Insulin's microvascular vasodilatory effects are inversely related to peripheral vascular resistance in overweight,
J M Hornstra1, E H Serné, E C Eringa
1Department of Internal Medicine, VU University Medical Center, Amsterdam, The Netherlands; Institute for Cardiovascular Research of the VU University Medical Center, Amsterdam, The Netherlands.
Objective:
The mechanisms underlying obesity-related hypertension are incompletely understood. Microvascular dysfunction might play a role by increasing peripheral vascular resistance (PVR). Metabolic and microvascular effects of insulin are impaired in obesity, but how these impairments contribute to disturbed blood pressure homeostasis is unclear. Specifically, it is unknown whether local microvascular vasoactive effects of insulin play a role in determining systemic vascular resistance. The aim of this study was to investigate the association between PVR and local microvascular effects of insulin.
Design And Methods:
Thirty-seven healthy, overweight subjects (age 25-55 years, BMI 25-30 kg/m(2) ) were cross-sectionally studied. Local insulin-mediated vasodilation was measured using skin laser Doppler fluxmetry combined with transcutaneous iontophoresis of insulin. For comparison, local vasodilatory effects of acetylcholine and sodium nitroprusside were measured. PVR was calculated from mean arterial pressure and cardiac output, assessed by pulse-dye densitometry.
Results:
PVR was inversely correlated with insulin-mediated vasodilation (r = -0.50; P < 0.01). This finding was maintained after adjustment for age, sex, blood pressure, and smoking. PVR was not associated with local microvascular effects of acetylcholine.
Conclusions:
Our study in overweight subjects suggests that insulin's role in the microvasculature may contribute to blood pressure control.
Related Concept Videos
Insulin: Dosing Regimen and Adverse Effects
The basal dose constitutes about 40%-50% of the total daily dose, with the rest as premeal insulin. The mealtime insulin dose should mirror...
Oral Hypoglycemic Agents: Biguanides and Glitazones
Pharmacokinetics in Obese Patients: Drug Absorption and Distribution
Vascular Resistance
The primary determinants of vascular resistance are vessel diameter, blood viscosity, and vessel length. Among these, vessel diameter plays the most significant role due to the fourth power relationship described by...
Carbohydrate Metabolism
Starch accounts for approximately 60% of the carbohydrates consumed by humans. Since amylase enzymes cannot function in the stomach's acidic environment, starch can only be digested in the mouth and small intestine. Simple sugars are found naturally in milk and fruits in the...
Type II Diabetes II: Pathophysiology


