Interindividual Variation in Cardiorespiratory Fitness: A Candidate Gene Study in Han Chinese People.

Cardiorespiratory fitness, as assessed through peak oxygen uptake (VO), is a powerful health indicator. We aimed to evaluate the influence of several candidate causal genetic variants on VO level in untrained Han Chinese people. A total of 1009 participants (566 women; age [mean ± SD] 40 ± 14 years, VO 29.9 ± 7.1 mL/kg/min) performed a maximal incremental cycling test for VO determination. Genomic DNA was extracted from peripheral whole blood, and genotyping analysis was performed on 125 gene variants. Using age, sex, and body mass as covariates, and setting a stringent threshold -value of 0.0004, only one single nucleotide polymorphism (SNP), located in the gene encoding angiotensin-converting enzyme (rs4295), was associated with VO (β = 0.87; < 2.9 × 10). Stepwise multiple regression analysis identified a panel of three SNPs (rs4295 = 1.1%, angiotensin II receptor type 1 rs275652 = 0.6%, and myostatin rs7570532 = 0.5%) that together accounted for 2.2% ( = 0.0007) of the interindividual variance in VO. Participants carrying six 'favorable' alleles had a higher VO (32.3 ± 8.1 mL/kg/min) than those carrying only one favorable allele (24.6 ± 5.2 mL/kg/min, < 0.0001). In summary, VO at the pre-trained state is partly influenced by several polymorphic variations in candidate genes, but they represent a minor portion of the variance.