Exercise, Hypertension, and Left Ventricular Mass

To the Editor.—  The study by Kelemen et al¹ showing that exercise is equivalent to exercise plus drug therapy with either propranolol or diltiazem in controlling hypertension is interesting and important.Left ventricular mass increased in all three study groups without a change in diastolic function. This finding begs the question of whether there is a "good" increase in left ventricular mass that results from exercise and a "bad" increase in left ventricular mass that results from hypertension untreated. One might argue that a desired result of treatment of hypertension is prevention of an increase in left ventricular mass or reduction in left ventricular mass if it has already increased.Because the study period lasted only 10 weeks, I question whether the conclusion that exercise had no deleterious effects is valid for longer periods. Studies to evaluate the efficacy of longer trials of exercise for control of high blood