AUTHOR=Lu Yuzhao , Ma Xin , Tazmini Kiarash , Yang Ming , Zhou Xiaobing , Wang Yang 

TITLE=Admission Serum Calcium Level and Short-Term Mortality After Acute Ischemic Stroke: A Secondary Analysis Based on a Norwegian Retrospective Cohort

JOURNAL=Frontiers in Neurology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2022.889518

DOI=10.3389/fneur.2022.889518

ISSN=1664-2295

ABSTRACT=Abstract
Background: Disturbed serum calcium levels are related to the risk of stroke. However, previous studies exploring the correlation between serum calcium and clinical outcome of ischemic stroke (IS) showed inconsistent results. In addition, evidence regarding the relationship between admission serum calcium and short-term mortality after IS is scarce.
Object: The study aimed to investigate the relationship between admission serum calcium and 30-day mortality in patients with IS.
Methods: A total of 876 IS patients from a Norwegian retrospective cohort were included for secondary analysis. The exposure variable and the primary outcome were albumin-corrected serum calcium (ACSC) at baseline and all-cause mortality within 30 days after the first admission, respectively. Multivariable logistic regression analysis was used to estimate the risk of 30-day mortality according to ACSC levels. Moreover, the potential presence of a nonlinear relationship was evaluated using the two-piecewise linear regression model with a smoothing function and threshold level analysis. The stability of the results was evaluated by unadjusted and adjusted models.
Results: The result of multiple regression analysis showed that ACSC at baseline was positively associated with the incidence of 30-day mortality after adjusting for the potential confounders (age, gender, serum glucose, hypertension, atrial fibrillation/atrial flutter, renal insufficiency, heart failure, chronic obstructive pulmonary disease, pneumonia, paralysis, and aphasia), (OR=2.43, 95% CI 1.43-4.12). When ACSC was translated into a categorical variable, the ORs and 95% CIs in the quartile 2 to 4 versus the quartile 1 were 1.23 (0.56, 2.69), 1.16 (0.51, 2.65), and 2.13 (1.04, 4.38), respectively (P for trend=0.0251). Moreover, the results of the two-piecewise linear regression and curve fitting revealed a linear relationship between ACSC and 30-day mortality. 
Conclusion: ACSC is positively associated with 30-day mortality in IS patients. The relationship between them is linear.