ACE inhibition versus angiotensin type 1 receptor antagonism: differential effects on PAI-1 over time.
ACE inhibition reduces plasminogen activator inhibitor-1 (PAI-1), a risk factor for myocardial infarction, whereas the effect of angiotensin receptor antagonism on PAI-1 is uncertain. The present study compares the time course of effects of ACE inhibition and angiotensin type 1 (AT1) receptor antagonism on morning plasma PAI-1 antigen. Blood pressure and endocrine, metabolic, and fibrinolytic variables were measured in 20 insulin-resistant (defined by fasting glucose >8.3 mmol/L, body mass index >28 kg/m2, or fasting serum triglyceride > or =2.8 mmol/L) hypertensive subjects (mean age, 47.9+/-2.1 years) (1) before and after 1 week of hydrochlorothiazide 12.5 mg/d, and (2) before and 1, 3, 4, and 6 weeks after addition of ramipril (escalated to 10 mg/d) or losartan (escalated to 100 mg/d). Hydrochlorothiazide decreased systolic (P=0.011) and diastolic (P=0.019) pressure. Ramipril (from 133.6+/-5.1/94.5+/-2.4 to 127.0+/-3.1/91.4+/-3.3 mm Hg) or losartan (from 137.0+/-3.9/93.1+/-2.9 to 123.7+/-2.6/86.4+/-2.1 mm Hg) further reduced systolic (P=0.009) and diastolic (P=0.037) pressure. The pressure effects of the 2 drugs were similar. Hydrochlorothiazide increased plasma PAI-1 (P=0.013) but not tissue-type plasminogen activator (tPA) (P=0.431) antigen. Addition of either ramipril or losartan significantly decreased plasma PAI-1 antigen (P=0.046). However, the effect of losartan on PAI-1 antigen was not sustained throughout the 6-week treatment period, such that there was a significant drugxtime interaction (P=0.043). tPA antigen decreased during either ramipril or losartan (P=0.032), but tPA activity decreased only during losartan (P=0.018). Short-term interruption of the renin-angiotensin-aldosterone system by either ACE inhibition or AT1 receptor antagonism decreases PAI-1 antigen, but the duration of this effect is greater for ACE inhibition than for AT1 receptor antagonism.
Brown
Nancy J
NJ
Division of Clinical Pharmacology, Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232-6602, USA. nancy.brown@mcmail.vanderbilt.edu
Kumar
Sandeep
S
Painter
Corrie A
CA
Vaughan
Douglas E
DE
D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001786:Blood Glucose / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D004232:Diuretics; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D006852:Hydrochlorothiazide / Q000627:therapeutic use; D006973:Hypertension / Q000097:blood / Q000188:drug therapy*; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology; D019808:Losartan / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood*; D017257:Ramipril / Q000627:therapeutic use; D044140:Receptor, Angiotensin, Type 1; D012084:Renin-Angiotensin System / Q000187:drug effects; D049993:Sodium Chloride Symporter Inhibitors / Q000627:therapeutic use; D010959:Tissue Plasminogen Activator / Q000097:blood; D016896:Treatment Outcome
D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D001786:Blood Glucose; D004232:Diuretics; D007328:Insulin; D017395:Plasminogen Activator Inhibitor 1; D044140:Receptor, Angiotensin, Type 1; D049993:Sodium Chloride Symporter Inhibitors; D006852:Hydrochlorothiazide; D010959:Tissue Plasminogen Activator; D019808:Losartan; D017257:Ramipril