Irisin Concentrations Research Articles

Correlation of mild cognitive impairment with the thickness of retinal nerve fiber layer and serum indicators in type 2 diabetic patients.

Cognitive Impairment arising from type 2 diabetes mellitus (T2DM) has garnered significant attention in recent times. However, there are few studies on the identification and diagnosis of markers of cognitive impairment. Notably, alterations in the Retinal Nerve Fiber Layer's (RNFL) thickness can potentially serve as an indicative measure of central nervous system changes. Further investigations have indicated that the decline in cognitive function within T2DM patients is intricately linked to persistent systemic inflammation and the accumulation of advanced glycosylation end products. Comprehensive studies are warranted to unveil these complex associations. This study aims to explore the potential of utilizing the RNFL thickness and serological concentrations of IL-18, irisin, CML, and RAGE as diagnostic indicators for Mild Cognitive Impairment (MCI) among individuals with T2DM. The thickness of RNFL were determined in all patients and controls using optical coherence tomography (OCT). The serum levels of IL-18, irisin, CML and RAGE were detected by ELISA kit. In addition, Cognitive assessment was performed by the Mini-Mental State Examination (MMSE) and the Montreal Cognitive assessment (MoCA). The average RNFL thickness in the right eye were decreased in T2DM and T2DM combined with MCI (T2DM-MCI) patients and were positively correlated with MoCA and MMSE scores. The serum levels of IL-18, CML and RAGE in T2DM and T2DM-MCI increased significantly (p<0.05) and were negative correlated with MoCA and MMSE scores. The level of irisin in T2DM and T2DM-MCI decreased significantly (p<0.05) and were positively correlated with MoCA and MMSE scores. The area under the ROC curve of T2DM-MCI predicted by the average RNFL thickness in the right eye, CML and RAGE were 0.853, 0.874 and 0.815. The diagnostic efficacy of the combination of average RNFL thickness in the right eye, CML, and RAGE for the diagnosis of T2DM-MCI was 0.969. The average RNFL thickness in the right eye, CML and RAGE have possible diagnostic value in T2DM-MCI patients.

Associations between total, free and bioavailable 25-hydroxyvitamin D forms with adiponectin and irisin in maternal-neonatal pairs at birth from Greece.

Apart from the well-established skeletal effects, vitamin D has been explored as a secretagogue influencing various adipokines, including adiponectin and irisin. Recent evidence suggests that specific forms of 25-Hydroxyvitamin D (25(OHD), such as free and bioavailable 25(OH)D, may provide more accurate measurements of vitamin D status. The relationship between vitamin D status and serum irisin and adiponectin concentrations remains largely unexplored, particularly during pregnancy. We analyzed data from 67 healthy maternal-neonatal pairs from Northern Greece at birth. Biochemical and hormonal tests were conducted on each maternal-neonatal pair. The vitamin D forms were estimated using validated mathematical models. Subsequently, regression analyses were conducted to determine the association between the vitamin D forms and adipokine levels. Bioavailable maternal 25(OH)D was inversely associated with neonatal irisin concentrations [β=-73.46 (-140.573 to -6.341), p=0.034]. No other associations were observed between maternal vitamin D status and neonatal adipokine concentrations. In conclusion, maternal bioavailable vitamin D concentrations are inversely associated with neonatal serum irisin concentrations, warranting further studies to evaluate the underlying mechanisms for this finding.

The relationship of cognitive functions with brain damage markers, myokines and neurotrophic factors in amateur soccer players.

Concussive and subconcussive head impatcs in sports have drawn more attention in recent years. Thus, the cognitive ability of soccer players and its relationship with circulating levels of irisin, brain-derived neurotrophic factor (BDNF), and neuron-specific enolase (NSE) were studied in this study. Fifteen amateur soccer players and 15 sedentary men volunteered to participate in this study. After evaluating the aerobic and anaerobic capacities of the participants, their cognitive performances were measured. Blood samples were obtained at rest, and the ELISA method was used to measure the concentrations of serum NSE, plasma BDNF, and irisin. There were no differences between groups in terms of cognitive abilities or serum NSE levels (P > 0.05). Plasma irisin (P = 0.019) and BDNF (P < 0.001) levels were higher in the soccer players than the sedentary subjects. There was a positive correlation between irisin and NSE (r = 0.461, P = 0.010) and BDNF (r = 0.405, P = 0.007) concentrations. General cognitive performance is maintained in amateur soccer players. This is accompanied by the unchanged NSE. However, elevated irisin and BDNF levels appear to be independent of cognitive performance.

Associations of Serum Irisin and Fibroblast Growth Factor-21 Levels With Bone Mineral Characteristics in Eumenorrheic Adolescent Athletes With Different Training Activity Patterns.

To describe serum irisin and fibroblast growth factor-21 (FGF-21) concentrations in healthy female adolescents with different training activity patterns and their associations with bone mineral properties and metabolic markers. A total of 62 adolescent girls aged 14-18years were recruited: 22 rhythmic gymnasts, 20 swimmers, and 20 untrained controls. Bone mineral characteristics by dual-energy X-ray absorptiometry, daily energy intake by dietary recall, serum irisin, FGF-21, undercarboxylated osteocalcin, and C-terminal telopeptide of type I collagen were measured in all girls. Whole body and lumbar spine areal bone mineral density and lumbar spine bone mineral content were higher in the rhythmic gymnasts group compared with swimmers and untrained controls groups (P < .05). Serum irisin, FGF-21, undercarboxylated osteocalcin, and C-terminal telopeptide of type I collagen levels were not significantly different between the groups. In the rhythmic gymnasts group, serum FGF-21 concentration was positively correlated with lumbar spine areal bone mineral density independently of confounding factors (r = .51; P = .027). Serum irisin and FGF-21 levels were not different between adolescent eumenorrheic girls with different training activity patterns. FGF-21 was positively associated with lumbar spine areal bone mineral density, which predominantly consists of trabecular bone in adolescent rhythmic gymnasts.

Myokines and Biomarkers of Frailty in Older Inpatients with Undernutrition: A Prospective Study.

Population aging might increase the prevalence of undernutrition in older people, which increases the risk of frailty. Numerous studies have indicated that myokines are released by skeletal myocytes in response to muscular contractions and might be associated with frailty. This study aimed to evaluate whether myokines are biomarkers of frailty in older inpatients with undernutrition. The frailty biomarkers were extracted from the Gene Expression Omnibus and Genecards datasets. Relevant myokines and health-related variables were assessed in 55 inpatients aged ≥ 65 years from the Peking Union Medical College Hospital prospective longitudinal frailty study. Serum was prepared for enzyme-linked immunosorbent assay using the appropriate kits. Correlations between biomarkers and frailty status were calculated by Spearman's correlation analysis. Multiple linear regression was performed to investigate the association between factors and frailty scores. The prevalence of frailty was 13.21%. The bioinformatics analysis indicated that leptin, adenosine 5'-monophosphate-activated protein kinase (AMPK), irisin, decorin, and myostatin were potential biomarkers of frailty. The frailty group had significantly higher concentrations of leptin, AMPK, and MSTN than the robust group (p < 0.05). AMPK was significantly positively correlated with frailty (p < 0.05). The pre-frailty and frailty groups had significantly lower concentrations of irisin than the robust group (p < 0.05), whereas the DCN concentration did not differ among the groups. Multiple linear regression suggested that the 15 factors influencing the coefficients of association, the top 50% were the ADL score, MNA-SF score, serum albumin concentration, urination function, hearing function, leptin concentration, GDS-15 score, and MSTN concentration. Proinflammatory myokines, particularly leptin, myostatin, and AMPK, negatively affect muscle mass and strength in older adults. ADL and nutritional status play major roles in the development of frailty. Our results confirm that identification of frailty relies upon clinical variables, myokine concentrations, and functional parameters, which might enable the identification and monitoring of frailty.

PLASMA BDNF/IRISIN RATIO ASSOCIATES WITH COGNITIVE FUNCTION IN OLDER ADULTS

Abstract Objectives To examine whether plasma biomarkers brain-derived neurotrophic factor (BDNF), irisin, clusterin and BDNF/irisin ratio (BIR) could differentiate people with mild cognitive impairment (MCI) from cognitively normal (CN) individuals, and to explore their relations with cognitive performance. Methods We included 124 participants with MCI and 126 CN participants from a community-based aged and cognitive health cohort. Plasma BDNF, irisin and clusterin were measured, and BIR was calculated. Global cognition was evaluated with Montreal Cognitive Assessment. T-tests, logistic regressions, and linear regressions were used to explore the relations between plasma biomarkers and cognitive function. Results The plasma levels of irisin, but not BDNF, was significantly different between MCI and CN groups. Higher irisin concentration was associated with increased probability for MCI (OR: 1.06, p = 0.004) after adjusting for covariates. By contrast, BDNF, but not irisin, was linearly correlated with cognitive performance (β = 0.14, p = 0.033). BIR values were positively correlated with cognitive performance (β= 0.14, p = 0.036), and significant differences on BIR values existed between MCI and CN groups. The MCI risk decreased by 53% (OR=0.47, p = 0.043) with each unit increase in BIR values after adjusting for covariates. Plasma BDNF and irisin concentrations increased with aging, whereas BIR values remained stable across the ages. No significant results of clusterin were observed in the above analyses. Conclusion Plasma BIR is a potentially reliable indicator which not only reflects the odds of the presence of MCI but also directly associates with cognitive performance in the aged population.

Relationship between Serum Irisin Level, All-Cause Mortality, and Cardiovascular Mortality in Peritoneal Dialysis Patients

Introduction: This study aimed to investigate the prospective role of serum irisin – a novel adipo-myokine – in all-cause mortality and cardiovascular (CV) mortality in patients on peritoneal dialysis (PD). Methods: A prospectively observational study was conducted with 154 PD patients. Baseline clinical data were collected from the medical records. Serum irisin concentrations were determined using enzyme-linked immunosorbent assay. Patients were divided into the high irisin group (serum irisin ≥113.5 ng/mL) and the low irisin group (serum irisin <113.5 ng/mL) based on the median value of serum irisin. A body composition monitor was used to monitor body composition. Cox regression analysis was utilized to find the independent risk factors of all-cause and CV mortality in PD patients. Results: The median serum irisin concentration was 113.5 ng/mL (interquartile range, 106.2–119.8 ng/mL). Patients in the high irisin group had significantly higher muscle mass and carbon dioxide combining power (CO2CP) than those in the low irisin group (p < 0.05). Serum irisin was positively correlated with pulse pressure, CO2CP, and muscle mass, while negatively correlated with body fat percentage (p < 0.05). During a median of follow-up for 60.0 months, there were 55 all-cause deaths and 26 CV deaths. Patients in the high irisin group demonstrated a higher CV survival rate than those in the low irisin group (p = 0.016). Multivariate Cox regression analysis showed that high irisin level (hazard ratio [HR], 0.341; 95% confidence interval [CI], 0.135–0.858; p = 0.022), age, and diabetic mellitus were independently associated with CV mortality in PD patients. However, serum irisin level failed to demonstrate a statistically significant relationship with all-cause mortality. Conclusion: Low serum irisin levels at baseline were independently predictive of CV mortality but not all-cause mortality in PD patients. Therefore, serum irisin could be a potential target for monitoring CV outcomes in PD patients.

The Acute and Chronic Effect of Endurance Versus Resistance Exercise on Circulating Irisin: A Systematic Review and Meta-Analysis

Abstract Background Exercise-induced release of irisin is associated with various improved health outcomes. However, the most effective exercise mode(s) to stimulate irisin release remain unclear. In this systematic review, we separately examine potential differences in (i) resting irisin concentrations (chronic change) after resistance (RT) and endurance training (ET) and (ii) the concentrations of irisin after a single bout (acute change) of resistance (RE) and endurance exercise (EE). Methods Searching was completed February 2022 in PubMed, CINAHL, Web of Science, Cochrane Library, SCOPUS, and SportDiscus. Studies were included by consensus of 2 reviewers, if they were randomized controlled trials (RCTs) or comparison studies with adults over 18 years and compared chronic change after RT and ET for any intervention duration or acute change after RE and EE. Risk of bias and quality of findings were independently assessed using PEDRo and GRADE, respectively. Irisin post means and standard deviations were extracted to calculate standardized mean differences (SMDs) and 95% confidence intervals using a random effect model. Results Of 174 studies screened, 8 chronic and 4 acute studies were included in the analysis, comprising a total of 332 participants. No difference between RT or ET for chronic irisin response was found (P = 0.380, SMD = 0.17, n = 248); however, there tended to be greater acute increases in circulating irisin after RE than EE (P &amp;lt; 0.001, SMD = 0.93, n = 56). Conclusions A greater effect of RE on irisin concentrations than EE was found in acute studies. Future research requires larger sample sizes and matched intensities.

THE EFFECT OF INTERMITTENT FASTING DIET AND LIGHT-INTENSITY PHYSICAL ACTIVITY ON SERUM IRISIN LEVELS ELDERLY INDIVIDUALS

Objective: This study aimed to evaluate the effects of exercise and intermittent fasting diet on certain anthropometric measurements and circulating irisin concentration in elderly individuals and to investigate the relationship between irisin and body fat percentage.&#x0D; Materials and Methods: 44 elderly volunteers (21 males and 23 females) with a mean age of 69±9 years, were randomly divided into 4 groups; Control (n=8), Bocce group (n=12), Intermittent Fasting group (n=12), Bocce and Intermittent Fasting group (n=12). The applications were continued for 12 weeks.&#x0D; Results: A comparison of the groups before and after the application showed no significant difference between serum irisin values (P &gt;0.05). Body fat percentage decreased significantly in all other groups besides the control group where it increased (P

Irisin protected hemopoietic stem cells and improved outcome of severe bone marrow failure

Acquired aplastic anemia (AA) is a bone marrow failure (BMF) disease, characterized by fatty bone marrow (BM) and BM hypocellularity resulted from auto-immune dysregulated T cells-mediated destruction of BM haemopoietic stem cells (HPSC). The objective of this study was to investigate potential therapeutic effect of irisin, a molecule involved in adipose tissue transition, on AA mouse model. Our results showed that the concentration of irisin in serum was lower in AA patients than in healthy controls, suggesting a role of irisin in the pathogenesis of AA. In the AA mice, irisin administration prolonged the survival rate, prevented or attenuated peripheral pancytopenia, and preserved HPSC in the BM. Moreover, irisin also markedly reduced BM adipogenesis. In vitro results showed that irisin increased both cell proliferation and colony numbers of HPSC. Furthermore, our results demonstrated that irisin upregulated the expression of mitochondrial ATPase Inhibitory Factor 1 (IF1) in HPSC, inhibited the activation of mitochondrial fission protein (DRP1) and enhanced aerobic glycolysis. Taken together, our findings indicate novel roles of irisin in the pathogenesis of AA, and in the protection of HPSC through stimulation of proliferation and regulation of mitochondria function, which provides a proof-of-concept for the application of irisin in AA therapy.

Time of day of exercise does not affect the beneficial effect of exercise on bone structure in older female rats.

Background: Circadian clock genes are expressed in bone and biomarkers of bone resorption and formation exhibit diurnal patterns in animals and humans. Disruption of the diurnal rhythms may affect the balance of bone turnover and compromise the beneficial effects of exercise on bone. Objective: This study investigated whether the time of day of exercise alters bone metabolism in a rodent model. We hypothesized that exercise during the active phase results in greater bone mass than exercise during the rest phase in older female rats. Methods: Fifty-five, female 12-month-old Sprague Dawley rats were randomly assigned to four treatment groups (n = 13-14/group). Rats were subjected to no exercise or 2h of involuntary exercise at 9m/min and 5days/wk for 15weeks using motor-driven running wheels at Zeitgeber time (ZT) 4-6 (rest phase), 12-14 (early active phase), or 22-24 (late active phase). ZT 0 is defined as light on, the start of the rest phase. A red lamp was used at minimal intensity during the active, dark phase exercise period, i.e., ZT 12-14 and 22-24. Bone structure, body composition, and bone-related cytokines in serum and gene expression in bone were measured. Data were analyzed using one-way ANOVA followed by Tukey-Kramer post hoc contrasts. Results: Exercise at different ZT did not affect body weight, fat mass, lean mass, the serum bone biomarkers, bone structural or mechanical parameters, or expression of circadian genes. Exercise pooled exercise data from different ZT were compared to the No-Exercise data (a priori contrast) increased serum IGF-1 and irisin concentrations, compared to No-Exercise. Exercise increased tibial bone volume/total volume (p = 0.01), connectivity density (p = 0.04), and decreased structural model index (p = 0.02). Exercise did not affect expression of circadian genes. Conclusion: These data indicate that exercise is beneficial to bone structure and that the time of day of exercise does not alter the beneficial effect of exercise on bone in older female rats.

Indoxyl sulfate induced frailty in patients with end-stage renal disease by disrupting the PGC-1α-FNDC5 axis.

Sarcopenia or frailty is common among patients with chronic kidney disease (CKD). The protein-bound uremic toxin indoxyl sulfate (IS) is associated with frailty. IS induces apoptosis and disruption of mitochondrial activity in skeletal muscle. However, the association of IS with anabolic myokines such as irisin in patients with CKD or end-stage renal disease (ESRD) is unclear. This study aims to elucidate whether IS induces frailty by dysregulating irisin in patients with CKD. The handgrip strength of 53 patients, including 28 patients with ESRD, was examined. Serum concentrations of IS and irisin were analyzed. CKD was established in BALB/c mice through 5/6 nephrectomy. Pathologic analysis of skeletal muscle was assessed through haematoxylin and eosin and Masson's trichrome staining. Expression of peroxisome proliferator-activated receptor-gamma coactivator PGC-1α and irisin were analyzed using real-time polymerase chain reaction and Western blotting. Handgrip strength was lower among patients with ESRD than among those without ESRD. In total, 64.3% and 24% of the patients in the ESRD and control groups had low handgrip strength, respectively (p < 0.05). Serum concentrations of IS were significantly higher in the ESRD group than in the control group (222.81 ± 90.67 μM and 23.19 ± 33.28 μM, respectively, p < 0.05). Concentrations of irisin were lower in the ESRD group than in the control group (64.62 ± 32.64 pg/mL vs. 99.77 ± 93.29 pg/mL, respectively, p < 0.05). ROC curves for low handgrip strength by irisin and IS were 0.298 (95% confidence interval (CI): 0.139-0.457, p < 0.05) and 0.733 (95% CI: 0.575-0.890, p < 0.05), respectively. The percentage of collagen was significantly higher in mice with 5/6 nephrectomy than in the control group. After resveratrol (RSV) treatment, the percentage of collagen significantly decreased. RSV modulates TGF-β signaling. In vitro analysis revealed that IS treatment suppressed expression of PGC-1α and FNDC5 in a dose-dependent manner, whereas RSV treatment attenuated IS-induced phenomena in C2C12 cells. IS was positively correlated with frailty in patients with ESRD through the modulation of the PGC-1α-FNDC5 axis. RSV may be a potential drug for reversing IS-induced suppression of the PGC-1α-FNDC5 axis in skeletal muscle.

Exercise ameliorating myocardial injury in type 2 diabetic rats by inhibiting excessive mitochondrial fission involving increased irisin expression and AMP-activated protein kinase phosphorylation.

Though exercise generates beneficial effects on diabetes-associated cardiac damage, the underlying mechanism is largely unclear. Therefore, we prescribed a program of 8-week treadmill training for type 2 diabetes mellitus (T2DM) rats and determined the role of irisin signaling, via interacting with AMP-activated protein kinase (AMPK), in mediating the effects of exercise on myocardial injuries and mitochondrial fission. Forty 8-week-old male Wistar rats were randomly divided into groups of control (Con), diabetes mellitus (DM), diabetes plus exercise (Ex), and diabetes plus exercise and Cyclo RGDyk (ExRg). Ex and ExRg rats received 8 weeks of treadmill running, and the rats in the ExRg group additionally were treated with a twice weekly injection of Cyclo RGDyk, an irisin receptor-αV/β5 antagonist. At the end of the experiment, murine blood samples and heart tissues were collected and analyzed with methods of ELISA, Western blot, real-time quantitative polymerase chain reaction, as well as immunofluorescence staining. Exercise effectively mitigated T2DM-related hyperglycemia, hyperinsulinemia, lipid dysmetabolism, and inflammation, which could be diminished by Cyclo RGDyk treatment. Additionally, exercise alleviated T2DM-induced myocardial injury and excessive mitochondrial fission, whereas the beneficial effects were blocked by the administration of Cyclo RGDyk. T2DM significantly decreased serum irisin concentrations and fibronectin type III domain-containing protein 5 (FNDC5)/irisin gene and protein expression levels in the rat heart, whereas exercise could rescue T2DM-reduced FNDC5/irisin expression. Blocking irisin receptor signaling diminished the exercise-alleviated mitochondrial fission protein expression and elevated AMPK phosphorylation. Exercise is effective in mitigating diabetes-related insulin resistance, metabolic dysfunction, and inflammation. Irisin signaling engages in exercise-associated beneficial effects on myocardial injury and excessive mitochondrial fission in diabetes rats involving elevated AMPK phosphorylation.

Nordic Walking training in BungyPump form improves cognitive functions and physical performance and induces changes in amino acids and kynurenine profiles in older adults.

Although impacts of physical activity on cognitive functions have been intensively investigated, they are still far from being completely understood. The aim of this study was to evaluate the effect of 12 weeks of the Nordic Walking training with BungyPump resistance poles (NW-RSA) on the amino acid and kynurenine profiles as well as selected myokine/exerkine concentrations, which may modify the interface between physical and cognitive functions. A group of 32 older adults participated in the study. Before and after the intervention, body composition, cognitive functions, and physical performance were assessed. Blood samples were taken before and 1 h after the first and last sessions of the NW-RSA training, to determine circulating levels of exercise-induced proteins, i.e., brain-derived neurotrophic factor (BDNF), irisin, kynurenine (KYN), metabolites, and amino acids. The NW-RSA training induced a significant improvement in cognitive functions and physical performance as well as a reduction in fat mass (p = 0.05). Changes were accompanied by a decline in resting serum BDNF (p = 0.02) and a slight reduction in irisin concentration (p = 0.08). Still, changes in irisin concentration immediately after the NW-RSA intervention depended on shifts in kynurenine-irisin dropped as kynurenine increased. The kynurenine-to-tryptophan and phenylalanine-to-tyrosine ratios decreased significantly, suggesting their possible involvement in the amelioration of cognitive functions. No changes of glucose homeostasis or lipid profile were found. Shifts in the concentrations of selected amino acids might have covered the increased energy demand in response to the NW-RSA training and contributed to an improvement of physical performance. Regular Nordic Walking training with additional resistance (BungyPump) improved cognitive functions and physical performance. These positive effects were associated with a reduced BDNF concentration and kynurenine-to-tryptophan ratio as well as changes in the amino acid profile.

Adipomyokines in children with obesity

Adipomyokines are synthesized and secreted into the bloodstream by cells of both muscle and adipose tissue. They can have both a negative metabolic effect, acting as pro-inflammatory adipokines in obesity, and a positive one, increasing in response to physical exertion in the form of myokines. To study the features of adipocytokine secretion in children with constitutionally exogenous obesity. The study included 80 patients: 60 adolescents aged 15 [13; 16] years with constitutionally exogenous obesity SDS BMI: 3.0 [2.6; 3.3] and 20 control group children aged 16 [15; 17] years without excess weight SDS BMI: -0.3 [-1.25; 0.33]. Commercial enzyme immunoassay kits were used to determine the level of adipomyokines. The compositional composition of the body was evaluated by bioimpedance analysis (InBody 770 analyzer, South Korea) in the morning, on an empty stomach. Statistical processing was carried out using STATISTICA v.12.0 (StatSoft Inc., USA). The results are presented in the form of median (Me) and quartiles (Q1; Q3) corresponding to 25 and 75 percentiles. The critical significance level (p) was assumed to be &lt;0.05. Levels of IL-6 and irisin are statistically significantly higher in obese adolescents compared to the control group: 0.55 [0.226; 1.35] pg/ml vs 0.202 [0.128; 0.652] pg/ml (p=0.041) and 11.16 [6.6; 22.76] mcg/ml vs 7.36 [6.48; 9.68] mcg/ml (p=0.043), respectively. Concentrations of IL-6, myostatin and decorin increase with an increase in the degree of obesity: grade I vs III: 0.226 [0.224; 0.398] vs 0.80 [0.36; 1.81] pg/ml (p=0,0197), 25,85 [21,53; 28,23] vs 31.41 [24.36; 35.06] ng/ml (p=0.03), 4065.3 [3244.9; 5245.5] vs 5322.5 [4199.8; 7702.4] pg/ml (p=0.0376), respectively. In obese children, IL-6 levels positively correlate with BMI, SDS BMI and the amount of adipose tissue, and myostatin - with BMI and SDS BMI. The concentration of irisin in the blood serum is significantly higher in obese girls than in obese boys and healthy girls. Obese patients, compared with lean peers, are characterized by a statistically significantly higher content of both fat and lean mass. With the progression of obesity, there is a statistically significant increase in the ratio of fat to lean mass (I degree - 0.66 [0.56; 0.7], III - 0.78 [0.68; 0.98] (p=0.0073). Patients with obesity and normal body weight have different levels of adipomyokines. An increase in the level of IL-6 with the progression of obesity is directly related to an increase in the content of adipose tissue. Further study of the features of adipocytokine secretion, their relationship with the features of the body composition and metabolic complications in obesity is required.

Association between Serum Irisin and Leptin Levels and Risk of Depressive Symptoms in the Diabetic Elderly Population.

Adipokines are considered to be involved in the pathogenesis of diabetes and depression. The associations of serum levels of leptin and irisin with depressive symptoms were investigated in elderly patients with type 2 diabetes (T2DM). 189 elderly diabetics were assessed with the 30-item Geriatric Depression Scale (GDS-30), and 57 patients with depressive symptoms and 132 controls were selected. Blood biochemical parameters, including serum irisin and leptin, were measured. Serum irisin levels were decreased and leptin concentrations were significantly higher in T2DM patients with depressive symptoms compared to controls. In all subjects, the irisin level was inversely correlated with the leptin level and the GDS-30 score, whereas the leptin level was highly correlated with BMI and the GDS-30 score. Higher levels of leptin and lower concentrations of irisin are, among other factors, variables indicative of predictive capacity for depressive symptoms in elderly patients with T2DM. The results indicated that irisin and leptin levels may be used as diagnostic markers of depressive symptoms in diabetic, elderly patients and as potential therapeutic targets for the treatment. Further prospective and more extensive studies are needed to clarify the role of these adipokines in the common pathogenesis of depression and diabetes.

Serum myostatin and irisin as predictive biomarkers of sarcopenia, malnutrition and mortality in patients with decompensated liver cirrhosis

Malnutrition and sarcopenia are nowadays considered the main complications of liver cirrhosis (LC). Myokines are signal peptides synthesized in muscles that regulate muscle strength and mass and mediate crosstalk between skeletal muscles and other organs. It is unknown whether circulating myokines can be used as biomarkers of malnutrition and sarcopenia and have independent prognostic value in LC. The purpose of the study was to assess the relationship of serum levels of myokines myostatin and irisin with nutritional status, skeletal muscle status, and survival in decompensated LC patients. 74 patients (55.30±11.40 years) were involved in the prospective study. Nutritional status was assessed using the Patient-Generated Subjective Global Assessment, and skeletal muscle mass was assessed using the Skeletal Muscle Index. The concentration of serum myostatin and irisin was determined by enzyme immunoassay. Statistical data processing was performed in SPSS22 (© SPSS Inc.). It was established that the concentration of serum myostatin and irisin is not related to the LC severity according to the Child-Turcotte-Pugh, Model For End-Stage Liver Disease, and the grade of ascites. Patients with overt encephalopathy have higher myostatin levels. Patients with severe hypoalbuminemia have higher serum myostatin and lower serum irisin levels. The development of malnutrition and sarcopenia in decompensated LC patients is associated with increased serum myostatin concentration and decreased serum irisin concentration. Serum myostatin level can predict sarcopenia (AUC 0.834 in males and 0.827 in females, p&lt;0.01). Serum irisin level can predict severe malnutrition (AUC 0.830, p&lt;0.001). The mortality of patients with high myostatin levels (above 5.25 ng/ml in males and 3.55 ng/ml in females) and low irisin levels (less than 1.72 ng/ml) is significantly higher. In conclusion, the circulating myokines levels may be useful in the assessment of nutritional and skeletal muscle status, and prediction of mortality in LC patients.

DECREASED SERUM LEVELS OF IRISIN PREDICTED HEART FAILURE IN PATIENTS WITH TYPE 2 DIABETES MELLITUS

Objective: Type 2 diabetes mellitus (T2DM) is a powerful risk factor for heart failure (HF) contributing to untoward clinical course of the condition. Although natriuretic peptides are validated biomarkers to rule out HF, the accuracy of them in prediction of HF in T2DM is not optimal. The aim of the study was to investigate whether serum irisin has additional discriminative capacity for HF in patients with T2DM. Design and method: We prospectively included 183 T2DM patients with aged 41 to 65 years (153 patients with any phenotypes of HF and 30 patients without HF) in the study. The following criteria such as age &gt; 18 years, established T2DM regardless of HF, and the levels of HbAc1 less 6.9% were used as inclusion ones. All patients underwent general examination, echocardiography and Doppler. The plasma levels of NT-proBNP and irisin were measured using ELISA Results: The Receive Operation Characteristics curve analysis showed that the well-balanced cut-off point for serum concentration of irisin (HF vs non-HF) were 10.4 ng/mL (area under curve [AUC] = 0.96 (95% CI = 0.88 – 1.00), sensitivity = 81.0%, specificity = 88.0%; P = 0.0001). Cutoff point of NT-proBNP (HF vs non-HF) was 750 pmol/L (AUC = 0.96; 95% CI = 0.59 - 0.98; sensitivity = 72.7%, specificity 76.5%, p = 0.0001). Multivariate logistic model yielded that the serum levels of irisin &lt; 10.4 ng/mL (OR = 1.30; P = 0.001) and NT-proBNP &gt; 750 pmol/mL (OR = 1.17; P = 0.042), left atrial volume index (LAVI) &gt; 34 mL/m2 (OR = 1.06; P = 0.042) remained to be strong predictors for HF, whereas LAVI did not. Add-on of irisin levels &lt; 10.4 ng/mL to the predictive model constructed from NT-proBNP (&gt; 750 pg/mL) significantly improved discriminatory potency of the whole model for HF. Conclusions: We found that decreased serum levels of irisin significantly predicted HF in T2DM patients. This finding may open a new approach for HF risk stratification in T2DM patients.

Down regulation of the inverse relationship between parathyroid hormone and irisin in male vitamin D-sufficient HIV patients.

Infection with the human immunodeficiency virus (HIV) predisposes to endocrine disorders, manifesting as a metabolic phenotype that affects the entire adipose-musculoskeletal unit (AMS). The present cross-sectional study aimed to investigate differences in irisin and adiponectin concentrations between people living with HIV and healthy controls, as well as to explore potential correlations between the levels of the aforementioned adipokines and markers of calcium homeostasis. 46 HIV-infected individuals and 39 healthy controls (all men) were included in the study. Anthropometric data, adipokine levels, 25-hydroxyvitamin D [(25(OH)D)] and parathyroid hormone (PTH) concentrations were evaluated in the two groups. Correlations for the relationship between adiponectin, irisin, and PTH levels were examined. The results were adjusted for several confounders, including 25(OH)D levels, anthropometry, physical activity, bone mineral density, testosterone levels, and exposure to ultraviolet B radiation. Mean adiponectin concentrations were significantly lower in the HIV group compared to the control group: 5868 ± 3668 vs 9068 ± 4277ng/mL, p = 0.011. The same was applicable to irisin concentrations: 8.31 ± 8.17 (HIV) vs 29.27 ± 27.23 (controls) ng/mL, p = 0.013. A statistically significant and negative correlation was observed between irisin and PTH in the control group (r = - 0.591; p = 0.033). In contrast, no significant correlation was observed between PTH and irisin in the HIV group (p = 0.898). Our results are the first to suggest a possible down regulation of the inverse relationship between PTH and irisin in HIV patients and to highlight that AMS dyshomeostasis could be involved in the development of skeletal and adipose HIV-related morbidities.

Changes in selected exerkines concentration post folk-dance training are accompanied by glucose homeostasis and physical performance improvement in older adults

The study aimed to evaluate the impact of selected exerkines concentration induced by folk-dance and balance training on physical performance, insulin resistance, and blood pressure in older adults. Participants (n = 41, age 71.3 ± 5.5 years) were randomly assigned to folk-dance (DG), balance training (BG), or control group (CG). The training was performed 3 times a week for 12 weeks. Physical performance tests—time up and go (TUG) and 6-min walk test (6MWT), blood pressure, insulin resistance, and selected proteins induced by exercise (exerkines) were assessed at baseline and post-exercise intervention. Significant improvement in TUG (p = 0.006 for BG and 0.039 for DG) and 6MWT tests (in BG and DG p = 0.001), reduction of systolic blood pressure (p = 0.001 for BG and 0.003 for DG), and diastolic blood pressure (for BG; p = 0.001) were registered post-intervention. These positive changes were accompanied by the drop in brain-derived neurotrophic factor (p = 0.002 for BG and 0.002 for DG), the increase of irisin concentration (p = 0.029 for BG and 0.022 for DG) in both groups, and DG the amelioration of insulin resistance indicators (HOMA-IR p = 0.023 and QUICKI p = 0.035). Folk-dance training significantly reduced the c-terminal agrin fragment (CAF; p = 0.024). Obtained data indicated that both training programs effectively improved physical performance and blood pressure, accompanied by changes in selected exerkines. Still, folk-dance had enhanced insulin sensitivity.