title: Is hypovitaminosis D associated with abdominal aortic aneurysm, and is there a dose-response relationship?
abstract: OBJECTIVE
  This study aims to investigate the association between plasma 25-hydroxyvitamin D (25(OH)D) concentrations with the presence of abdominal aortic aneurysm (AAA) and aortic diameter.
  
  
  METHODS
  An observational study of 4233 community-dwelling men aged 70-88 years, who participated in a randomised controlled trial of screening for AAA.
  
  
  METHODS
  Infrarenal aortic diameter measured by ultrasound and 25(OH)D by immunoassay.
  
  
  RESULTS
  A total of 311 men (7.4%) with AAA (defined as aortic diameter ≥ 30 mm) comprised the study. Multivariable models were adjusted for age, smoking, cardiovascular disease, hypertension, diabetes, dyslipidaemia, body mass index and serum creatinine concentration. Amongst men with the lowest 25(OH)D quartile of values compared with the highest quartile, the adjusted odds ratio of having an AAA increased in a graded fashion from 1.23 (95% confidence interval (CI) 0.87-1.73) for AAA ≥ 30 mm to 5.42 (95% CI 1.85-15.88) for AAA ≥ 40 mm. Similarly, there was a dose-response relationship between 25(OH)D concentrations and the size of the AAA: every 10-nmol l(-1) decrease in 25(OH)D levels was associated with 0.49 mm (95% CI 0.11-0.87) increase in mean aortic diameter.
  
  
  CONCLUSIONS
  Low vitamin D status is associated with the presence of larger AAA in older men, and there is a graded inverse relationship between 25(OH)D concentrations and AAA diameter. Further research is needed to clarify the mechanisms underlying these associations.
authors.affiliation: Western Australian Centre for Health and Ageing, Centre for Medical Research, Western Australian Institute for Medical Research, Perth, Australia. ewong@meddent.uwa.edu.au
authors.forename: Y Y E
authors.initials: YY
authors.lastname: Wong
authors.forename: L
authors.initials: L
authors.lastname: Flicker
authors.forename: B B
authors.initials: BB
authors.lastname: Yeap
authors.forename: K A
authors.initials: KA
authors.lastname: McCaul
authors.forename: G J
authors.initials: GJ
authors.lastname: Hankey
authors.forename: P E
authors.initials: PE
authors.lastname: Norman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000453:epidemiology*; D015415:Biomarkers / Q000097:blood; D015897:Comorbidity; D003430:Cross-Sectional Studies; D006801:Humans; D007118:Immunoassay; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D016017:Odds Ratio; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012307:Risk Factors; D014463:Ultrasonography; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*; D014904:Western Australia / Q000453:epidemiology
chemical_list: D015415:Biomarkers; D014807:Vitamin D; C104450:25-hydroxyvitamin D