In a case-control study, atherosclerotic risk factors were uncommon in childhood and did not appear to be associated with the pathogenesis of arterial ischemic stroke in children or in early young adulthood.
But by the fourth and fifth decades of life, these risk factors were strongly associated with a significant risk for stroke, heightening that risk almost tenfold.
“While strokes in childhood and very early adulthood are not likely caused by atherosclerotic risk factors, it does look like these risk factors increase throughout early and young adulthood and become significant risk factors for stroke in the 30s and 40s,” lead author Sharon N. Poisson, MD, MAS, associate professor of neurology at the University of Colorado, Aurora, Colorado, told theheart.org | Medscape Cardiology.
The findings were published online August 1 in JAMA Neurology.
In this study, the researchers focused on arterial ischemic stroke, not hemorrhagic stroke. “We know that high blood pressure, diabetes, smoking, obesity, all of these are risk factors for ischemic stroke, but what we didn’t know is at what age do those atherosclerotic risk factors actually start to cause stroke,” Poisson said.
To find out more, she and her team did a case control study of data in the Kaiser Permanente Northern California system, which had been accumulating relevant data over a period of 14 years, from January 1, 2000, through December 31, 2014.
The analysis included 141 children and 455 young adults with arterial ischemic stroke and 1382 age-matched controls.
The children were divided into two age categories: ages 29 days to 9 years and ages 10-19 years.
In the younger group, there were 69 cases of arterial ischemic stroke. In the older age group, there were 72 cases.
Young adults were divided into three age categories: 20-29 years (n = 71 cases), 30-39 years (144 cases), and 40-49 years (240 cases).
Among pediatric controls, 168 children aged 29 days to 9 years (46.5%) and 196 children aged 10-19 years (53.8%) developed arterial ischemic stroke.
There were 121 cases of ischemic stroke among young adult controls who were in the 20-29–years age group, 298 cases among controls in the 30-39–years age group, and 599 cases in the 40-49–years age group.
Both childhood cases and controls had a low prevalence of documented diagnoses of atherosclerotic risk factors (ARFs). The odds ratio (OR) of having any ARFs on arterial ischemic stroke was 1.87 for ages 0-9 years, and 1.00 for ages 10-19.
However, cases rose with age.
The OR was 2.3 for age range 20-29 years, 3.57 for age range 30-39 years, and 4.91 for age range 40-49 years.
The analysis also showed that the OR associated with multiple ARFs was 5.29 for age range 0-9 years, 2.75 for age range 10-19 years, 7.33 for age range 20-29 years, 9.86 for age range 30-39 years, and 9.35 for age range 40-49 years.
Multiple risk factors were rare in children but became more prevalent with each decade of young adult life.
The presumed cause of arterial ischemic stroke was atherosclerosis. Evidence of atherosclerosis was present in 1.4% of the 10-19–years age group, 8.5% of the 20-29–years age group, 21.5% of the 30-39–years age group, and 42.5% of the 40-49–years age group.
“This study tells us that, while stroke in adolescence and very early adulthood may not be caused by atherosclerotic risk factors, starting to accumulate those risk factors early in life clearly increases the risk of stroke in the 30s and 40s. I hope we can get this message across, because the sooner we can treat the risk factors, the better the outcome,” Poisson said.
Prevention Starts in Childhood
Prevention of cardiovascular disease begins in childhood, which is a paradigm shift from the way cardiovascular disease was thought of a couple of decades ago, noted pediatric cardiologist Guilherme Baptista de Faia, MD, from the Ann & Robert H. Lurie Children’s Hospital in Chicago, Illinois.
“Our guidelines for risk factor reduction in children aim to address how or when do we screen for these risk factors, how or when do we intervene, and do these interventions impact cardiovascular outcomes later in life? This article is part of the mounting research that aims to understand the relationship between childhood cardiovascular risk factors and early cardiovascular disease,” Baptista de Faia said.
“There has been an interesting progression in our understanding of the impact of CV risk factors early in life. Large cohorts such as Bogalusa Heart Study, Risk in Young Finns Study, Muscatine Study, the Childhood Determinants of Adult Health, CARDIA, and the International Childhood Cardiovascular Cohorts (i3C) have been instrumental in evaluating this question,” he said.
The knowledge that atherosclerotic risk factors in children can lead to acceleration of atherosclerosis in later life opens the door to preventive medicine, Baptista de Faia, who was not part of the study, said.
“This is where preventive medicine comes in. If we can identify the children at increased risk, can we intervene to improve outcomes later in life?” he said. Familial hypercholesterolemia is “a great example of this,” he added. “We can screen children early in life, there is an effective treatment, and we know from populations studies that early treatment significantly decreases the risk for cardiovascular disease later in life.”
Poisson reports that she received grants from the National Institutes of Health (NIH) during the conduct of this study, which was supported by the NIH.
JAMA Neurol. Published online August 1, 2022. Abstract