Oral glucose loading attenuates endothelial function in normal individual

Abstract

Background: We evaluated the relationship between glucose fluctuation and vascular endothelial function.

Material and methods: We recruited 25 healthy individuals with no family history of diabetes (14 subjects and 11 controls). Brachial artery flow-mediated dilation (FMD) and elapsed time when the after-hyperaemia maximum brachial artery diameter is reached; the peak times (PT) of each study subject were measured before and at 60, 120, and 180 min after 75-g oral glucose loading. FMD and PT of controls were measured for four consecutive hours in the fasting state from morning. Also, brachial-ankle pulse wave velocity (baPWV) of each subject was measured at 180 min after 75-g oral glucose loading.

Results: Flow-mediated dilation of the study subjects was significantly lower at 60, 120 and 180 min than at pre-load, and significantly lower than that of the controls at 60 and 120 min, but not significantly different at 0 and 180 min. There was no significant difference between the PT of the subjects and the controls during 75-g oral glucose loading. In contrast, the PT of the subjects was significantly shorter than that of the controls at 120 and 180 min, but showed no significant difference at 0 and 60 min. Moreover, baPWV had no significant relationship with FMD.

Conclusions: Our study showed that oral glucose loading attenuates FMD and shortens elapsed time at the maximum after-hyperaemia diameter, and the effect of glucose fluctuation on atherosclerosis in individuals with normal glucose tolerance remains despite only the attenuation of endothelial function.