Advances in Exercise, Fitness, and Performance Genomics in 2010
This review of the exercise genomics literature emphasizes the strongest articles published in 2010 as defined by sample size, quality of phenotype measurements, quality of the exercise program or physical activity exposure, study design, adjustment for multiple testing, quality of genotyping, and other related study characteristics. One study on voluntary running wheel behavior was performed in 448 mice from 41 inbred strains. Several quantitative trait loci for running distance, speed, and duration were identified. Several studies on the alpha-3 actinin (ACTN3) R577X nonsense polymorphism and the angiotensin-converting enzyme (ACE) I/D polymorphism were reported with no clear evidence for a joint effect, but the studies were generally underpowered. Skeletal muscle RNA abundance at baseline for 29 transcripts and 11 single nucleotide polymorphisms (SNPs) were both found to be predictive of the VO2max response to exercise training in one report from multiple laboratories. None of the 50 loci associated with adiposity traits are known to influence physical activity behavior. However, physical activity seems to reduce the obesity-promoting effects of at least 12 of these loci. Evidence continues to be strong for a role of gene-exercise interaction effects on the improvement in insulin sensitivity after exposure to regular exercise. SNPs in the cAMP-responsive element binding position 1 (CREB1) gene were associated with training-induced HR response, in the C-reactive protein (CRP) gene with training-induced changes in left ventricular mass, and in the methylenetetrahydrofolate reductase (MTHFR) gene with carotid stiffness in low-fit individuals. We conclude that progress is being made but that high-quality research designs and replication studies with large sample sizes are urgently needed.
From 2000 to 2009, our international group of exercise genetics and genomics investigators published an annual comprehensive and cumulative review of the published literature in the area of genomics relative to exercise, fitness, and performance. As discussed in last year's publication, this annual project eventually became too large of an effort to publish in terms of the number of journal pages it required and the effort necessary from the coauthors to review and summarize the published literature annually and, more importantly, to maintain the gene map and summary tables that were an important part of the publication. As a result, the review evolved into a substantially shorter version, with the goal of summarizing the literature published in the preceding year (actually 2008 and 2009 in the initial version) and focusing only on the strongest studies based on design, sample size, phenotypes, novelty, and potential effect. Thus, this review is no longer intended to be a comprehensive and cumulative summary of all published literature addressing genomics relative to exercise, fitness, and performance.
The present article is the second annual version of the focused review of the "scientifically strongest and substantively most important articles in exercise genomics" and covers the calendar year 2010. As indicated in the introduction to last year's review, this new version intends to be highly selective in choosing articles for presentation to provide an ongoing and updated source for exercise and sports medicine scientists to understand the current literature in this area and to better grasp the necessary components of a high-quality exercise genomics study. Also, we hope this effort will help people identify the gaps in our knowledge concerning genomics and genetics relative to exercise, fitness, and performance.
In this review, we have selected articles focusing on (a) physical activity level, (b) muscular strength and power, (c) endurance performance, (d) adiposity, (e) glucose and insulin metabolism, and (f) hemodynamic traits.
Abstract and Introduction
Abstract
This review of the exercise genomics literature emphasizes the strongest articles published in 2010 as defined by sample size, quality of phenotype measurements, quality of the exercise program or physical activity exposure, study design, adjustment for multiple testing, quality of genotyping, and other related study characteristics. One study on voluntary running wheel behavior was performed in 448 mice from 41 inbred strains. Several quantitative trait loci for running distance, speed, and duration were identified. Several studies on the alpha-3 actinin (ACTN3) R577X nonsense polymorphism and the angiotensin-converting enzyme (ACE) I/D polymorphism were reported with no clear evidence for a joint effect, but the studies were generally underpowered. Skeletal muscle RNA abundance at baseline for 29 transcripts and 11 single nucleotide polymorphisms (SNPs) were both found to be predictive of the VO2max response to exercise training in one report from multiple laboratories. None of the 50 loci associated with adiposity traits are known to influence physical activity behavior. However, physical activity seems to reduce the obesity-promoting effects of at least 12 of these loci. Evidence continues to be strong for a role of gene-exercise interaction effects on the improvement in insulin sensitivity after exposure to regular exercise. SNPs in the cAMP-responsive element binding position 1 (CREB1) gene were associated with training-induced HR response, in the C-reactive protein (CRP) gene with training-induced changes in left ventricular mass, and in the methylenetetrahydrofolate reductase (MTHFR) gene with carotid stiffness in low-fit individuals. We conclude that progress is being made but that high-quality research designs and replication studies with large sample sizes are urgently needed.
Introduction
From 2000 to 2009, our international group of exercise genetics and genomics investigators published an annual comprehensive and cumulative review of the published literature in the area of genomics relative to exercise, fitness, and performance. As discussed in last year's publication, this annual project eventually became too large of an effort to publish in terms of the number of journal pages it required and the effort necessary from the coauthors to review and summarize the published literature annually and, more importantly, to maintain the gene map and summary tables that were an important part of the publication. As a result, the review evolved into a substantially shorter version, with the goal of summarizing the literature published in the preceding year (actually 2008 and 2009 in the initial version) and focusing only on the strongest studies based on design, sample size, phenotypes, novelty, and potential effect. Thus, this review is no longer intended to be a comprehensive and cumulative summary of all published literature addressing genomics relative to exercise, fitness, and performance.
The present article is the second annual version of the focused review of the "scientifically strongest and substantively most important articles in exercise genomics" and covers the calendar year 2010. As indicated in the introduction to last year's review, this new version intends to be highly selective in choosing articles for presentation to provide an ongoing and updated source for exercise and sports medicine scientists to understand the current literature in this area and to better grasp the necessary components of a high-quality exercise genomics study. Also, we hope this effort will help people identify the gaps in our knowledge concerning genomics and genetics relative to exercise, fitness, and performance.
In this review, we have selected articles focusing on (a) physical activity level, (b) muscular strength and power, (c) endurance performance, (d) adiposity, (e) glucose and insulin metabolism, and (f) hemodynamic traits.