J Korean Diabetes Assoc.
2000 Oct;24(5):574-586.
The Effect of Acute Hyperglycemia on Endothelial Function in Type 2 Diabetes
- Affiliations
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- 1Department of Internal Medicine, Keimyung University Dongsan Medical Center, Taegu, Korea.
Abstract
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BACKGROUND: Multiple studies in patients with diabetes demonstrate impaired
endothelial-dependent vasodilation. But the mechanisms of vascular dysfunction
in type 2 diabetes are still controversial. Some risk factors, such as dyslipidemia,
hypertension and obesity, are commonly associated with type 2 diabetes. These
risk factor may cause endothelial dysfunction. And hyperglycemia may have a
specific role in the increased risk of vascular complications in diabetes but it
remains unclear. The purpose of this study was to examine whether endothelial
dysfunction occurs when acute hyperglycemia is induced by oral glucose
loading.
METHOD: Using the high-resolution ultrasound, we measured flow-mediated
vasodilation (endothelial dependent vasodilation: FMD) during oral glucose
tolerance test in 11 men (mean age: 59+/-5 years) with type 2 diabetes without
chronic diabetic complications. For statistical analysis, we used paired t-test,
generalized linear method (GLM) to compare FMD before and after glucose
loading.
RESULT: Flow-mediated vasodilation was diminished after glucose loading (13.2+/-
6.4%, 7.3+/-3.3*%, 12.8+/-5.6%, in fasting, at 1- and 2-h, respectively; *p<0.001 vs
fasting). Superoxide anion formation by neutrophils was increased after glucose
loading (4.65+/-2.8, 6.17+/-2.2, in fasting, at 1-h respectively: p<0.05 vs fasting)(
10-7nmol/106cells/30min). Endothelial independent vasodilation was not significantly
affected by glucose loading. The concentration of triglyceride were not changed
after glucose loading.
CONCLUSION
This study shows that acute hyperglycemia induced by 75 gm oral
glucose intake results in endothelial dysfunction. These results suggest that
prolonged and repeated hyperglycemia may play an important role in the
developement and progression of vascular complication in diabetes.