Is Hypovitaminosis D Associated with Abdominal Aortic Aneurysm, and is There a Dose–response Relationship?

ObjectiveThis 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.DesignAn observational study of 4233 community-dwelling men aged 70–88 years, who participated in a randomised controlled trial of screening for AAA.MethodsInfrarenal aortic diameter measured by ultrasound and 25(OH)D by immunoassay.ResultsA 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.ConclusionsLow 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.