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The terminology for high blood pressure is changing, as reflected in the table below and in the information on these pages. In short, the term "hypertension" corresponds to the clinical condition that requires drug therapy. Previously, "high blood pressure" and "hypertension" meant the same thing. Today, however, it is widely accepted than blood pressures greater than 120/80 mm Hg (or 115/75 mm Hg, according to a stricter standard defined by the World Health Organization) are problematic--these are now "high blood pressure" or "non-optimal blood pressures." Because the risk of caridiovascular disease doubles with each increment of 20/10 mm Hg above 115/75 mm Hg, and the strength of this relationship is consistent above and below the threshold for drug therapy, a recent report from the World Health Organization Global Burden of Disease Study concluded that

...interventions only targeting specific subgroups, such as those with a blood pressure over a certain threshold level, will only partially address the disease burden. Cardiovascular prevention strategies should include a component that attempts to lower risk factors such as blood pressure across the whole population. Even small changes,if experienced across an entire population, have the potential to result in remarkably large benefits, particularly if they are complemented by strategies that aim to focus on identifying and treating individuals at the highest absolute risk of disease [Lawes 2006].

Approximately 21% of the adults in San Francisco have been diagnosed with hypertension, according to the California Health Interview Survey [CHIS]. Among African American San Franciscans the prevalence is approximately 50%. Although this picture reflects national trends, it is at variance from our national health objective for 2010 of reducing the proportion of adults with adults to 16% [MMWR 2005].

Between 1991 and 2001, the prevalence of hypertension increased by approximately 3% in the United States [MMWR 2004]. The higher one's blood pressure the greater the chance of heart attack, heart failure, stroke, and kidney disease. Hypertension is a major contributor to cardiovascular disease.

The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JCN 7) classifies blood pressures as follows:

BP Classification Systolic mmHg Diastolic mmHg Lifestyle Modification Drug Therapy (see the most recent expert guidelines)
Normal <120 and <80 Encourage No
Prehypertension 120-139 or 80-89 Yes No, unless compelling indications
Stage 1 Hypertension 140-159 or 90-99 Yes Yes
Stage 2 Hypertension ≥160 or ≥100 Yes Yes

From a public health perspective [Rose 2001], the "blood pressure problem" is much greater than the large number of "hypertension cases." Beginning at 115/75 mm Hg, the risk of cardiovascular disease doubles with each increment of 20/10 mmHg. Worldwide, non-optimal blood pressures (systolic pressures above 115 mm Hg) account for 65% of stroke, 49% of ischemic heart disease, and 14% of other cardiovascular disease (including hypertensive heart disease and hypertensive kidney disease) [Lawes 2006].

A considerable burden comes from non-optimal blood pressures that are below the arbitrary cut-off point for drug therapy. In a prospective cohort analysis of 8,960 adults with "prehypertension" (defined in above table), the relative risk of cardiovascular disease was 2.33 for systolic pressures 130-139 mm Hg and 1.81 for systolic pressures 120-29 mm Hg. At these blood pressures, the relative risks were much higher for diabetics and for blacks [Kshirsagar 2006].

Lowering the blood pressures of the entire population, even by small amounts, holds the potential for large benefits [Rose 2001; Lawes 2006].

High Blood Pressure

Overview

Contribution to overall disease burden in SF

Downstream (Health Consequences)

Upstream (Causes)

What can be done?

Web resources

MEDLINE strategies

Updated March 8, 2010 • Please send feedback to:
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