Impact of Genetic Polymorphisms on Electrochemical Parameters and Acid-Base Disorders in Brazilian Runners During a 105-Kilometer Ultramarathon

Background/objectives: This study focused on a group of 22 elite male mountain runners from Brazil (average age of 35.9 ± 6.5 years) with the objective of exploring the possible roles of the ACTN3 R577X, ACE I/D, and CK MM A/G NcoI genetic variants in shaping electrochemical profiles and maintaining acid-base homeostasis during a 105-km ultramarathon. Methods: Genotyping for each polymorphism (ACTN3: RR, RX, XX; ACE: DD, ID, II; CK MM: AA, AG, GG) was conducted using PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism), and saliva samples were used to obtain DNA. Analyses of electrochemical and acid-base disturbances were performed in real time. Results: It was observed that athletes who completed the race in less time had lower calcium concentrations (Rs = 0.35; p = 0.016). Pre-race, the RX genotype showed a 14.19% reduction in potassium levels compared to RR (p = 0.01). The GG genotype showed potassium levels 19.36% higher than AA (p = 0.01) and a 6.11% increase in hematocrit values compared to AA (p = 0.03). Additionally, the AG genotype exhibited hematocrit values 5.44% higher than AA (p = 0.03). Post-race, the XX genotype demonstrated higher hematocrit values compared to RX, with an increase of 8.92% (p = 0.03). The II genotype showed a 0.27% increase in pH compared to ID (p = 0.02) and a 20.42% reduction in carbon dioxide levels (p = 0.01). Conclusions: The findings emphasize the impact of the examined polymorphisms on the modulation of electrochemical factors and the maintenance of acid-base equilibrium in athletes during 105 km ultramarathons.