weight loss and high blood pressure. from wikipedia

Wednesday October 15, 2008 (foodconsumer.org) -- More Americans now than ever live with high blood pressure and many do not know they have the condition, according to a new study published in the Nov. 2008 issue of hypertension.

The study found the incidence of high blood pressure increased from 50.3 percent to 55.5 percent between 1994 and 2004 while the rate of hypertension increased from 32.3 to 36.1 percent.

Paul D. Sorlie, Ph.D and colleagues, authors of the study, from the U.S. National Heart, Lung, and Blood Institute said the ever-increasing rate of Americans with high blood pressure may be related to the obesity epidemic and suggested that more prevention effort needs to be invested in preventing obesity.

The suggestion came in agreement with that by Mulrow CD and colleagues from Audie L Murphy Memorial Veteran Hospital, Health Sciences Center at San Antonio who published a review on the issue in the Cochrane database of systematic reviews (Online).

Mulrow et al. found that when people lost weight through dieting, they also lowered their blood pressure significantly.

It is not news that weight loss can help lower blood pressure in those who are hypertensive. Many studies linked weight loss and caloric restriction with a decreased incidence of hypertension.

According to the review authors, in 1998a meta-analysis of data from 12 protective studies including 5 randomized controlled trials found loss of 1 kg of body weight resulted in loss of 2.4 mm Hg systolic and 1.5 mm Hg diastolic blood pressure in obese hypertensive patients.

The current review involved 18 trials that met the reviewers’ criteria for them to examine the association between weight loss dieting and the change in blood pressure in patients with high blood pressure.

The analysis of data from six of the trials of 361 men and women showed that weight loss in the range of 4 to 8 percent of body weight was associated with a decrease of 3 mm Hg systolic and diastolic blood pressure in study subjects.

Data from three trials of 363 participants showed that antihypertensive medications reduced blood pressure by 6 mm HG in systolic and 5 mm Hg in diastolic blood pressure.   But people using a weight-losing diet required less intensive antihypertensive drug therapy.

The authors concluded that "Weight-reducing diets in overweight hypertensive persons can affect modest weight loss in the range of 3-9% of body weight and are probably associated with modest blood pressure decreases of roughly 3 mm Hg systolic and diastolic."

And "weight-reducing diets may decrease dosage requirements of persons taking antihypertensive medications."

High blood pressure can increase the risk for heart disease, stroke, congestive heart failure, and kidney disease later in life. The condition kills an estimated 300,000 people in the United States each year.  

An estimated 30 percent of American adults suffer hypertension with the highest rate in African Americans and the lowest rate in Mexican Americans. And about 28 percent of people have pre-hypertension.

High blood pressure is known by some as a silent killer and at least one third of the patients actually are not aware of their having the condition, according to an official document from the Centers for Disease Control and Prevention.

For many people, it is not easy to get their high blood pressure under control.   Sorlie and colleagues estimated that of those who had high blood pressure, 72 percent knew they had the condition and 61 percent received treatment, but only 35 percent had their blood pressure under control.

Editor’s note: The review was withdrawn for unknown reason.