Evaluation of the 18-bp deletion/insertion variant of the VEGF gene in athletes.

The skeletal muscle capillary supply mainly determines the highest exercise capacity. Vascular endothelial growth factor (VEGF) is the major growth factor during the angiogenesis process. Therefore, we aimed to investigate whether the VEGF insertion/deletion (I/D) variant differs between athletes and sedentary controls in the Turkish population. Three hundred sixteen subjects, including 146 athletes from different branches and 170 sedentary people, voluntarily participated in this study. Genomic DNA was isolated and genotyped using polymerase chain reaction (PCR) analysis for the VEGF I/D variant. The results were evaluated statistically. In this study, the athletes and the controls showed a statistically significant difference in the genotype and allele distribution of the VEGF I/D variant. The athletes had a more prevalent D allele and D/D genotype than the controls (p = 0.008 and p = 0.034, respectively). There was a statistically significant association between the patients and the controls in terms of D/D vs. I/I + I/D genotypes (p = 0.018). There was no significant difference in VEGF I/D genotype distribution according to sports branches. Athletic performance is a complex trait influenced by genetic and environmental factors. As far as we know, this is the first study to evaluate the VEGF I/D variant in athletes in Turkey. According to our results in this study, we concluded that the VEGF I/D variant, D/D genotype, and D allele are associated with sport performance in the Turkish population. However, there is a need for studies with large samples in which environmental and emotional factors will also be taken into account.

Evaluation of a circadian rhythm gene (PER3) VNTR variant in Turkish athletes.

OBJECTIVE: Circadian rhythmicity has been shown to contribute to the regulation of key physiological and cognitive processes related to performance. The period homolog 3 (PER3) is expressed in a circadian pattern in the suprachiasmatic nucleus. Therefore, in this study, we aimed to evaluate the role of the variable tandem repeat (VNTR) variant of the PER3 gene in athletic performance in the Turkish population. METHODS: This study included 223 subjects, which consisted of 123 athletes and 100 sedentary controls. Blood samples were drawn from all subjects. DNA was extracted from whole-blood samples. The PER3 VNTR variant was genotyped using the polymerase chain reaction-restriction method (PCR). The results of the analyses were evaluated for statistical significance. RESULTS: The mean ages of athletes and controls were 22 ± 2.814 and 23 ± 3.561, respectively. Endurance athletes in the group were 21.1%, and sprint athletes were 78.9%. There was no statistical significance in terms of PER3 VNTR genotype distribution or allele frequency. In the recessive model, a statistically significant association was observed when the athletes were compared with the controls according to 4/4 + 4/5 versus 5/5 genotype (p = 0.020). CONCLUSION: In this case-control study, for the first time in our country, we obtained findings suggesting that the PER3 VNTR variant may affect sports performance in the Turkish population. Results need to be replicated in different ethnic and larger samples.

The evaluation of superoxide dismutase 1 gene insertion/deletion variant in athletes.

OBJECTIVE: Regular exercise benefits health by increasing the body's antioxidant defenses. However, excessive exercise can produce excessive reactive oxygen species, which can lead to oxidative stress. Superoxide dismutase is the primary enzyme involved in the elimination of reactive oxygen species. This study aimed to determine the relationship between the SOD1 gene insertion/deletion variant and elite athletes. METHODS: A total of 305 subjects, including 165 elite athletes from different branches and 140 sedentary individuals, participated in this study. The SOD1 insertion/deletion variant was genotyped using polymerase chain reaction. The results were evaluated statistically. RESULTS: There was no statistical significance between the athletes and control groups in terms of SOD1 insertion/deletion genotype distribution and allele frequency. Then, we evaluated the groups as females and males. There were no female athletes carrying the D/D genotype. The SOD1 I/I genotype and the I allele were more prevalent in female athletes than in the control group. There was a significant difference in terms of SOD1 I/I: I/D+D/D in females (p=0.028). SOD1 genotype and allele distribution did not differ between male athletes and male controls. CONCLUSION: As far as we know, this is the first study to evaluate the SOD1 insertion/deletion variant in athletes in Turkey. Our results showed that the SOD1 I allele was more common in female athletes, but not in male athletes.

Does Tennis Training Improve Attention? New Approach.

This study aimed to examine the effect of a tennis training program on improving attention. METHODS: A total of 40 tennis players from a Tennis Club, 20 in the experimental group (EG) and 20 in the control group (CG), participated in the study. The EG athletes received 40 serve balls from the trainer twice a week for nine weeks. The researcher applied the "d2 attention test" to the EG and CG before and after the nine-week period. RESULTS: After comparing the pretest and posttest attention averages of the experimental group, there was a significant difference in the TN, TN-E, and CP mean scores (p < 0.001). In the comparison of the pretest and posttest attention averages of the CG, there was no significant difference in the TN, TN-E, and CP mean scores (p > 0.05). The comparison of the pretest attention averages of the EG and CG revealed no significant difference in the TN, TN-E, and CP mean scores (p > 0.05). The comparison of the posttest attention averages of the EG and CG revealed a significant difference in the mean scores of TN, TN-E, and CP (p < 0.05). There was a statistically significant difference between the posttest-pretest differences in the TN, TN-E, and CP values of the EG and CG (p < 0.05). CONCLUSIONS: The study concluded that tennis training aimed at developing attention improved the results in the attention test.

ACTN3 R577X variant: could it be a determinant of sports performance in elite athletes in a Turkish population?

ACTN3 gene, which encodes a-actinin-3 and actin-binding protein, has been found to be associated with strong athletic performance, especially among track and field athletes. Therefore, in this study, our aim was to compare the allelic and genotype frequencies of the ACTN3 R577X variant among elite athletes specialized in different branches, and nonathletic controls in Turkey. In the present study, 316 subjects, including 168 athletes and 148 sedentary controls were genotyped for the ACTN3 R577X variant. Genotyping was conducted by polymerase chain reaction (PCR) method. Additionally, we evaluated the groups by dividing them as females and males. There were 48 females and 120 males in the athletes group, and 43 females and 105 males in the control group. Genetic associations were evaluated by chi-squire test or Fisher's exact test. There was a significant difference between the athletes and controls in terms of the ACTN3 R577X variant. ACTN3 RR and XX genotypes increased in the controls compared to the athletes, while RX genotype was higher in the athletes than the controls (P = 0.030). Then we evaluated the groups by separating them as females and males. Genotype distribution of the ACTN3 R577X differed between the male athletes and the male controls (P = 0.046). ACTN3 R577X RX genotype increased in the male athletes compared to the male control (P = 0.046). But ACTN3 R577X genotype and allele distribution was not significant between female athletes and female control group (P>0.05). As far as we know, this study is the largest series examining the ACTN3 R577X variant in Turkish athletes. Our results support that the ACTN3 R577X variant has a heterozygous advantage in athletic performance in the Turkish population. However, epigenetic, gene-gene and gene-environment interactions affects athlete performance should not be forgotten.

Does circadian rhythm have an impact on anaerobic performance, recovery and muscle damage?

This study aimed to examine the effect of circadian rhythms (CR) on anaerobic performance and subsequent recovery, muscle damage, and respiratory muscle strength. Twenty diurnally active male football players (age, 22.20 ± 3.14 y) were asked to perform the Wingate anaerobic power test three times for 30 s each at 09:00, 14:00 and 19:00 h, with a minimum recovery period of 1 week between each testing day. Pretest oral temperature, respiratory muscle strength, oxygen saturation, and rating of perceived exertion were recorded at three different time of the day. To examine post-exercise recovery, heart rate (HR) and lactic acid (LA) levels were recorded before and after the tests. Blood samples were collected 20 min after each test to assess muscle damage. The body temperature taken at 19:00 h was the highest of the three (p < .01). After the tests, the LA value at 19:00 h was higher than that at 09:00 h (p < .05). According to CR, the HR values measured after anaerobic exercise were higher at 14:00 h (p < .05). The peak power value was higher at 14:00 h than at 19:00 h (p < .058). CR does not affect muscle damage and respiratory muscle strength. Further, at 14:00 h, anaerobic power was higher and recovery occurred faster compared to the other test times of 09:00 and 19:00 h. Therefore, it is recommended that anaerobic training should be performed early in the afternoon.