THE QUESTION Does the amount of time spent sleeping affect a person's blood pressure?

THE QUESTION Does the amount of time spent sleeping affect a person's blood pressure?

THIS STUDY involved 578 middle-age adults whose blood pressure was measured periodically over five years. None were taking anti-hypertensive drugs. Their sleep was monitored twice during the study, for three days each time, using wrist sensors that recorded periods of rest and activity. People who slept the fewest hours were the most likely to have the highest blood pressure and to have developed hypertension during the five-year span. For each hour less of sleep, the risk for hypertension rose 37 percent. Men slept less than women, blacks less than whites.

WHO MAY BE AFFECTED? People of middle age. Nearly a third of all adults in the United States have high blood pressure, with the likelihood increasing with age. Rates also are higher among blacks.

CAVEATS The study did not determine whether getting more sleep would reduce a person's blood pressure. Some participants may have had sleep apnea, the breathing disorder that disrupts sleep and is considered a risk factor for hypertension, because the sensors used to monitor sleep did not detect the condition. The authors theorized that "the well-documented higher (blood pressure) in African Americans and men might be partly related to sleep duration."

FIND THIS STUDY June 8 issue of Archives of Internal Medicine.

LEARN MORE ABOUT hypertension at www.nhlbi.nih.gov/health and www.americanheart.org (click on "Diseases and Conditions").

— The Washington Post