Obese patients often have increased blood pressure, researchers report. Also, many do not experience a nighttime dip in blood pressure as occurs in normal-weight individuals, and this could lead to heart damage.

Dr. Vasilios Kotsis from the University of Mississippi Medical Center in Jackson and colleagues studied the relationship between body mass index (BMI) - a measure of weight in relation to height - and blood pressure patterns in 3216 patients who were seen at a hypertension clinic but had never been treated with blood pressure-lowering drugs.

Only 35 patients were underweight, whereas 1,057 were normal weight, 1,299 were overweight, and 825 were obese. The subjects wore a monitor to record their blood pressure over a 24-hour period.

Blood pressure increased significantly with increasing BMI, the team reports in the American Heart Association’s journal Hypertension.

“Obese individuals had increased 24-hour, daytime and nighttime blood pressure levels compared to non-obese individuals,” Kotsis commented to Reuters Health. Moreover, blood pressures during the night were more likely to be as high as during the day in overweight and obese individuals.

Obesity-induced hypertension is “one of the most significant” conditions related obesity, Kotsis noted.

“Primary care doctors must focus on obesity-induced hypertension in order to prevent future cardiovascular complications such as heart failure in their obese patients,” he said. “Body weight reduction, lifestyle modifications and antihypertensive treatment could reduce obese patients’ cardiovascular risk.”

SOURCE: Hypertension, April 2005.