June 24, 2000 — While heart disease is still primarily thought of as a condition of middle and later years, younger people may be at a higher risk than previously thought. According to a new study, heart disease is becoming more common among American teen-agers and young adults as smoking and junk foods become more of an everyday occurrence in their lives.
It is now clearly established that all young adults over the age of 20 should have their cholesterol checked every five years by a doctor, lead author Henry C. McGill, Jr., MD, tells WebMD. “This procedure would pick up many more of the young persons at very high risk of heart disease 20 to 30 years later, and would give them a chance to change their lifestyles or, if required, use cholesterol-lowering drugs in time to reduce their risk greatly.” McGill is with the department of pathology and medicine at the Southwest Foundation for Biomedical Research in San Antonio.
“This suggests that we should be teaching our younger generations about heart disease risk factors at a much earlier age and not be waiting until they hit middle age when it already may be too late,” Robert Kloner, MD, who was not involved in the study, tells WebMD. He is research director of the Heart Institute at Good Samaritan Hospital in Los Angeles and professor of medicine at the University of Southern California.
The investigators examined young people aged 15 to 34 who had died in a car accident, homicide, or suicide and found that even in men as young as 15, over 2% of them had advanced cholesterol plaques in the arteries of their heart. More than 20% of men aged 30 to 34 had these advanced plaques. Such plaques can turn into atherosclerosis, or hardening of the arteries. That can lead to complete blockages, heart attacks, and strokes.
While there were no significant racial differences, there was a gender disparity. No advanced plaques were found in 15- to 19-year-old women, and they were present in less than 8% of the women aged 30 to 34.
The prevalence of actual blockages in the heart also increased with age and was seen in more than 3% of men 15 to 19 years old and in close to 19% of men in the 30 to 34 year old group. Blockages were not seen in women under the age of 25, and even among the older women, they had much fewer blockages compared to the men.
Kloner is not surprised by the high incidence of plaques in young adults. “When you turn on TV at any time you will see at least four to five ads per hour for junk food,” he says.
He also points out that smoking remains a popular pastime among young people. “At LA County Hospital, I not infrequently see young people in their 20s or early 30s who’ve experienced large [heart attacks], and some go on to bypass surgery. The most common risk factor in these patients is smoking, and obesity and cholesterol abnormalities are also very common.”
McGill agrees that the environment or lifestyle is the major factor in the high incidence of heart disease in young adults living in industrialized countries. “There is a genetic component in all these risk factors — some persons, including children, are more susceptible to high blood cholesterol, obesity, and so on,” he says. “However, there probably has not been a change in the genetic basis of these conditions for hundreds of years. Undoubtedly, the alarming epidemic of obesity in U.S. children and adults is an example of the effect of recent changes in lifestyle — abundant, tasty, calorie-rich food combined with reduced physical activity.”
The researchers did find that specific risk factors were seen more commonly among young people with more advanced heart disease. Young people with high LDL “bad” cholesterol, a low HDL “good” cholesterol, or high blood pressure were more likely to have more severe cholesterol plaques in the heart. Overweight individuals, regardless of their age, also showed more of these plaques.
“The most important message of this study,” says McGill, “is that prevention of adult heart attacks must begin in childhood. But whether physicians should measure blood cholesterol in children under 20 years is a more difficult question to answer. Eventually, in an ideal health care system, it may be feasible to measure blood cholesterol in all children or adolescents.”