The Association Between GLUT1 Gene SNP/A-2841T Polymorphism And Inter-individual Variability In Response To HiHiLo Training

Abstract

Inter-individual variability in improvement after altitude training has been shown to be the reflection of differences genetic constitution. GLUT1 is a target gene of HIF-1 (Hypoxia inducible factor-1), which plays a central role in the oxygen-sensing pathway. In the hypoxic environment, the expression of GLUT 1 gene increases significantly. PURPOSE: To explore the association between GLUT1 gene SNP/A-2841T polymorphism and inter-individual variability in response to HiHiLo (Living high- exercise high- training low) training. METHODS: Seventy-two healthy, unrelated college level athletes (21.10±1.37) underwent a four-week HiHiLo training program (hypoxia exposure 10 hr/d and hypoxia training 3 times per week at 75%VO2max). Genomic DNA was extracted from white cells of peripheral blood and SNP/A-2841T polymorphism was analyzed by PCR-RFLP; VO2max and SaO2 were measured before and after HiHiLo training. RESULTS: After PCR-RFLP with HpyCH4 V, three genotypes were observed: AA genotype carries: 39, AT genotype carries: 26 and TT genotype carries: 7. Genotype distributions were in Hardy-Weinberg equilibrium. There was a nonsignificant trend for a great increase in SaO2 at rest in AT genotype carriers compared to AA and TT genotype carriers in response to HiHiLo training (D0.81±1.47 vs. D-0.13 ±1.48, D-0.64 ±1.38, P=0.07). After HiHiLo training, there was no significant difference in SaO2 recovery during quantified workload exercise in the three genotype carriers (D-0.78 ± 1.81 vs. D-1.47± 1.28, D-1.63 ± 1.02). Similarly, DVO2max was not significantly different among the three genotype carriers (D0.24 ± 0.44 vs. D0.15±0.29, D0.01±0.50). CONCLUSION: AT genotype carriers of SNP/A-2841T polymorphism may be more sensitive to the HiHilo training than AA and TT groups. However, there was no association between GLUT1 gene SNP/A-2841T polymorphism and inter-individual variability in response to HiHiLo training. Whether GLUT1 gene SNP/A-2841T polymorphism is a genetic factor responsible for inter-individual variability in response to HiHilo training needs further examination.