Elevated global DNA methylation (GDM) has been linked to increased risk of cardiovascular disease. We recently reported an association between the epigenomic measure of GDM and maximal aerobic capacity as well as body composition in females. Throughout the course of this testing one question that arose was whether GDM is stable from week to week and month to month, and whether it is affected by acute exercise.
PURPOSE: The aim of this study was to determine the variation of GDM over time, and following acute aerobic and anaerobic exercise.
METHODS: Seventeen participants (age = 29±5 yrs, ht = 162±26 cm; wt = 73±14 kg) provided resting capillary blood samples during the morning each week for four weeks (wk 1, wk 2, wk 3, wk 4) and at two months (mo 2) and three months (mo 3). Additionally, these same participants completed a maximal aerobic test to exhaustion (VO2max) as well as a series of three repeated Wingate anaerobic cycle tests, providing blood samples before (pre) and after (post) the bouts. DNA from leukocytes was isolated, and methylation was analyzed using a commercially available kit. Variation over time was analyzed using a one-way ANOVA, while differences attributable to acute exercise was analyzed using a 2(time) x 2(exercise type) repeated measures ANOVA. Significance was accepted at p<0.05.
RESULTS: Global DNA methylation did not vary over time (p = 0.105; wk 1 = 1.3±1.1%, wk 2 = 1.0±1.7%, wk 3 = 1.3±0.8%, wk 4 = 2.2±1.3%, mo 2 = 1.4±0.9%, mo 3 = 2.0±1.9%). Additionally, acute aerobic exercise to maximal exertion did not alter GDM (p = 0.71; pre 1.9±1.0%, post = 1.5±0.8%), and neither did acute anaerobic exercise (p = 0.97; pre = 1.9±1.0%, post = 2.1±1.1%).
CONCLUSIONS: These findings provide evidence that the epigenomic marker of global DNA methylation is a relatively stable measure that does not vary over the course of several months. Additionally, this measure is unaffected by acute exercise perturbations whether aerobic or anaerobic in nature. As GDM is associated with aerobic fitness and body composition, it would be of interest to determine whether chronic adaptations to exercise training results in beneficial changes in this epigenomic marker.
