The Effects of Angiotensin I-Converting Enzyme (ACE) I/D and Alpha-Actinin-3 (ACTN3) R/X Gene Polymorphisms on Human Physical Performance and Health within Malaysian Population

Abstract

A disparity population data set in the current literature with limited reports among Asian samples, coupled with the inconsistent findings among different ethnic groups, and lack of information for the involvement of angiotensin I-converting enzyme (ACE) I/D and alpha-actinin-3 (ACTN3) R/X gene polymorphisms in training adaptation have limited the ability of researchers to draw meaningful conclusions pertaining to the effects of these polymorphisms on human physical performance and health. Therefore, this doctoral research implemented three series of studies to examine the effects of ACE I/D and ACTN3 R/X gene polymorphisms on human physical performance and health within the Malaysian population. In the first study, DNA samples were retrieved via buccal cell from 180 Asians from Malaysia (70 males, 110 females) aged 20.4 ± 1.6 years, and 180 Caucasians from Australia (62 males, 118 females) aged 23.3 ± 3.6 years. In the second study, DNA samples were retrieved from 180 well-trained Malaysian athletes (148 males, 32 females) aged 20.5 ± 1.9 years, 180 Malaysian sedentary controls, and 33 intermittent Australian athletes (all males) aged 20.7 ± 4.0 years. Endurance and muscular performances of Malaysian athletes were evaluated with 20 meters Yo-Yo intermittent recovery level 2 and maximal voluntary contraction tests, respectively. In the third study, thirty normotensive, untrained males (ACE genotype: II = 10, ID = 10, and DD = 10), undergone isometric handgrip training (four sets of 2 minutes isometric contractions at 30% of maximal voluntary contraction, with 1 minute resting interval) 3 days per week for 8 weeks. The result from the first study indicated that the distribution of ACE I/D gene polymorphism varied among different ethnic groups, but not to ACTN3 R/X gene polymorphism. The findings obtained from the second study demonstrated that: a) The effects of these polymorphisms on endurance and strength/power performances did not vary by ethnicity, b) The ACE D allele and ACTN3 R allele conferred an advantage in activities that require strength/power, and c) The ACE I allele and ACTN3 X allele did not influence endurance performance. Finding from the final study demonstrated that ACE I/D gene polymorphism had a positive influence in cardiovascular and muscular adaptations following isometric handgrip training among normotensive men. Overall, this research reaffirms the notion that strength/power performance is influenced by the ACE D allele and ACTN3 R allele. In addition, this research concludes that the ACE I/D gene polymorphism modulates response to isometric handgrip training in normotensive men