Effect of HMG-CoA reductase inhibitors on blood pressure in hypertensive patients treated with blood pressure-lowering agents: retrospective study using an anti-hypertensive drug database

1 S. Hashimoto, 1,2 H. Urushihara, 2 S. Hinotsu, 1 S. Kosugi, 2 K. Kawakami

1. Clinical Research Coordinator Course, Graduate School of Medicine and Public Health, Kyoto University, Kyoto (Japan)

2. Department of Pharmacoepidemiology, Graduate School of Medicine and Public Health, Kyoto University, Kyoto (Japan)

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• Cardiology

Background and Objectives: We used a Japanese antihypertensive drug database to investigate the blood pressure-lowering effect of statins in hypertensive patients receiving antihypertensive medication. We also examined the class effect of antihypertensive drugs on blood pressure lowering by statins.

Material and Methods: The Risk/Benefit Assessment of Drugs-Analysis and Response (RAD-AR) Council has developed an antihypertensive drug database which contains the results of post-marketing surveillance for various antihypertensive agents from 143,509 antihypertensive users in clinical settings. Antihypertensive patients in the database with concurrent hyperlipidemia were grouped into statin users and non-users, and changes in systolic and diastolic blood pressure over a three-month period were compared. Further, the class effects of antihypertensive drugs on the lipid lowering effects of statins were also investigated.

Results: A total of 1,070 statin users and 1,974 non-users were analyzed. Changes in systolic blood pressure were significantly greater in the statin user than in the non-user group (mean difference: 1.63 mmHg, p = 0.03). In contrast, no significant effect of statin use was observed on the change in diastolic blood pressure (DBP) (0.87 mmHg, p = 0.08). When stratified by antihypertensive class, reductions in blood pressure were greater in statin user groups for all antihypertensive classes without statistical significance, except for a significant change in DBP in those receiving beta-blockers (mean difference: 2.98 mmHg, p = 0.03).

Discussion: The present study documented that statin’s effect on blood pressure in hypertensive patients with hyperlipidemia in clinical setting is statistically significant but has a minimal significance. With regard to class differences among antihypertensive agents, the decrease was greatest in the DBP of patients treated with beta-blockers. In contrast, no significant changes were seen in the ACE inhibitor or Ca antagonist subgroups. One possible explanation for the differential effects of antihypertensive class in our study might be the lack of a vasodilatation effect.

Corresponding Author: Koji Kawakami, MD; e-mail: kawakami.koji.4e@kyoto-u.ac.jp