May 14 (HealthDay News) -- While research suggests that moderate alcohol consumption may have health benefits, heavy drinking increases blood pressure, stiffens blood vessels and causes more rigid heart muscles in men and enlarged hearts in women -- all risk factors for cardiovascular disease, a new study warns.

Men who drink more than 21 units of alcohol per week and women who drink more than 14 units of alcohol a week put themselves at serious risk for hypertensive heart disease, heart failure and stroke, the researchers found.

"These shocking findings illustrate the extreme risks that heavy drinkers are exposing themselves to -- some of which are particularly pronounced in women," lead investigator Dr. Azra Mahmud, a cardiovascular lecturer and hypertension specialist at the Trinity Centre for Health Science, St. James Hospital, Dublin, Ireland, said in a prepared statement.

"We want to make sure people aren't getting mixed messages about alcohol. The potentially fatal effects of heavy drinking may more than counteract the well-documented benefits of sensible alcohol intake," Mahmud said.

The study included 100 women and 100 men (mean age 46, all healthy) who were divided into three groups: non-drinkers, moderate drinkers (males, less than 21 units of alcohol per week; females, less than 14 units per week) and heavy drinkers (males, more than 21 units per week; females, more than 14 units per week).

The participants underwent a number of tests including ultrasound of heart to assess arterial stiffness and pulse wave velocity to measure aortic blood pressures and wave reflections in the aorta.

The results showed that heavy drinking is associated with arterial stiffening and impaired left ventricular (LV) relaxation in males, and LV structural changes, including LV enlargement (hypertrophy), in females. Of special note, women who were heavy drinkers had an enlarged heart even without high blood pressure or stiff arteries.

"The excessive consumption of alcohol causes significant arterial and ventricular stiffening and an enlarged heart; factors associated with poor cardiovascular outcomes in hypertensive populations," Mahmud said. "Trends in heavy drinking continue to rise, and it is high time to recognize the potential of an alcohol-induced epidemic of cardiovascular disease. Binge and heavy drinkers must consider their behavior and control their intake before it's too late."

The study was expected to be presented Wednesday at the American Society of Hypertension annual meeting, in New Orleans.

Cardiovascular disease (CVD) is the leading cause of death worldwide. About 17.5 million people die from CVD each year, and that toll could increase to almost 20 million by 2015.

SOURCE: American Society of Hypertension, news release, May 14, 2008