values was investigated by analyzing their intra-individual and inter-study variation. Moreover, cluster analysis and meta-regression were used for determining the influence of biological factors and methodological procedures on MFO and FATmax.

RESULTS

Sixty-four manuscripts were selected from 146 records; 23 studies only recruited men (n = 465), 14 studies only evaluated women (n = 575), and 27 studies included individuals from both sexes (n = 6434). The majority of the evaluated subjects were middle-aged adults (aged 40-60 y; 84%) with a poor cardiorespiratory fitness (≤ 43 mL·kg-1·min-1; 81%), and the reported MFO ranged from 0.27 to 0.33 g·min-1. The relative heart rate at FATmax (coefficient of variation [CV]: 8.8%) showed a lower intra-individual variation compared with relative oxygen uptake (CV: 17.2%). Furthermore, blood lactate levels at FATmax ranged from 1.3 to 2.7 mmol·L-1 while the speed and power output at FATmax fluctuated from 4 to 5.1 km·h-1 and 42.8-60.2 watts, respectively. Age, body mass index, cardiorespiratory fitness, FATmax, the type of ergometer and the stoichiometric equation used to calculate the MFO independently explained MFO values (R2 = 0.85; p < 0.01). The MFO in adolescents was superior in comparison with MFO observed in young and middle-aged adults. On the other hand, the MFO was higher during treadmill walking in comparison with stationary cycling. Body fat and MFO alone determined 29% of the variation in FATmax (p < 0.01), noting that individuals with body fat > 35% showed a heart rate of 61-66% HRpeak while individuals with < 35% body fat showed a heart rate between 57 and 64% HRpeak. Neither biological sex nor the analytical procedure for computing the fat oxidation kinetics were associated with MFO and FATmax.

CONCLUSION

Relative heart rate rather than relative oxygen uptake should be used for establishing FATmax reference values in patients with obesity. A heart rate of 61-66% HRpeak should be recommended to patients with > 35% body fat while a heart rate of 57-64% HRpeak should be recommended to patients with body fat < 35%. Moreover, training volume must be higher in adults to achieve a similar fat oxidation compared with adolescents whereas exercising on a treadmill requires a lower training volume to achieve significant fat oxidation in comparison with stationary cycling.

Asprosin levels in women with and without the polycystic ovary syndrome: a systematic review and meta-analysis

Objective: This systematic review and meta-analysis aimed at summarizing the evidence concerning circulating asprosin, and related endocrine and metabolites in women with and without the polycystic ovary syndrome (PCOS).Method: We performed a comprehensive literature search in Pubmed, Web of Science, Scielo, and Chinese National Knowledge Infrastructure for studies published until May 20, 2022, that evaluated circulating asprosin levels in women with and without PCOS, regardless of language. The quality of studies was assessed with the Newcastle-Ottawa Scale. Random-effects models were used to estimate mean differences (MD) or standardized MD (SMD) and their 95% confidence interval (CI).Results: We evaluated eight studies reporting 1,050 PCOS cases and 796 controls of reproductive age. Participants with PCOS were younger (MD = -2.40 years, 95% CI -2.46 to -2.33), with higher values of asprosin (SMD = 2.57, 95% CI 1.64-3.50), insulin (SMD = 2.73, 95% CI 1.18-4.28), homeostatic model assessment of insulin resistance (SMD = 2.70, 95% CI 0.85-4.55), luteinizing hormone (SMD = 2.33, 95% CI 0.60-4.06), total testosterone (SMD = 4.06, 95% CI 1.89-6.22), dehydroepiandrosterone sulfate (SMD = 2.38, 95% CI 0.37-4.40), and triglycerides (SMD = 1.20, 95% CI 0.13 to 2.27). Moreover, PCOS women had lower circulating levels of sex hormone-binding globulin (SMD = -3.36, 95% CI -4.92 to -1.80), and high-density lipoprotein-cholesterol (SMD = -0.85, 95% CI -1.69 to -0.01); with no significant differences observed for glucose, total cholesterol, and low-density lipoprotein-cholesterol levels.Conclusion: Circulating asprosin levels were significantly higher in women with PCOS as compared to those without the syndrome.

Whole-Body Cryotherapy Alters Circulating MicroRNA Profile in Postmenopausal Women

The incidence of metabolic syndrome (MetS) increases with age, especially in women. The role of microRNAs (miRs) in the regulation of metabolism is postulated. The aim of the study is to identify miRs that may be markers of MetS and to assess changes in miRs expression as a result of 10 and 20 whole-body cryotherapy treatments (WBC; 3 min, -120 °C) in postmenopausal women with MetS (M-60, BMI 30.56 ± 5.38 kg/m2), compared to healthy postmenopausal (H-60, BMI 25.57 ± 2.46 kg/m2) and healthy young women (H-20, BMI 22.90 ± 3.19 kg/m2). In a fasting state, before 1 WBC and after 10 WBCs, as well as 20 WBCs, the expression of miR-15a-5p, miR-21-5p, miR-23a-3p, miR-146a-5p, miR-197-3p, miR-223-3p, fasting blood glucose (FBG) and blood lipid profile were determined. miR-15a-5p and miR-21-5p were down-regulated in M-60, while miR-23a-3p and miR-197-3p were up-regulated, and miR-223-3p down-regulated in M-60 and H-60, compared to H-20. Significant positive correlations between up-regulated (mostly for miR-23-3p and miR-197-3p) and significant negative correlations between down-regulated (mostly for miR-15a-5p) miRs and markers of body composition as well as metabolic disorders were observed. After 20 WBCs, miR-15a-5p expression was up-regulated in all groups. In H-60, down-regulation of miR-197-3p expression occurred after 10 WBCs and 20 WBCs. Following 10 WBCs, FBG decreased in all groups, which intensified in M-60 post-20 WBCs. In our research, it has been shown that miR-23a-3p and miR-197-3p are accurate markers of MetS and MetS risk factors, while miR-15a-5p and miR-23a-3p are precise markers of body composition disorders. WBC is an effective treatment for up-regulating miR-15a-5p and lowering glucose levels in young and postmenopausal women and down-regulating miR-197-3p expression in postmenopausal women. It may be an adjunctive effective treatment method in MetS and hyperglycemia.

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.

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 muscle strength and body mass index with risk factors for metabolic syndrome and its prevalence in Korean adult women

Background

The aim of this study was to investigate the effects of muscle strength and BMI (body Mass Index) on Metabolic syndrome (MetS) risk factors and prevalence in Korean adult women, using data from the Korea National Health and Nutrition Examination Survey.

Methods

A total of 3189 Korean adults women participated in the cross-sectional study. Participants were measured BMI, MetS risk factors including waist-circumference (WC), fasting glucose (FG), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), and handgrip strength as muscle strength.

Results

As a result ‘high BMI & Low muscle strength’, ‘low BMI & low muscle strength’, and ‘high BMI & high muscle strength’ groups had a significantly higher prevalence of Mets [OR (Odd ratio): 1.49, 95% CI (confidence interval): 1.01 2.20; OR: 5.77, 95% CI: 4.32 7.17; OR: 10.46, 95% CI: 8.05 13.59] than ‘low BMI & high muscle strength’ group; and after adjusting smoking, menstruation status, and drinking rate, the OR were 1.07 (95% CI: 0.71–1.61), 4.89 (95% CI: 3.60–6.55), and 7.38 (95% CI: 5.63–9.68), respectively.

Conclusions

These findings indicated that increasing muscle strength and lowering BMI through regular physical activity and exercise are effective methods to reduce the prevalence of risk factors for Mets.

Diet and exercise interventions reduce serum asprosin and the corresponding hypothalamic– pituitary–gonad-axis dysfunction in obese men

Background: Asprosin (ASP) is a recently discovered adipocyte factor that participates in glucose metabolism and inflammatory reactions. Recent findings suggest that it may be involved in the regulation of sex hormone secretion in the hypothalamic-pituitary-gonad (HPG) axis, but no studies have been reported in related populations. The purpose of this study was to evaluate the changes in serum ASP levels in healthy men and obese men, as well as before and after exercise weight loss, and to investigate male hypogonadism, insulin resistance, inflammatory response, and relationships induced by ASP and obesity.

Methods: Thirty-eight young male volunteers were recruited and divided into a normal group (n = 20) and an obese group (n = 18) according to their body mass index. Fourteen of the obese men underwent a 14-week exercise and diet intervention (first 8 weeks of aerobic exercise at 60%–70% HR_max for 30–50 min/4 days a week). Beginning at week 9, the intensity was increased to 75% HR_max. Participants in the obese groups maintained a calorie-restricted diet throughout the study period.

Results: Serum ASP levels in the obese group were significantly higher than those in the normal group, and serum gonadotropin-releasing hormone (GnRh), luteinizing hormone (LH), and testosterone (T) levels were decreased. After 14 weeks of exercise and diet intervention, serum ASP decreased significantly, the levels of body weight, lean body weight, body fat rate, fasting insulin (FINS), homeostatic model assessment for insulin resistance, TNF-α, IL-6, and IL-1β decreased significantly, and the serum GnRH, LH, and T levels increased significantly. ASP was positively correlated with body weight, body fat percentage, FINS, tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β and negatively correlated with relative lean body weight and serum LH and T levels.

Conclusion: The serum ASP levels were increased in obese men compared with those of normal weight individuals, resulting in a chronic inflammatory reaction, high serum insulin, and HPG axis injury. Fourteen weeks of exercise and diet intervention effectively alleviated this phenomenon. It has been speculated that ASP might regulate male reproductive function by regulating the inflammatory response and insulin sensitivity.

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.

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.