Are you a "dipper" or "nondipper?” A recent study suggests that men with "nondipping” nighttime blood pressure are at greater risk for heart failure even when their daytime blood pressure was taken into account.

If you’ve had high blood pressure for many years, it can take a major toll on your health. It can damage both large and small arteries, leading to strokes as well as diseases of the heart, kidneys, and eyes. Fortunately, by controlling your blood pressure, you can help prevent or slow the progression of many of these complications.

Now a study reported in the Journal of the American Medical Association (Volume 295, page 2859 ) suggests that blood pressure that fails to take the normal overnight dip may be a sign that your heart is in trouble. Researchers found that in 951 elderly Swedish men, those whose blood pressure remained relatively high at night were more than twice as likely to develop heart failure.

In heart failure, the heart cannot pump blood well enough to meet the body’s needs, leading to symptoms like fatigue and breathlessness. High blood pressure is one of the most important risk factors for heart failure, but no studies had examined whether changes in blood pressure over 24 hours -- measured with a portable ambulatory blood pressure monitor -- could help predict the disease.

The new study suggests that when blood pressure fails to take the dip normally seen during sleep, the added stress on the heart and blood vessels may lead to heart failure. Men with "nondipping” nighttime blood pressure were at greater risk for heart failure even when their daytime blood pressure was taken into account. It’s too soon, however, to start strapping portable blood pressure monitors onto everyone. More studies are needed to see how important nighttime blood pressure is in predicting heart health.