Please use this identifier to cite or link to this item: http://ahro.austin.org.au/austinjspui/handle/1/13569
Title: Acute effects of blood pressure elevation on insulin clearance in normotensive healthy subjects.
Authors: O'Callaghan, Christopher J;Komersova, K;Louis, William J
Affiliation: University of Melbourne, Department of Medicine, Austin and Repatriation Medical Center, Heidelberg, Australia.
Issue Date: 1-Jan-1998
Citation: Hypertension; 31(1): 104-9
Abstract: Reduced clearance of insulin from plasma contributes to the hyperinsulinemia associated with essential hypertension (EH); however, the association between impaired insulin clearance and EH remains unexplained. Whether elevated blood pressure (BP) affects insulin clearance is unknown; therefore, we used the hyperinsulinemic euglycemic clamp to determine the effects of BP elevation on insulin clearance and sensitivity in eight healthy volunteers. Placebo infusion increased mean BP by 2.6+/-1.6 mm Hg, which was significantly less than rises produced by phenylephrine, an alpha1-adrenoceptor agonist (+11+/-1.8 mmHg, P<.05), or by angiotensin II (+13+/-1.3 mmHg, P<.01). Although beta-adrenoceptor stimulation with isoproterenol did not change mean BP (+3.6 mm Hg, P=NS), it significantly increased systolic pressure (+23+/-2.8 mm Hg versus +2.3+/-4.6 mm Hg with placebo P<.01). Insulin secretion (ie, C-peptide concentrations) was not affected by any of the treatments; however, phenylephrine significantly reduced the metabolic clearance rate of insulin (MCRinsulin) (16.6+/-1.0 mL/kg per minute with placebo versus 13.6+/-0.7 mL/kg per minute with phenylephrine, P<.01) and thereby increased plasma insulin concentrations (66+/-5.1 microU/mL with placebo versus 79+/-4.1 microU/mL with phenylephrine, P<.05). Phenylephrine also increased glucose utilization (42+/-5.8 micromol/kg per minute during placebo versus 58+/-4.8 micromol/kg per minute during phenylephrine, P<.05); however, this was proportional to the increased insulin concentrations; therefore, insulin sensitivity was unchanged. MCRinsulin and plasma insulin concentrations were not affected by angiotensin II; however, glucose utilization increased to 51+/-2.7 micromol/kg per minute (P<.01 versus placebo), indicating insulin sensitivity was increased. MCRinsulin was unaffected by isoproterenol. Thus, alpha-adrenergic stimulation but not increased BP per se is a potent regulator of insulin clearance and plasma insulin concentrations.
Internal ID Number: 9449399
URI: http://ahro.austin.org.au/austinjspui/handle/1/13569
URL: http://www.ncbi.nlm.nih.gov/pubmed/9449399
Type: Journal Article
Subjects: Adrenergic alpha-Agonists.pharmacology
Adrenergic beta-Agonists.pharmacology
Adult
Angiotensin II.pharmacology
Blood Glucose.metabolism
Blood Pressure.physiology
Double-Blind Method
Glucose Clamp Technique
Humans
Hyperinsulinism.metabolism
Insulin.administration & dosage.blood.metabolism.secretion
Isoproterenol.pharmacology
Male
Metabolic Clearance Rate.drug effects
Phenylephrine.pharmacology
Appears in Collections:Journal articles

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