Aims/hypothesis. Diabetes mellitus is associated with an increased incidenc
e of atherosclerosis. How early functional and structural alterations of la
rge arteries that may preceed atherosclerosis occur in the course of this d
isease has, however, never been conclusively documented.
Methods. We evaluated arterial wall distensibility in the radial artery, co
mmon carotid artery and abdominal aorta in 133 patients (aged 35.4 +/- 0.9
years, means +/- SEM) with Type I (insulin-dependent) diabetes mellitus and
no macrovascular complications. Arterial distensibility was derived from c
ontinuous measurements of arterial diameter through echotracking techniques
and use of either the Langewouters (radial artery) or the Reneman (carotid
artery and aorta) formula. The same echotracking techniques enabled us to
obtain radial artery and carotid artery wall thickness. Data were compared
with those from 70 age-matched normotensive control subjects.
Results. In diabetic patients arterial distensibility was consistently less
(p < 0.01) than in control subjects, the reduction averaging 26%, 14% and
25% for the radial artery, carotid artery and aorta, respectively. This was
accompanied by an increase (p < 0.01) in both radial and carotid artery wa
ll thickness. The changes were more pronounced in patients with microalbumi
nuria, retinopathy or neuropathy or both. They were evident also in those w
ithout microvascular complications. This was the case also when subjects in
whom diabetes was associated with hypertension (n = 30) were excluded from
data analysis. Carotid and aortic wall abnormalities showed a relation wit
h the duration of disease and blood pressure whereas radial artery abnormal
ities showed a relation with glycated haemoglobin.
Conclusion/interpretation. Type I diabetes is characterised by diffuse arte
rial wall stiffening and thickening which progress with the severity of the
disease but can clearly be seen also in the absence of any diabetic-relate
d complication. This suggests that in diabetes stiffening and thickening ar
e an early marker of vascular damage.