Serum fibroblast growth factor 21 in overweight and obese Thai children and adolescents: Its relation to glucose metabolism and its change after glucose loading

Objectives Fibroblast growth factor 21 (FGF21) has been demonstrated to be beneficial for glucose metabolism in animal and in vitro studies. However, its role in humans is still unclear. This study aimed to determine serum FGF21 in relation to glucose metabolism in obese children and to evaluate serum FGF21 changes during an oral glucose tolerance test (OGTT). Design, patients and measurements A cross-sectional study of 301 obese children was conducted in a tertiary hospital. All children underwent an OGTT and had their fasting serum FGF21 and adiponectin measured. A subgroup of 71 children had their serum FGF21 levels serially measured at 0, 60 and 120 min during the OGTT. Results Serum FGF21 levels were progressively increased in children with normal glucose tolerance without hyperinsulinaemia, normal glucose tolerance with hyperinsulinaemia and abnormal glucose tolerance [median (IQR): 72 (34-148), 96 (55-182), 122 (75-220) pg/ml, respectively, P = 0·003]. Log serum FGF21 was associated with homoeostatic model assessment of insulin resistance (r = 0·174, P = 0·002). There was no correlation between log serum FGF21 and serum adiponectin level. During the OGTT, there were changes in serum FGF21 levels with a decrease in FGF21 at 60 min from the baseline and an increase above the baseline at 120 min. Conclusions Serum FGF21 level was highest in obese children with the highest insulin resistance or abnormal glucose tolerance. Log serum FGF21 was not correlated with serum adiponectin. Changes in serum FGF21 levels during the OGTT were observed.