Influence of the duration of type 2 diabetes on early functional and morphological markers of atherosclerosis compared to the impact of coexisting classic cardiovascular risk factors.
OBJECTIVE
The increased incidence of atherosclerotic macrovascular disease in type 2 diabetic patients is associated both with diabetes specific factors and coexisting classic cardiovascular risk factors as components of the metabolic syndrome. The aim of this study was to investigate the association between the duration of diabetes and early functional and morphological markers of atherosclerosis compared to the impact of coexisting cardiovascular risk factors such as hypertension, dyslipoproteinemia and cigarette smoking.


METHODS
63 type 2 diabetic patients and 25 non-diabetic control subjects were investigated. Lumen diameter of the brachial artery was measured by high-resolution ultrasound at rest and after 5-min suprasystolic arterial compression. Endothelium-independent dilatation of the brachial artery was measured 4 min after sublingual administration of 400 mug of glycerol trinitrate (GTN). Percentage change of arterial lumen diameter during reactive hyperemia (FMD%) and after GTN administration (GTN%) relative to the baseline measurements were calculated. The intima-media thickness (IMT) of the common carotid artery was measured bilaterally and averages were calculated.


RESULTS
FMD% (3.8+/-0.8% vs. 6.9+/-0.9%; p<0.01) and GTN% (5.6+/-0.7% vs. 14.9+/-1.7%; p<0.01) were reduced in the diabetic patients compared to their control subjects. IMT was increased in diabetic patients compared to their controls (0.82+/-0.02 mm vs. 0.62+/-0.02 mm; p<0.01). The age-adjusted diabetes duration was inversely related to FMD% (r=-0.27; p=0.016). On multiple regression analysis including packyears, hypertension, hypercholesterolemia, and hypertriglyceridemia, only diabetes duration remained a significant independent determinant of FMD. GTN% and IMT were not associated with diabetes duration, packyears, hypertension, hypercholesterolemia, and hypertriglyceridemia when all variables were taken into account.


CONCLUSIONS
The present data lend support to the suggestion that diabetic specific factors compared to coexisting cardiovascular risk factors such as hypertension, hyperlipoproteinemia, and smoking are of major importance for the pathogenesis of endothelial dysfunction in type 2 diabetes, because only the diabetes duration was shown to be related to endothelium-dependent vasodilation when all variables were taken into account.
Meyer
M F
MF
Department of Internal Medicine, University Clinic Bergmannsheil, Ruhr-University Bochum, Germany. martin.meyer-2@rub.de
Lieps
D
D
Schatz
H
H
Klein
H H
HH
Pfohl
M
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D000368:Aged; D000369:Aged, 80 and over; D050197:Atherosclerosis / Q000097:blood / Q000209:etiology* / Q000473:pathology*; D015415:Biomarkers / Q000097:blood; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000473:pathology*; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications* / Q000473:pathology; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D006937:Hypercholesterolemia / Q000150:complications; D006973:Hypertension / Q000150:complications; D015228:Hypertriglyceridemia / Q000150:complications; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D013997:Time Factors; D014463:Ultrasonography
D015415:Biomarkers; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human