Laboratory of Genetics and Molecular Cardiology, University of São Paulo Medical School, São Paulo, Brazil.
Int J Sports Physiol Perform. 2015 Jul;10(5):636-41. doi: 10.1123/ijspp.2014-0205. Epub 2015 Jan 8.
To study the relationship between the ACTN3 R577X polymorphism and oxygen uptake (VO2) before and after exercise training.
Police recruits (N=206, 25±4 y) with RR (n=75), RX (n=97), and XX (n=33) genotypes were selected. After baseline measures, they underwent 18 wk of running endurance training. Peak VO2 was obtained by cardiopulmonary exercise testing.
Baseline body weight was not different among genotypes. At baseline, XX individuals displayed higher VO2 at anaerobic threshold, respiratory compensation point, and exercise peak than did RR individuals (P<.003). Endurance training significantly increased VO2 at anaerobic threshold, respiratory compensation point, and exercise peak (P<2×10(-6)), but the differences between XX and RR were no longer observed. Only relative peak VO2 exercise remained higher in XX than in RR genotype (P=.04). In contrast, the increase in relative peak VO2 was greater in RR than in XX individuals (12% vs 6%; P=.02).
ACTN3 R577X polymorphism is associated with VO2. XX individuals have greater aerobic capacity. Endurance training eliminates differences in peak VO2 between XX and RR individuals. These findings suggest a ceiling-effect phenomenon, and, perhaps, trained individuals may not constitute an adequate population to explain associations between phenotypic variability and gene variations.
研究 ACTN3 R577X 多态性与运动训练前后摄氧量（VO2）的关系。
选择具有 RR（n=75）、RX（n=97）和 XX（n=33）基因型的警察新兵（N=206，25±4 岁）。在基线测量后，他们接受了 18 周的跑步耐力训练。最大 VO2 通过心肺运动测试获得。
基因型之间的基线体重没有差异。在基线时，XX 个体在无氧阈、呼吸补偿点和运动峰值时的 VO2 高于 RR 个体（P<.003）。耐力训练显著增加了无氧阈、呼吸补偿点和运动峰值时的 VO2（P<2×10(-6)），但 XX 和 RR 之间的差异不再存在。只有 XX 基因型的相对峰值 VO2 仍然高于 RR 基因型（P=.04）。相比之下，RR 个体的相对峰值 VO2 增加幅度大于 XX 个体（12%比 6%；P=.02）。
ACTN3 R577X 多态性与 VO2 相关。XX 个体具有更大的有氧能力。耐力训练消除了 XX 和 RR 个体之间峰值 VO2 的差异。这些发现表明存在一个上限效应现象，也许，经过训练的个体可能不能构成一个充分的群体来解释表型变异性与基因变异之间的关联。
