title: Cardiovascular mortality - Comparing risk factor associations within couples and in the total population - The HUNT Study.
abstract: BACKGROUND
  To compare associations of conventional risk factors with cardiovascular death within couples and in the population as a whole.
  
  
  METHODS
  We analysed baseline data (1995-97) from the HUNT2 Study in Norway linked to the national Causes of Death Registry. We compared risk within couples using stratified Cox regression.
  
  
  RESULTS
  During 914776 person-years, 3964 cardiovascular deaths occurred, and 1658 of the deaths occurred among 1494 couples. There were consistently stronger associations of serum lipids and blood pressure with cardiovascular mortality within couples compared to the population as a whole. For instance, for systolic blood pressure (per 20mmHg), the hazard ratio (HR) within couples was 1.28 (95% confidence interval: 1.17, 1.40) compared to 1.16 (1.12, 1.20) in the total population, and for diastolic pressure (per 10mmHg), the corresponding HRs were 1.16 (1.07, 1.26) and 1.11 (1.08, 1.13). Anthropometric factors (BMI, waist circumference, waist-hip ratio) as well as diabetes, smoking, physical activity, and education, showed nearly identical positive associations within couples and in the total population.
  
  
  CONCLUSIONS
  Prospective population studies may tend to slightly underestimate associations of these factors with cardiovascular mortality.
authors.affiliation: Department of Public Health, Faculty of Medicine, Norwegian University of Science and Technology, 7491 Trondheim, Norway; Forensic Department, Research Centre Bröset, St. Olav's University Hospital Trondheim, Trondheim, Norway. Electronic address: johan.h.bjorngaard@ntnu.no.
authors.forename: Johan Håkon
authors.initials: JH
authors.lastname: Bjørngaard
authors.affiliation: Department of Public Health, Faculty of Medicine, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
authors.forename: Gunnhild Åberge
authors.initials: GÅ
authors.lastname: Vie
authors.affiliation: Department of Public Health, Faculty of Medicine, Norwegian University of Science and Technology, 7491 Trondheim, Norway; HUNT Research Center, Norwegian University of Science and Technology, Levanger, Norway.
authors.forename: Steinar
authors.initials: S
authors.lastname: Krokstad
authors.affiliation: Department of Public Health, Faculty of Medicine, Norwegian University of Science and Technology, 7491 Trondheim, Norway; Regional Center for Health Care Improvement, St Olav Hospital, Trondheim, Norway.
authors.forename: Imre
authors.initials: I
authors.lastname: Janszky
authors.affiliation: Department of Public Health, Faculty of Medicine, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
authors.forename: Pål R
authors.initials: PR
authors.lastname: Romundstad
authors.affiliation: Department of Public Health, Faculty of Medicine, Norwegian University of Science and Technology, 7491 Trondheim, Norway; Regional Center for Health Care Improvement, St Olav Hospital, Trondheim, Norway.
authors.forename: Lars J
authors.initials: LJ
authors.lastname: Vatten
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000401:mortality*; D002423:Cause of Death / Q000639:trends; D005190:Family; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D011446:Prospective Studies; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D013997:Time Factors
keywords: Cardiovascular mortality; Confounding; Couples; Population study; Risk factors