TUESDAY, April 18, 2006 (HealthDay News) -- Fewer years spent in school are associated with the earlier appearance of the first signs of future heart trouble, a long-term study suggests.
There was a direct relationship between level of education and the amount of coronary artery calcium found in the nearly 3,000 study participants, who were followed for 15 years.
The finding appears in the April 19 issue of the Journal of the American Medical Association.
Calcium is important because it indicates the development of artery-blocking plaque deposits that eventually cause atherosclerosis -- sometimes called hardening of the arteries -- and thus is "an indicator of the early phases of coronary disease," said lead study author Lijing L. Yan.
Many studies have shown that poorer, less-educated people have more medical problems, such as heart disease, said Yan, a research assistant professor of preventive medicine at Northwestern University's Feinberg School of Medicine. But this new study is different because it eliminated such social factors as access to medical care and the quality of care, she said.
The researchers used CT scans to measure the amount of calcium in blood vessels of the participants.
They found that individuals who never completed high school were four times more likely to have detectable calcium deposits than those who finished college and had a graduate education. And compared to study participants with a graduate degree, people with just a high school education were twice as likely to have early signs of heart disease.
The study tried to account for factors affecting the development of calcium deposits, such as blood pressure, cholesterol, obesity and physical activity, Yan said. "They do partially explain what we observed," she said, "but they are not the full story. Other factors are involved. Perhaps [study participants without a college degree] have high stress levels, perhaps there are many other factors. We really don't know."
Even when the known risk factors were taken into account, the incidence of calcium was 2.6 times higher for those with the least education compared to those with the most, the study found.
The lesson for doctors is that "they should know the educational level of their patients and be aware of this association," Yan said. "The bigger lesson at the societal level is that we should be doing better for people with low educational levels."
It's a familiar lesson, said Dr. Catarina I. Kiefe, director of the division of preventive medicine at the University of Alabama, who helped design the study.
"We have known for a long time that a person's socioeconomic status is associated with health," Kiefe said. "The more disadvantaged you are, the less healthy you are. This finding is just an extension of the general rule that the lower on the ladder you are, the worse your health."
For more on atherosclerosis, visit the American Heart Association.