Background: The AB/CD British Hypertension Society guidelines predict that the blood-pressure response to antihypertensive agents A (angiotensin-converting enzyme inhibitors and angiotensin receptor blockers) or B (beta blockers) drugs is better in those aged<55 years, whereas that to agents C (calcium channel blockers) or D (diuretics) agents is better in those aged>or=55 years.
Methods: We conducted a cohort study of 175 consecutive, untreated, hypertensive whites (55% men), aged 19 to 80 years and prospectively randomized to either A/B or C/D antihypertensive agents, and in whom there was no compelling reason to choose a particular drug. Blood pressure (BP) was measured using a semiautomated device (Omron 705CM, Tokyo, Japan) at baseline and 4 weeks after therapy in a single, blind fashion.
Results: There was no difference in baseline BP (mean+/-SEM, A/B, 163+/-2/97+/-1 v C/D, 163+/-2/95+/-1 mm Hg). Whereas the A/B drugs were more effective in younger than older patients, expressed as percentage of reduction (13%+/-1%/12%+/-1% v 8.5%+/-1%/7%+/-1%, P<.01), as absolute reduction, or by classification of mean+/-SEM blood pressure into stages of hypertension, the C/D drugs were no more effective than A/B drugs in those aged>55 years.
Conclusions: The arbitrary choice of age 55 years to predict the response to antihypertensive agents in a white population is not supported by our data. A prospective, multicenter study is required to underpin guideline recommendations in relation to using age as a determinant for choice of a particular antihypertensive drug in defined hypertensive populations.