The effect of aspirin on blood pressure in untreated hypertensive
patients and antihypertensive patients: a meta-analysis
Abstract
Aspirin is essential in the primary and secondary prevention of
hypertension. However, the effect of aspirin on blood pressure (bp) in
hypertensive patients has been controversial. Therefore, we
quantitatively evaluated the effect of aspirin on the bp in untreated
hypertensive patients and antihypertensive patients. We searched the
PubMed, Embase and Cochrane library electronic databases for articles
published prior to June 2019. The overall effect of aspirin on changes
in systolic and diastolic bp was estimated by using random-effects
models according to the I2 statistic. A total of 15 randomized
controlled trials (including 27 studies) met the criteria and were
included in the review. For untreated patients with mild hypertension,
taking aspirin significantly reduced systolic bp by 1.83 mm Hg (95% CI:
-3.15~-0.5, P =0.007) and diastolic bp by 1.32 mm Hg
(95% CI: -2.82~0.19, P =0.09). Other subgroup analyses
suggest different effects on bp with different aspirin doses, duration
and time of administration. Compared with taking aspirin in the morning,
taking aspirin before bedtime significantly reduced systolic bp by 2.97
mm Hg (95% CI: -3.78~ -2.17, P <0.00001) and
decreased diastolic bp by 2.16 mm Hg (95% CI: -2.87~
-1.44, P <0.00001). However, for patients on antihypertensive
therapy, taking aspirin has no significant effect on bp and did not
interfere with the antihypertensive drug treatment. Overall, for
untreated hypertensive patients, aspirin can reduce bp, and may have a
time-dependent effect. However, aspirin was not found to have an effect
on bp in antihypertensive patients.