title: Serum 25-hydroxyvitamin D, calcium, phosphorus, and electrocardiographic QT interval duration: findings from NHANES III and ARIC.
abstract: BACKGROUND
  Disturbances in 25-hydroxyvitamin D, calcium, and phosphorus concentrations have been associated with increased risks of total and cardiovascular mortality. It is possible that changes in electrocardiographic QT interval duration may mediate these effects, but the association of 25-hydroxyvitamin D, phosphorus, and calcium concentrations with QT interval duration has not been evaluated in general population samples.
  
  
  OBJECTIVE
  The objective of the study was to evaluate the association of 25-hydroxyvitamin D, phosphorus, and calcium concentrations with QT interval duration in two large samples of the U.S. general population.
  
  
  METHODS
  This study included cross-sectional analyses the Third National Health and Nutrition Survey (NHANES III) and the Atherosclerosis Risk in Communities (ARIC) study.
  
  
  METHODS
  The study was conducted in the general community.
  
  
  METHODS
  Patients included 7,312 men and women from NHANES III and 14,825 men and women from the ARIC study.
  
  
  METHODS
  Serum 25-hydroxyvitamin D, total and ionized calcium, and inorganic phosphorus were measured in NHANES III, and serum total calcium and inorganic phosphorus were measured in ARIC.
  
  
  METHODS
  QT interval duration was obtained from standard 12-lead electrocardiograms.
  
  
  RESULTS
  In NHANES III, the multivariate adjusted differences in average QT interval duration comparing the highest vs. the lowest quartiles of serum total calcium, ionized calcium, and phosphorus were -3.6 msec (-5.8 to -1.3; P for trend = 0.005), -5.4 msec (-7.4 to -3.5; P for trend <0.001), and 3.9 msec (2.0-5.9; P for trend <0.001), respectively. The corresponding differences in ARIC were -3.1 msec (-4.3 to -2.0; P for trend <0.001), -2.9 msec (-3.8 to -1.9; P for trend <0.001), and 2.3 msec (1.3-3.3; P for trend <0.001). No association was found between 25-hydroxyvitamin D concentrations and QT interval duration.
  
  
  CONCLUSIONS
  In two large samples of the general population, QT interval duration was inversely associated with the serum total and ionized calcium and positively associated with serum phosphorus.
authors.affiliation: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 2024 East Monument Street, Baltimore, Maryland 21205, USA.
authors.forename: Yiyi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Wendy S
authors.initials: WS
authors.lastname: Post
authors.forename: Darshan
authors.initials: D
authors.lastname: Dalal
authors.forename: Sandeep
authors.initials: S
authors.lastname: Bansal
authors.forename: Elena
authors.initials: E
authors.lastname: Blasco-Colmenares
authors.forename: Suzanne
authors.initials: S
authors.lastname: Jan De Beur
authors.forename: Alvaro
authors.initials: A
authors.lastname: Alonso
authors.forename: Elsayed Z
authors.initials: EZ
authors.lastname: Soliman
authors.forename: Eric A
authors.initials: EA
authors.lastname: Whitsel
authors.forename: Ramón
authors.initials: R
authors.lastname: Brugada
authors.forename: Gordon F
authors.initials: GF
authors.lastname: Tomaselli
authors.forename: Eliseo
authors.initials: E
authors.lastname: Guallar
mesh_terms: D002118:Calcium / Q000097:blood*; D003430:Cross-Sectional Studies; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010758:Phosphorus / Q000097:blood*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D014807:Vitamin D; D010758:Phosphorus; C104450:25-hydroxyvitamin D; D002118:Calcium