Prognostic value of day-of-event serum calcium and magnesium for predicting 1-year prognosis after intracerebral hemorrhage

Aim To investigate whether serum calcium and magnesium on the day of symptom onset contribute to prognosis at 1 year after intracerebral hemorrhage (ICH). Methods We prospectively enrolled patients admitted < 24 h after symptom onset of primary ICH to West China Hospital between January 2012 and October 2014. Blood samples were collected at admission to determine the concentration of serum calcium and magnesium. We analyzed associations of the serum concentration of calcium and magnesium with unfavorable outcome (defined as modified Rankin scale, mRS ≥ 3) at 1 year. Results We included 874 patients (mean age 59.1 ± 13.5 years, 67.6% males), of whom 470 patients had mRS ≥ 3 and 284 patients died at 1 year. Compared to patients with the highest tertile level of calcium concentration (≥ 2.29 mmol/L), patients in the lowest tertile (≤ 2.15 mmol/L) had higher odds of unfavorable outcome (odds ratio, OR 1.61, 95% confidence interval [CI] 1.04–2.50, P = 0.034). The Kaplan–Meier survival curve revealed a significant difference of cumulative survival rate across calcium tertiles (log-rank P value = 0.038). There was no significant association between serum concentration of magnesium and functional outcome at 1 year. Conclusion A reduced serum concentration of calcium on the day-of-event was associated with unfavorable outcome at 1 year after ICH. Future studies are needed to illustrate the pathophysiological mechanism of calcium and whether calcium could be a treatment target for improving outcomes after ICH.