Further evidence that cholesterol-lowering statins may have the added benefit of reducing high blood pressure has emerged from a meta-analysis by researchers from Italy and the UK.
The study, recently published in the American Heart Association journal Hypertension, found that patients on statin therapy experienced a “small but statistically significant” reduction in systolic blood pressure and a trend to reduction in diastolic blood pressure. These ancillary effects suggest that, in hypertensive patients for whom a statin is indicated (e.g., because of concomitant hypercholesterolaemia, diabetes and/or a previous myocardial infarction), the therapy may reduce the dose and volume of drugs required to achieve satisfactory blood pressure control, the authors comment.
The meta-analysis by researchers from Federico II University Medical School in Naples, St George’s, University of London in the UK, and Warwick Medical School in the UK looked at 20 randomised controlled trials of statin therapy involving 828 patients in total. Of these, 291 patients were given a statin, 272 were on placebo and 265 were enrolled in crossover trials with a statin and placebo (or, in one case, the lipid-lowering drug probucol). Some of the studies included only hypertensive patients, others involved either normotensive or treated hypertensive patients under reasonably good control, and a few recruited only normotensive patients. Some other studies were confined to, or excluded, patients with Type 1 or Type 2 diabetes.
To date, studies investigating the antihypertensive effect of statins in patients with hypertension associated with hypercholesterolaemia have been rare and relatively small, the authors noted. Nonetheless, a number of other studies not specifically directed at this end – including two recently published large statin trials – have indicated that statins may have an influence on blood pressure levels. Further insights have been hampered by inadequate trial design, small or very small sample sizes, too-short treatment periods or modification of concomitant antihypertensive therapy during the study, the researchers added. None of the large trials that demonstrated the value of statins in primary and secondary prevention of cardiovascular disease could be included in the meta-analysis, as either blood pressure (BP) levels were not reported and/or concomitant antihypertensive therapy in patients with high BP was not constant over the course of the study.
Pronounced effect in high bp patients
The analysis revealed that systolic blood pressure was significantly lower in patients on statins than in those on placebo or probucol. The effect was more pronounced when the analysis was restricted to studies with baseline systolic BP of more than 130 mm Hg. There was also a trend towards lower diastolic blood pressure in patients on statins versus those in control groups in studies with a baseline diastolic blood pressure of more than 80 mm Hg. In general, the authors pointed out, the higher the baseline blood pressure, the greater the effect of statin therapy on BP. This response was unrelated to age, changes in serum cholesterol or the length of trial.
The observed benefits of statins for blood pressure were definitely less marked than the average effect of regular antihypertensive therapy and they reached statistical significance only for systolic BP, the authors observed. Nonetheless, the statin effect was clinically relevant, “also considering that in most of the studies included … the average BP at entry was lower than that observed in most trials of antihypertensive therapy and that, in addition, in several studies the patients were already placed on regular treatment for high BP”. Clarification was needed, the researchers added, as to whether the relationship between statins and blood pressure was a class effect or was specific to one or other drugs in the class.