Relationship of serum magnesium concentration to risk of short-term outcome of acute ischemic stroke

Objective. To assess whether serum magnesium concentration can predict risk of short-term outcome of acute ischemic stroke. Methods. Between January 1, 2006 and December 31, 2008, 1493 patients with acute ischemic stroke were recruited from four hospitals in Shandong province, P. R China. Data on demographic characteristics, life style risk factors, history of cardiovascular disease, admission blood pressure and other clinical characteristics were collected from all subjects. The short-term outcome was defined as neurological deficiency NIHSS >= 10 or death (NIHSS >= 10/death). The Cox proportion hazard regression model was used to evaluate the association between serum magnesium concentration and risk of short-term outcome of acute ischemic stroke. Results. Serum magnesium concentration in subjects with NIHSS >= 10/death was lower than those with NIHSS < 10 (p < 0.05). When comparing the highest quartile of serum magnesium concentration with the lowest quartile in an unadjusted model, there was a decreased risk of NIHSS >= 10/death in individuals with the highest quartile; the risk ratio (RR) was 0.47 (p < 0.05). However, after adjustment for age, sex, serum calcium concentration, serum potassium concentration and other covariates, the fourth and the third quartiles of serum magnesium concentration were associated with decreased risks of NIHSS >= 10/death; the RRs were 0.40 and 0.56 (all p < 0.05), respectively. The dose-response relationship between serum magnesium concentration and risk of NIHSS >= 10/death was not materially altered after adjustment for other covariates (p-value for trend = 0.002). Conclusion. Higher serum magnesium concentration was associated with lower risk of NIHSS >= 10/death; there was a dose-response relationship between serum magnesium concentration and risk of NIHSS >= 10/death.