Using cluster analysis, when participants were divided into 2 groups based on the change in irisin, those with greater change experienced a greater decrease in BMI at 6 months. The Δ change in irisin from baseline to 12 months was associated with changes in IL-6 (r = 0.674, P = .01). The change in myostatin from baseline to 6 months or 12 months was not associated with changes in BMI, HOMA-IR, irisin, or IL-6. Discussion | Our study provides, for the first time to our knowledge, evidence of an association between myokines and bariatric surgery in youths with severe obesity. The changes in irisin and myostatin suggest that the postsurgical improvements in cardiometabolic health may be associated, partly, with these novel muscle-derived mediators. Increase in irisin may suggest induction of fat browning and combustion. 1 The postsurgical decrease in myostatin may reflect a counteractive adaptation to preserve muscle mass. 3 Identification of 2 distinct groups of participants with varying magnitudes of changes in irisin and myostatin using cluster analysis, despite the small sample size, is intriguing and may suggest potential heterogeneity in Roux-en-Y gastric bypass response. This needs further validation in larger samples. Studies in adults are sparse and contradictory, with levels of irisin decreasing after bariatric surgery in 1 study and remaining unchanged in another. 4,5 It remains unclear whether the postsurgical changes in myokines are secondary to weight loss or owing to the bariatric surgery itself. Postsurgical decrease in myostatin we found is similar to that in adults. 6 Limitations of the study include small sample size, inclusion of only female youths, and lack of racial/ethnic diversity, DXA-derived body composition, and values of the myokines in healthy control individuals. This study implicates myokines in the beneficial effects of bariatric surgery, but further validation in diverse cohorts is warranted. Modulation of signaling pathways of the myokines may have a potential role in the treatment of severe obesity and cardiometabolic disease.
Background Certain adipose tissue depots infer higher cardiometabolic risk than body mass index (BMI). Purpose To assess breast adipose tissue (BrAT) attenuation as a novel imaging biomarker for cardiometabolic risk. Material and Methods We studied 151 women (mean age = 56 ± 1 years) across the weight spectrum. BrAT attenuation, abdominal adipose tissue cross-sectional areas (CSA), and attenuation were quantified using non-contrast computed tomography (CT) scans. Cardiometabolic risk factors were assessed from medical records. Results BrAT attenuation was lower in obese women compared to lean women. BrAT attenuation was inversely associated with BMI, waist circumference, abdominal fat CSA, fasting glucose, and triglycerides ( P ≤ 0.02), and positively associated with abdominal adipose tissue attenuation ( P < 0.001). BrAT attenuation had a sensitivity of 90% but a specificity of only 35% in detecting the metabolic syndrome (area under the curve = 0.63). Conclusion BrAT attenuation is associated with cardiometabolic risk markers and could serve as an imaging biomarker for opportunistic risk assessment in patients undergoing CT examination of the chest.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.