SELECTIVE ALPHA(1)-ADRENERGIC INHIBITION IMPROVES DECREASED GLUCOSE DISPOSAL IN PATIENTS WITH ESSENTIAL-HYPERTENSION

This study evaluated insulin secretion and insulin sensitivity before and after short-term oral administration of doxazosin in patients with essential hypertension. The hypertensive group consisted of 11 nonobe se subjects (aged 41.0 +/- 2.5 years (mean +/- SEM), body mass index 2 4.0 +/- 0.53 kg/m(2)). The normotensive group consisted of 12 subjects matched to the hypertensive group for age and body mass index. The hy pertensive group showed significantly higher concentrations of prestim ulated and stimulated plasma insulin and plasma C peptide than normal groups. The insulin-mediated glucose disposal rate during euglycaemic clamp (M-value) was significantly lower in the hypertensive group than in normal controls (7.32 +/- 0.56 vs 8.88 +/- 0.34 mg/kg/min, P < 0.0 5). After one month of doxazosin treatment blood pressure was signific antly reduced (P < 0.05), The short-term administration of doxazosin i mproved the M-value significantly to 8.60 +/- 0.62 mg/kg/min without a significant change in stimulated plasma C-peptide level. These data s how that hypertension is associated with increased insulin secretion a nd impaired insulin sensitivity. Selective alpha(1)-adrenergic inhibit ion with doxazosin improves the decreased glucose disposal rate associ ated with hypertension.