Award Date

11-2014

Degree Type

Honors Thesis

Department

Kinesiology and Nutrition Sciences

Advisor 1

James Navalta

Number of Pages

31

Abstract

Global DNA Methylation (GDM), an epigenomic modification has been linked to the development of cardiovascular disease and its risk factors. Our focus was to identify potential relationships between epigenetic alterations and both cardiovascular fitness and body composition measures. Purpose: As increases in aerobic fitness have a beneficial effect on cardiovascular disease, one purpose was to determine if a relationship was evident between global DNA methylation and VO2max. A secondary purpose was to determine if the relationship extends to body composition measured via Dual X-ray Absorbtometry (DXA). Methods: Fifty-two (male n=25, female n=27) subjects provided a blood sample for DNA isolation, underwent a DXA scan, and completed a maximal exertion exercise test on a treadmill for the determination of maximal aerobic capacity (VO2max). Global DNA methylation (GDM) (%) was evaluated utilizing a commercially available ELISA kit, and correlated with BMI, percent body fat (%BF), and VO2max using Pearson’s correlation coefficient with significance accepted at p≤0.05. Participants were divided into high and low groups according to median score and differences were determined by the independent t-test. Results: When the overall group was considered, GDM was not significantly correlated with any measure (BMI r=-0.15, p=0.27; %BF r=-0.20, p=0.14; VO2max r=0.24, p=0.09). When separated by gender, males displayed no significant correlations for any variable. In females, GDM was significantly correlated with BMI (r=-0.38, p=0.05), % BF (r=-0.43, p=0.02), and VO2max (r=0.39, p=0.04). Also, when the t-test was preformed there were no differences in the whole group or in the female group, but there were differences in the male group for %BF (p=0.007) and BMI (p=0.028). Conclusion: The results provide evidence that as BMI and % body fat increases, GDM decreases in females when they were tested for a relationship. In addition, epigenetic modifications appear to be associated with aerobic fitness in women. Future research should be directed toward identifying the gender difference observed from this data. The men in this study had significantly lower body fat (21±9 vs 29±8%) and greater VO2max (54±10 vs 46±9 ml/kg/min) compared to the women. Upon examining the data via the t-test in men, our results show that greater %GDM are found in the lower groups for %BF and BMI. It is possible that epigenomic effects are associated with a threshold of body fatness, and future studies should investigate this possibility.

Keywords

Aerobic exercises; Body composition; Body mass index; Cardiovascular fitness; Cardiovascular system--Diseases; DNA; DNA--Methylation

Disciplines

Exercise Science | Human and Clinical Nutrition | Kinesiology | Nutrition

Language

English

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