Serum Irisin Levels Research Articles

Evaluation of pregnancy toxemia in goats: Metabolic profile, hormonal findings, and redox balance

Pregnancy toxemia entails the development of hyperketonemia due to the negative energy balance that occurs in the last trimester of pregnancy in dairy goats. There are a limited number of studies on new diagnostic biomarkers and the pathophysiology of pregnancy toxemia in goats. This study assessed the hormones spexin and irisin and redox biomarker and metabolic profile changes in goats with pregnancy toxemia. The study included 36 hair goats, with 12 in the subclinical pregnancy toxemia (SPT) group, 12 in the clinical pregnancy toxemia (CPT) group, and 12 in the control group (CG). Spexin, irisin, and insulin hormone concentrations were determined by ELISA, while metabolic profile parameters were evaluated with an automatic chemical analyzer and redox balance by spectroscopy. In the goats with pregnancy toxemia, serum levels of spexin, irisin, insulin, and glucose were significantly lower than those of CG goats. The SPT group had significantly higher ischemia-modified albumin concentrations than CG goats, while the CPT group had significantly lower native thiol concentrations compared to CG animals. The concentrations of beta-hydroxybutyric acid and non-esterified fatty acids in the groups with pregnancy toxemia were significantly higher than those of control animals. In the diagnosis of pregnancy toxemia, spexin had sensitivity of 90 %, specificity of 95 %, and an area under the curve value of 0.988, while irisin had sensitivity of 90 %, specificity of 91 %, and an AUC value of 0.979. In this study, both spexin and irisin hormones showed excellent performance in the diagnosis of pregnancy toxemia. In addition, pregnancy toxemia was found to cause increased oxidative stress and significant changes in metabolic and endocrine metabolism in goats. Measuring these biomarkers in both healthy dairy goats and those with pregnancy toxemia may contribute significantly to the management and diagnosis of herd health.

The silent predictors: exploring galectin-3 and Irisin’s tale in severe COVID-19

ObjectiveThis study aimed to evaluate the roles of galectin-3 and irisin as biomarkers in predicting severe outcomes in COVID-19 patients.ResultsWe analyzed serum levels of galectin-3 and irisin in 59 patients with severe COVID-19 and 30 healthy controls. Elevated galectin-3 levels were associated with increased risks of mortality, need for intensive care, and severe acute respiratory distress syndrome. The optimal cut-off value for galectin-3 was 13.47 ng/ml, with a sensitivity of 72.7% and specificity of 76.6%. Irisin levels did not differ significantly between survivors and non-survivors at admission or on the 3rd day post-admission, but approached significance on the 7th day. These findings suggest that galectin-3 could be a valuable prognostic biomarker for severe COVID-19 outcomes, while irisin’s role remains to be clarified in further studies.

A Comparative Analysis of Serum Irisin Levels and Body Composition Indices in Women With and Without Polycystic Ovary Syndrome (PCOS).

Introduction Polycystic ovarian syndrome (PCOS) is a prevalent endocrine-metabolic disorder impacting women of reproductive age, often manifesting during adolescence. This study aimed to determine serum irisin levels in subjects with PCOS compared to healthy controls and explore the correlation between irisin levels and body composition indices. Methods A cross-sectional study was conducted at a tertiary care hospital. Thirty-three women with PCOS and 32 healthy, age-matched controls were recruited. Relevant socio-demographic and clinical data were collected, and body composition was analyzed using bioelectrical impedance analysis (BIA). Serum irisin levels were measured using enzyme-linked immunosorbent assay (ELISA), and statistical analysis was performed using CoGuide software (Evidencian Research Associates, Bengaluru, India). Results PCOS subjects exhibited significantly higher levels of clinical features associated with hyperandrogenism, including elevated systolic (SBP) and diastolic blood pressure (DBP), body mass index, waist-hip ratio, total cholesterol, low-density lipoproteins (LDL), serum testosterone, body fat percentage, subcutaneous fat percentage, visceral fat percentage, and fat mass index, along with lower high-density lipoprotein levels and lean mass percentage, compared to controls. Serum irisin levels were significantly higher in PCOS cases (10.82 (8.5-14.31) ng/mL) than in controls (2.57 (2.19-4.65) ng/mL). There was a moderate positive correlation between serum irisin and SBP, DBP, hirsutism, total cholesterol, LDL, visceral fat, and serum testosterone levels. Weak correlations were observed between serum irisin and other body fat indices. Subjects with metabolic syndrome exhibited higher irisin levels and significantly elevated body composition indices, including body fat percentage, visceral fat percentage, fat mass index, and fat-free mass index, compared to those without metabolic syndrome. Conclusions PCOS subjects have elevated serum irisin levels, which correlate positively with clinical and biochemical hyperandrogenism, total cholesterol, LDL, and visceral fat. These findings suggest that irisin may play a role in the metabolic and hormonal dysregulation observed in PCOS.

Simultaneous determination and association between serum levels of irisin and chemerin in PCOS.

To determine the serum levels of irisin, chemerin and insulin in women with polycystic ovary syndrome, and to compare their levels with respect to bodyweight and body mass index. The case-control study was conducted at the Department of Clinical Chemistry, College of Medicine, Mustansiriyah University, Baghdad, Iraq, from December 2020 to February 2022, and comprised healthy controls in group I who were matched for bodyweight and body mass index with polycystic ovary syndrome women in group II. Subjects and cases were inducted using purposive sampling technique Subgroups were also formed on the basis of normal body mass index, and overweight-obese status. Serum irisin, chemerin, insulin and free testosterone levels, anthropometric measurements, lipid profile as well as hormonal and biochemical parameters were noted. Data was analysed using SPSS 25. Of the 88 subjects, 32(36.4%) were in group I with mean age 25.1±4.7 years, and 56(63.6%) in group II with mean age 25.0±6.3 years (p>0.05). Both the groups were divided into two equal subgroups A and B. Group II had significantly higher mean body mass index (p=0.007) and adult body fat (p=0.018). Group II women had significantly high fasting serum insulin levels (p<0.001) and homeostatic model assessment for insulin resistance values (p<0.001). Serum irisin had significant positive correlation with serum chemerin (p=0.014) in group II. Serum free testosterone, irisin and chemerin were significantly higher (p<0.001) in group II compared to group I except for chemerin which showed no significant differences among women with normal body mass index (p=0.071). Serum levels of irisin and chemerin could serve as biomarkers of polycystic ovary syndrome.

Irisin levels in type 2 diabetes mellitus with and without non-alcoholic fatty liver disease: a case-control study

Background: Fatty liver disease, particularly non-alcoholic fatty liver disease (NAFLD), affects around 25% of adults globally and up to 40% in developed countries. Often coexisting with type 2 diabetes mellitus (T2DM), NAFLD is linked to insulin resistance and metabolic syndrome. Irisin, a myokine induced by exercise, shows promise in enhancing insulin sensitivity, reducing hepatic steatosis, and improving metabolic health. Despite its potential, further research is needed to fully understand irisin's mechanisms and clinical implications in NAFLD and T2DM. Objectives: This study investigates the irisin levels in T2DM patients with and without NAFLD and compares them with healthy controls. Methods: A case-control study has been conducted involving 90 T2DM patients and 90 healthy controls, aged 30-55 years, recruited from SCB Medical College, Cuttack, between September 2021 and August 2022. Participants were screened for NAFLD using the Hepatosis Steatosis Index (HSI) and divided into four groups: T2DM with NAFLD, T2DM without NAFLD, controls with NAFLD, and controls without NAFLD. Serum irisin levels were measured using ELISA. Anthropometric data, physical activity, and various biochemical parameters were assessed and analyzed. Results: The irisin levels were significantly lower in T2DM patients compared to healthy controls (p = 0.001). Among T2DM patients, those with NAFLD had lower irisin levels than those without NAFLD, though not statistically significant (p = 0.299). Significant correlations were observed between irisin levels and insulin sensitivity markers such as HOMA-IR and QUICKI across different groups. Conclusion: Lower irisin levels in T2DM patients, particularly those with NAFLD, highlight its potential role in the pathogenesis of metabolic disorders. Further research is needed to elucidate irisin's therapeutic implications in T2DM and NAFLD.

Evaluation of serum irisin level and severity of erectile dysfunction in diabetic males: a cross sectional prospective study

BackgroundIrisin is an exercise-induced myokine that alleviates endothelial dysfunction and reduces insulin resistance in type 2 diabetes mellitus (T2DM). The current study aimed to assess the serum level of irisin in T2DM men with erectile dysfunction (ED) compared to T2DM patients with normal erectile function and healthy controls, as well as investigate the association between serum irisin level and the severity of ED in T2DM patients.Patients and methodsA cross-sectional study was conducted on 90 males, divided into three groups: 32 T2DM patients with ED, 24 T2DM patients without ED, and 34 healthy controls. Socio-demographic characteristics and scores of the validated Arabic version of the international Index of Erectile Function-5 (ArIIEF-5), Generalized Anxiety Disorder-7 (GAD-7) and Patient Health Questionnaire-9 (PHQ-9) were obtained. Furthermore, routine laboratory tests employed for diabetes monitoring and serum levels of total testosterone and irisin were assessed within these groups.ResultsT2DM men with ED had significantly lower serum levels of irisin and testosterone, as well as a lower ArIIEF-5 score, but their GAD-7 and PHQ-9 scores were significantly higher than those without ED or controls (p < 0.001). Among T2DM men, serum irisin levels positively associated with ArIIEF-5 scores and serum testosterone (r = 0.413, p = 0.002; r = 0.936, p < 0.001, respectively) but negatively associated with glycosylated hemoglobin levels (r = -0.377, p = 0.004). Multivariate regression analysis to predict ED in T2DM patients found that GAD-7 score was the only most significant predictor for ED (ꞵ = − 1.176, standard error = 0.062, p < 0.001).ConclusionThe current study had demonstrated that irisin positively correlated with the ArIIEF-5 and serum testosterone but negatively correlated with HbA1c in T2DM men. Nevertheless, further validation of these findings is necessary through cohort studies.

Study on changes in serum irisin level in free-flap transplantation and the correlation of serum irisin level with flap blood flow

Background and aimsThe beneficial effect of myokine irisin on ischemia-reperfusion of skin flaps has been rarely reported in clinical studies. This study was designed to determine whether irisin plays a protective role in flap transplantation and identify the factors affecting serum irisin levels. Materials and methodsWe analyzed the changes in serum irisin levels and flap blood flow before and after surgery in 40 patients who underwent skin-flap transplantation. Factors affecting serum irisin levels were analyzed by metabolic parameter measurements. ResultsPreoperative serum irisin levels were positively correlated with blood flow in the skin flap 7 days post-surgery. The increase in serum irisin levels in the first 3 days after surgery positively correlated with flap blood flow. A longer duration of high-intensity exercise, higher skeletal muscle content, lower body mass index, and waist-to-hip ratio were associated with higher irisin levels. Fasting blood glucose and glycosylated hemoglobin levels showed significant negative correlations with serum irisin levels. Several other indicators, including sex, were not associated with serum irisin levels. ConclusionsSerum irisin levels benefit blood flow recovery during flap transplantation. Better outcomes may be achieved by adjusting the timing and intensity of the exercise and controlling the patient's body size.

Irisin preserves mitochondrial integrity and function in tubular epithelial cells after ischemia-reperfusion-induced acute kidney injury.

A myokine secreted by skeletal muscles during exercise called irisin mitigates ischemia-reperfusion (I/R) injury in epithelial cells of various organs by limiting damage to mitochondria. We test whether irisin may preserve the mitochondrial integrity and function in renal tubular epithelial cells and protect against ischemia-reperfusion-induced acute kidney injury (AKI). We correlated serum irisin levels with serum creatinine and BUN levels from both AKI patients and healthy individuals. In mice with irisin administration, various renal injury markers such as serum creatinine, BUN, kidney injury molecule-1 (Kim-1), and neutrophil gelatinase-associated lipocalin (NGAL), and renal histopathology were assessed after I/R. To identify the potential mechanisms of the protective of irisin's protective effect, we perfused proximal tubules under confocal microscopy and analyzed kidney tissues by qPCR, western blot, and immunohistochemistry. Serum irisin correlated inversely with serum creatinine and BUN levels were significantly lower in AKI patients than in healthy subjects. Administering irisin to mice after I/R decreased biomarker levels for AKI including serum creatinine, BUN, Kim-1, NAGL and lessened histological changes. In kidney tissues of mice, irisin upregulated the mitochondrial autophagy marker protein microtubule-associated protein 1 light chain 3 (LC3), the mitochondrial autophagy pathway-related proteins PTEN-induced putative kinase 1 (PINK1) and Parkinson's disease 2 parkin (PARK2) and downregulated the reactive substrate protein sequestosome 1 (P62) and mitochondrial membrane proteins translocase of outer mitochondrial membrane 20 (TOM20) and translocase of inner mitochondrial membrane 23 (TIM23). Irisin protects against renal I/R injury, which may involve the preservation of mitochondrial integrity and function.

Effects of High-Intensity Intermittent Training on Metabolic Parameters and Irisin Levels in High-Fat-Fed Rats

Objective: To investigate the effects of high-intensity intermittent training (HIIT) on preventing significant weight gain and provide scientific theoretical support and practical guidance for reducing the occurrence of obesity. Methods: Twenty-four Sprague-Dawley rats were randomly divided into four groups: the control sedentary group (CS), the high-fat sedentary group (HS), the high-fat continuous exercise group (HE), and the high-fat intermittent exercise group (HI). The HE and HI groups underwent five days of continuous low-intensity exercise and eight weeks of high-intensity intermittent exercise. Weekly monitoring included measurements of food intake and body weight. An automatic biochemical analyzer was used to assess blood lipid and glucose levels, while ELISA kits measured serum insulin and irisin content. H&amp;E staining was used to observe adipocyte size. Results: In the HS group, body weight, blood lipid levels, blood glucose levels, and adipocyte size significantly increased, while the QUICKI index decreased. In the HI group, body weight, blood lipid levels, blood glucose levels, and adipocyte size decreased, and the QUICKI index increased. The effects of high-intensity intermittent exercise were superior to those of continuous low-intensity exercise. In the HI group, serum irisin levels did not change significantly after exercise, while in the HE group, there was a slight upward trend in irisin levels. Conclusion: A high-fat diet induced abnormal metabolism in rats. HIIT effectively prevents metabolic abnormalities induced by a high-fat diet, and its effects are more pronounced than those of low-intensity exercise. HIIT stimulates the secretion of blood irisin, affecting secretion levels, and may represent a novel mechanism for maintaining metabolic homeostasis. This has important implications for controlling significant weight gain.

Do functionality, strength, vascularization, inflammatory and biopsychosocial status improve by biopsychosocial model-based exercise in SSc?

This study aimed to investigation of the effects of the Cognitive Exercise Therapy Approach (Bilişsel Egzersiz Terapi Yaklaşımı-BETY), a supervised biopsychosocial model-based exercise intervention, on functionality, muscle strength, vascularization, anti-inflammatory and biopsychosocial status in Systemic Sclerosis (SSc) patients. Thirty-seven SSc patients were included. Twenty of them were recruited into the study group (SG) undergoing BETY group exercise sessions three times a week for three months and 17 were in the control group (CG) following a home exercise program. Assessments tools were the Modified Rodnan Skin Score (mRSS), Scleroderma Health Assessment Questionnaire (SHAQ), Modified Hand Mobility in Scleroderma (mHAMIS), Duruoz Hand Index (DHI), Six Minute Walk Test (6MWT), skeletal muscle strength measurements using an isokinetic dynamometer (Biodex System 3 Pro), Shear Wave Elastography (SWE), ELISA kits (for tumor necrosis factor-alpha, Interleukin-6, IL-10, serum irisin level), BETY-Biopsychosocial Questionnaire (BETY-BQ), Hospital Anxiety and Depression Scale (HADS), and Short Form-36 (SF-36). The SG demonstrated improvements in SHAQ, mHAMIS, 6MWT, BETY-BQ, HADS, and SF-36 values, excluding the DHI scores (p < 0.05). In contrast, CG showed worsening in SHAQ-general scleroderma symptoms and HADS scores compared to SG (p < 0.05). IL-10 and TNF-alpha increased in both groups, also various vascular parameters were significantly different changed in SG than CG (p < 0.05). Muscle strength values improved in the SG but decreased in the CG however this was statistically not significant (p > 0.05). BETY can be recommended as a nonpharmacologic approach to the disease management of SSc patients.

Efficacy of tibial cortex transverse transport in treating diabetic foot ulcer and its effect on serum omentin-1 and irisin levels

ObjectiveDiabetic foot ulcer (DFU) is a common and debilitating complication of diabetes that is associated with an increased risk of lower-limb amputation and a reduced life expectancy. Tibial cortex transverse transport (TTT) has become a newly alternative surgical method to facilitate ulcer healing and prevent lower limb amputation. Herein, we investigated the efficacy of TTT in treating DFU and changes of serum omentin-1 and irisin levels.MethodsThis study prospectively recruited 52 consecutive patients with DFU who were treated with TTT. The follow-up was performed weekly during the first 12 weeks postoperatively and every 3 months until 1 year after TTT. The serum levels of vascular endothelial growth factor (VEGF), omentin-1, and irisin in DFU patients undergoing TTT were determined by ELISA methods on the preoperative 1st day, postoperative 2nd week and 4th week.ResultsThe wound healing rate was 92.3% (48/52) at the 1-year follow-up. The visual analog scale (VAS) pain scores of patients showed a significant reduction at the 4th week after TTT (p < 0.001). The dorsal foot skin temperature, ankle brachial index, and dorsal foot blood flow of patients were significantly increased at the 4th week after TTT (p < 0.001). Results of ELISA methods showed the serum levels of VEGF, omentin-1, and irisin on the 2nd week and 4th week after TTT were notably elevated compared to the levels determined on the preoperative 1st day (p < 0.001). The serum levels of VEGF, omentin-1, and irisin on the 4th week after TTT were also significantly higher than the levels determined on the 2nd week after TTT (p < 0.001).ConclusionTTT could promote the wound healing and reduce the risk of lower limb amputation, demonstrating promising clinical benefits in the treatment of DFU. Increased expressions of serum proangiogenic factors including VEGF, omentin-1, and irisin were noted in the early stage after TTT, which may provide a new mechanism of TTT promoting wound heal.

Swimming exercise alleviates pathological bone features in curdlan-injected SKG mice by inducing irisin expression

This study assessed the therapeutic potential of swimming exercise in the curdlan-injected SKG mouse model and investigated the modulatory effects of irisin on inflammation. Curdlan-injected SKG were randomly assigned to either a home-cage group or a swimming group for 6 weeks. Changes in clinical arthritis scores and ankle thickness were measured weekly. Post-swimming program, mice were anesthetized for collection of vastus lateralis muscle and blood, which was followed by histological analysis, micro-CT imaging of the ankle joints, and the measurement of pro-inflammatory cytokines and irisin levels. Additionally, curdlan-injected SKG mice were intravenously injected with recombinant irisin protein and observed. Finally, serum levels of irisin in healthy control and ankylosing spondylitis (AS) patient groups were measured by ELISA. The swimming group of curdlan-injected SKG mice exhibited significant improvements in arthritis and enthesitis compared to the home-cage group. In particular, micro-CT and histological analyses revealed a notable reduction in pathological bone features in the swimming group compared to the home-cage group. Muscle endurance was also enhanced in the swimming group compared to the home-cage group, as determined by the wire-hanging test. Intriguingly, irisin levels not only were statistically increased in the swimming group but, also, TNF-α, IL-1β, and IL-6 levels were decreased. Additionally, injection of irisin protein slightly attenuated both arthritis and enthesitis in curdlan-injected SKG mice. Meanwhile, irisin serum levels were declined in AS patients. Overall, we found that swimming exercise attenuated pathological bone features in an AS animal model, potentially mediated by increased irisin serum levels with associated anti-inflammatory effects.

Association of serum irisin levels with glucose and lipid metabolism among adolescents in Yinchuan City from 2017 to 2020

To explore the relationship between serum irisin levels and glucose and lipid metabolism among adolescents in Yinchuan City. From 2017 to 2020, a conbination of convenient sampling and stratified cluster random sampling method were used to select 1219 adolescents aged 12 to 18 years old in Yinchuan City as research subjects. The height and weight were measured using the height and sitting height meter and the bioelectrical impedance analyzer. Blood indicators such as fasting plasma glucose(FPG), totalcholesterol(TC), triglyceride(TG), low-density lipoprotein cholesterol(LDL-C) and high-density lipoprotein cholesterol(HDL-C) were measured using fully automatic biochemical analyzer. Serum irisin levels were measured by enzyme-linked immunosorbent assay(ELISA). Binary logistic regression was used to analyze the correlation between irisin and abnormal glucose and lipid metabolism. The FPG, TC, HDL-C and LDL-C levels of subjects in the highest tertile of irisin levels were significantly lower than those of subjects in the lowest tertile of irisin levels(F values were 5.13, 3.15, 3.07 and 5.01, P&lt;0.05), and the differences were statistically significant(all P&lt;0.05). The serum irisin levels in the hyperglycemia group(t=2.87, P&lt;0.01), hypercholesterolemia group(t=2.36, P=0.02) and hyperLDL-Cemia group(t=2.34, P=0.02) were significantly lower than those in the normoglycemia group, normal TC group and normal LDL-C group. Meanwhile, the irisin level in the low HDL-Cemia group(t=-2.57, P=0.01) was significantly higher than that in the normal HDL-C group, and the differences were statistically significant(P&lt;0.05). Participants in the highest tertile of irisin had 0.51, 0.49 and 0.50 times the risk of hyperglycemia(OR=0.51, 95%CI 0.29-0.87), hypercholesterolemia(OR=0.49, 95%CI 0.27-0.89) and hyperLDL-cemia(OR=0.50, 95%CI 0.25-0.99) compared with those in the lowest tertile. Low levels of irisin are associated with the occurrence of hyperglycemia, hypercholesterolemia, and hyperLDL-Cemia in adolescents.

The time course of irisin release after an acute exercise: relevant implications for health and future experimental designs.

This study aimed to analyze the acute impact of exercise on serum irisin levels in 22 young (YA, 24.6 ± 3.5 yrs) and in 12 middle-aged male adults (MA, 54.6 ± 5.7 yrs) 15 min and 24 h after an incremental cycling exercise test to exhaustion. ELISA assay was used for serum irisin detection. Circulating irisin increased significantly from baseline (9.0 ± 2.0 ng/ml) to 15 min post-exercise (10.2 ± 2.0 ng/ml, P < 0.001), but the greatest increment was detected after 24 h (13.5 ± 2.5 ng/ml, P < 0.001) reaching more than 50% of the basal release. Levels were significantly higher in YA (9.7 ± 1.7 to 11.1 ± 1.8 to 14.5 ± 2.2 ng/ml) than MA (7.6 ± 1.6 to 8.7 ± 1.5 to 11.8± 2.2 ng/ml) for all measured time-points (P < 0.05). Nevertheless, MA showed a comparable increase in serum irisin levels when compared to YA. These findings highlight the importance of acute physical exercise as a countermeasure against age-related deterioration of skeletal muscle mass and function in both YA and MA.

Interaction between inflammatory bowel disease, physical activity, and myokines: Assessment of serum irisin levels.

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, showed a wide spectrum of intestinal and extra-intestinal manifestations, which rendered the patients physically inactive and impaired their quality of life. It has been found that physical activity is a non-pharmacological intervention that improves the quality of life for those patients. Irisin is one member of the myokines secreted by muscle contraction during exercise and could be used as an anti-inflammatory biomarker in assessing the physical activity of IBD patients. In addition, experimental studies showed that exogenous irisin significantly decreased the inflammatory markers and the histological changes of the intestinal mucosa observed in experimental colitis. Furthermore, irisin produces changes in the diversity of the microbiota. Therefore, endogenous or exogenous irisin, via its anti-inflammatory effects, will improve the health of IBD patients and will limit the barriers to physical activity in patients with IBD.

The Comparison of Irisin, Subfatin, and Adropin in Normal-Weight and Obese Polycystic Ovary Syndrome Patients.

A combination of genetic and environmental factors contribute to the highly common, complex, and varied endocrine condition known as polycystic ovary syndrome (PCOS) in women. PCOS primarily affects women between the ages of 15 and 35 who are in the early to late stages of pregnancy. Thus, this study aimed to evaluate the serum levels of irisin, subfatin, and adropin in PCOS with and without obesity compared to the control group. The present cross-sectional study was conducted in 2022 at Al-Nahrain University/Department of Chemistry (Baghdad, Iraq). The serum levels of irisin, subfatin, and adropin were measured with the enzyme-linked immunosorbent assay (ELISA) method. Body mass index, lipid profile, insulin, fasting glucose, follicle-stimulating hormone, and luteinizing hormone levels were also evaluated. The data were analyzed using one-way analysis of variance (ANOVA) by GraphPad Prism software version 8.0.2. A P<0.05 was considered statistically significant. The study population comprised PCOS patients (n=90, divided into 45 obese and 45 normal weight) and healthy women (n=30). According to the results, the serum levels of irisin were significantly higher (P<0.001) in obese and normal-weight PCOS patients than controls. While adropin and subfatin were significantly lower in PCOS than controls (P<0.001). Moreover, there are higher levels of serum insulin, fasting glucose, and luteinizing hormone in PCOS women than in healthy women. According to the findings, PCOS patients had a higher level of irisin than the controls. In addition, decreased subfatin and adropin levels were observed in PCOS patients compared with healthy women. Further research is required to confirm these results in the future.

FNDC5 prevents oxidative stress and neuronal apoptosis after traumatic brain injury through SIRT3-dependent regulation of mitochondrial quality control

Mitochondrial dysfunction and oxidative stress are important mechanisms for secondary injury after traumatic brain injury (TBI), which result in progressive pathophysiological exacerbation. Although the Fibronectin type III domain-containing 5 (FNDC5) was reported to repress oxidative stress by retaining mitochondrial biogenesis and dynamics, its possible role in the secondary injury after TBI remain obscure. In present study, we observed that the level of serum irisin (the cleavage product of FNDC5) significantly correlated with the neurological outcomes of TBI patients. Knockout of FNDC5 increased the lesion volume and exacerbated apoptosis and neurological deficits after TBI in mice, while FNDC5 overexpression yielded a neuroprotective effect. Moreover, FNDC5 deficiency disrupted mitochondrial dynamics and function. Activation of Sirtuin 3 (SIRT3) alleviated FNDC5 deficiency-induced disruption of mitochondrial dynamics and bioenergetics. In neuron-specific SIRT3 knockout mice, FNDC5 failed to attenuate TBI-induced mitochondrial damage and brain injuries. Mechanically, FNDC5 deficiency led to reduced SIRT3 expression via enhanced ubiquitin degradation of transcription factor Nuclear factor erythroid 2-related factor 2 (NRF2), which contributed to the hyperacetylation and inactivation of key regulatory proteins of mitochondrial dynamics and function, including OPA1 and SOD2. Finally, engineered RVG29-conjugated nanoparticles were generated to selectively and efficiently deliver irisin to the brain of mice, which yielded a satisfactory curative effect against TBI. In conclusion, FNDC5/irisin exerts a protective role against acute brain injury by promoting SIRT3-dependent mitochondrial quality control and thus represents a potential target for neuroprotection after TBI.

Low serum irisin levels predicted newly atrial fibrillation in patients with any phenotypes of chronic heart failure

Abstract Background Atrial fibrillation (AF) continues to be a major health problem among patients with known cardiovascular disease including heart failure (HF). AF is not only powerful risk factor for newly HF, but also it contributes to untoward clinical course of the condition. Although, natriuretic peptides are well-validated biomarkers to predict poor clinical outcomes of HF, their accuracy for AF in patients with different phenotypes of HF is not optimal. Recent studies showed that adipocytokines including irisin affect the risk of AF occurrence. We hypothesized that serum irisin can have additional discriminative potency for AF among HF in patients. Methods The study group comprised 541 consecutive patients with chronic HF aged 41 to 76 years recruited for the study from October 2020 to December 2022. We included 153 patients with any phenotypes of HF who were hospitalized due to paroxysmal or persistent AF and a control group of 388 age- and sex-matched individuals admitted to hospitals due to exacerbation of HF. All patients included in the study were examined by conventional general clinical and physical investigations, B-mode echocardiography and Doppler. The plasma levels N-terminal-natriuretic pro-peptide (NT-proBNP), high sensitivity (hs) C-reactive protein, tumor necrosis factor-alpha (TNF-alpha), hs-troponin T, adropin, apelin, leptin, adiponectin, and irisin were measured using ELISA. Results Compared with patients from control groups, patients with AF had greater left atrial volume index (LAVI), higher serum levels of NT-proBNP, hs-CRP, TNF-alpha, and lower left ventricular ejection fraction (LVEF), irisin and apelin levels. There were no significant difference between groups in left ventricular mass index, the serum levels of hs-troponin T, adropin, leptin, and adiponectin. Multivariate linear regression adjusted to LVEF and LAVI revealed that irisin and NT-proBNP were the predictors for AF. We found that the well-balanced cut-off point for serum concentration of irisin (AF versus non-AF) were 10.5 ng/mL (area under curve [AUC] = 0.96, sensitivity = 81.0%, specificity = 88.0%; P = 0.0001). Cutoff point of NT-proBNP that distinguished patients with AF and without AF was 750 pmol/L (AUC = 0.96; sensitivity = 72.7%, specificity 76.5%, р = 0.0001). Multivariate Cox regression model yielded that the serum levels of irisin &amp;lt; 10.5 ng/mL (odds ratio [OR] = 1.40; P = 0.001) and NT-proBNP &amp;gt; 750 pmol/mL (OR = 1.22; P = 0.012), LAVI &amp;gt; 34 mL/m2 (OR = 1.06; P = 0.010) remained to be strong predictors for newly AF. Add-on of irisin &amp;lt; 10.5 ng/mL to the predictive model constructed from NT-proBNP (&amp;gt; 750 pg/mL) significantly improved discriminatory potency of the whole model for HF. Conclusion We found that decreased serum levels of irisin significantly predicted newly AF in patients with any phenotypes of HF.

Low irisin levels predict acutely decompensated heart failure in type 2 diabetes mellitus patients

Abstract Funding Acknowledgements None. Background Acutely decompensated heart failure (ADHF) continues to be associated with unacceptably increasing in-hospital mortality rates and one-year mortality rates. Distinct scenarios of the natural course of ADHF relate to clinical heterogeneity among patients admitted to hospitals, cardiac dysfunction etiology, precipitating factors contributing to heart failure (HF) decompensation including type 2 diabetes mellitus (T2DM). The aim of this study was to determine the discriminative value of irisin for ADHF in T2DM patients with hemodynamically stable chronic HF. Methods A total of 738 patients with T2DM were prescreened using the local database of "Vita Center" (Ukraine). Using criteria of inclusion (male/female with age of ≥18 years, established T2DM with hemodynamically stable chronic HF, glycosylated hemoglobin &amp;lt; 6.9%, informed consent to participate in the study), we enrolled 489 patients with T2DM with concomitant chronic HF I-IV New York Heart Association (NYHA) functional classes. We enrolled 480 T2DM patients with any phenotype of HF and followed them for 52 weeks. Hemodynamic performances and the serum levels of biomarkers were detected at the study entry. The primary clinical end-point was ADHF that led to urgent hospitalization. Results We found that the serum levels of N-terminal natriuretic pro-peptide (NT-proBNP) were higher (1719 [980-2457] pmol/mL vs. 1057 [570-2607] pmol/mL, respectively) and the levels of irisin were lower (4.96 [3.14-6.85] ng/mL vs. 7.95 [5.73-9.16] ng/mL) in ADHF patients than in those without ADHF. The ROC curve analysis showed that the estimated cut-off point for serum irisin levels (ADHF versus non-ADHF) was 7.85 ng/mL (area under curve [AUC] = 0.869 (95% CI = 0.800-0.937), sensitivity = 82.7%, specificity = 73.5%; p = 0.0001). The multivariate logistic regression yielded that the serum levels of irisin &amp;lt; 7.85 ng/mL (OR = 1.20; p = 0.001) and NT-proBNP &amp;gt; 1215 pmol/mL (OR = 1.18; p = 0.001) retained the predictors for ADHF. Kaplan-Meier plots (Figure) showed a significant difference of clinical end-point accumulations in patients with HF depending on irisin levels (&amp;lt;7.85 ng/mL versus ≥7.85 ng/mL). The intra-class correlation coefficient for inter-observer reproducibility of LV dimensions was 0.88 (95% CI = 0.83–0.92), of LVEF was 0.93 (95% CI = 0.90–0.97), of LAVI was 0.92 (95% CI = 0.89–0.94), and of E/e’ was 0.90 (95% CI = 0.87–0.94). Along with it, the intra-class correlation coefficient for the intra-observer reproducibility of LV dimensions was 0.91 (95% CI = 0.88–0.95), of LVEF was 0.94 (95% CI = 0.90–0.98), of LAVI was 0.95 (95% CI = 0.93–0.97), and of E/e’ was 0.92 (95% CI = 0.90–0.95). In conclusion, we established that decreased levels of irisin were associated with ADHF presentation in chronic HF patients with T2DM independently from NT-proBNP.Flow chart of the study designThe Kaplan–Meier analysis of ADHF

DIAGNOSTIC VALUE OF SERUM IRISIN LEVELS IN HYPERTENSIVE PATIENTS WITH SEVERE OBSTRUCTIVE SLEEP APNEA SYNDROME

Objective: To observe the diagnostic value of serum irisin level in patients with hypertension for severe obstructive sleep apnea syndrome. Design and method: A total of 156 hypertensive patients were selected from the Hypertension Center of the People 's Hospital of Xinjiang Uygur Autonomous Region from September 2019 to January 2020. Baseline data, PSG and ABPM were collected and serum irisin levels were measured. According to AHI, the patients were divided into severe OSAS group (n=79 cases) and non-severe OSAS group (n=77 cases). Results: Male patients in severe OSAS group were significantly more than those in non-severe OSAS group, and abdominal circumference and neck circumference in severe OSAS group were greater than those in non-severe OSAS group. Serum irisin concentration in severe OSAS patients was lower than that in non-severe OSAS group, and the difference was statistically significant(14.94 ng/ml vs 42.34 ng/ml, p &lt; 0.001). Serum irisin concentration was negatively correlated with AHI (r=-0.359, p &lt; 0.01). The critical value of serum irisin concentration was 38.07 mg/ml by ROC curve, the AUC is 0.761, the sensitivity was 86.07%, the specificity was 61.07%, the positive predictive value was 69.38%, and the negative predictive value was 81.03%. Conclusions: In hypertensive population, the serum irisin concentration of OSA patients was negatively correlated with the severity of OSAS. Serum irisin level can be used as a diagnostic index for severe OSAS patients.