title: Red cell distribution width is associated with incident myocardial infarction in a general population: the Tromsø Study.
abstract: BACKGROUND
  Red cell distribution width (RDW), a measure of the variability in size of circulating erythrocytes, is associated with mortality and adverse outcome in selected populations with cardiovascular disease. It is scarcely known whether RDW is associated with incident myocardial infarction (MI). We aimed to investigate whether RDW was associated with risk of first-ever MI in a large cohort study with participants recruited from a general population.
  
  
  RESULTS
  Baseline characteristics, including RDW, were collected for 25 612 participants in the Tromsø Study in 1994-1995. Incident MI during follow-up was registered from inclusion through December 31, 2010. Cox regression models were used to calculate hazard ratios with 95% confidence intervals for MI, adjusted for age, sex, body mass index, smoking, hemoglobin, white blood cells, platelets, and other traditional cardiovascular risk factors. A total of 1779 participants experienced a first-ever MI during a median follow-up time of 15.8 years. There was a linear association between RDW and risk of MI, for which a 1% increment in RDW was associated with a 13% increased risk (hazard ratio 1.13; 95% CI, 1.07 to 1.19). Participants with RDW above the 95th percentile had 71% higher risk of MI compared with those with RDW in the lowest quintile (hazard ratio 1.71; 95% CI, 1.34 to 2.20). All effect estimates were essentially similar after exclusion of participants with anemia (n=1297) from the analyses.
  
  
  CONCLUSIONS
  RDW is associated with incident MI in a general population independent of anemia and cardiovascular risk factors.
authors.affiliation: K.G. Jebsen Thrombosis Research and Expertise Center (TREC), Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway (T.S., J.L., T.S.E., J.B., I.N., E.B.M., S.K.B., J.B.H.) Hematological Research Group (HERG), Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway (T.S., J.L., T.S.E., J.B., S.K.B., J.B.H.) Division of Internal Medicine, University Hospital of North-Norway, Tromsø, Norway (T.S., S.K.B., J.B.H.).
authors.forename: Tove
authors.initials: T
authors.lastname: Skjelbakken
authors.affiliation: K.G. Jebsen Thrombosis Research and Expertise Center (TREC), Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway (T.S., J.L., T.S.E., J.B., I.N., E.B.M., S.K.B., J.B.H.) Hematological Research Group (HERG), Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway (T.S., J.L., T.S.E., J.B., S.K.B., J.B.H.).
authors.forename: Jostein
authors.initials: J
authors.lastname: Lappegård
authors.affiliation: K.G. Jebsen Thrombosis Research and Expertise Center (TREC), Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway (T.S., J.L., T.S.E., J.B., I.N., E.B.M., S.K.B., J.B.H.) Hematological Research Group (HERG), Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway (T.S., J.L., T.S.E., J.B., S.K.B., J.B.H.).
authors.forename: Trygve S
authors.initials: TS
authors.lastname: Ellingsen
authors.affiliation: Division of Epidemiology, Department of Family and Preventive Medicine, School of Medicine, University of California San Diego, La Jolla, CA (E.B.C.).
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Barrett-Connor
authors.affiliation: K.G. Jebsen Thrombosis Research and Expertise Center (TREC), Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway (T.S., J.L., T.S.E., J.B., I.N., E.B.M., S.K.B., J.B.H.) Hematological Research Group (HERG), Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway (T.S., J.L., T.S.E., J.B., S.K.B., J.B.H.) Department of Medical Biochemistry, University Hospital of North-Norway, Tromsø, Norway (J.B.).
authors.forename: Jan
authors.initials: J
authors.lastname: Brox
authors.affiliation: Department of Community Medicine, UiT The Arctic University of Norway, Tromsø, Norway (M.L., I.N., T.W.).
authors.forename: Maja-Lisa
authors.initials: ML
authors.lastname: Løchen
authors.affiliation: K.G. Jebsen Thrombosis Research and Expertise Center (TREC), Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway (T.S., J.L., T.S.E., J.B., I.N., E.B.M., S.K.B., J.B.H.) Department of Community Medicine, UiT The Arctic University of Norway, Tromsø, Norway (M.L., I.N., T.W.).
authors.forename: Inger
authors.initials: I
authors.lastname: Njølstad
authors.affiliation: Department of Community Medicine, UiT The Arctic University of Norway, Tromsø, Norway (M.L., I.N., T.W.).
authors.forename: Tom
authors.initials: T
authors.lastname: Wilsgaard
authors.affiliation: K.G. Jebsen Thrombosis Research and Expertise Center (TREC), Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway (T.S., J.L., T.S.E., J.B., I.N., E.B.M., S.K.B., J.B.H.) Brain and Circulation esearch Group, Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway (E.B.M.) Department of Neurology and Neurophysiology, University Hospital of North-Norway, Tromsø, Norway (E.B.M.).
authors.forename: Ellisiv B
authors.initials: EB
authors.lastname: Mathiesen
authors.affiliation: K.G. Jebsen Thrombosis Research and Expertise Center (TREC), Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway (T.S., J.L., T.S.E., J.B., I.N., E.B.M., S.K.B., J.B.H.) Hematological Research Group (HERG), Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway (T.S., J.L., T.S.E., J.B., S.K.B., J.B.H.) Division of Internal Medicine, University Hospital of North-Norway, Tromsø, Norway (T.S., S.K.B., J.B.H.).
authors.forename: Sigrid K
authors.initials: SK
authors.lastname: Brækkan
authors.affiliation: K.G. Jebsen Thrombosis Research and Expertise Center (TREC), Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway (T.S., J.L., T.S.E., J.B., I.N., E.B.M., S.K.B., J.B.H.) Hematological Research Group (HERG), Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway (T.S., J.L., T.S.E., J.B., S.K.B., J.B.H.) Division of Internal Medicine, University Hospital of North-Norway, Tromsø, Norway (T.S., S.K.B., J.B.H.).
authors.forename: John-Bjarne
authors.initials: JB
authors.lastname: Hansen
mesh_terms: D000328:Adult; D000368:Aged; D004909:Erythrocyte Indices; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000453:epidemiology; D009664:Norway / Q000453:epidemiology; D016016:Proportional Hazards Models; D011446:Prospective Studies
keywords: blood cells; cardiovascular disease; epidemiology; risk factors