FGF21 Levels and Bone Mineral Density in Metabolically Healthy and Metabolically Unhealthy Obese Children.

Introduction: The harmful or beneficial effect of obesity on bone mineral density (BMD) remains controversial in children and adolescence. Fibroblast growth factor 21 (FGF21) is a metabolic factor that plays a specific role in the regulation of carbohydrate and lipid metabolism. However, the role of FGF-21 in bone metabolism seems paradoxical and complex.

Objective: It was aimed to determine whether serum FGF21 level is associated with BMD in obese children and adolescents.

Methods: The study was conducted with the participation of children and adolescents aged 8-18 years. 98 children were included in the study group and 44 children were included in the control group. BMD, in addition to the routine obesity workup, which includes fasting blood glucose, fasting insulin levels, lipid profile, and liver enzymes; serum FGF21 levels have been analyzed.

Results: The mean age of the obese group was 13.34 ± 2.24 years and the mean age of the control group was 13.48 ± 2.87 years. According to the International Diabetes Federation criteria, 15 of 98 (15.3%) patients are MS (metabolically unhealthy). FGF-21 levels were 193,54±139,62 mg/dl in the obese group and 158,69±151,81 mg/dl in the control group (p=0.06). There was no difference between the FGF-21 and BMD z-score values of girls and boys in the obese and control groups (p>0.05).

Conclusion: BMD-z score increases in obese children compared to the control group. It is observed that BMD-z score increases more when metabolic risk factors accompany it. There was no significant relationship between FGF21 levels and BMD z-score values in obese children.