Vascular function and carotid intimal-medial thickness in children with insulin-dependent diabetes mellitus.
OBJECTIVE
The objective of this study was to evaluate endothelium-dependent vasodilation and carotid intimal-medial thickness (IMT) in children with insulin-dependent diabetes mellitus.


BACKGROUND
Diabetes mellitus is an established risk factor for atherosclerosis. Vascular complications of diabetes are not clinically evident in diabetic children. However, preclinical atherosclerosis is more common in young subjects exposed to cardiovascular risk factors. Endothelial function and carotid IMT, known to be abnormal in preclinical atherosclerosis, have not been studied concurrently in a pediatric population exposed to a risk factor for atherosclerosis.


METHODS
We studied 31 diabetic teenagers (age 15.0 +/- 2.4 years; duration of diabetes 6.8 +/- 3.9 years) and 35 age-matched healthy children (age 15.7 +/- 2.7 years). Using high-resolution vascular ultrasound, we compared carotid IMT and brachial artery responses to reactive hyperemia (endothelium-dependent vasodilation) and to sublingual nitroglycerin (endothelium-independent vasodilation).


RESULTS
There was no difference in baseline brachial artery diameter between the two groups. Endothelium-dependent vasodilation was significantly lower in diabetic children compared with healthy children (4.2 +/- 3.8% vs. 8.2 +/- 4.2%, p < 0.001). There was no difference in endothelium-independent vasodilation (17 +/- 6% vs. 18 +/- 6%, p = NS) or mean carotid IMT between the groups (0.33 +/- 0.05 vs. 0.32 +/- 0.08 mm, p = NS). Endothelium-dependent brachial vasodilation correlated with blood glucose levels (r = 0.58, p = 0.001) and was weakly and inversely related to the duration of diabetes (r = -0.4, p = 0.02), total cholesterol, and low-density lipoprotein cholesterol levels.


CONCLUSIONS
Endothelial function is impaired in children with diabetes mellitus within the first decade of its onset and precedes an increase in carotid IMT. The relative timing of these events is important in the evaluation of strategies to prevent progression of atherosclerosis and other vascular complications in this patient population.
Singh
Tajinder P
TP
Division of Cardiology, Department of Pediatrics, Wayne State University, Detroit, MI 48201, USA. tsingh@dmc.org
Groehn
Harvey
H
Kazmers
Andris
A
D000293:Adolescent; D000367:Age Factors; D017668:Age of Onset; D001161:Arteriosclerosis / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000503:physiopathology; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000503:physiopathology; D002339:Carotid Arteries / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000150:complications* / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D012307:Risk Factors; D013997:Time Factors; D017539:Tunica Intima / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D014463:Ultrasonography; D014664:Vasodilation / Q000502:physiology*