Interaction Between the VNTR of the DAT1 Gene and DAT1 Methylation in Relation to Impulsivity in Combat Sports Athletes

<b>Background</b>: Dopaminergic signaling is a key mechanism in behavioral regulation and impulse control. While <i>DAT1</i> promoter methylation has been linked to behavioral dysregulation in clinical groups, its role in high-functioning populations such as elite athletes remains unclear. <b>Objectives</b>: To compare <i>DAT1</i> promoter methylation, <i>DAT1</i> VNTR genotype, and impulsivity between elite combat sport athletes and matched controls, and to assess potential gene-environment interactions. <b>Methods</b>: The study included 209 male participants (100 elite combat athletes, 109 controls). Methylation of 33 CpG sites within the <i>DAT1</i> promoter was quantified from peripheral blood DNA. <i>DAT1</i> VNTR genotypes were determined via PCR and gel electrophoresis. Impulsivity was assessed using the Barratt Impulsiveness Scale (BIS-11). Group differences and interactions were analyzed using analysis of variance (ANOVA), non-parametric tests, and post hoc comparisons. <b>Results</b>: Athletes displayed significantly higher overall <i>DAT1</i> promoter methylation and lower impulsivity scores across all BIS-11 subscales compared with controls. A significant group × genotype interaction for methylation indicated genotype-specific epigenetic differences by athletic status. No differences in VNTR genotype or allele frequencies were observed. <b>Conclusions</b>: Elevated <i>DAT1</i> promoter methylation in elite athletes may be associated with enhanced behavioral control, potentially reflecting neurobiological adaptations to high-intensity training. These results highlight the need to integrate genetic and epigenetic perspectives in sports science. Longitudinal and multi-omics studies are warranted to determine causal links and evaluate the potential of epigenetic markers as indicators of performance-related traits.