Quantifying the risks of hypertension, age, sex and smoking in patients with abdominal aortic aneurysm

Background: The prevalence of abdominal aortic aneurysm (AAA) in a communit y-based sample of men and women aged 65-79 years was correlated with known risk factors. In addition, the effect of high blood pressure and the use of antihypertensive medication on growth of AAAs were studied. Methods: Aortic diameter was assessed by ultrasonography and data on risk f actors were collected by self-administered questionnaire for 5356 men and w omen as part of a randomized controlled trial. Results: Current hypertension increased the risk of having an aortic aneury sm by 30-40 per cent while use of antihypertensive medication increased the risk by 70-80 per cent, adjusting for current blood pressure. There was no clear relationship between hypertension and growth rates of existing aneur ysms in this study, although these results were largely from data on small aneurysms. Men were nearly six times more likely to develop an AAA than wom en; the risk increased by 40 per cent every 5 years after the age of 65 yea rs. Smoking was an independent risk factor for AAA, with level of exposure being more significant than duration. Conclusion: Male sex, smoking and hypertension are strong risk factors for the development of AAA. In this study hypertension did not significantly in crease the growth rate of existing aneurysms. Smoking remains the most impo rtant avoidable risk factor for AAA. The analyses presented here suggest th at selection for screening, other than by age and sex, is not worthwhile.