Exploring the genotypic variants of FTO rs9939609 and their associations with obesity-related and metabolic characteristics among young adult women in Surabaya, Indonesia

Background and aim: Obesity is a global public health concern, resulting from complex interactions among genetic, behavioral, and environmental factors. The fat mass and obesity-associated (FTO) rs9939609 variant is a well-established genetic determinant of adiposity and metabolic regulation; however, its role in healthy young adult women, particularly in Indonesia, remains underexplored. We aimed to investigate the association between the FTO rs9939609 polymorphism and obesity-related anthropometric, body composition, and metabolic traits in young adult women. Methods: This cross-sectional study enrolled 69 normal-weight and overweight-obese young adult women. Anthropometric measures, body composition, and metabolic profiles were assessed. FTO rs9939609 genotyping was performed using amplification refractory mutation system–polymerase chain reaction (ARMS-PCR) and validated by Sanger sequencing. Comparisons between groups were conducted under a dominant genetic model (TT vs AT+AA) using independent-sample t, Mann-Whitney and Chi-square tests, with a significance threshold of p < 0.05. Results: Overweight–obese participants exhibited significantly greater central adiposity, fat mass, visceral fat, and low-density lipoprotein (LDL) cholesterol levels, along with lower high-density lipoprotein (HDL) cholesterol levels. The TT genotype was the most prevalent in both groups. No significant association was observed between the FTO rs9939609 polymorphism and obesity risk. Similarly, the dominant genetic model, showed no significant effects on anthropometric, body composition, or metabolic parameter, even after adjustment for body mass index (BMI). Conclusions: The FTO rs9939609 polymorphism was not significantly associated with obesity-related traits in healthy young adult women.