Leptin-Independent Association Between SNVs in the Leptin Gene and HDL-C and Apo-AI in Children

Polymorphisms in the leptin gene (LEP) have been associated with leptin levels and anthropometric variables; however, their association with lipid profiles remains under study. We aimed to determine the relationship between LEP single-nucleotide variants (SNVs) and body mass index (BMI), leptin levels, and lipid profiles in prepubertal children. This cross-sectional study included a population-based sample of 1270 males and females aged 6-to-8 years. Lipid and leptin levels were quantified, and the SNVs G19A and G2548A were analyzed by real-time PCR using predesigned TaqMan™ Genotyping Assays. We found that both LEP SNVs were significantly associated with leptin levels after adjusting for sex. No significant associations between the studied SNVs and BMI were observed in our population. Additionally, both SNVs were associated with apolipoprotein AI (Apo-AI) levels in females, whereas G2548A was also associated with high-density lipoprotein cholesterol (HDL-C) levels after adjusting for sex. These associations remained statistically significant after adjusting for leptin levels. No association was found between SNVs and other lipid variable levels. Our results indicate that polymorphisms in the LEP gene influence not only leptin levels but also lipid metabolism, as evidenced by their association with Apo-AI and HDL-C, independent of plasma leptin concentrations.