title: Renal function is related to severity of coronary artery calcification in elderly persons: the Rotterdam study.
abstract: BACKGROUND
  Coronary artery calcification (CAC) has been proposed to be the underlying mechanism of the increased risk of coronary heart disease with reductions in glomerular filtration rate (GFR). Since renal function diminishes with aging we examined the association between GFR and CAC in the Rotterdam Study, a population-based study of elderly individuals.
  
  
  METHODS
  The study was performed in 1703 subjects without a history of coronary heart disease. GFR was estimated using the modification of diet in renal disease equation. We used analysis of covariance to test for mean differences in CAC between GFR tertiles.
  
  
  RESULTS
  The mean CAC scores in the middle and lowest GFR tertile did not significantly differ from the mean CAC score in the highest GFR tertile (geometric mean CAC score 4.1 and 4.3 vs 4.2). In a multivariable model the mean CAC score did also not differ between the GFR tertiles. As the interaction term between age and GFR was significant (P = 0.037), we divided the population in two age categories based on median age of 70 years. Below 70 years, the mean CAC scores did not differ between the GFR tertiles. Above median age, mean CAC score in the lowest GFR tertile was significantly higher than the mean CAC score in the highest tertile in a multivariable model (CAC 4.9 vs 4.5, p = 0.010).
  
  
  CONCLUSIONS
  In this population-based study we observed that the association between CAC and GFR is modified by age. In participants at least 70 years of age, a decrease in GFR was associated with increased CAC.
authors.affiliation: Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands. a.barzouhiel@erasmusmc.nl
authors.forename: Abdelilah
authors.initials: A
authors.lastname: El Barzouhi
authors.forename: Suzette
authors.initials: S
authors.lastname: Elias-Smale
authors.forename: Abbas
authors.initials: A
authors.lastname: Dehghan
authors.forename: Rozemarijn
authors.initials: R
authors.lastname: Vliegenthart-Proença
authors.forename: Matthijs
authors.initials: M
authors.lastname: Oudkerk
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.forename: Jacqueline C M
authors.initials: JC
authors.lastname: Witteman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002114:Calcinosis / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology*; D003324:Coronary Artery Disease / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000502:physiology*; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D011153:Population; D012307:Risk Factors; D012720:Severity of Illness Index