Vitamin D deficiency and the long-term risk of new-onset abdominal aortic aneurysm and severe aortic events: a multicenter propensity score-matched cohort study.

BACKGROUND: Vitamin D deficiency (VDD) is prevalent among older adults and may influence vascular inflammation, extracellular matrix remodeling, and aortic wall integrity; however, its association with incident abdominal aortic aneurysm (AAA) remains uncertain. METHODS: This multicenter retrospective propensity score-matched cohort study used the TriNetX Global Collaborative Network to evaluate the association between vitamin D deficiency (VDD; serum 25-hydroxyvitamin D < 20 ng/mL) and the long-term risk of incident AAA in adults aged ≥50 years, compared with normal vitamin D status (≥30 ng/mL). A 1-year landmark design was applied, with follow-up extending up to 10 years after the index date. The primary outcome was incident AAA. The exploratory secondary outcomes included ruptured AAA, aortic dissection, thoracic aortic aneurysm, non-aortic aneurysm, and all-cause mortality. RESULTS: After propensity score matching, 466,332 patients were included in each cohort. VDD was associated with a higher risk of incident AAA than normal vitamin D status (0.66% vs. 0.45%; hazard ratio [HR] 1.40, 95% confidence interval [CI], 1.33-1.48; p < 0.001). Among the exploratory secondary outcomes, VDD showed higher nominal hazards of ruptured AAA (HR 3.06, 95% CI 2.05-4.58; p < 0.001), aortic dissection (HR 1.34, 95% CI 1.15-1.56; p < 0.001), thoracic aortic aneurysm (HR 1.13, 95% CI 1.08-1.20; p < 0.001), and all-cause mortality (HR 1.48, 95% CI 1.46-1.50; p < 0.001), whereas non-aortic aneurysms showed a weaker near-null association (HR 1.05, 95% CI 1.00-1.10; p = 0.053). This association persisted across sensitivity analyses and multivariable adjustments. CONCLUSION: Vitamin D deficiency was associated with an increased long-term risk of incident AAA, whereas the association with ruptured AAA was exploratory and should be interpreted cautiously because of the small number of events. Given the observational design and modest absolute risk difference, prospective studies are needed to determine whether this association is causal or clinically actionable.