Evidence That Hyperglycemia After Recovery From Hypoglycemia Worsens Endothelial Function and Increases Oxidative Stress and Inflammation in Healthy Control Subjects and Subjects With Type 1 Diabetes
- Antonio Ceriello1,2⇓,
- Anna Novials1,2,
- Emilio Ortega1,2,
- Lucia La Sala1,
- Gemma Pujadas1,
- Roberto Testa3,
- Anna Rita Bonfigli3,
- Katherine Esposito4 and
- Dario Giugliano4
- 1Department of Endocrinology, Hospital Clínic de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- 2Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Barcelona, Spain
- 3Metabolic and Nutrition Research Center on Diabetes, Italian National Research Center on Aging (INRCA)-Instituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Ancona, Italy
- 4Division of Metabolic Diseases, Center of Excellence for Cardiovascular Diseases, 2nd University of Naples (SUN), Naples, Italy
- Corresponding author: Antonio Ceriello, .
Currently there is debate on whether hypoglycemia is an independent risk factor for atherosclerosis, but little attention has been paid to the effects of recovery from hypoglycemia. In normal control individuals and in people with type 1 diabetes, recovery from a 2-h induced hypoglycemia was obtained by reaching normoglycemia or hyperglycemia for another 2 h and then maintaining normal glycemia for the following 6 h. Hyperglycemia after hypoglycemia was also repeated with the concomitant infusion of vitamin C. Recovery with normoglycemia is accompanied by a significant improvement in endothelial dysfunction, oxidative stress, and inflammation, which are affected by hypoglycemia; however, a period of hyperglycemia after hypoglycemia worsens all of these parameters, an effect that persists even after the additional 6 h of normoglycemia. This effect is partially counterbalanced when hyperglycemia after hypoglycemia is accompanied by the simultaneous infusion of vitamin C, suggesting that when hyperglycemia follows hypoglycemia, an ischemia–reperfusion-like effect is produced. This study shows that the way in which recovery from hypoglycemia takes place in people with type 1 diabetes could play an important role in favoring the appearance of endothelial dysfunction, oxidative stress, and inflammation, widely recognized cardiovascular risk factors.
- Received February 22, 2012.
- Accepted May 15, 2012.
- © 2012 by the American Diabetes Association.
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