[Associations of hydration status with metabolic dysfunction-associated steatotic liver disease and parameters of liver transient elastography in children].

<b>Objective:</b> To explore the association of hydration status with metabolic dysfunction-associated steatotic liver disease (MASLD) and parameters of liver transient elastography in children. <b>Methods:</b> Participants were enrolled from the child cohort conducted to study sensitization, puberty, obesity, and cardiovascular risk (PROC), including 1 643 children surveyed at baseline from October 2018 to June 2019 and 1, 501 children followed up in April 2023. Data on hydration status, MASLD, and liver transient elastography parameters (for 1 499 children) were collected. Hepatic steatosis was defined as ultrasonic attenuation parameter (UAP)≥249 dB/m, and hepatic fibrosis was defined as liver stiffness measurement (LSM)≥8.0 kPa. For children with MASLD, hepatic steatosis or fibrosis were defined as unfavorable liver outcomes. Poisson regression and generalized estimating equations were used to determine the associations of hydration status with MASLD, hepatic steatosis, hepatic fibrosis, and the number of unfavorable liver outcomes when baseline data combined follow-up data. <b>Results:</b> At baseline, 1 643 children aged [<i>M</i> (<i>Q</i>₁, <i>Q</i>₃)] 6.6 (6.4, 6.8) years, with 828 boys (50.4%) were enrolled. Dehydration was present in 35.0% of children (575/1 643) at baseline and 76.2% (1 144/1 501) of children at follow-up (<i>P</i><0.001). The incidence of MASLD during follow-up was higher than that at baseline [12.7% (191/1 501) vs 6.9% (113/1 643), <i>P</i><0.001]. Compared to children with normal hydration, dehydrated children had increased risks of MASLD (<i>RR</i>=1.77, 95%<i>CI</i>: 1.42-2.20), hepatic steatosis (<i>RR</i>=1.28, 95%<i>CI</i>: 1.08-1.52), hepatic fibrosis (<i>RR</i>=1.65, 95%<i>CI</i>: 1.09-2.50), and more unfavorable liver outcomes (<i>RR</i>=1.47, 95%<i>CI</i>: 1.25-1.73) when baseline data combined follow-up data. <b>Conclusion:</b> Children's dehydration status is linked to unfavorable liver outcomes, including MASLD, hepatic steatosis and fibrosis, as assessed by transient elastography.