Plasma magnesium and risk of ischemic stroke among women.
BACKGROUND AND PURPOSE
Lower plasma magnesium levels may be associated with higher blood pressure and endothelial dysfunction, but sparse prospective data are available for stroke.


METHODS
Among 32,826 participants in the Nurses' Health Study who provided blood samples in 1989 to 1990, incident ischemic strokes were identified and confirmed by medical records through 2006. We conducted a nested case-control analysis of 459 cases, matched 1:1 to controls on age, race/ethnicity, smoking status, date of blood draw, fasting status, menopausal status, and hormone use. We used conditional logistic regression models to estimate the multivariable adjusted association of plasma magnesium and the risk of ischemic stroke and ischemic stroke subtypes.


RESULTS
Median magnesium levels did not differ between ischemic stroke cases and controls (median, 0.86 mmol/L for both; P=0.14). Conditional on matching factors, women in the lowest magnesium quintile had a relative risk of 1.34 (95% confidence interval, 0.86-2.10; P trend=0.13) for total ischemic stroke compared with women in the highest quintile. Additional adjustment for risk factors and confounders did not substantially alter the risk estimates for total ischemic stroke. Women with magnesium levels<0.82 mmol/L had significantly greater risk of total ischemic stroke (multivariable relative risk, 1.57; 95% confidence interval, 1.09-2.27; P=0.01) and thrombotic stroke (multivariable relative risk, 1.66; 95% confidence interval, 1.03-2.65; P=0.03) compared with women with magnesium levels≥0.82 mmol/L. No significant effect modification was observed by age, body mass index, hypertension, or diabetes mellitus.


CONCLUSIONS
Lower plasma magnesium levels may contribute to higher risk of ischemic stroke among women.
['Adebamowo|Sally N|SN|', 'Jiménez|Monik C|MC|', 'Chiuve|Stephanie E|SE|', 'Spiegelman|Donna|D|', 'Willett|Walter C|WC|', 'Rexrode|Kathryn M|KM|']
D000368:Aged D002545:Brain Ischemia D016022:Case-Control Studies D005260:Female D006801:Humans D008274:Magnesium D008875:Middle Aged D011446:Prospective Studies D012307:Risk Factors D020521:Stroke
plasma magnesium ischemic stroke