Risk Factors in 50-year-old Men Predicting Development of Abdominal Aortic Aneurysm – A prospective Cohort Study with 15 Years of Follow-up

Introduction: Abdominal aortic aneurysm (AAA) is an asymptomatic, potentially lethal condition associated with several well-known risk factors including age, smoking and male gender. The aim of this prospective study is to identify risk factors predicting a future development of AAA. Methods: Datasets from the Westmannia Cardiovascular Risk Factors Study (WICTORY) conducted between 1990-1999, have been combined with cases of individuals who have undergone ultrasound examination of the infrarenal aortic diameter as part of the Västmanland County's ongoing AAA screening program which commenced in 2007, or for other purposes. The study analyses 5,817 men aged 50 at the time they participated in WICTORY and who underwent an ultrasound examination of the infrarenal aorta on average 15 years later. The risk for later development of AAA was analyzed with a Cox regressionmodel. Results: The prevalence of AAA in our study is 2.6%. Age, smoking status, angina pectoris treatment, prior MI, blood pressure treatment, body mass index, waist circumference, systolic blood pressure, heart rate and total cholesterol level were found to be associated with the development of AAA later in life in the univariate analysis. In the adjusted model, current smokers at age 50 had eleven times higher risk of later developing AAA (HR 11.178 (CI 6.277 - 19.908), P < 0.001). Former smokers did not suffer a similar risk of AAA development. Elevated total-cholesterol at baseline was associated with later AAA development (HR 1.275 (CI 1.119-1.451), P < 0.001), as well as increasing age (HR 1.702 (CI 1.153 - 2.512), P = 0,007) and waist circumference (HR 1.019 (CI 1.002 - 1.037), P = 0.031). Conclusion: Both the well-known and the less established possible predictors for future development of AAA identified in this study can support improvement of strategic preventive measures towards specific risk groups and thereby possibly reduce the risk of developing AAA later in life.Tabled 1VariableUnadjustedAdjustedP-valueHR (95% CI)P-valueHR (95% CI)Age (years)1.634 (1.123-2.377)0.0101.702 (1.153-2.512)0.007Smoking status - Former1.770 (0.917-3.418)0.0891.596 (0.825-3.089)0.165Smoking status - Current11.973 (6.736-21.282)<0.00111.178 (6.277-19.908)<0.001BP Treatment1.919 (1.142-3.225)0.0141.480 (0.840-2.606)0.175Prior MI3.247 (1.330-7.927)0.0102.111 (0.817-5.450)0.123Waist Circumference (cm)1.031 (1.014-1.048)<0.0011.019 (1.002-1.037)0.031Systolic BP (mm HG)1.011 (1.002-1.020)0.0181.007 (0.998-1.017)0.144Total Cholestorol (mmol/l)1.382 (1.227-1.556)<0.0011.275 (1.119-1.451)<0.001[Results from unadjusted/adjusted Cox regression analyses of the association between risk factors and later development of AAA.] Open table in a new tab [Results from unadjusted/adjusted Cox regression analyses of the association between risk factors and later development of AAA.] Disclosure: Nothing to disclose