Year: 2025 | Month: June | Volume: 15 | Issue: 6 | Pages: 241-250
DOI: https://doi.org/10.52403/ijhsr.20250631
The Association of Fat Mass and Obesity-Associated (FTO) rs9939609 Gene Polymorphisms with Leptin Levels in Obese Subjects
Ni Putu Tesi Maratni1, Desak Made Wihandani1, Gde Ngurah Indraguna Pinatih2
1Department of Biochemistry, Faculty of Medicine, Udayana University, Denpasar, Indonesia
2Department of Clinical Nutrition, Faculty of Medicine, Mahasaraswati University, Denpasar, Indonesia
Corresponding Author: Ni Putu Tesi Maratni
ABSTRACT
Background: Obesity is a multifactorial disorder that involves intricate interactions between environmental and hereditary factors. Single nucleotide polymorphism (SNP) rs9939609 in the fat mass and obesity-associated (FTO) gene has been linked to an increased risk of obesity. The hormone leptin, an essential component of energy balance regulation, is highly expressed in obese people, which is indicative of increased fat mass; nevertheless, the physiological effects of leptin are frequently hindered by paradoxical leptin resistance. The purpose of this study is to investigate the relationship between FTO polymorphisms and leptin levels in obesity.
Methods: This cross-sectional study included 79 individuals aged 18-60 years with BMI ≥25 kg/m², recruited from Prof. dr. I.G.N.G. Ngoerah General Hospital. The enzyme-linked immunosorbent assay method was used to measure serum leptin levels. The FTO gene, containing the rs9939609 variant, was amplified using the polymerase chain reaction, and then the amplified DNA was sequenced to determine the genotype (AA, AT, or TT).
Results: A total of 53 females and 26 males were genotyped. Of the individuals, 32 (40.51%) were TT, 41 (51.90%) were AT, and six (7.59%) were AA. The one-way ANOVA test results showed that at least one genotype had significantly different leptin levels than the others (p=0.013). The post hoc Tukey HSD test revealed that obese people with the AA genotype had elevated levels of leptin (8.19±2.05 ng/ml) compared to the wild-type (p = 0.046). Obese people who carry at least one copy of A allele (AT) had lower levels of leptin (5.02 ± 2.08 ng/ml) compared to homozygous (AA) (p = 0.009).
Conclusions: Balinese obese patients with the AA genotype for the rs9939609 polymorphism had noticeably greater serum leptin levels than those of the TT or AT genotype which further contributes to dysregulated eating patterns leading to obesity.
Key words: FTO, leptin, obesity, polymorphism, rs9939609.