The study, published in Journal of the American Heart Association, the Open Access Journal of the American Heart Association/American Stroke Association, found that children from socially and economically disadvantaged families and neighborhoods appear more likely to have thicker carotid artery walls, which in adults may indicate higher risk of heart attack and stroke later on.
The carotid arteries supply blood to the brain. An ultrasound test of the arteries’ inner layers, the intima, and media may detect the early development of atherosclerosis, or “hardening of the arteries,” which underlies the development of cardiovascular disease later in life.
“We know that socioeconomically disadvantaged people are at greater risk of health problems, including more cardiovascular disease earlier in life, and we also know that atherosclerosis is a life-long process that starts in childhood,” said David P. Burgner, Ph.D., senior study author and senior research fellow at Murdoch Children’s Research Institute in Melbourne, Australia. “For this study, we wanted to determine if there is an association between socioeconomic position and the thickness of the carotid artery wall in mid-childhood.”
Researchers analyzed both family and neighborhood socioeconomic position data from 1,477 Australian families. Socioeconomic measures included income, education and the occupation of parents, as well as the relative socioeconomic status of the immediate neighborhood. Between the ages of 11 and 12, the children’s right carotid artery was imaged and maximum carotid intima-media thickness measured.
The study found that while both family and neighborhood socioeconomic position were associated with carotid artery inner layer thickness, the family association was stronger.
Also, children whose family socioeconomic position was in the bottom fourth (most disadvantaged) at age 11-12 were 46 percent more likely to have thicker carotid measurement, i.e. above the 75th percentile.
Thickness in carotid artery measurements at age 11-12 were linked to socioeconomic position as early as age 2-3 years.
Researchers said that when they considered traditional cardiovascular risk factors, including body weight, blood pressure and exposure to second-hand smoke, their findings did not change.
“It is surprising to see that these traditional risk factors do not appear responsible for our findings,” said Richard S. Liu, M.B.B.S., lead author, resident medical officer and Ph.D. student at the Murdoch Children’s Research Institute. “There’s a suggestion that there may be additional factors driving this association.”
Based on their other research studies, the authors propose that infection and inflammation may be among the additional underlying factors. Infection, which leads to inflammation, is more common among those who are socioeconomically disadvantaged, they noted.