title: Plasma calcium as a predictor of cardiovascular disease in a community-based cohort.
abstract: OBJECTIVE
  Primary hyperparathyroidism and calcium supplementation have been linked to cardiovascular outcomes. The study objective was to examine plasma calcium as a predictor of cardiovascular disease in the general population, as results from previous cohort studies are conflicting.
  
  
  METHODS
  Plasma calcium was measured in 4003 participants (aged 25-84 years) in the 1994/1995 Busselton Health Survey. Using a Cox proportional hazards model, we examined albumin-corrected calcium as a predictor of total mortality, cardiovascular mortality and cardiovascular events up to the end of 2010.
  
  
  RESULTS
  At baseline, there were significant positive relationships between plasma calcium and each of body mass index, systolic and diastolic blood pressure, glucose and total cholesterol. During the follow-up period, 666 participants died (278 from cardiovascular disease) and 652 had incident cardiovascular events. After adjustment for age and sex, each additional 0.1 mm of albumin-corrected calcium at baseline was associated with a hazard ratio (HR) of 1.09 [95% confidence interval (CI) 0.99, 1.20; P = 0.062] for total mortality, 1.06 (95% CI 0.92, 1.23; P = 0.41) for cardiovascular mortality and 1.13 (95% CI 1.03, 1.24; P = 0.012) for cardiovascular events. These associations were attenuated by further adjustment for standard cardiovascular risk factors with HR 1.03 (95% CI 0.94, 1.14), 0.99 (95% CI 0.86, 1.16) and 1.05 (95% CI 0.95, 1.15), respectively.
  
  
  CONCLUSIONS
  After adjustment for age and sex, plasma calcium is a predictor of cardiovascular events. This appears to be mediated by conventional cardiovascular risk factors, and calcium is not an independent predictor of cardiovascular disease.
authors.affiliation: Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, WA, Australia. john.walsh@health.wa.gov.au
authors.forename: John P
authors.initials: JP
authors.lastname: Walsh
authors.forename: Mark L
authors.initials: ML
authors.lastname: Divitini
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Knuiman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002118:Calcium / Q000097:blood*; D002318:Cardiovascular Diseases / Q000097:blood / Q000453:epidemiology* / Q000401:mortality; D015331:Cohort Studies; D006801:Humans; D008875:Middle Aged; D016016:Proportional Hazards Models; D012307:Risk Factors; D014904:Western Australia / Q000453:epidemiology
chemical_list: D002118:Calcium