CHICAGO (AP) - Younger men should be just as concerned about high blood pressure as middle-aged and older men because it puts them at significant risk of dying from cardiovascular diseases such as heart attacks and strokes later in life, a study found.

The findings suggest that prevention should begin in childhood, said Dr. Martha Daviglus, one of the study's authors and a professor at the Northwestern University Medical School.

The study, in Monday's issue of the Archives of Internal Medicine, is significant because most previous research focused on middle-aged and older men and most screening and treatment guidelines have been based on those findings, Daviglus said.

The study, based on data collected on 10,874 Chicago men ages 18-39 who were studied from 1967 to '73 and then followed for an average of 25 years, is the most comprehensive yet on the long-term effects of high blood pressure in young men, said Daviglus, of the university's Department of Preventive Medicine.

Almost 62 percent of those studied had high-normal blood pressure or stage 1 hypertension. High-normal is a reading of 130-139 (systolic pressure) over 85-89 (diastolic pressure) and stage 1 hypertension is 140-159 over 90-99, Daviglus said. Optimal blood pressure is below 120 over 80 and normal is 120-129 over 80-85, she said.

After 25 years, 197 of the men had died of coronary heart disease, 257 of cardiovascular disease and 759 of all causes - some of which might also be attributed to high blood pressure because other diseases, such as renal and kidney diseases, are affected by high blood pressure, Daviglus said.

Life expectancy was shortened by 2.2 years for men with high-normal blood pressure and by 4.1 years for those with stage 1 hypertension.

Men with high-normal blood pressure had a 34 percent higher risk of dying from coronary heart disease, and those with stage 1 hypertension had a 50 percent higher risk of dying of coronary heart disease, Daviglus said.

"When you're young, you never believe you're going to have heart disease," she said. "But if we educate young people and show them the data - that yes, this is really going to affect you - they may change their lifestyle." She said many doctors do not prescribe medication to treat high blood pressure in young men because of concerns about potential side effects of long-term drug use. But she said the study may indicate that some men need to begin medication earlier. Also, young men should be screened for blood pressure and doctors should stress lifestyle changes early, she said.

The finding that many young men had elevated blood pressure shows that prevention should begin in childhood by encouraging diets with more fruits and vegetables and less salt, and more exercise, she said.

Dr. David A. Meyerson, a Johns Hopkins cardiologist and spokesman for the American Heart Association who was not involved in the research, said the study provided important proof about the need for early prevention.

"The study affirms our strongly held belief that a population-wide effort for health promotion and disease prevention by lifestyle modification should begin early in life and be continued lifelong," said Meyerson. "Lifestyle modification for most is painless and, if started early, can dramatically reduce disease in the future."

Copyright 2001 The Associated Press. All rights reserved.