Impact of alpha- versus beta-blockers on hypertensive target organ damage: results of a double-blind, randomized, controlled clinical trial.
In hypertensive disease, the extent of target organ damage determines the prognosis. We conducted a 6-month, double-blind randomized study to compare the effects of an alpha1-adrenoreceptor blocker (bunazosin) with those of a beta1-adrenoreceptor blocker (metoprolol) on early hypertensive target organ damage at a similar level of blood pressure reduction. The study consisted of 43 patients (29 men and 14 women) of varying ages (mean age 52 +/- 9 years) with essential hypertension World Health Organization stage I-II. Both the alpha- and the beta-blocker lowered blood pressure to a similar extent measured by 24-h blood pressure monitoring. The left ventricular mass was comparably reduced in both cohorts (alpha-blocker 284 +/- 80 v 259 +/- 67 g, P < .05, beta-blocker 282 +/- 74 v 254 +/- 70 g, P < .05). Treatment with the alpha-blocker led to reduced total peripheral resistance (22.9 +/- 8.0 v 19.9 +/- 5.3 U, P < .05), whereas therapy with the beta-blocker resulted in an elevated total peripheral resistance (25.5 +/- 8.4 v 28.5 +/- 9.3 U, P < .10; P < .05 for the difference in both groups). Renal plasma flow remained constant in the alpha-blocker treated group but decreased in the beta-blocker treated group (508 +/- 141 v 477 +/- 134 mL/min/1.73 m2, P < .05). Glomerular filtration rate as measured by inulin clearance tended to increase after treatment with the alpha-blocker (112 +/- 20 v 115 +/- 18 mL/min/1.73 m2, P < .10) in accordance with a decrease of serum creatinine (1.00 +/- 0.14 v 0.93 +/- 0.12 mg/dL, P < .001). Plasma cholesterol and LDL cholesterol was lowered after treatment with the alpha-blocker (238 +/- 48 v 312 +/- 37 mg/dL; P < .001, and 153 +/- 32 v 130 +/- 25 mg/dL; P < .05) while remaining unchanged in group treated with the beta-blocker. Left ventricular hypertrophy was similarily reduced with alpha- and with beta-blockade at a comparable reduction of 24-h blood pressure. Alpha-blockers effected a more favorable renal and systemic hemodynamic profile than beta-blockers, but only long-term prospective studies will answer the question whether these hemodynamic effects result into a better cardiovascular prognosis.
Schmieder
R E
RE
Department of Medicine IV/Nephrology, University Erlangen-Nürnberg, Nürnberg, Germany.
Langenfeld
M R
MR
Gatzka
C D
CD
Weidinger
G
G
Schobel
H P
HP
D000317:Adrenergic alpha-Antagonists / Q000627:therapeutic use*; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D015331:Cohort Studies; D004311:Double-Blind Method; D004452:Echocardiography; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000503:physiopathology; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D011507:Proteinuria / Q000652:urine; D012079:Renal Circulation
D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D008055:Lipids