Serum FGF21 Levels in Obese Korean Children and Adolescents

Fibroblast growth factor-21 and Visfatin as potential predictors for metabolic risk factors in obese children

Fibroblast growth factor-21 (FGF-21) and Visfatin are associated with obesity. However; reviewing the literature; no studies were found to assess their role as potential markers for the metabolic disorders related to obesity in children. Assess the relations between serum FGF-21 and Visfatin with obesity and its metabolic disorders, and their use as potential predictors for metabolic risk factors in a sample of Egyptian obese children. This cross-sectional study included 111 Egyptian children (45 males and 66 females); aged 6-10 years to avoid the effect of puberty (prepubertal). The exclusion criteria (by full History taking and clinical examination) were the presence of any sign of puberty according to Tanner stage, the presence of identified causes of obesity (genetic syndromes, chromosomal or endocrinal disorders), chronic diseases (cardiovascular, gastrointestinal, and respiratory), or drug use like steroids; that would interfere with the type of obesity and affect the normal growth of the children. Also, any child with a BMI between 85 and 95th percentiles (overweight) was excluded from the study. All participating obese children were suffering from exogenous simple obesity. They were classified according to their body mass index (BMI) percentiles into 72 obese (BMI ≥ 95th), and 39 control non-obese ones (BMI > 15th to < 85th), based on the Egyptian Growth Charts for children and adolescents. Ethical approvals were granted from both the Ethics Committee of the "National Research Centre" and the "Faculty of Postgraduate Childhood Studies" (Approval No. 17/125). Also, informed written consent was taken from either of the parents and assent from the participating children. They were subjected to blood pressure assessment, anthropometric measurements (weight [Wt], height [Ht], BMI, waist [WC], and hip [HC] circumferences), and laboratory evaluation (Visfatin, FGF-21, LDL, HDL, TG, cholesterol, fasting glucose, insulin, and calculation of HOMA-IR). Mann-Whitney test and Spearman's correlation test were applied. Obese children had significantly higher values than control ones regarding all the studied clinical (SBP, DBP), anthropometric parameters (Wt, Ht, BMI, WC, and HC), FBG, Insulin, HOMA-IR, Visfatin, and FGF-21, and had significantly lower values regarding HDL and Cholesterol. Among obese children, both FGF-21 and Visfatin had significant negative correlations with BMI and HC. At the same time, serum FGF-21 had a highly significant positive correlation with HDL. Visfatin and FGF-21 had highly significant positive correlations with each other. In the control group, both serum Visfatin or FGF-21 had insignificant correlations with each other and with all the studied clinical and anthropometric parameters. FGF-21 and Visfatin are related to the obesity markers, but they cannot be used as potential predictors for metabolic disturbance in obese prepubertal children; both had insignificant correlations with the metabolic risk factors.

Altered Red Blood Cell Fatty Acid and Serum Adipokine Profiles in Subjects with Obesity

BACKGROUND

Adipokines, as well as the fatty acid profile of red blood cell (RBC) membranes, are known to play important roles in the development and progression of metabolic complications induced by obesity. Thus, the objective of this study is to compare the serum adipokine profile and the RBC membrane fatty acid profile of normal-weight and obese adults, and to analyze their relationship with serum biochemical parameters.

METHODS

An observational case-control study was performed in 75 normal-weight and obese adult subjects. Biochemical serum parameters, eight serum adipokines and the RBC membrane fatty acid profiles were measured. Associations between parameters were established using regression analysis.

RESULTS

Subjects with obesity showed increased levels of leptin, fibroblast growth factor 21 (FGF21) and overexpressed nephroblastoma (NOV/CCN3), decreased adiponectin, and similar levels of vaspin and chemerin compared to normal-weight subjects. Significant positive and negative correlations were found with triglycerides and high-density lipoprotein-cholesterol (HDL-c), respectively. An increase in the total ω-6 fatty acids in the RBC membrane fatty acid profiles in subjects with obesity was observed, because of higher levels of both dihomo-γ-linolenic acid (DGLA) and arachidonic acid (AA), and decreased total ω-3 fatty acids, mainly due to lower levels of docosahexaenoic acid (DHA). The ω-6/ω-3 ratio in the RBCs was significantly higher, suggesting an inflammatory status, as was also suggested by a reduced adiponectin level. A negative association between DGLA and adiponectin, and a positive association between DHA and serum triglycerides, was observed.

CONCLUSIONS

Important alterations in serum adipokine and RBC fatty acid profiles are found in subjects with obesity.

Relationship Between the Serum FGF21 Level and Growth in Children of Short Stature

BACKGROUND

This study investigated the relationship between fibroblast growth factor 21 (FGF21) levels and growth in children with growth hormone deficiency (GHD) and idiopathic short stature (ISS), and the effects of the FGF21 level on response to growth hormone (GH) treatment.

METHODS

We included 171 pre-pubertal children with a GHD (n = 54), ISS (n = 46), and normal height (n = 71). Fasting FGF21 levels were measured at baseline and every 6 months during GH treatment. Factors associated with growth velocity (GV) after GH therapy were investigated.

RESULTS

The FGF21 level was higher in short children than in the controls without significant difference between the GHD and ISS groups. In the GHD group, the FGF21 level was inversely associated with the free fatty acid (FFA) level at baseline (r = -0.28, P = 0.039), however, was positively correlated with the FFA level at 12 months (r = 0.62, P = 0.016). The GV over 12 months of GH therapy was positively associated with the delta insulin-like growth factor 1 level (β = 0.003, P = 0.020). The baseline log-transformed FGF21 level was inversely associated with GV with marginal significance (β = -0.64, P = 0.070).

CONCLUSION

The FGF21 level was higher in children of short stature, both those with GHD and the ISS, than in children with normal growth. The pretreatment FGF21 level negatively affected the GV of children with GH-treated GHD. These results suggest the existence of a GH/FFA/FGF21 axis in children.

Circulating FGF21 vs. Stress Markers in Girls during Childhood and Adolescence, and in Their Caregivers: Intriguing Inter-Relations between Overweight/Obesity, Emotions, Behavior, and the Cared-Caregiver Relationship

Fibroblast growth factor-21 (FGF21) acts on several brain regions, including the hypothalamic paraventricular nucleus, which is involved in the regulation of the hypothalamic-pituitary-adrenal (HPA) axis. The purpose of this study was to investigate the interrelations between FGF21 and stress indices in girls, as well as in their caregivers. 78 girls, aged between 5 and 15 years, were studied; 50 of them were overweight and obese (OB) and 28 in the control group (C). Serum FGF21 and hair and diurnal salivary cortisol were measured. Children participants filled in the Children’s Depression Inventory (CDI) and the State-Trait Anxiety Inventory for Children (STAIC), while their caregivers filled in the State-Trait Anxiety Inventory (STAI), the Perceived Stress Scale (PSS), and the Holmes-Rahe Stress Events Scale (HRSES). The OB group girls had significantly higher levels of FGF21 than the C group (p < 0.001). In contrast to the C group, in whom FGF21 levels were positively correlated with both hair and salivary AUCg cortisol concentrations (p = 0.045 and p = 0.007, respectively), no such correlations were observed in the OB group. In the caregivers of the OB group, STAI-state (r = 0.388, p = 0.008), STAI-trait (r = 0.4, p = 0.006), PSS (r = 0.388, p = 0.008), and HRSES (r = 0.358, p = 0.015) scores, all correlated positively with the FGF21 levels of the children under their care. FGF21 concentrations positively correlated with hair and salivary cortisol levels in the C group only. These findings may represent an interesting correlation dictated by bi-directional empathy links between the primary caregivers and the children under their care.

Novel Adipokines CTRP1, CTRP9, and FGF21 in Pediatric Type 1 and Type 2 Diabetes: A Cross-Sectional Analysis

INTRODUCTION

Pediatric obesity and diabetes has increased over the last several decades. While the role of common adipokines on metabolic parameters has been well studied in adults, the relationship of novel adipokines and hepatokines in pediatric type 1 (T1D) and type 2 diabetes (T2D) is not well understood. This study assessed novel adipokines C1q/TNF-related proteins (CTRP1 and CTRP9), and hepatokine fibroblast growth factor 21 (FGF21) in youth with T1D and T2D diabetes.

METHODS

Participants (n = 80) with T1D (n = 40) enrolled in the Pediatric Diabetes Consortium (PDC) T1D NeOn registry, and T2D (n = 40) from the PDC T2D registry. Cross-sectional analysis compared adipokines (CTRP1, CTRP9, FGF21) between T1D and T2D, and regression models assessed adipokine relationship with clinical characteristics.

RESULTS

The mean age of the participants was 14.9 ± 2 years, and 50% were female. T2D participants had a shorter diabetes duration (p = 0.0009), higher weight (p < 0.0001), and BMI (p < 0.0001) than T1D participants. CTRP9 levels were higher in T1D (13,903.6 vs. 3,608.5 pg/mL, p = 0.04) than T2D, and FGF21 levels were higher in T2D (113.1 vs. 70.6 pg/mL, p = 0.03) than T1D, with no differences in CTRP1. In regression analysis of T1D, CTRP9 was positively associated with C-peptide (p = 0.006), and FGF21 was positively associated with hemoglobin A1c (p = 0.04). In T2D, CTRP1 was positively associated with HbA1c (p < 0.001) and glucose (p = 0.004), even after controlling for age, sex, and BMI.

CONCLUSIONS

CTRP9 levels are higher in youth with T1D compared to T2D, and FGF21 levels are higher in youth with T2D than T1D. Novel adipokines are related to metabolic homeostasis in the inflammatory milieu of pediatric diabetes.

Serum Fibroblast Growth Factor 21 Levels in Children and Adolescents with Hashimoto’s Thyroiditis before and after l-Thyroxin Medication: A Prospective Study

Backgrounds and Objectives: Fibroblast growth factor 21 (FGF-21) is a complex hormone, sharing common sites of action with thyroid hormones. We investigated the association among FGF-21 levels, resting metabolic rate (RMR), and l-thyroxin (LT4) treatment in children and adolescents with Hashimoto’s thyroiditis. Materials and Methods: A total of 60 youngsters with chronic autoimmune thyroiditis (AIT) (30 with subclinical hypothyroidism, 30 with euthyroidism) and 30 age and sex-matched healthy participants (5–18 years old) were enrolled in the study. Anthropometric, biochemical parameters, and RMR levels were assessed in all participants; serum FGF-21 levels were measured in the control group and the group with subclinical hypothyroidism before and six months after medication with LT4. Results: FGF-21 levels were lower in the treatment group compared with the healthy ones, but this difference was not statistically significant (p > 0.05); despite the increase in FGF-21 levels after six months of LT4 treatment, this difference was not statistically significant (p > 0.05). Free thyroxin (FT4) levels correlated well with FGF-21 levels (r = 0.399, p < 0.01), but further analysis revealed no interaction between these two variables. Both patient groups presented elevated triglyceride (TG) levels compared to controls (p < 0.05). LT4 treatment had no impact on RMR and lipid or liver or glycaemic parameters. An increase in fat mass and fat-free mass were reported, independently of FGF-21 levels. Conclusions: In youngsters with subclinical hypothyroidism due to Hashimoto’s thyroiditis, the serum FGF-21 levels are not significantly lower than in healthy individuals and increase after treatment with LT4 without a statistical significance. Further studies with a large number of young patients and severe hypothyroidism are recommended to confirm our results.

FTO and PLAG1 Genes Expression and FTO Methylation Predict Changes in Circulating Levels of Adipokines and Gastrointestinal Peptides in Children

Adipokines and gastrointestinal tract hormones are important metabolic parameters, and both epigenetic factors and differential gene expression patterns may be associated with the alterations in their concentrations in children. The function of the FTO gene (FTO alpha-ketoglutarate dependent dioxygenase) in the regulation of the global metabolic rate is well described, whereas the influence of protooncogene PLAG1 (PLAG1 zinc finger) is still not fully understood. A cross-sectional study on a group of 26 children with various BMI values (15.3–41.7; median 28) was carried out. The aim was to evaluate the dependencies between the level of methylation and expression of aforementioned genes with the concentration of selected gastrointestinal tract hormones and adipokines in children. Expression and methylation were measured in peripheral blood mononuclear DNA by a microarray technique and a restriction enzyme method, respectively. All peptide concentrations were determined using the enzyme immunoassay method. The expression level of both FTO and PLAG1 genes was statistically significantly related to the concentration of adipokines: negatively for apelin and leptin receptor, and positively for leptin. Furthermore, both FTO methylation and expression negatively correlated with the concentration of resistin and visfatin. Cholecystokinin was negatively correlated, whereas fibroblast growth factor 21 positively correlated with methylation and expression of the FTO gene, while FTO and PLAG1 expression was negatively associated with the level of cholecystokinin and glucagon-like peptide-1. The PLAG1 gene expression predicts an increase in leptin and decrease in ghrelin levels. Our results indicate that the FTO gene correlates with the concentration of hormones produced by the adipose tissue and gastrointestinal tract, and PLAG1 gene may be involved in adiposity pathogenesis. However, the exact molecular mechanisms still need to be clarified.

Metabolic Spectrum of Liver Failure in Type 2 Diabetes and Obesity: From NAFLD to NASH to HCC

Liver disease is the spectrum of liver damage ranging from simple steatosis called as nonalcoholic fatty liver disease (NAFLD) to hepatocellular carcinoma (HCC). Clinically, NAFLD and type 2 diabetes coexist. Type 2 diabetes contributes to biological processes driving the severity of NAFLD, the primary cause for development of chronic liver diseases. In the last 20 years, the rate of non-viral NAFLD/NASH-derived HCC has been increasing rapidly. As there are currently no suitable drugs for treatment of NAFLD and NASH, a class of thiazolidinediones (TZDs) drugs for the treatment of type 2 diabetes is sometimes used to improve liver failure despite the risk of side effects. Therefore, diagnosis, prevention, and treatment of the development and progression of NAFLD and NASH are important issues. In this review, we will discuss the pathogenesis of NAFLD/NASH and NAFLD/NASH-derived HCC and the current promising pharmacological therapies of NAFLD/NASH. Further, we will provide insights into "adipose-derived adipokines" and "liver-derived hepatokines" as diagnostic and therapeutic targets from NAFLD to HCC.

The Effect of a Life-Style Intervention Program of Diet and Exercise on Irisin and FGF-21 Concentrations in Children and Adolescents with Overweight and Obesity

Overweight and obesity in childhood and adolescence represent major public health problems of our century, and account for increased morbidity and mortality in adult life. Irisin and Fibroblast Growth Factor 21 (FGF-21) have been proposed as prognostic and/or diagnostic biomarkers in subjects with obesity and metabolic syndrome, because they increase earlier than other traditional biomarkers. We determined the concentrations of Irisin and FGF-21 in children and adolescents with overweight and obesity before and after one year of a life-style intervention program of diet and physical exercise and explored the impact of body mass index (BMI) reduction on the concentrations of Irisin, FGF-21 and other cardiometabolic risk factors. Three hundred and ten (n = 310) children and adolescents (mean age ± SD: 10.5 ± 2.9 years) were studied prospectively. Following one year of the life-style intervention program, there was a significant decrease in BMI (p = 0.001), waist-to-hip ratio (p = 0.024), waist-to-height ratio (p = 0.024), and Irisin concentrations (p = 0.001), and an improvement in cardiometabolic risk factors. There was no alteration in FGF-21 concentrations. These findings indicate that Irisin concentrations decreased significantly as a result of BMI reduction in children and adolescents with overweight and obesity. Further studies are required to investigate the potential role of Irisin as a biomarker for monitoring the response to lifestyle interventions and for predicting the development of cardiometabolic risk factors.

Serum Levels of Fibroblast Growth Factor 21 Are Positively Associated with Aortic Stiffness in Patients with Type 2 Diabetes Mellitus

Aortic stiffness (AS), assessed using carotid–femoral pulse wave velocity (cfPWV), is associated with cardiovascular disease in type 2 diabetes mellitus (T2DM). The relationship between serum fibroblast growth factor 21 (FGF-21) and AS in T2DM patients was evaluated. Fasting serum FGF-21 levels of 130 T2DM patients were measured using an enzyme immunoassay kit. A validated tonometry system was used to measure cfPWV (>10 m/s indicated AS). Of these T2DM patients, 34.6% were defined as the AS group. T2DM patients with AS were older; exhibited higher systolic blood pressure, diastolic blood pressure, and body fat mass; higher triglyceride, fasting glucose, glycosylated hemoglobin, and creatinine levels; higher urine albumin-to-creatinine ratios and serum FGF-21 levels; and lower estimated glomerular filtration rates. The FGF-21 level (odds ratio = 1.005, 95% confidence interval: 1.002–1.009, p = 0.002) as well as systolic blood pressure was an independent predictor of AS and positively correlated to cfPWV values (β = 0.369, p < 0.001) in T2DM patients. For T2DM patients, serum FGF-21 level could be a predictor for AS.

The role of chemerin in the pathogenesis of cholelithiasis in children and adolescents

BACKGROUND AND AIM

Adipokines and hepatokines are proteins secreted by adipose tissue and the liver. To date, the levels of adipokines and hepatokines in cholelithiasis have only been evaluated in studies in adult patients. The purpose of our research was to assess the levels of circulating adipokines: chemerin, vaspin, progranulin, retinol-binding protein 4 (RBP-4) and hepatokine: fibroblast growth factor 21 (FGF-21) and to compare their concentrations in paediatric patients with and without cholelithiasis.

METHODS

The prospective study included 54 children and adolescents diagnosed with gallstones and 26 controls. Fasting serum levels of adipokines and hepatokine were determined by enzyme-linked immunosorbent assays.

RESULTS

The serum levels of chemerin, FGF-21 and RBP-4 were significantly higher in children and adolescents with gallstones compared to the control group. Elevated levels of triglycerides, RBP-4, and a homeostatic model for assessing insulin resistance (HOMA-IR) were observed in overweight or obese patients compared to patients with normal weight and cholelithiasis. Chemerin concentrations were increased in the normal-weight children and adolescents with cholelithiasis compared to the control group. Children and adolescents with gallstones and abnormal weight had significantly higher levels of chemerin, FGF-21 and RBP-4 than healthy controls.

CONCLUSION

Elevated serum chemerin levels were significantly higher in non-obese patients with cholelithiasis than in non-obese controls, suggesting a potential role of chemerin in the development of cholelithiasis in children and adolescents.

Effect of Fibroblast Growth Factor 21 on the Development of Atheromatous Plaque and Lipid Metabolic Profiles in an Atherosclerosis-Prone Mouse Model

Fibroblast growth factor 21 (FGF21) is a hormonal regulator of lipid and glucose metabolism. We aimed to investigate the effect of an FGF21 analogue (LY2405319) on the development of atherosclerosis and its associated parameters. ApoE^−/− mice were fed an atherogenic diet for 14 weeks and were randomly assigned to control (saline) or FGF21 (0.1 mg/kg) treatment group (n = 10/group) for 5 weeks. Plaque size in the aortic arch/valve areas and cardiovascular risk markers were evaluated in blood and tissues. The effects of FGF21 on various atherogenesis-related pathways were also assessed. Atherosclerotic plaque areas in the aortic arch/valve were significantly smaller in the FGF21 group than in controls after treatment. FGF21 significantly decreased body weight and glucose concentrations, and increased circulating adiponectin levels. FGF21 treatment alleviated insulin resistance and decreased circulating concentrations of triglycerides, which were significantly correlated with plaque size. FGF21 treatment reduced lipid droplets in the liver and decreased fat cell size and inflammatory cell infiltration in the abdominal visceral fat compared with the control group. The monocyte chemoattractant protein-1 levels were decreased and β-hydroxybutyrate levels were increased by FGF21 treatment. Uncoupling protein 1 expression in subcutaneous fat was greater and fat cell size in brown fat was smaller in the FGF21 group compared with controls. Administration of FGF21 showed anti-atherosclerotic effects in atherosclerosis-prone mice and exerted beneficial effects on critical atherosclerosis pathways. Improvements in inflammation and insulin resistance seem to be mechanisms involved in the mitigation of atherosclerosis by FGF21 therapy.

FGF21 and its Relationship with Inflammatory and Metabolic Parameters in HIV Patients after Antiretroviral Treatment

BACKGROUND

Fibroblast Growth Factor 21 (FGF21) serum levels are associated with insulin resistance and metabolic syndrome in HIV patients.

OBJECTIVE

To quantify FGF21 levels in HIV patients using antiretroviral therapy (ART) and to analyze a possible association between serum FGF21 levels and lipid profile, levels of proinflammatory cytokines, and atherogenic risk factors.

MATERIALS AND METHODS

Twenty patients with HIV infection, who received ART in a scheme consisting of Tenofovir/Emtricitabine+Lopinavir/Ritonavir, were enrolled in this study. The serum levels of FGF21, inflammatory parameters (IL-6 and IL-1β), glucose, cholesterol, triglycerides, and insulin were determined at baseline and after 36 weeks of treatment. The homeostatic model assessment for insulin resistance (HOMA-IR) and the atherogenic risk factor were also calculated.

RESULTS

After 36 weeks, serum FGF21 levels decreased significantly (p=0.011), whereas IL-6 levels (r=0.821, p=0.0001) and the CD4+ T cell count (r=0.446, p=0.048), showed a positive correlation with the decrease in FGF21 levels. There was an increase in total cholesterol (r=-0.483, p=0.031), LDL (r=-0.496, p=0.026), VLDL (r=-0.320, p=0.045), and the atherogenic index factor (r=-0.539, p=0.014), these values showed a negative correlation with FGF21 levels.

CONCLUSION

The decrease of serum FGF21 levels due to ART is associated with the alteration in lipid profile and an increased risk for cardiovascular diseases. These variations are predictors of inflammatory status in HIV patients using antiretroviral therapy.

Fibroblast growth factor 21 (FGF21) in children and adolescents with chronic kidney disease

Fibroblast growth factor 21 (FGF21) is one of the members of endocrine arm of FGF family. Its actions as a glucose and lipids metabolism regulator are widely known. Although the mechanism of FGF21 action in kidneys is still under investigation, FGF21 was considered as a marker of early kidney function decline. While many researchers focused on adult subjects in this matter, there are no data regarding children. Therefore, we have investigated the relationship between plasma or urine FGF21 levels and kidney function in a group of 42 pediatric patients with chronic kidney disease (CKD). Anthropometrical parameters and blood pressure were taken, routine biochemical tests were performed. The concentration of FGF21 in serum and urine was determined by enzyme immunoassay. The results revealed significantly higher serum FGF21 concentration among children from CKD group. However, serum FGF21 level was not related to gender, proteinuria, eGFR or renal replacement therapy. Urine FGF21 concentration correlated negatively with albuminuria and positively with eGFR. Documented negative correlation of FGF21 fractional excretion and eGFR is not enough to support the role of FGF21 as a biomarker for predicting kidney disease progression in children and adolescents. Other mechanisms including local kidney FGF21 production or enhanced excretion due to higher extrarenal production may result in higher urine FGF21 concentrations.

Klotho and fibroblast growth factors 19 and 21 serum concentrations in children and adolescents with normal body weight and obesity and their associations with metabolic parameters

BACKGROUND

Fibroblast growth factor 19 (FGF19), fibroblast growth factor 21 (FGF21) and Klotho are regulators of energy homeostasis. However, in the pediatric population, the relationships between obesity, metabolic disorders and the aforementioned factors have not been clearly investigated. We analyzed the role of FGF19, FGF21 and Klotho protein in children with normal body weight as well as in overweight and obese subjects and explored their associations with insulin resistance (IR) and metabolic syndrome (MS) and its components.

METHODS

This was a cross-sectional study conducted in a group of hospitalized children and adolescents. Laboratory investigations included serum analysis of FGF19, FGF21, and Klotho with ELISA kits as well as the analysis of the lipid profile and ALT serum concentrations. Moreover, each subject underwent an oral glucose tolerance test (OGTT) with fasting insulinemia measurement to detect glucose tolerance abnormalities and calculate the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) index. Furthermore, the clinical analysis included blood pressure measurement, body fat percentage estimation and assessment of the prevalence of MS and its components.

RESULTS

The study was conducted with 174 children/adolescents aged 6-17 years with normal body weight (N = 48), obesity (N = 92) and overweight (N = 34). Klotho concentration was significantly higher in the obese children [median 168.6 pg/ml (90.2 to 375.9)]) than in the overweight [131.3 pg/ml (78.0 to 313.0)] and normal-body-weight subjects [116.6 pg/ml (38.5 to 163.9)] (p = 0.0334) and was also significantly higher in insulin-resistant children than in insulin-sensitive children [185.3 pg/ml (102.1 to 398.2) vs 132.6 pg/ml (63.9 to 275.6), p = 0.0283]. FGF21 was elevated in patients with MS compared to the FGF21 levels in other subjects [136.2 pg/ml (86.5 to 239.9) vs 82.6 pg/ml (41.8 to 152.4), p = 0.0286]. The multivariable model showed that FGF19 was an independent predictor of IR after adjusting for pubertal stage and BMI Z-score.

CONCLUSIONS

Klotho levels were associated with body weight status in children and adolescents. Moreover, Klotho, FGF19 and FGF21 concentrations correlated with IR status and/or components of MS.

Fibroblast Growth Factor-21 to Adiponectin Ratio: A Potential Biomarker to Monitor Liver Fat in Children With Obesity

Background: There is a pressing need for effective and non-invasive biomarkers to track intrahepatic triglyceride (IHTG) in children at-risk for non-alcoholic fatty liver disease (NAFLD), as standard-of-care reference tools, liver biopsy and magnetic resonance imaging (MRI), are impractical to monitor the course disease. Objective: We aimed to examine the association between serum fibroblast growth factor (FGF)-21 to adiponectin ratio (FAR) and IHTG as assessed by MRI in children with obesity. Methods: Serum FGF21 and adiponectin levels and IHTG were measured at two time points (baseline, 6 months) in obese children enrolled in a clinical weight loss program. The association between percent change in FAR and IHTG at final visit was examined using a multiple linear regression model. Results: At baseline, FAR was higher in the subjects with NAFLD (n = 23, 35.8 ± 41.9 pg/ng) than without NAFLD (n = 35, 19.8 ± 13.7 pg/ng; p = 0.042). Forty-eight subjects completed both visits and were divided into IHTG loss (≥1% reduction than baseline), no change (within ±1% change), and gain (≥1% increase than baseline) groups. At 6 months, the percent change in FAR was different among the three groups (p = 0.005). Multiple linear regression showed a positive relationship between percent change in FAR and the final liver fat percent in sex and pubertal stage-similar subjects with NAFLD at baseline (slope coefficient 6.18, 95% CI 1.90-10.47, P = 0.007), but not in those without NAFLD. Conclusions: Higher value in percent increase in FAR is positively associated with higher level of IHTG percent value at 6 months in children with baseline NAFLD. FAR could be a potential biomarker to monitor the changes in IHTG in children with NAFLD.

Comparative Effect of Aqueous and Methanolic Bupleuri Radix Extracts on Hepatic Uptake of High-Density Lipoprotein and Identification of the Potential Target in HFD-Fed Mice

Our previous study found saikosaponin b₂ (SSb₂) increased high-density lipoprotein (HDL) uptake in HepG2 cells. SSb₂ is only found in aqueous Bupleuri Radix extract, and it is one of the secondary saponins derived from saikosaponin d (SSd), which exists in the methanolic extract. This study aimed to compare the effect of aqueous extract of Bupleuri Radix on hepatic uptake of HDL with methanolic extract and to reveal the underlying mechanism of enhancing HDL uptake in mice fed with high-fat diet (HFD). Cellular HDL uptake in each group was quantified by flow cytometry. Bioactive components bound to the HepG2 cytomembrane were detected with HPLC-DAD. RNA sequencing was performed to screen the underlying target on hepatic HDL-uptake, and western blotting was conducted to verify differential protein expression. Significant increases of HDL uptake by HepG2 cells were observed in all groups of aqueous extract of Bupleuri Radix, while no effect or negative effect was observed in the methanolic extract. Saikosaponin b₁ (SSb₁) and SSb₂ were detected in the desorption elute of the aqueous extract from the HepG2 cytomembrane, while saikosaponin a (SSa) and SSd were not found. Remarkable upregulation of FGF21 in HFD-fed mice liver was affirmed after treatment with aqueous extract. This study suggested that aqueous Bupleuri Radix extract could promote hepatic HDL uptake in vitro but methanolic extract could not, and FGF21 might be the potential target.