CFTR genotype-related body water and electrolyte balance during a marathon.
The aim of this investigation was to determine the influence of CFTR genotype on body water and electrolyte balance during a marathon. Fifty-one experienced runners completed a marathon race. Before and after the race, body mass and a sample of venous blood were obtained. During the race, sweat samples were collected using sweat patches, and fluid and electrolyte intake were obtained using self-reported questionnaires. Thirty-eight participants (74.5% of the total) were 7T/7T homozygotes, 11 (21.6%) were 7T/9T heterozygotes, and one participant presented the rare genotype 5T/7T. Another participant with 9T/9T presented the mutation p.L206W. Participants with 7T/7T showed higher sweat sodium concentrations (42.2 ± 21.6 mmol/L) than 7T/9T (29.0 ± 24.7 mmol/L; P = 0.04). The runner with the 5T/7T genotype (10.2 mmol/L) and the participant with the p.L206W mutation (20.5 mmol/L) exhibited low-range sweat sodium concentrations. However, post-race serum sodium concentration was similar in 7T/7T and 7T/9T (142.1 ± 1.3 and 142.4 ± 1.6 mmol/L, respectively; P = 0.27) and did not show abnormalities in participants with the 5T/7T genotype (140.0 mmol/L) and the p.L206W mutation (143.0 mmol/L). Runners with the CFTR-7T/7T genotype exhibited increased sweat sodium concentrations during a marathon. However, this phenotype was not related with increased likelihood of suffering body water and electrolyte imbalances during real competitions.
Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain.
J
J
Del Coso
Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain.
B
B
Lara
Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain.
J J
http://orcid.org/0000-0003-4153-5100
JJ
Salinero
Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain.
F
F
Areces
Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain.
D
D
Ruiz-Vicente
Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain.
C
C
Gallo-Salazar
Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain.
J
J
Abián-Vicén
Chair of Genomic Medicine, Camilo José Cela University, Madrid, Spain.
R
R
Cacabelos
D000328:Adult; D054874:Athletic Performance; D001835:Body Weight; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics*; D004326:Drinking; D005221:Fatigue / Q000235:genetics; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D008875:Middle Aged; D009154:Mutation; D063806:Myalgia / Q000235:genetics; D009994:Osmolar Concentration; D012420:Running / Q000502:physiology*; D012964:Sodium / Q000032:analysis* / Q000097:blood; D013542:Sweat / Q000737:chemistry*; D014882:Water-Electrolyte Balance / Q000235:genetics*
C505032:CFTR protein, human; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D012964:Sodium
Sweat; chloride; cystic fibrosis; endurance exercise; hyponatremia; salt