Reduced aortic wall stress in diabetes mellitus.
OBJECTIVE
Most risk factors are similar for abdominal aortic aneurysm (AAA) and atherosclerosis, e.g. smoking, male gender, age, high blood pressure, hyperlipidemia. Diabetes mellitus however, is a risk factor for atherosclerosis, but diabetic patients seldom develop AAA. The reason for this discrepancy is unknown. Increased aortic wall stress seems to be an etiologic factor in the formation, growth and rupture of AAA in man. The aim of our study was to study the wall stress in the abdominal aorta in diabetic patients compared with healthy controls.


METHODS
39 patients with diabetes mellitus and 46 age - and sex matched healthy subjects were examined with B-mode ultrasound to determine the lumen diameter (LD) and intima-media thickness (IMT) in the abdominal aorta (AA) and the common carotid artery (CCA). Diastolic blood pressure (DBP) was measured non-invasively in the brachial artery. LaPlace law was used to calculate circumferential wall stress.


RESULTS
Age, DBP, and LD in the abdominal aorta were not significantly different in the diabetic patients compared to controls. IMT in the AA was larger in the diabetic patients, 0.89+/-0.17 vs 0.73+/-0.11 mm (p<.001). Accordingly aortic wall stress was reduced in the diabetics, 7.8+/-1.7 x 10(5) vs 9.7+/-1.9 x 10(5)dynes/cm(2) (p<.001).


CONCLUSIONS
Wall stress in the abdominal aorta is reduced in diabetes mellitus. This is mainly due to a thicker aortic wall compared to healthy controls. The reduced aortic wall stress coincides with the fact that epidemiological studies have shown a decreased risk of aneurysm development in diabetic patients.
Astrand
H
H
Department of Medicine and Care, University of Linköping, Division of Vascular Surgery, Jönköping Hospital, Sweden. hakan.astrand@lj.se
Rydén-Ahlgren
A
A
Sundkvist
G
G
Sandgren
T
T
Länne
T
T
D000328:Adult; D000368:Aged; D001012:Aorta, Abdominal / Q000503:physiopathology*; D017544:Aortic Aneurysm, Abdominal / Q000453:epidemiology; D001696:Biomechanical Phenomena; D001794:Blood Pressure; D017536:Carotid Artery, Common / Q000473:pathology; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology / Q000503:physiopathology*; D003925:Diabetic Angiopathies / Q000453:epidemiology; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017539:Tunica Intima / Q000473:pathology; D017540:Tunica Media / Q000473:pathology