Predictors of blood pressure response to the angiotensin receptor blocker candesartan in essential hypertension

Background: Response to antihypertensive drugs varies widely among individuals. Methods: We studied characteristics that might be predictive of blood pressure (BP) response in 203 African-American and 236 non-Hispanic white subjects with essential hypertension treated with candesartan, 32 mg/day for 6 weeks, after a drug-free washout period of at least 4 weeks (baseline). Measurements at enrollment, baseline, and at the end of the treatment were incorporated into linear regression models to quantify their additive contributions to predicting response. Results: Enrollment measurements predictive of a greater response were non-Hispanic white ethnicity, female gender, the interaction between ethnicity and gender, and lower body weight. Of baseline measurements, higher BP and higher plasma renin activity (PRA) made additional contributions to predicting a greater response. Of the measurements made at the end of the study, only a larger increase in PRA from baseline contributed to predicting a greater response. The combined effects of all the identified predictors accounted for 39 and 33% of the interindividual variation in systolic and diastolic BP responses, respectively (P < 0.001 for both). Conclusions: These results indicate that easily determined characteristics such as ethnicity, gender, body weight, as well as pretreatment levels of BP and PRA predict a substantial fraction of the BP response to candesartan and support the notion that characteristics associated with a poor response to diuretic therapy are associated with better responses to an angiotensin receptor blocker (ARB).