Smoking habits and antihypertensive treatment

Five hypertension intervention trials (HDFP, MRFIT, Australian National BP Study, IPPPSH, MRC) were analyzed for the effect of smoking on antihypertensive therapy and final outcome in coronary and all-cause mortality. In addition, an observational study of primary screenees for MRFIT was reviewed. Thus, the hypertensive population evaluated in this paper amounts to 135,851 patients. HDFP revealed that smokers had about twice the mortality rates compared to nonsmokers regardless of the treatment group to which they were randomized. The annual incidence of events in the Australian Study among nonsmokers in the placebo group was even lightly lower than in smokers under active therapy. The results of the MRFIT showed that smoking had a particularly deleterious impact on those hypertensives whose cholesterol levels were elevated. In this group, the coronary death rates were 10 times higher than in nonsmokers with lower cholesterol levels. Although the treatment with beta-blockers reduced the coronary event rates in the MRC and in IPPPSH, this beneficial effect was absent in smokers. However, in trials in which diuretic treatment is effective in nonsmokers, it is equally effective in smokers.