Hyperglycemia increases muscle blood flow and alters endothelial function in adolescents with type 1 diabetes.
Alterations of blood flow and endothelial function precede development of complications in type 1 diabetes. The effects of hyperglycemia on vascular function in early type 1 diabetes are poorly understood. To investigate the effect of hyperglycemia on forearm vascular resistance (FVR) and endothelial function in adolescents with type 1 diabetes, FVR was measured before and after 5 minutes of upper arm arterial occlusion using venous occlusion plethysmography in (1) fasted state, (2) euglycemic state (~90 mg/dL; using 40 mU/m(2)/min insulin infusion), and (3) hyperglycemic state (~200 mg/dL) in 11 adolescents with type 1 diabetes. Endothelial function was assessed by the change in FVR following occlusion. Seven subjects returned for a repeat study with hyperglycemia replaced by euglycemia. Preocclusion FVR decreased from euglycemia to hyperglycemia (P = 0.003). Postocclusion fall in FVR during hyperglycemia was less than during euglycemia (P = 0.002). These findings were not reproduced when hyperglycemia was replaced with a second euglycemia. These results demonstrate that acute hyperglycemia causes vasodilation and alters endothelial function in adolescents with type 1 diabetes. In addition they have implications for future studies of endothelial function in type 1 diabetes and provide insight into the etiology of macrovascular and microvascular complications of type 1 diabetes.
Department of Pediatrics, West Virginia University, Charleston, WV 25302, USA.
Amanda S
AS
Dye
Hong
H
Huang
John A
JA
Bauer
Robert P
RP
Hoffman
D000293:Adolescent; D001783:Blood Flow Velocity; D002097:C-Reactive Protein / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000473:pathology; D005260:Female; D015309:Glucose Clamp Technique; D006801:Humans; D006943:Hyperglycemia / Q000503:physiopathology*; D007328:Insulin / Q000378:metabolism; D008297:Male; D009132:Muscles / Q000378:metabolism*; D010991:Plethysmography / Q000379:methods; D012307:Risk Factors; D014664:Vasodilation / Q000502:physiology*
D007328:Insulin; D002097:C-Reactive Protein