Sex Differences in Hydration Biomarkers and Test-Retest Reliability Following Passive Dehydration.
Int J Sport Nutr Exerc Metab
; 34(2): 88-100, 2024 Mar 01.
Article
em En
| MEDLINE
| ID: mdl-38215737
ABSTRACT
This study investigated (a) differences between males and females for changes in serum, tear, and urine osmolality, hematocrit, and urine specific gravity following acute passive dehydration and (b) assessed the reliability of these biomarkers separately for each sex. Fifteen males (age 26.3 ± 3.5 years, body mass 76 ± 7 kg) and 15 females (age 28.8 ± 6.4 years, body mass 63 ± 7 kg) completed a sauna protocol twice (5-28 days apart), aiming for 4% body mass loss (BML). Urine, blood, and tear markers were collected pre- and postdehydration, and change scores were calculated. Male BML was significantly greater than that of females in Trial 1 (3.53% ± 0.55% vs. 2.53% ± 0.43%, p < .001) and Trial 2 (3.36% ± 0.66% vs. 2.53% ± 0.44%, p = .01). Despite significant differences in BML, change in hematocrit was the only change marker that displayed a significant difference in Trial 1 (males 3% ± 1%, females 2% ± 1%, p = .004) and Trial 2 (males 3% ± 1%, females 1% ± 1%, p = .008). Regression analysis showed a significant effect for sex (male) predicting change in hematocrit (ß = 0.8, p = .032) and change in serum osmolality (ß = -3.3, p = .005) when controlling for BML but not for urinary or tear measures. The intraclass correlation coefficients for females (ICC 2, 1) were highest for change in urine specific gravity (ICC = .62, p = .006) and lowest for change in tear osmolarity (ICC = -.14, p = .689), whereas for males, it was posthematocrit (ICC = .65, p = .003) and post tear osmolarity (ICC = .18, p = .256). Generally, biomarkers showed lower test-retest reliability in males compared with females but, overall, were classified as poor-moderate in both sexes. These findings suggest that the response and reliability of hydration biomarkers are sex specific and highlight the importance of accounting for BML differences.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Caracteres Sexuais
/
Desidratação
Tipo de estudo:
Prognostic_studies
Limite:
Adult
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Female
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Humans
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Male
Idioma:
En
Revista:
Int J Sport Nutr Exerc Metab
Assunto da revista:
CIENCIAS DA NUTRICAO
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MEDICINA ESPORTIVA
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METABOLISMO
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Austrália