Fibroblast Growth Factor 21 (FGF-21) and Its Relation to Obesity, Metabolic Syndrome, and Nonalcoholic Fatty Liver in Children: A Longitudinal Analysis

• Published in: The journal of clinical endocrinology and metabolism 2012-06, Vol.97 (6), p.2143-2150
• Main Authors: Reinehr, Thomas, Woelfle, Joachim, Wunsch, Rainer, Roth, Christian L
• Format: Article
• Language: English
• Subjects: Adolescent; Biological and medical sciences; Blood pressure; Body fat; Body mass index; Body weight loss; Child; Children; Cross-Sectional Studies; Disease resistance; Endocrinopathies; Exercise - physiology; Fatty liver; Fatty Liver - metabolism; Fatty Liver - therapy; Feeding. Feeding behavior; Female; Fibroblast growth factors; Fibroblast Growth Factors - metabolism; Fibroblasts; Follow-Up Studies; Fundamental and applied biological sciences. Psychology; Growth factors; Homeostasis; Humans; Insulin resistance; Leptin; Lipids; Liver diseases; Longitudinal Studies; Male; Medical sciences; Metabolic syndrome; Metabolic Syndrome - metabolism; Metabolic Syndrome - therapy; Non-alcoholic Fatty Liver Disease; Nutrition therapy; Obesity; Obesity - metabolism; Obesity - therapy; Primary care; Primary Health Care - methods; Risk Reduction Behavior; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Vertebrates: endocrinology; Weight Loss - physiology; Weight Reduction Programs
• ISSN: 0021-972X; 1945-7197
• DOI: 10.1210/jc.2012-1221

Context: Fibroblast growth factor 21 (FGF-21), a potent activator of glucose uptake, has been proposed to be related to insulin resistance, metabolic syndrome (MetS), nonalcoholic fatty liver disease (NAFLD), and weight status. Objective: Our objective was to study the relationships between FGF-21, parameters of MetS, and NAFLD before and after weight loss in obese children. Design and Setting: This was a cross-sectional comparison between obese and normal-weight children and longitudinal 1-yr follow-up study in obese children participating in a lifestyle intervention in a primary care setting. Patients: Patients included 60 obese and 40 lean children of same age, gender, and pubertal stage. Intervention: The outpatient 1-yr intervention program was based on exercise, behavior, and nutrition therapy. Main Outcomes Measures: We evaluated fasting serum FGF-21, weight status [body mass index (BMI) expressed as sd score (SDS)], body fat, insulin resistance index (homeostasis model assessment), leptin, transaminases, free fatty acids (FFA), waist circumference, blood pressure, and lipids. Results: Compared with the normal-weight children, obese children demonstrated significantly (P < 0.001) increased FGF-21, leptin, and homeostasis model assessment levels. FGF-21 was significantly (P < 0.05) correlated to BMI, SDS-BMI, FFA, and leptin both in cross-sectional and longitudinal analyses but not to any additional analyzed parameter. Children with and without MetS or NAFLD did not differ significantly with respect to their FGF-21 concentrations. A decrease of SDS-BMI was associated with a significant (P = 0.038) decrease of FGF-21 levels (mean −34%). Conclusions: FGF-21 concentrations are reversibly increased in obese children and are related to leptin and FFA. However, our data do not support a significant relationship between FGF-21, insulin resistance, and features of MetS or NAFLD in children.