Blood pressure, hypertension, and the risk of aortic aneurysm in the UK Biobank

Abstract Background Although an association between elevated blood pressure and risk of aortic aneurysm is established, few studies have investigated the association with aortic aneurysm subtypes. We investigated the association between systolic and diastolic blood pressure and hypertension status with the risk of aortic aneurysm in the UK Biobank. Methods The analysis included 495,542 men and women aged 37–73 years at recruitment between 2006 and 2010. Aortic aneurysm cases were identified by linkage to hospitalization and mortality records. Multivariable Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between blood pressure and hypertension and risk of aortic aneurysm overall and for subtypes. Results During a mean follow-up of 12.3 years, 3,346 incident aortic aneurysm cases were identified. Hypertension vs. no hypertension was associated with increased risk (HR, 95% CI) of aortic aneurysm (1.17, 1.08–1.27), and for thoracic (1.23, 1.04–1.46), abdominal (1.16, 1.04–1.30), and non-ruptured (1.18, 1.08–1.28) aortic aneurysm, and suggestively with unspecified site aortic aneurysm (1.18, 0.96–1.46) and aortic aneurysm mortality (1.26, 0.87–1.82), but not ruptured aortic aneurysm (1.02, 0.67–1.58). Systolic blood pressure was not associated with risk of aortic aneurysm overall or for any subtype. Diastolic blood pressure was positively associated with aortic aneurysm (1.74, 1.26–2.41, p trend <0.0001) for ≥ 110 vs. <80 mmHg, abdominal aortic aneurysm (1.95, 1.28–2.96, p trend <0.0001), unspecified site aortic aneurysm (2.02, 0.94–4.33, p trend =0.005), non-ruptured aortic aneurysm (1.79, 1.29–2.47), and aortic aneurysm mortality (2.32, 0.56–9.58, p trend <0.0001), and with ruptured aortic aneurysm (2.48, 1.22–5.03, p trend <0.0001 for 100–109 vs. <80 mmHg), while the association with thoracic aortic aneurysm was less clear (1.30, 0.64–2.63). These associations were strengthened and positive associations emerged for systolic blood pressure and abdominal and non-ruptured aortic aneurysm in sensitivity analyses when excluding participants with prevalent ischemic heart disease, stroke, those using hypertension medications and the first 3 years of follow-up. Conclusion We found that hypertension status and higher diastolic blood pressure were associated with increased risk of aortic aneurysm overall and most aortic aneurysm subtypes. No association was observed for systolic blood pressure. Although further studies are needed on aortic aneurysm subtypes, these findings provide strong support that controlling blood pressure is important for reducing the risk of aortic aneurysm.