OCTOBER 01, 2006

High Blood Pressure Can Lower Fat Metabolism

According to research published in the June 2006 issue of the Journal of Nuclear Cardiology, the hearts of patients with muscle thickening (hypertrophy) due to high blood pressure (BP) have an energy metabolism that fails to use fat as energy. Researchers from Washington University explained that these hearts get less energy because of their reduced fat metabolism, which leads them to rely more heavily on carbohydrates, which produce less energy per molecule than fatty acids.

"With hypertrophy, the heart has a higher energy demand because there's more muscle to feed," the investigators explained. "With less fat metabolism, a greater reliance on carbohydrates may represent a shift to a less-efficient fuel."

The researchers studied patients who had high BP that led to hypertrophy and found that the greater the muscle mass of the hypertrophic heart the lower the ability to burn fat. A normal heart muscle alternates between using fats and carbohydrates as fuel, depending on availability. When people with a hypertrophic heart experience low blood sugar, however, their hearts cannot switch to fatty acids as normal hearts would, leaving them energy-deficient.

Low-fat Dairy Could Help Lower BP

According to a report published in the August 2006 issue of Hypertension: Journal of the American Heart Association, eating low-fat dairy products could help lower blood pressure (BP). The researchers used data from food questionnaires filled out by 4797 men and women who were participating in the National Heart, Lung, and Blood Institute's Family Heart Study. The participants had an average age of 52 years. They were enrolled in the study to help determine genetic and nongenetic causes of coronary heart disease, atherosclerosis, and cardiovascular risk factors, such as hypertension.

The researchers, led by Luc Djoussé, MD, MPh, DSc, of the Division of Aging at Brigham and Women's Hospital and Harvard Medical School, Boston, Mass, found that those who ate more dairy products had lower systolic BP. When divided into groups based on the number of servings eaten daily, those who ate the most had systolic BP readings of 2.6 mm Hg lower than those who ate the fewest. These people also had a 36% lower chance of having high BP. The greatest positive effects, however, were shown in those who ate dairy products with the lowest amount of saturated fats. In these groups, those who consumed more dairy products (with less fat) had systolic BP readings of 3.5 mm Hg lower and had a 54% lower chance of having high BP than those who ate fewer.

Hypertension Could Limit Walking Ability in Seniors

The findings of a study by researchers at Rush University Medical Center in Chicago, Ill, suggest that higher blood pressure (BP) could be linked to a decline in walking ability as patients get older. The study results were published in the August 2006 issue of the Journal of Gerontology: Medical Sciences.

Researchers studied 888 elderly Catholic clergy who are participating in the Religious Orders Study. The investigators measured the participants' BP at baseline, established the presence of vascular diseases and diabetes, assessed cognitive function, and noted medications. They assessed gait and balance throughout the study using performance-based tasks, including the time and number of steps taken to walk 8 feet, the time to sit up and down 5 times, and the ability to stand with eyes open and eyes closed.

Controlling for age and gender, the researchers found that a 10-mm Hg increase in systolic BP was associated with a greater decline in lower limb function. On average, lower limb function was reduced 28.7% faster in patients with a systolic BP of 160 mm Hg than in those with a normal systolic reading.

Exercise Encouraged to Reduce Hypertension

A US study has reinforced the benefits of exercise in seniors with mildly high blood pressure (BP). These patients should be cautious, however, because exercise tends to raise BP initially and could lead to adverse cardiac effects. Elderly patients should consult with their physicians before taking up any form of exercise.

Researchers at Johns Hopkins University School of Medicine in Baltimore, Md, performed the analysis. They studied the effects of exercise on cardiac size and left ventricular function of older men and women participating in the Senior Hypertension and Physical Exercise (SHAPE) study. The patients were randomly assigned either to participate or not to participate in supervised exercise for 1 hour a day 3 times a week.

After 6 months, those who exercised had higher peak oxygen intake on a treadmill, greater strength, and lower body fat, diastolic BP, and insulin resistance than those who did not exercise. The results of the study were published in the July 2006 edition of Heart.