Application of prazosin is associated with an increase of insulin sensitivity in obese patients with hypertension

Abstract
The aim of this study was to determine whether insulin sensitivity measured by the euglycaemic insulin clamp technique is lower in patients with primary hypertension than in matched healthy control subjects, and whether this sensitivity was affected after 12 weeks of antihypertensive treatment with the alpha 1-adrenoceptor blocking drug prazosin. Twelve moderately obese normoglycaemic patients (four men), with hypertension not previously treated with pharmacological agents and diastolic blood pressure above 100 mm Hg, and 12 healthy matched control subjects participated. Supine blood pressure decreased 12/5 mmHg (pp=0.001) during prazosin treatment (mean dosage 5.3±1.6 mg/day (SD)). During euglycaemic insulin clamp studies the control subjects showed a higher mean glucose uptake than the untreated hypertensive patients (7.5±1.0 and 5.8±1.9 mg·kg b.w.−1·min−1, respectively, pp=0.21). During prazosin treatment, however, the disappearance rate of glucose decreased during the intravenous glucose tolerance test (from 1.7±0.9 to 1.3±0.6, pppp<0.01). This study shows that treatment of moderately obese hypertensive patients with prazosin is associated with an increase of the insulin-mediated glucose disposal and a decrease of the insulin response to an intravenous glucose load.