Cross-classification of JNC VI blood pressure stages and risk groups in the Framingham Heart Study.

BACKGROUND The recently published Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI) includes a classification of blood pressure stages and a new risk stratification component. Patients with high-normal blood pressure or hypertension are stratified into risk group A (no associated cardiovascular disease risk factors, no target organ damage or cardiovascular disease); group B (> or =1 associated cardiovascular disease risk factor excluding diabetes, no target organ damage or cardiovascular disease); or group C (diabetes or target organ damage or cardiovascular disease). OBJECTIVE To examine the prevalence of risk groups and blood pressure stages in a community-based sample. METHODS We evaluated 4962 subjects from the Framingham Heart Study and Framingham Offspring Study examined between 1990 and 1995. We cross-classified men and women separately according to their JNC VI blood pressure stages and risk groups. RESULTS In the whole sample, 43.7% had optimal or normal blood pressure and 13.4% had high-normal blood pressure; 12.9% had stage 1 hypertension and 30.0% had stage 2 or greater hypertension or were receiving medication. As blood pressure stage increased, the proportion of subjects in group A decreased, whereas the proportion in group C increased. Among those with high-normal blood pressure or hypertension, only 2.4% (all women) were in risk group A, 59.3% were in group B, and 38.2% were in group C. In the high-normal or hypertensive group, 39.4% qualified for lifestyle modification as the initial intervention according to JNC VI recommendations, whereas 60.6% were eligible for initial drug therapy or were already receiving drug therapy. Nearly one third of high-normal subjects were in risk group C, in which early drug therapy may be needed. Among those in stage 1, only 4.0% were in group A, in which prolonged lifestyle modification is recommended. CONCLUSIONS These results provide a foundation for estimating the number of individuals with hypertension who fall into different risk groups that require different treatment approaches. With nearly 50 million individuals with hypertension in the United States, there are important implications for clinicians and policymakers if JNC VI recommendations are widely adopted in clinical practice.