AUTHOR=Zhang Shuo , Ji Jiaqi , Gao Siqi , Yang Shu , Song Zeyi , Li Jianmin , Liu Junjie 

TITLE=Association between SpO2 and the risk of death in elderly T2DM patients with cerebral infarction: a retrospective cohort study

JOURNAL=Frontiers in Neurology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2024.1344000

DOI=10.3389/fneur.2024.1344000

ISSN=1664-2295

ABSTRACT=<sec><title>Objective</title><p>This study aimed to evaluate the SpO<sub>2</sub> (transcutaneous oxygen saturation) -mortality link in elderly T2DM (diabetes mellitus type 2) patients with cerebral infarction and identify their optimal SpO<sub>2</sub> range.</p></sec><sec><title>Methods</title><p>In this investigation, we employed a comprehensive approach. Initially, we screened the MIMIC-IV database, identifying elderly T2DM patients with cerebral infarction, utilizing specific ICD-9 and ICD-10 codes. We then harnessed the power of restricted cubic splines to craft a visual representation of the correlation between SpO<sub>2</sub> and 1-year mortality. To enhance our analysis, we harnessed Cox multivariate regression, allowing us to compute adjusted hazard ratios (HR) accompanied by 95% confidence intervals (CIs). Additionally, we crafted Cumulative Mortality Curve analyses, augmenting our study by engaging in rigorous subgroup analyses, stratifying our observations based on pertinent covariates.</p></sec><sec><title>Results</title><p>In this study, 448 elderly T2DM patients with cerebral infarction were included. Within 1-year post-discharge, 161 patients (35.94%) succumbed. Employing Restricted Cubic Spline analysis, a statistically significant <italic>U</italic>-shaped non-linear relationship between admission ICU SpO<sub>2</sub> levels and 1-year mortality was observed (<italic>P</italic>-value &lt; 0.05). Further analysis indicated that both low and high SpO<sub>2</sub> levels increased the mortality risk. Cox multivariate regression analysis, adjusting for potential confounding factors, confirmed the association of low (≤94.5%) and high SpO<sub>2</sub> levels (96.5–98.5%) with elevated 1-year mortality risk, particularly notably high SpO<sub>2</sub> levels (&gt;98.5%) [HR = 2.06, 95% CI: 1.29–3.29, <italic>P</italic>-value = 0.002]. The cumulative mortality curves revealed the following SpO<sub>2</sub> subgroups from high to low cumulative mortality at the 365th day: normal levels (94.5% &lt; SpO<sub>2</sub> ≤ 96.5%), low levels (SpO<sub>2</sub> ≤ 94.5%), high levels (96.5% &lt; SpO<sub>2</sub> ≤ 98.5%), and notably high levels (&gt;98.5%). Subgroup analysis demonstrated no significant interaction between SpO<sub>2</sub> and grouping variables, including Sex, Age, Congestive heart failure, Temperature, and ICU length of stay (LOS-ICU; <italic>P</italic>-values for interaction were &gt;0.05).</p></sec><sec><title>Conclusions</title><p>Striking an optimal balance is paramount, as fixating solely on lower SpO<sub>2</sub> limits or neglecting high SpO<sub>2</sub> levels may contribute to increased mortality rates. To mitigate mortality risk in elderly T2DM patients with cerebral infarction, we recommend maintaining SpO<sub>2</sub> levels within the range of 94.5–96.5%.</p></sec>