Serum FGF21 Levels in Obese Korean Children and Adolescents

Background : Serum fibroblast growth factor 21 (FGF21) has been suggested to be a possible biomarker for early detection of metabolic syndrome and type 2 diabetes in adults. However, few studies have investigated the correlation between FGF21 levels and metabolic parameters in children. This study sought to evaluate the relationship between FGF21 and metabolic parameters in obese Korean children and adolescents. Methods : Fasting serum FGF21 and adiponectin levels as well as fasting insulin, glucose, transaminases, and lipid profiles were measured by enzyme-linked immunosorbent assays in 45 lean and 70 obese children aged 7–14 years. Independent t-test and multivariate correlation analysis were used to evaluate the relationship between FGF21 and metabolic parameters. Results : Serum FGF21 was significantly higher in obese children than in lean children. Serum FGF21 levels were positively correlated with insulin resistance index homeostasis model assessment (HOMA-IR) (r=0.355, P=0.004) and triglycerides (r=0.423, P<0.001) and were negatively correlated with high-density lipoprotein (HDL) cholesterol (r=−0.412, P<0.001). After adjustment for body mass index, triglycerides, HDL cholesterol and adiponectin, FGF21 levels showed a significant correlation with only HOMA-IR on multivariate linear regression analysis. Conclusion : Serum FGF21 levels were higher in obese children and significantly correlated with HOMA-IR. Therefore, FGF21 could be a biomarker for obesity-induced insulin resistance in children and adolescents as indicated in adults

Slater-Pauling behavior of interfacial magnetic properties of 3d transition metal alloy/Pt structures

Ferromagnet (FM)/heavy metal (HM) bilayers are core structures for current-induced magnetization switching and chiral magnetic structure generation. Static and dynamic properties of the FM moment depend substantially on interfacial perpendicular magnetic anisotropy (iPMA) and interfacial Dzyaloshinskii-Moriya interaction (iDMI). Therefore, it is of crucial importance to control iPMA and iDMI, and to understand their underlying physics. Here we experimentally show that both iPMA and iDMI exhibit similar Slater-Pauling-like dependence on the FM variation as the saturation magnetization (MS) does. We measure MS, iPMA, and iDMI of the FM/HM bilayers with HM fixed to Pt and FM varied from Mn (electron number Z = 25) to Ni (Z = 28), including their alloys for fractional Z. Our result indicates that the density of states structure important for the Slater-Pauling dependence is crucial also for iPMA and iDMI. This provides a useful method to engineer chiral magnetic textures.11Nsciescopu