Diabetic glucose instability linked with early vascular dysfunction
MedWire News: Day-to-day fluctuations in glucose levels are associated with impaired vascular structure and function in diabetes patients, Spanish researchers report.
Their findings come from a case-control study that evaluated preclinical atherosclerosis in Type 1 diabetes and its relationship with glucose profile and endothelial and inflammatory markers.
The study was undertaken by Ignacio Conget (Hospital Clínic I Universitari, Barcelona, Spain) and colleagues and is reported in the journal Diabetes & Vascular Disease Research.
Conget's team enrolled 38 patients with Type 1 diabetes and no additional cardiovascular risk factors or micro/macrovascular complications and 22 nondiabetic individuals matched for age and gender.
In diabetic patients, brachial artery flow-mediated dilatation (FMD) was significantly lower and intima-media thickness (IMT) in both femoral and carotid arteries was significantly higher compared with in controls.
Among diabetes patients, greater carotid IMT values were associated with older age, a longer duration of disease, and greater femoral IMT. Carotid IMT was not correlated with metabolic, endothelial, or inflammatory markers, however.
Most interestingly, glucose variability, calculated from the mean amplitude of glycemic excursions (MAGE), correlated negatively with FMD and positively with IMT in the carotid artery.
By contrast, persistent hyperglycemia, assessed from glycated hemoglobin values, was associated with neither IMT nor FMD.
In their discussion, the authors note that "despite the assumption that glucose variability is greater than in Type 2 diabetes," it remains controversial as to whether glucose fluctuations are an independent risk factor for complications in Type 1 diabetes.
"We report signals of preclinical atherosclerosis in subjects with Type 1 diabetes even in the absence of major cardiovascular risk factors and micro- or macrovascular disease," they conclude.
"Our findings also suggest that daily glucose instability could negatively impact vascular function and structure."
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By Joanna Lyford