A population-based case-control study of the familial risk of abdominal aortic aneurysm
Presented at the Sixty-second Vascular Annual Meeting, San Diego, Calif, Jun 4-8, 2008.
Received 1 June 2008; accepted 6 August 2008. published online 25 November 2008.
Background
Several studies have reported a familial clustering of abdominal aortic aneurysm (AAA) supporting that AAA is an inheritable disease, but few population-based studies can be found. Possible gender differences regarding hereditary patterns have been reported.
Objective
The aim of this study was to investigate the risk of developing an AAA for first-degree relatives of patients with AAA in Sweden and compare them with matched controls and their relatives.
Methods and Materials
All persons (3183) born after 1932, diagnosed with AAA between 2001 and 2005, and a random selection of 15,943 age-, gender-, and region-matched controls were included. First-degree relatives of cases and controls were identified via the Multigeneration Register. Family history of AAA for cases and controls was assessed by linking the relatives to the Hospital Discharge Register and Cause of Death Register. The data were analyzed by conditional logistic regression.
Results
The overall relative risk of AAA associated with family history compared to no family history was 1.9 (95% confidence interval [CI] 1.6-2.2). Comorbidities were more common among the cases than the controls (P < .0001) but the relative risks remained unchanged after adjustment for comorbidities. Stratification for absence or presence of comorbidities showed no significant difference between the two groups (P = .29). The relative risk of AAA for first-degree relatives was similar for women and men (P = .22 for gender differences), ie, the relative risk of AAA was not dependent on the gender of the index person.
Conclusion
In this nationwide survey, the relative risk of developing AAA for first-degree relatives to persons diagnosed with AAA was approximately doubled compared to persons with no family history. Neither the gender of the index person nor the first-degree relative influenced the risk of AAA.
aDepartment of Molecular Medicine and Surgery, Stockholm, Sweden
cDepartment of Internal Medicine, Clinical Epidemiology Unit, Karolinska Institutet, Stockholm, Sweden
bDepartment of Vascular Surgery, Karolinska University Hospital, Stockholm, Sweden
Correspondence: Emma Larsson, MD, Department of Vascular Surgery, N2:06, Karolinska University Hospital, 171 76 Stockholm, Sweden
The study was funded by financial support provided by the Swedish Heart-Lung Foundation (Go Red), by the European Society of Vascular Surgery, and through the regional agreement on medical training and clinical research (ALF) between Stockholm County Council and the Karolinska Institutet.
ABSTRACT