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The influence of antihypertensive therapy on the structural arteriolar changes in essential hypertension: different effects of enalapril and hydrochlorothiazide
Author(s) -
DAHLÖF B.,
HANSSON L.
Publication year - 1993
Publication title -
journal of internal medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.625
H-Index - 160
eISSN - 1365-2796
pISSN - 0954-6820
DOI - 10.1111/j.1365-2796.1993.tb00743.x
Subject(s) - enalapril , hydrochlorothiazide , medicine , blood pressure , essential hypertension , vascular resistance , cardiology , diuretic , hemodynamics , angiotensin converting enzyme
. Objectives . To assess the peripheral and central haemodynamics, in particular the effect on minimal resistance in the hand, with an ACE inhibitor in comparison with a diuretic. Design . Double‐blind randomized parallel group study. Subjects . Twenty‐eight previously untreated men with essential hypertension (supine diastolic blood pressure > 95 mmHg repeatedly on placebo). Methods/intervention . Casual and intra‐arterial blood pressure, dye‐dilution technique, water plethysmography at rest and at ischaemia, enalapril ( n = 14), hydrochlorothiazide ( n = 14). Results . After 6 months the mean arterial pressure was reduced from 112.7 to 96.9 mmHg (change –15.9 mmHg; 95% confidence interval (CI) –21.9, –9.8) on enalapril and from 110.1 to 101.5 mmHg (change –8.6 mmHg; CI –14.4, –2.8). Heart rate did not change on any of the therapies. Enalapril reduced blood pressure mainly through a reduction in total peripheral resistance (Δ –3.0 PRU 100 ; CI –5.6, –0.4) while hydrochlorothiazide reduced blood pressure mainly through a reduction in cardiac output (Δ –0.8 l/min −1 CI –1.5, –0.07). Minimal vascular resistance (mean of right and left hand) displayed a significant time × treatment interaction indicating a different trend with enalapril than hydrochlorothiazide with a change of –0.12 PRU 100 (CI –0.33, 0.05) on enalapril and a change of 0.14 (CI –0.29, 0.56) on hydrochlorothiazide. The resistance level after 6 months was significantly higher on hydrochlorothiazide than on enalapril ( P = 0.0105). Conclusion . Enalapril reduced blood pressure through vasodilatation and hydrochlorothiazide through decreased cardiac output. The two therapies also affected minimal vascular resistance (an indirect measure of vascular wall thickness) differently; with enalapril showing a favourable response in contrast to hydrochlorothiazide.