Leptin, Soluble Leptin Receptor, Lipid Profiles, and LEPR Gene Polymorphisms in Thai Children and Adolescents

Objective: To evaluate the relationships between leptin, soluble leptin receptor, lipid profiles, and LEPR gene polymorphisms in child and adolescent Thai subjects. Design: Cross-sectional study of Thai children and adolescents. Subjects: 116 male and 65 female at risk for overweight/overweight child and adolescent Thai subjects, and 33 male and 62 female healthy child and adolescent Thai subjects (age: 5–19 years). Measurements: Leptin levels, soluble leptin receptor levels, lipid profiles, LEPR gene polymorphisms. Results: Significantly higher levels of cholesterol, triglyceride, low-density lipoprotein cholesterol (LDL-C), and leptin levels were observed in at risk for overweight/overweight group. On the other hand, high-density lipoprotein cholesterol (HDL-C) and soluble leptin receptor levels were significantly lower in the same group. Serum soluble leptin receptor levels were significantly negatively correlated with leptin. The at risk for overweight/overweight subjects with the Lys656Lys homozygous wild type LEPR gene had significantly higher cholesterol and LDL-C levels than those with Lys656Asn heterozygous and Asn656Asn homozygous mutant type. In contrast, subjects with Lys656Lys homozygous wild type had significantly lower leptin levels than those with Lys656Asn heterozygous and Asn656Asn homozygous mutant type. There was a statistically significant association between body mass index (BMI) and hyperleptinemia (odds ratio; OR = 2.49, p = 0.000) and females had more increased risk of hyperleptinemia than males (OR = 15.74, p = 0.004) in adolescent Thai subjects. Conclusion: The present study is the first report of Lys656Asn polymorphism of the LEPR gene associated with cholesterol, LDL-C, and leptin levels in Thai children and adolescents. Serum leptin levels were significantly higher in the at risk for overweight/overweight. In contrast, there were significantly lower soluble leptin receptor levels in the same group. In addition, there was a statistically significant association between BMI, sex, and hyperleptinemia in adolescent Thai subjects.