One must consider this new information alongside the results of a recent review by Dr. Peter M. Rothwell of John Radcliffe Hospital, Oxford, England (Lancet 2010;375:938-48). This review, which strongly supports the findings reported by Dr. Sever, emphasizes the importance of BP variability as a predictor of stroke risk. Moreover, studies have shown that only dihydropyridine calcium channel blockers and thiazide diuretics minimize BP variability, and this may account for their benefits in terms of stroke reduction. This information strongly suggests that BP variability is an important predictor of stroke.
These observations should draw attention to lifestyle factors that can affect BP variability, including high salt intake, excessive periods of stress, excessive alcohol consumption, and untreated sleep apnea.
The authors are to be praised for considering this type of analysis. It reinforces the important use of ambulatory BP monitoring to help detect variability in everyday BP in individuals who have labile office pressures.
GEORGE BAKRIS, M.D., professor of medicine at the University of Chicago, was a member of the Seventh Report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) writing committee. He reported financial relationships with Abbott, GlaxoSmithKline, Novartis, Merck, Gilead, and other companies.
