αlpha-
Actinin-3 (ACTN3 R577X, rs.1815739) polymorphism is a
genetic variation that shows the most consistent influence on
metabolic pathway and
muscle phenotype. XX
genotype is associated with higher metabolic
efficiency of
skeletal muscle; however, the
role of ACTN3 polymorphism in
oxygen transport and utilization system has not yet been investigated. Therefore, the aim of this study was to determine the influence of ACTN3 polymorphisms on hematological and
iron metabolism response induced by
marathon race. Eighty-one Brazilian amateur
male endurance runners participated in the study.
Blood samples and
urine were collected before; immediately after; and 1, 3, and 15 days after the
marathon race.
Urine, hematological
parameters,
iron metabolism, and ACTN3 genotyping analyses were performed. The
marathon race induced a decrease in
erythrocytes, Hb, and Ht, and an increase in
hematuria,
creatinine,
myoglobin,
red cell distribution width,
mean corpuscular hemoglobin concentration,
mean corpuscular hemoglobin, direct and indirect
bilirubin and
erythropoietin. Moreover, na elevation immediately or 1 day after the
marathon race follows a reduction 3 or 15 days after the
marathon race were observed on
transferrin saturation and
iron and
transferrin levels. Hematological
parameters and
iron metabolism changes induced by
marathon race were not observed in XX
genotypes.
Hematuria and decreased
erythrocytes, Hb, Ht, and
iron and
transferrin levels were observed only in RR and/or RX
genotypes but not in XX
genotypes. The percentage of runners with
hematuria, leukocyturia,
iron deficiency,
creatinine,
myoglobin, and
bilirubin imbalance was higher in RR compared to XX
genotypes. ACTN3 polymorphism is associated with
iron metabolism and hematological responses after endurance
exercise. Despite these results being based on a small sample, they highlight protective
role of the XX
genotype on hematological and renal changes induced by long-distance
exercise. Therefore, these findings should be further replicated.(AU)