This survey compared HIF1 gene polymorphism rs11549465 among elite/ amateur power athletes vs. non-athletes. Analyze showed that the HIF1 gene TC genotype occurrence in Iranian population (elite and amateur karate-kas and non-athletes, in both male and female) were significantly different among high incidence of CC, TC and TT; respectively. It’s worth noting that HIF1 genotype frequency and T/C allele occurrence incidence between all groups (among elite, amateur and non-athlete) were not statistically differences significant and wasn’t associated with the physical performance´s levels of karate-kas.
Our results were in confirm by the results that reported by Eynon et al. (2011) that did not find significant differences in their survey in HIF1A genotype distribution and Ser582 allele frequency of endurance and sprinters athletes vs. controls (15). These results showed that HIF1A Ser allele carriers are not more predisposed to power-orientated karate-kas.
Our survey doesn’t confirm previews studies by Ahmetov et al (2008) that reported a association between the HIF1A Pro582Ser polymorphism and increased levels of Russian sprint/strength weightlifters achievement and Zoll et al. (2006) that showed long exercise plan (i.e., 6 weeks) significantly (up to 104%) increased hif-1 gene expression in Quadriceps muscle, too (11, 18).
Differences in the sports conditions, training design (frequency and duration), methods of DNA extraction, size of subjects, and experience and training sessions of subjects, etc…could explain these discrepancies, likely. Especially our study, had blood sampling protocol instead of muscle biopsies. Mounier et al (2009) found decrease in transcriptional regulations of the hif-1α gene when they used muscle biopsy; while it didn't change when they had blood sampling to extract DNA (7). In our survey DNA was extracted from peripheral blood samples.
Differences in races of subjects (i.e. Russian [Ahmetov et al; 2008] and Polish [Cięszczyk; 2011] groups) and multiple sportive field of subjects (i. e. Runners/ Swimmers/ Weightlifters together in some mentioned surveys) are another possible explanation, too (11, 12). In the studies by Khaledi et al (2014) on Iranian professional athletes (include of Olympic and world championship in variant branches) vs. non-athletes about ACTN3, PGC-1α, ACE, CKMM, PPARγ polymorphisms, and Salehi et al (2011) on 148 Iranian national teams (in different sports) vs. 175 non-athletes aboutACTN3, didn’t find significant differences, too (19).
Semenza (2010) narrated that HIF-1α protein stability is regulated by the mechanisms that are oxygen-independent (20). Cooper et al (2007) reported that acute exercise is attended by reduced partial pressure of oxygen, too (21). Oxygen privation, among erythropoietin (EPO), VEGF and HIF-1α modulates several genes of oxygen homeostasis (22). Hypoxia condition product the ROS that likely reduce Fe2+ availability, which inhibits the activity of factor inhibiting HIF-1 (6).
In the state of hypoxia many factors such as the amount of ATP in muscles, high enzymatic performance for energy supply via glycolysis and phosphagenic systems, creatine phosphate, glycogen, etc... affecting the high anaerobic ability (11).
From the other hand, a complex interaction of psychological, socio-cultural, and etc factors result in variation of athletic performance (23). Mitchell et al (2005) reported that karate-Do is a low dynamic and high static sport; hence it need moderate total cardiovascular demands, too (24). Aligned with it Batavani et al (2017) had been proposed to be the association between the CK-MM gene A/G genotype and brilliant karate-kas performance (19). Aerobic energy supply and power ability of muscles among exercise are important, too. Indeed elite karate performance is a polygenic trait, with over one polymorphism like ACE and CKMM association (19). Also, elite performance in karate seems depends on the simultaneous presence of multiple fitness factors such skill, speed and etc..., likely.
Indeed might be having a suggestion that the HIF1A Pro582Ser polymorphism is not important in karate athletes. Hence, for some branches of sport which are yielded by intensive training, suitable genetic is not enough to attach the optimal sport performances, basically. However, the effect of genes for adaptation and responding to exercise, unable to be ignored (25). Athletic performance that predicted by genetic profiles examination alone, is not reliably (26). The most branches of sports need the combination of sprint or power and endurance demands together such as many other factors, including a broad variety of genetic, physical, environmental and psychological elements to reach the success, too (3). Specially, it be suggested that between the HIF1 gene polymorphism and athletic status replicate additional large scale prospective studies in some worldwide branches of sports, separately. However, this conclusion needs to be supported by more experimental surveys about HIF1A polymorphisms in professional athletes. Döring et al (2010) and Mason et al (2007) have written the articles about the role of the HIF1A gene as a genetic marker associated with endurance athlete performance, too (27, 28).