BLOOD-PRESSURE REACTIVITY IN THE EVALUATION OF RESTING BLOOD-PRESSUREAND MOOD RESPONSES TO PINDOLOL AND PROPRANOLOL IN HYPERTENSIVE PATIENTS

Objective: The purpose of this exploratory study was to evaluate the r elationship of blood pressure reactivity during exercise to treatment responsiveness to two commonly used beta-adrenergic blocking agents, p ropranolol and pindolol.Design: Prospective, placebo-controlled, balan ced, cross-over clinical trial. Setting: University-affiliated medical center. Patients: A convenience sample of 19 white male subjects with mild to moderate essential hypertension were studied. The mean age wa s 63.4 years (SD = 5.2). The mean resting systolic blood pressure (SBP ) was 158.6 mm Hg (SD = 12.3) and mean resting diastolic blood pressur e (DBP) was 96.4 mm Hg (SD = 8.6). They had no clinical evidence of se condary hypertension, diabetes, heart, liver, pulmonary, or renal dise ase. Outcome Measures: Resting blood pressure; blood pressure reactivi ty to exercise; self-report measures of depressive symptoms, and mood disturbances. Intervention: Antihypertensive medication was tapered of f and subjects were free of all prescription drugs for 2 weeks. Subjec ts were randomly assigned to propranolol-pindolol or pindolol-proprano lol group. Each 4- to 6-week treatment phase was preceded by a 2-week placebo phase. At the end of the initial placebo phase and each active drug treatment phase, subjects were assessed for depression and mood disturbances by use of standardized measures and were given a graded e xercise test on a cycle ergometer. Resting blood pressure was assessed weekly and before each exercise test. Results: Significant relationsh ips between DBP reactivity to exercise during the placebo phase and th e degree of blood pressure and mood responsiveness to pindolol and pro pranolol treatment were observed. Subjects demonstrating high DBP reac tivity required high doses of beta-blocker for resting DBP reduction, and these subjects showed the least change in mood at high doses. Simi lar patterns were found for the relationship of SBP reactivity and blo od pressure and mood responsiveness to drug treatment, but these relat ionships were not statistically significant. Conclusions: DBP reactivi ty to exercise during the placebo phase provides unique information ab out the essential hypertensive patient. DBP reactivity and drug dose w ere important determinants of resting blood pressure and mood responsi veness to both pindolol and propranolol. DBP reactivity and perhaps SB P reactivity may be useful measures in the study of central adrenergic and peripheral cardiovascular pathophysiology.