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This Article Full Text Full Text (PDF) All Versions of this Article: 293/5/E1274    most recent 00114.2007v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Sommerfield, A. J. Articles by Frier, B. M. Search for Related Content PubMed PubMed Citation Articles by Sommerfield, A. J. Articles by Frier, B. M.

Vessel wall stiffness in type 1 diabetes and the central hemodynamic effects of acute hypoglycemia

¹Department of Diabetes, Royal Infirmary, Edinburgh; ²Department of Clinical Pharmacology, Addenbrooke's Hospital, Cambridge; and ³Department of Clinical Pharmacology, Western General Hospital, Edinburgh, United Kingdom

Submitted 20 February 2007 ; accepted in final form 21 August 2007

Objective: To examine the effects of intravenous insulin and acute hypoglycemia on arterial wall stiffness and central hemodynamic responses in adults with and without type 1 diabetes. Research Design and Methods: In 30 young male volunteers [10 nondiabetic (Group 1); 10 with type 1 diabetes, <5 yr duration (Group 2); 10 with type 1 diabetes, >15 yr duration (Group 3)], intravenous insulin was administered to provoke an acute autonomic reaction (R) to hypoglycemia. Heart rate, peripheral blood pressure, and pulse wave analysis (radial artery) were monitored. Augmentation index (AIx), a measure of arterial wall stiffness and wave reflection, and central arterial pressure were recorded. Results: At baseline, no significant differences were observed between Groups 1 and 2 in either AIx or in central arterial pressure, but in Group 3, both measures were significantly higher. All three groups exhibited similar responses to intravenous infusion of insulin and to hypoglycemia: AIx fell progressively from baseline to R, peripheral systolic blood pressure increased, and central systolic pressure decreased. Conclusion: Compared with age- and sex-matched nondiabetic controls, people who had type 1 diabetes for a long duration had increased stiffness of vessel walls. The opposing responses in peripheral and central systolic pressures during hypoglycemia may be related to the reduction in AIx, which causes diminished amplification of the systolic pressure wave. Changes in AIx are probably mediated by a direct action of insulin on arterial endothelium, or changes in heart rate. These functional changes may contribute to the increased cardiovascular morbidity that is associated with type 1 diabetes of long duration.

arterial wall stiffness; central arterial pressure; insulin