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Effect of beta-blocking drugs on beta-cell function and insulin sensitivity in hypertensive non-diabetic patients . The effects of two beta-blocking drugs on endogenous insulin secretion and insulin sensitivity were investigated in a double-blind cross-over study in 13 hypertensive patients . The patients were randomly allocated to each of three 2-week treatment periods with propranolol 80 mg b.i.d. , atenolol 50 mg b.i.d . and placebo b.i.d . Endogenous insulin secretion was assessed by measuring serum insulin and C-peptide before and 6 min after iv administration of glucagon ; insulin sensitivity was determined by measuring insulin binding to erythrocytes , and as the glucose disappearance rate ( KITT ) after i.v . insulin . Fasting concentrations of serum free fatty acids ( S-FFA ) and plasma gastric inhibitory polypeptide ( P-GIP ) were also recorded during the three study periods . Both propranolol and atenolol reduced blood pressure , heart rate and S-FFA concentrations compared to placebo , and all patients showed measurable plasma concentrations of propranolol and atenolol . The results can be considered representative , therefore , of clinical beta-blockade . The two drugs did not significantly influence the fasting blood glucose level . There was an increase in fasting and glucagon-stimulated serum C-peptide concentration during propranolol therapy compared with placebo ( p = 0.037 and p = 0.030 , respectively ) , although this was not reflected by a significant change in serum insulin . Propranolol and atenolol did not significantly influence insulin binding to erythrocytes , but they clearly reduced the glucose disappearance rate KITT was compared to placebo ( p = 0.0036 and p = 0.0003 ) , respectively ) . The findings support the view that beta-blocking drugs can influence glucose metabolism by mechanisms other than inhibition of endogenous insulin secretion .
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Intervention_Pharmacological
propranolol 80 mg b.i.d.
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Intervention_Pharmacological
atenolol 50 mg b.i.d .
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Intervention_Control
and placebo b.i.d .
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Intervention_Pharmacological
propranolol
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Intervention_Pharmacological
atenolol
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Intervention_Control
placebo
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Intervention_Pharmacological
Propranolol
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Outcome_Physical
blood pressure , heart rate and S-FFA concentrations
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Outcome_Physical
clinical beta-blockade
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Outcome_Physical
fasting blood glucose level .
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Outcome_Physical
fasting and glucagon-stimulated serum C-peptide concentration
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Outcome_Physical
serum insulin
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Outcome_Physical
insulin binding to erythrocytes
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Outcome_Physical
glucose disappearance rate KITT
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Outcome_Physical
glucose metabolism
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Outcome_Physical
endogenous insulin secretion .
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Participant_Condition
hypertensive non-diabetic patients .
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Participant_Condition
13 hypertensive patients .