Insulin therapy improves endothelial function in type 2 diabetes.
A total of 75 in vivo endothelial function tests (intrabrachial artery infusions of endothelium-dependent [acetylcholine] and -independent [sodium nitroprusside] vasoactive agents) were performed in 18 type 2 diabetic patients (aged 58+/-2 years, body mass index 28.5+/-0.6 kg/m(2), and fasting plasma glucose 229+/-11 mg/dL) and 27 matched normal subjects. These tests were performed before and 6 months after combination therapy with insulin and metformin and before and 6 months after metformin therapy only. Before insulin therapy, blood flow responses to acetylcholine (15 microg/min) were significantly blunted in type 2 diabetic patients (7.5+/-0.7 mL x dL(-1) x min(-1)) compared with normal subjects (11.6+/-0.9 mL x dL(-1) x min(-1), P<0.01). During insulin therapy, the acetylcholine response increased by 44% to 10.8+/-1.6 mL x dL(-1) x min(-1) (P<0.05). Insulin therapy also significantly increased the blood flow responses to both low and high doses of sodium nitroprusside. We conclude that insulin therapy improves endothelium-dependent and -independent vasodilatation. These data support the idea that insulin therapy has beneficial rather than harmful effects on vascular function.
Vehkavaara
S
S
Department of Medicine, Division of Endocrinology and Diabetology, Helsinki, Finland.
Mäkimattila
S
S
Schlenzka
A
A
Vakkilainen
J
J
Westerbacka
J
J
Yki-Järvinen
H
H
D001786:Blood Glucose / Q000032:analysis; D001794:Blood Pressure; D001823:Body Composition; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology*; D004359:Drug Therapy, Combination; D004730:Endothelium, Vascular / Q000187:drug effects / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007328:Insulin / Q000627:therapeutic use*; D008055:Lipids / Q000097:blood; D008297:Male; D008687:Metformin / Q000627:therapeutic use; D008875:Middle Aged
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin; D008055:Lipids; D008687:Metformin