Abdominal aortic aneurysm: incidence in a population at risk.

One hundred twenty patients aged fifty years and over underwent screening by ultrasound for abdominal aortic aneurysms as part of their routine follow-up visit to a cardiologist. The overall incidence of aneurysm greater than or equal to 4 centimeters in diameter was 5%. In the 84 men with aortas less than 4 centimeters, the average aorta size was 2.4 centimeters. In the 30 women with aortas less than 4 centimeters, the average aorta size was significantly smaller, 1.9 centimeters (p less than .001). It was discovered that men who smoke and have hypertension have a statistically significant increase in aorta size compared to those men without these risk factors (less than .05). The results indicate that the incidence of abdominal aortic aneurysm is probably high enough in this population to justify screening by ultrasound.