Association of circulating irisin levels with metabolic and metabolite profiles of Korean adolescents

ContextIrisin, a novel exercise-induced myokine, has been suggested to regulate energy metabolism.ObjectiveWe studied the relationship between circulating irisin and metabolic and metabolite profiles of Korean adolescents, and investigated the effects of physical activity, obesity, and metabolic syndrome (MetS) on irisin levels.Materials and MethodsData were obtained from the Korean Children–Adolescents Study. Our cross-sectional study included 618 adolescents (370 normal-weight and 248 obese adolescents; 316 boys and 302 girls) aged 12–15 years. Body composition was determined using an impedance body composition analyzer and general participant characteristics and lifestyle information were obtained from questionnaires. Serum irisin levels were measured using a commercial kit.ResultsMean body mass index (BMI) was 19.4 kg/m² in normal-weight adolescents and 31.4 kg/m² in obese adolescents. Circulating irisin was positively correlated with adiposity indices, including BMI z-score, waist circumference, percent body fat, fat mass, fat-free mass, fat mass to fat-free mass ratio, and lipid and glucose metabolism markers, including total cholesterol, low-density lipoprotein cholesterol (LDL-C), triglycerides, glucose, insulin, and homeostasis model assessment-estimated insulin resistance (all p ≤ 0.006). Of these, increased body fat mass [standardized (Std) ß, 0.23; p < 0.0001], LDL-C (Std ß, 0.14; p = 0.0005) and fasting glucose (Std ß, 0.08; p = 0.0383) were the main independent factors associated with higher irisin levels. Moreover, elevated serum irisin was associated with the risk of obesity [odds ratio (OR], 2.2; confidence interval (CI), 1.19–3.87] and MetS (OR, 2.0; CI, 1.15–3.47). Furthermore, irisin and branched-chain amino acids were positively associated (p < 4 × 10^− 4 for Bonferroni correction). Additionally, in the normal-weight group, girls had higher irisin levels than boys (p = 0.006) and adolescents who engaged in regular physical activity had higher levels of irisin than sedentary adolescents (p = 0.0388). The relationship between physical activity and irisin levels was not observed in obese adolescents.ConclusionsElevated serum irisin was independently associated with the risk of obesity and positively correlated with unhealthy metabolic parameters and metabolites. Moreover, irisin levels were higher in active versus sedentary adolescents in the normal-weight group, but not in the obese group. Our findings suggest that irisin plays an important role in metabolic disorders and may be affected by physiopathological status.     

Bioresorbable elastomeric vascular tissue engineering scaffolds via melt spinning and electrospinning

Current surgical therapy for diseased vessels less than 6 mm in diameter involves bypass grafting with autologous arteries or veins. Although this surgical practice is common, it has significant limitations and complications, such as occlusion, intimal hyperplasia and compliance mismatch. As a result, cardiovascular biomaterials research has been motivated to develop tissue-engineered blood vessel substitutes. In this study, vascular tissue engineering scaffolds were fabricated using two different approaches, namely melt spinning and electrospinning. Small diameter tubes were fabricated from an elastomeric bioresorbable 50:50 poly(l-lactide-co-ε-caprolactone) copolymer having dimensions of 5 mm in diameter and porosity of over 75%. Scaffolds electrospun from two different solvents, acetone and 1,1,1,3,3,3-hexafluoro-2-propanol were compared in terms of their morphology, mechanical properties and cell viability. Overall, the mechanical properties of the prototype tubes exceeded the transverse tensile values of natural arteries of similar caliber. In addition to spinning the polymer separately into melt-spun and electrospun constructs, the approach in this study has successfully demonstrated that these two techniques can be combined to produce double-layered tubular scaffolds containing both melt-spun macrofibers (<200 μm in diameter) and electrospun submicron fibers (>400 nm in diameter). Since the vascular wall has a complex multilayered architecture and unique mechanical properties, there remain several significant challenges before a successful tissue-engineered artery is achieved.     

Game-based brain training for improving cognitive function in community-dwelling older adults: A systematic review and meta-regression

BackgroundGiven that increasing aging is associated with a natural decline in cognitive function, identifying effective interventions that can help to prevent cognitive decline in older adults is a research priority.ObjectiveTo synthesize the best evidence to assess the effectiveness of game-based brain training in improving cognitive function and to evaluate the preferred design features of the intervention.MethodsTwelve databases, trial registries, and gray literature resources were systematically searched for in randomized controlled trials. Meta-analysis and random-effects meta-regression were conducted using Comprehensive Meta-analysis Software 3.0. Overall effect was measured using Hedges’s g and determined using Z-statistics. Cochran’s Q test and I² were used to investigate heterogeneity. The Grading of Recommendation, Assessment, Development, and Evaluation system was used to assess overall quality of evidence.ResultsFifteen trials among 759 older adults were conducted. Meta-analysis revealed that game-based brain training significantly improved processing speed (g = 0.23), selective attention (g = 0.40), and short-term memory (g = 0.35) versus a control group. Our subgroup analyses emphasized that non-time pressure games, multiplayer, computer platform, provider support, sessions ≤ 3 times per week for ≤ 60 min. each comprised a preferable design. Meta-regression identified game design (β = 0.211, p = 0.008) that had statistically significant effects on processing speed. Egger’s regression asymmetry test (p = 0.293) suggested no publication bias.ConclusionsGame-based brain training can be considered a supplementary intervention for improving cognitive functions in community-dwelling older adults. Future trials should use well-designed trials with large sample sizes.     

Frailty among older people in a community setting in China

Frailty is the most common manifestation of serious health issues in the world, and it is becoming more prevalent worldwide as the aging population grows. Changes that occur in an individual during the aging process have physical, psychological, social, and environmental aspects that make an individual more frail. In China, older people may live in communities for aging individuals. This study aimed to describe the presence and severity of frailty and to analyze influencing factors among this population in China. The Frailty Index 35 (FI-35) scale, which includes 35 items in physical, psychological, social, and environmental domains, was used to investigate frailty. The FI-35 score ranges from zero to one, with a score closer to one indicating greater frailty. Biographical, socioeconomic, and lifestyle factors were measured as potential determinants of frailty. We relied on the November 2017–February 2018 waves of the Chinese cross-sectional study survey that comprised a sample of 513 adults, aged 60 or older, who were living in China. Linear regression was performed to identify factors associated with FI-35 scores. We categorized the determinants of frailty into three models: Model 1: biographical variables; Model 2: biographical and socioeconomic variables; and Model 3: biographical, economic, and lifestyle variables. Frailty scores ranged from 0.00 to 0.89, with a median of 0.31, and the prevalence of frailty was 67.6%. The final model obtained after variable selection included age, minority status, marriage status, income, diet, and exercise. The adjusted R-squared indicated that the analysis explained 13.8% of the variance in frailty scores. Adding household, marriage status, education level, medical insurance, and income as elements in Model 2 explained 25.7%. Adding diet, smoking, drinking, exercise, and hobbies in Model 3 explained 27.9%. The degree of frailty varies considerably among Chinese community-dwelling older people and is partly determined by biographical, socioeconomic, and lifestyle factors.     

Inter-method variability of hepatitis B surface antigen quantification in a cohort of Egyptian patients with chronic hepatitis B virus

Background and study aimsHepatitis B (HB) surface antigen (HBsAg) levels can predict clinical and treatment outcomes in chronic HB virus (HBV) infection. We aimed to compare the performance of two different assays [Elecsys® (Roche) and Architect? (Abbott)] for HBsAg quantification and evaluate HBsAg levels in the various immune phases in a cohort of Egyptian patients with chronic HBV.Patients and methodsQuantitative HBsAg by Elecsys® and Architect? assays, measurement of routine biochemical and serological markers, and transient elastography were performed in 92 patients with chronic HBV. Results of the two assays and other tests were compared.ResultsNinety-two treatment-naive patients with chronic HBV, (70% males; mean age, 36.1 ± 10.5 years) were recruited from Cairo Fatemic Hospital. Patients were categorized as HBeAg positive (n = 22) and HBeAg negative (n = 70). The Architect? and Elecsys® assays were significantly correlated (intraclass correlation coefficient: 0.913; 95% CI: 0.870–0.943; p < 0.001). However, Deming regression, Passing and Bablok, and Bland–Altman statistical analyses showed discordance among the assays. HBsAg levels by both assays were significantly higher in the HBeAg positive than patients with HBeAg-negative (p = 0.033 and 0.013, respectively). HBsAg levels in the Architect? and Elecsys® assays were significantly higher in HBeAg-negative chronic hepatitis than in HBeAg-negative chronic infection (p = 0.002 and 0.004, respectively)ConclusionBoth assays for qHBsAg were found to be simple and reproducible tests that could classify patients and provide additional evidence on the natural history of HBV.