Geneticists have compiled a profile of the ideal marathon runner

Denis Strigun, Naked Science

Researchers from Camilo Jose Sela University have found that creatine kinase and myoglobin levels as biomarkers of rhabdomyolysis during exercise are associated with polymorphisms of seven genes. The results of the work are presented in the journal PLoS ONE (Del Coso et al., Optimum polygenic profile to resist exertional rhabdomyolysis during a marathon).

Rhabdomyolysis is a syndrome in which muscle tissue cells are destroyed against the background of infections, injuries or physical exertion. Despite the fact that patients without complications may be allowed to exercise, the condition increases the risk of death, including due to renal failure or arrhythmia, especially in warm countries. At the same time, the etiology of rhabdomyolysis has not been studied enough: for example, it is unclear what distinguishes healthy people from patients with comparable physical activity. Past studies have shown that creatine kinase, an enzyme that catalyzes creatine and ATP from the "fuel" of the body under physical exertion, creatine phosphate, can serve as a biomarker of the syndrome.

A number of studies also suggest that resistance to muscle weakness and limited range of motion, characteristic of rhabdomyolysis, is associated with genetic variations. In particular, it is known that in homozygous girls, already at the stage of embryogenesis, the α-actinin-3 (ACTN3) gene involved in the stabilization of skeletal muscles may contain a single nucleotide polymorphism (SNP) rs1815739. In addition, the severity of symptoms may be associated with the family of insulin-like growth factors (IGF), among other things, mediating the action of somatotropic hormone. Thus, according to a 1985 article, IGF2 polymorphisms are able to reduce the risk of muscle damage.

Scores on the polymorphism scale for each gene in groups with low (black) and high (white) levels of creatine kinase. Independently, each gene makes a minor contribution (here and below are the figures from the article in PLoS ONE).

To test the hypothesis of a correlation between creatine kinase and rhabdomyolysis, as well as to assess the relationship of the syndrome with genetic variations, the staff of the Laboratory of Autonomous and Exercise Physiology conducted an experiment with 67 participants of the 2015 Rock'n'ROLL Madrid Marathon. A day before the race and immediately after it, the subjects performed two high jumps with maximum effort on a power platform, after which scientists took blood samples from them. 

Biomaterial was studied for creatine kinase level and polygenic combinations of polymorphisms of seven genes: ACTN3(rs1815739), IGF2 (s3213221), ACE (rs4340), CKMM (rs1803285), IL6 (rs1800795), MLCK(rs28497577) and TNFa (rs1800629).

The effect of SNPs was evaluated on a scale from 0 to 2, where 0 – high levels of creatine kinase, 1 – average level and 2 – low levels of creatine kinase. Additionally, the athletes assessed the subjective feeling of physical activity on the Borg scale and pain in the legs – on a visual analog scale. According to the results, on average, athletes from the group with an initially low (less than 400 units per liter of blood) enzyme level received a higher total score on the polymorphism scale: 5.2 ±1.4 versus 4.4±1.7 with increased (more than 400 units) creatine kinase. A similar correlation was observed for myoglobin, a protein whose growth is also associated with rhabdomyolysis.

Distribution of total points on the polymorphism scale

It is noteworthy that the level of pain and load, a decrease in the height of the jump and an increase in the effort required for it before and after the race were comparable in both groups. According to the authors, the data obtained confirm that creatine kinase and myoglobin, due to the general influence of these polymorphisms, can serve as biomarkers of the syndrome. In the future, such a genetic profile can be used to assess the readiness of athletes for competitions. Meanwhile, scientists have repeatedly pointed out the positive effects of running. So, in humans, such types of activity are associated with the volume of the brain, and running protected mice from cancerous tumors.

Portal "Eternal youth" http://vechnayamolodost.ru  10.04.2017