======  Urea/Creatinine Ratio ======

{{rss>https://pubmed.ncbi.nlm.nih.gov/rss/search/1VmNOZgUnBp0VRcwqAERuOIFHR1gv5B00nG-dgTUZudTlB-gaF/?limit=15&utm_campaign=pubmed-2&fc=20250321055320}}
 

Blood [[Urea/Creatinine Ratio]] is considered to be an ideal [[biomarker]] of [[dehydration]]. 
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Zhang et al. investigated the association between the [[Urea/Creatinine Ratio]] trajectory and [[delayed cerebral ischemia]] (DCI) as well as functional  [[aneurysmal subarachnoid hemorrhage prognosis]]. Additionally, they explored the role of DCI as a mediator and its interaction with [[dehydration]].

Consecutive aSAH patients were reviewed. A latent class growth mixture model (LCGMM) was applied to classify the dehydration trajectory over 7 days. Multivariate logistic regression was conducted to examine associations between dehydration trajectories, DCI, and poor outcome. Furthermore, causal mediation analysis combined with a four-way decomposition approach was employed to quantify the extent to which DCI mediates or interacts with dehydration in influencing poor outcomes.

A total of 519 aSAH patients were included. By applying the LCGMM method, we categorized participants into three dehydration trajectory groups: low group (n=353), decreasing group (n=97), and high group (n=69). Multivariate analysis demonstrated that dehydration trajectory was independently associated with both DCI and poor outcome. The effect of dehydration trajectory on poor outcome was partially mediated by DCI, involving both pure mediation and mediated interaction. Specifically, the excess relative risk of DCI was decomposed into four components: controlled direct effect (66.42%), mediation only (16.35%), interaction only (6.09%), and mediated interaction (11.16%).

Among aSAH patients, dehydration trajectory was significantly associated with poor functional outcome, with DCI serving as a partial mediator through both direct and interaction effects
((Zhang P, Tu Q, Tong M, Shi K, Yang T, Wang J, Zhang W, Pang Q, Li Z, Xu Z. Association between dehydration trajectory, delayed cerebral ischemia, and functional outcome in patients with aneurysmal subarachnoid hemorrhage: assessment of interaction and mediation. J Neurointerv Surg. 2025 Mar 20:jnis-2024-022953. doi: 10.1136/jnis-2024-022953. Epub ahead of print. PMID: 40113247.))
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Zhang et al. provide compelling evidence that dehydration trajectory over time is a key determinant of outcomes in aSAH, with delayed cerebral ischemia playing a partial mediating role. Their application of advanced statistical techniques adds [[credibility]] and depth to the findings. However, [[limitation]]s related to the [[surrogate marker]] for [[hydration]], retrospective design, and need for [[external validation]] should temper [[overinterpretation]]. Nonetheless, this work lays a strong foundation for further [[prospective]], [[mechanistic]], and interventional research.