Background: Although magnesium is important in the biology of blood pressure regulation, little clinical data exist on the association of hypermagnesemia and blood pressure.
Method: We examined the association of hypermagnesemia and SBP in a cross-sectional study of 10 521 ICU patients from a single tertiary care medical center, 6% of whom had a serum magnesium above 2.6 mg/dl at time of admission.
Results: In a multivariable analysis, hypermagnesemia was associated with SBP 6.2 mmHg lower [95% confidence interval (CI) −8.2, −4.2, P < 0.001] than in patients with admission values of serum magnesium 2.6 mg/dl or less. Each mg/dl increase in serum magnesium was associated with a decrease in SBP of 4.3 mmHg (95% CI −5.5, −3.1, P < 0.001). In addition, hypermagnesemic patients had a 2.48-fold greater likelihood (95% CI 2.06, 3.00, P < 0.001) of receiving intravenous vasopressors during the first 24 h of ICU care, independent of admission SBP.
Conclusion: Our findings add support to the biologic importance of magnesium regulation in blood pressure control.
aBeth Israel Deaconess Medical Center, Department of Medicine
bHarvard-MIT Division of Health Sciences and Technology
cSchool of Public Health and Health Systems, University of Waterloo, Waterloo, Ontario, Canada
Correspondence to John Danziger, MD, MPhil, 185 Pilgrim Road, Farr 8, Boston, MA 02215, USA. Tel: +1 617 632 9880; fax: +1 617 632 9890; e-mail: firstname.lastname@example.org
Abbreviations: BUN, blood urea nitrogen; ICU, intensive care unit; ESRD, end stage renal disease; TRPM, transient receptor potential melastatin; WBC, white blood cell count
Received 22 January, 2013
Revised 9 May, 2013
Accepted 12 June, 2013