RESUMO
Objective To investigate the distribution characteristics of (CAG)n polymorphism in the exonl of the androgen receptor (AR) gene and its relation to the sensitivity of hypoxic training in men of Han nationality from northern China. Methods Sixty five healthy young men of Han nationality completed HiHiLo training under simulated normobaric hypoxic environment for 4 weeks. They stayed under the condition of 14.3-14.8% O_2 (simulating 2800～3000m) during nighttime and carried out hypoxic training under the condition of 14.8-15.4% O_2 (simulating 2500～2800m) 3 times per week at the intensity of 75% individual VO_2max. VO_2max and body weight of the subjects were measured. GeneScan method was used to identify the repeat alleles (genotypes) of CAG polymorphism. Results (1) Fifteen alleles (CAG)12,(CAG)16-28,(CAG)30 repeat alleles (genotypes) were observed in the subjects, in which (CAG)22 was the most common allele; (2) When 21 and 22 alleles were used as the cut point, the baseline of body weight in those carrying shorter genotypes was significantly lower than that in those carrying longer genotypes; (3) △VO_2max and △rVO_2max in men carrying shorter genotypes were significantly higher than that in men carrying longer genotypes after hypoxic training. Conclusion The result reveals that AR (CAG)n polymorphism is associated with the sensitivity of simulated normobaric hypoxic HiHiLo training in men of Han nationality from northern China, especially in those carrying shorter genotypes of AR CAG.