Background: Patients affected by AAA have a tendency to generalized dilatation, increased vascular stiffness and cardiovascular risk. There is a pronounced genetic predisposition for AAA, but it is unknown whether first-degree relatives without AAA, have a generalized dilating diathesis, or defect arterial wall mechanics. The aim of the study was to investigate the arterial diameter and wall properties in first-degree relatives without AAA, and compare them with controls without a family history of AAA.

Methods: 71 non-smoking relatives to patients with AAA (41m/30f; 41–70years) and 66 age and sex-matched controls were included. The abdominal aorta, carotid, common femoral, and the popliteal artery were investigated by ultrasound.

Results: No arterial dilatation was found, but rather a tendency of narrowing. The relatives had higher heart rate (HR) (P<.01) and diastolic blood pressure (DBP) than controls. The males had also higher systolic blood pressure (SBP). After adjusting for HR, the difference in SBP in males disappeared but the DBP remained increased (P<.05), and MAP became increased in males (P<.05).

The distensibility coefficient (DC) and the compliance coefficient (CC) were decreased in all arteries in the males but only in the aorta in females (P<.05). After adjusting DC and CC for MAP and HR, stiffness was normalized.

Conclusion: No general arterial dilatation in AAA relatives without aortic aneurysmal disease can be found, supporting the hypothesis that the dilating diathesis is linked to the aneurysmal manifestation in the abdominal aorta. Although the threat of aneurysmal dilatation and rupture seems to be lacking, BP, HR and arterial stiffness are increased, indicating raised cardiovascular risk in this population.