Angiotensin-Converting Enzyme Ins/Del Polymorphism and Body Composition: The Intermediary Role of Hydration Status

FREQUENCY OF GENE ACE I POLYMORPHISM I-D IN ATHLETES OF DIFFERENT SPORTS

ABSTRACT Introduction: The angiotensin-converting enzyme I-D (ACE) polymorphism gene is one of the most widely investigated genetic variations in sports science. Apparently, allele I is related to endurance sports, while allele D is related to power-strength activities. Nevertheless, studies have presented controversial results when it comes as to its occurrence in a variety of sports. Objective: This study aims to evaluate the frequency of gene ACE polymorphism I-D in professional athletes of collective or individual sports. Methods: Five mL blood were collected from 189 subjects divided into two groups: athletes (AG, n=127, wrestling, taekwondo, soccer, futsal and handball) and non-athletes (NAG, n=62). The athletes group was subdivided by group modalities, into: collective and individual. Both groups were further subdivided into male and female. Thus, we have the groups FAC= collective female, FAI= individual female, MAC= collective male, and MAI= individual male. The statistical analysis was carried out by frequency test, and the Hardy- Weinberg equilibrium by the x² test. Results: The results for the AG group indicated the following frequencies: DD=7%, ID=44% and II=49%. Allele frequency: D=29% and I=71%. For the NAG, the results were: DD=6.5%, ID=45.2% and II=48%. Allele frequency: D=29% and I=71%. The AG genotypic and allele frequencies did not differ statistically from those of the NAG (p= 0.982 and p= 0.984, respectively). However, we noticed that the genotypes II and ID frequencies were significantly higher than those of the DD. Conclusion: It can be concluded that the genotypic and allelic I-D frequencies of the ACE gene do not seem to influence performance in either group or individual sports. ACTN3 genotype frequencies did not vary significantly between male and female control subjects, and overall, there was no significant deviation from Hardy-Weinberg (H-W) equilibrium. Level of evidence I; Diagnostic studies–Investigating diagnostic test.

Mitochondrial DNA methylation and copy number predict body composition in a young female population

Background

Since both genomic and environmental factors are involved in obesity etiology, several studies about the influence of adiposity on both nuclear DNA and mitochondrial DNA methylation patterns have been carried out. Nevertheless, few evidences exploring the usage of buccal swab samples to study mitochondrial DNA epigenetics can be found in literature.

Methods

In this study, mitochondrial DNA from buccal swabs collected from a young Caucasian population (n = 69) have been used to examine potential correlation between mitochondrial DNA copy number and methylation with body composition (BMI, WHtR and bioimpedance measurements).

Results

A negative correlation between mitochondrial DNA copy number and BMI was measured in females (p = 0.028), but not in males. The mean percentage of D-loop methylation is significantly higher in overweight than in lean female subjects (p = 0.003), and a specific CpG located in the D-loop shows per se an association with impaired body composition (p = 0.004). Body composition impairment is predicted by a combined variable including mtDNA copy number and the D-loop methylation (AUC = 0.785; p = 0.009).

Conclusions

This study corroborates the hypothesis that mitochondrial DNA carries relevant information about body composition. However, wider investigations able to validate the usage of mtDNA methylation from buccal swabs as a biomarker are warranted.

Exercise Response Efficiency: A Novel Way to Enhance Population Health?

The rates of obesity and its related comorbidities have increased substantially over the last 30 years, with approximately 35% of all US adults now classified as obese. Whilst the causes of obesity are both complex and multifactorial, one contributor is a reduction in leisure time physical activity, with no concurrent reduction in energy intake. Physical activity interventions have been demonstrated to promote fat loss, yet more than 50% of US adults undertake no leisure time physical activity at all, with a lack of time and enjoyment often cited as the main drivers of rising inactivity levels. Furthermore, recent evidence has demonstrated that a sub-group of individuals may experience no improvement in a given fitness or health-related measure following a specific training programme, suggesting that there may be optimal exercise types for different groups of individuals. In this paper, we introduce the concept of exercise response efficiency, whereby individuals are matched to the training type from which they are most likely to derive the greatest improvements for the least time commitment. We propose that a more precise targeting of exercise interventions is likely to drive more rapid improvements in health, thereby promoting exercise adherence and enjoyment, whilst simultaneously reducing obesity and mortality risks. Such an innovation would, we suggest, confer important public health benefits.