title: Serum Magnesium and the Risk of Death From Coronary Heart Disease and Sudden Cardiac Death.
abstract: BACKGROUND
  Low serum magnesium has been implicated in cardiovascular mortality, but results are conflicting and the pathway is unclear. We studied the association of serum magnesium with coronary heart disease (CHD) mortality and sudden cardiac death (SCD) within the prospective population-based Rotterdam Study, with adjudicated end points and long-term follow-up.
  
  
  RESULTS
  Nine-thousand eight-hundred and twenty participants (mean age 65.1 years, 56.8% female) were included with a median follow-up of 8.7 years. We used multivariable Cox proportional hazard models and found that a 0.1 mmol/L increase in serum magnesium level was associated with a lower risk for CHD mortality (hazard ratio: 0.82, 95% CI 0.70-0.96). Furthermore, we divided serum magnesium in quartiles, with the second and third quartile combined as reference group (0.81-0.88 mmol/L). Low serum magnesium (≤0.80 mmol/L) was associated with an increased risk of CHD mortality (N=431, hazard ratio: 1.36, 95% CI 1.09-1.69) and SCD (N=217, hazard ratio: 1.54, 95% CI 1.12-2.11). Low serum magnesium was associated with accelerated subclinical atherosclerosis (expressed as increased carotid intima-media thickness: +0.013 mm, 95% CI 0.005-0.020) and increased QT-interval, mainly through an effect on heart rate (RR-interval: -7.1 ms, 95% CI -13.5 to -0.8). Additional adjustments for carotid intima-media thickness and heart rate did not change the associations with CHD mortality and SCD.
  
  
  CONCLUSIONS
  Low serum magnesium is associated with an increased risk of CHD mortality and SCD. Although low magnesium was associated with both carotid intima-media thickness and heart rate, this did not explain the relationship between serum magnesium and CHD mortality or SCD. Future studies should focus on why magnesium associates with CHD mortality and SCD and whether intervention reduces these risks.
authors.affiliation: Department of Epidemiology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands (B.T.K., M.N.N., M.G.L., O.H.F., A.H., B.H.S.) Department of Internal Medicine, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands (B.T.K., R.Z., B.H.S., E.J.H.) Inspectorate for Health Care, Utrecht, The Netherlands (B.T.K., B.H.S.).
authors.forename: Brenda C T
authors.initials: BC
authors.lastname: Kieboom
authors.affiliation: Department of Epidemiology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands (B.T.K., M.N.N., M.G.L., O.H.F., A.H., B.H.S.).
authors.forename: Maartje N
authors.initials: MN
authors.lastname: Niemeijer
authors.affiliation: Department of Epidemiology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands (B.T.K., M.N.N., M.G.L., O.H.F., A.H., B.H.S.) Department of Cardiology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands (M.G.L., J.W.D.) Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA (M.G.L., A.H.).
authors.forename: Maarten J G
authors.initials: MJ
authors.lastname: Leening
authors.affiliation: Department of Medical Informatics, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands (M.E.B.).
authors.forename: Marten E
authors.initials: ME
authors.lastname: van den Berg
authors.affiliation: Department of Epidemiology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands (B.T.K., M.N.N., M.G.L., O.H.F., A.H., B.H.S.).
authors.forename: Oscar H
authors.initials: OH
authors.lastname: Franco
authors.affiliation: Department of Cardiology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands (M.G.L., J.W.D.).
authors.forename: Jaap W
authors.initials: JW
authors.lastname: Deckers
authors.affiliation: Department of Epidemiology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands (B.T.K., M.N.N., M.G.L., O.H.F., A.H., B.H.S.) Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA (M.G.L., A.H.).
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.affiliation: Department of Internal Medicine, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands (B.T.K., R.Z., B.H.S., E.J.H.).
authors.forename: Robert
authors.initials: R
authors.lastname: Zietse
authors.affiliation: Department of Epidemiology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands (B.T.K., M.N.N., M.G.L., O.H.F., A.H., B.H.S.) Department of Internal Medicine, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands (B.T.K., R.Z., B.H.S., E.J.H.) Inspectorate for Health Care, Utrecht, The Netherlands (B.T.K., B.H.S.).
authors.forename: Bruno H
authors.initials: BH
authors.lastname: Stricker
authors.affiliation: Department of Internal Medicine, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands (B.T.K., R.Z., B.H.S., E.J.H.).
authors.forename: Ewout J
authors.initials: EJ
authors.lastname: Hoorn
mesh_terms: D000368:Aged; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000401:mortality; D015415:Biomarkers / Q000097:blood; D002340:Carotid Artery Diseases / Q000175:diagnosis / Q000401:mortality; D059168:Carotid Intima-Media Thickness; D002423:Cause of Death; D003327:Coronary Disease / Q000097:blood* / Q000175:diagnosis / Q000401:mortality*; D016757:Death, Sudden, Cardiac / Q000453:epidemiology*; D015536:Down-Regulation; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D016014:Linear Models; D008274:Magnesium / Q000097:blood*; D008275:Magnesium Deficiency / Q000097:blood* / Q000175:diagnosis / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009426:Netherlands / Q000453:epidemiology; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors
chemical_list: D015415:Biomarkers; D008274:Magnesium
keywords: cardiovascular diseases; death, sudden; epidemiology; mortality; risk factors