AUTHOR=Gasser Benedikt , Franchi Martino V. , Ruoss Severin , Frei Annika , Popp Werner L. , Niederseer David , Catuogno Silvio , Frey Walter O. , Flück Martin 

TITLE=Accelerated Muscle Deoxygenation in Aerobically Fit Subjects During Exhaustive Exercise Is Associated With the ACE Insertion Allele

JOURNAL=Frontiers in Sports and Active Living

VOLUME=Volume 4 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/sports-and-active-living/articles/10.3389/fspor.2022.814975

DOI=10.3389/fspor.2022.814975

ISSN=2624-9367

ABSTRACT=Introduction: The insertion/deletion polymorphism in the gene for the major regulator of vascular tone, angiotensin converting enzyme (ACE I/D) affects muscle capillarisation and mitochondrial biogenesis with endurance training. We tested whether changes of leg muscle oxygen saturation (SmO2) during exhaustive exercise and recovery would depend on the aerobic fitness status and the ACE I/D polymorphism.
Methods: 34 healthy subjects (age: 31.8 +/- 10.2 years, 17 men, 17 female) performed an incremental exercise test to exhaustion. SmO2 in Musculus vastus lateralis (VAS) and musculus gastrocnemius (GAS) was recorded with near-infrared spectroscopy. Effects of the aerobic fitness status (based on a VO2peak cut-off value of 50 mlO2 min-1 kg-1) and the ACE-I/D genotype (detected by PCR) on kinetic parameters of muscle deoxygenation and reoxygenation were assessed with univariate ANOVA.
Results: Deoxygenation with exercise was comparable in VAS and GAS (p=0.321). In both leg muscles deoxygenation and reoxygenation was 1.5-fold higher in the fit than the unfit volunteers. Differences in muscle deoxygenation, but not VO2peak, were associated with gender-independent (p>0.58) interaction effects between aerobic fitness x ACE-I/D genotype; being reflected in a two-fold accelerated deoxygenation of VAS for aerobically fit than unfit ACE-II genotypes, and a two-fold higher deoxygenation of GAS for fit ACE-II genotypes than fit D-allele carriers.
Discussion: Aerobically fit subjects demonstrated increased rates of leg muscle deoxygenation and re-oxygenation. Together with the higher muscle deoxygenation in aerobically fit ACE-II genotypes, this suggests that an ACE-I/D genotype-based personalization of training protocols might serve to best improve aerobic performance.