Impaired endothelium-dependent vasodilation in patients with insulin-dependent diabetes mellitus

Circulation. 1993 Dec;88(6):2510-6. doi: 10.1161/01.cir.88.6.2510.

Abstract

Background: Endothelium-dependent vasodilation is abnormal in experimental models of diabetes mellitus. We postulated that abnormalities of endothelial function are also present in patients with insulin-dependent diabetes mellitus and may contribute to the pathogenesis of vascular disease in these individuals.

Methods and results: Vascular reactivity was measured in the forearm resistance vessels of 15 patients with insulin-dependent diabetes mellitus and 16 age-matched normal subjects. No patient had hypertension or dyslipidemia. Each subject was pretreated with aspirin to inhibit endogenous production of prostanoids. Methacholine chloride (0.3 to 10 micrograms/min) was administered via the brachial artery to assess endothelium-dependent vasodilation. Sodium nitroprusside (0.3 to 10 micrograms/min) and verapamil (10 to 300 micrograms/min) were infused intra-arterially to assess endothelium-independent vasodilation; phenylephrine (0.3 to 3 micrograms/min) was administered to examine vasoconstrictor responsiveness. Forearm blood flow was determined by venous occlusion plethysmography, and dose-response curves were generated for each drug. Basal forearm blood flow in diabetic and normal subjects was comparable (2.6 +/- 0.2 versus 2.1 +/- 0.3 mL x 100 mL-1 x min-1, respectively; P = NS). The forearm vasodilative response to methacholine was less in diabetic than in normal subjects. At the highest dose of methacholine, the forearm blood flow increased 9.5 +/- 1.1 mL x 100 mL-1 x min-1 in diabetic subjects and 15.3 +/- 1.4 mL.100 mL-1 x min-1 in normal subjects (P < .01). The forearm blood flow responses to nitroprusside and verapamil and the forearm vasoconstrictor responses to phenylephrine were similar in diabetic and healthy subjects. In diabetic subjects, endothelium-dependent vasodilation correlated inversely with serum insulin concentration but not with glucose concentration, glycosylated hemoglobin, or duration of diabetes.

Conclusions: Endothelium-dependent vasodilation is abnormal in forearm resistance vessels of patients with insulin-dependent diabetes mellitus. This abnormality may be relevant to the high prevalence of vascular disease that occurs in these individuals.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Blood Flow Velocity / drug effects
  • Blood Glucose / metabolism
  • Diabetes Mellitus, Type 1 / blood
  • Diabetes Mellitus, Type 1 / physiopathology*
  • Diabetic Angiopathies / etiology
  • Endothelium, Vascular / drug effects
  • Endothelium, Vascular / physiopathology*
  • Female
  • Forearm / blood supply
  • Glycated Hemoglobin / metabolism
  • Humans
  • Insulin / blood
  • Male
  • Methacholine Chloride / pharmacology
  • Nitric Oxide / physiology
  • Nitroprusside / pharmacology
  • Phenylephrine / pharmacology
  • Vasodilation / drug effects
  • Vasodilation / physiology*
  • Verapamil / pharmacology

Substances

  • Blood Glucose
  • Glycated Hemoglobin A
  • Insulin
  • Methacholine Chloride
  • Nitroprusside
  • Phenylephrine
  • Nitric Oxide
  • Verapamil