Abstract

The leptin (LEP) gene polymorphism is one of the most common polymorphisms and is believed to be associated with high circulating LEP levels that can occur in obese individuals. Thus, this study purposed to determine the relationship of LEP1 and LEP2 gene polymorphisms with overweight/obese and non-obese adolescents in Palembang and their correlation with various metabolic and anthropometric parameters. This research was an analytical and observational study. A total of 50 blood samples from adolescents (aged 10-18 years) were analyzed in this study. Standard laboratory protocols for serum lipid measurements, deoxyribonucleic acid (DNA) extraction, allele analysis by polymerase chain reaction (PCR), and LEP and insulin analysis by enzyme-linked immunosorbent assay (ELISA) were employed. The study revealed the allelic frequencies for gene LEP1: non-obese (G = 0.45, A = 0.55) and obese (G = 0.87, A = 0.13), and gene LEP2: non-obese (G = 0.54, A = 0.45) and obese (G = 0.67, A = 0.33). The frequencies of alleles in the LEP1 gene showed a statistically significant association with nutritional status (p = 0.011), while there was no significant association between genotypes in the LEP gene and nutritional status. The level of LEP was 6.39 + 1.12 in non-obese and 11.57 + 1.68 in obese, with p 0.000; and the triglyceride level was 82.56 ± 43.22 in non-obese and 113.72 ± 54.03 in obese, with p 0.029. In conclusion, this study shows that LEP levels and the polymorphism in the LEP1 gene are associated with obese adolescents.

Key words: Leptin, LEP gene, metabolic, obesity, polymorphism