Nutritional deficiencies may contribute to potential increased stroke risk in children and adolescents, researchers suggest.
SAN ANTONIO—A low BMI in children and adolescents may be associated with an increased risk of stroke, according to research presented at the 2010 International Stroke Conference. This is contrary to findings in adults, in whom a higher BMI increases the risk of stroke, and suggests that in children nutritional deficiencies may play a role in stroke pathogenesis.
In a nested, case-control study drawn from the 2.3 million children enrolled in the Northern California Kaiser Permanente Medical Care Program between 1993 and 2003, Nancy K. Hills, PhD, and colleagues at the University of California, San Francisco, examined the link between BMI and stroke in children and adolescents ages 2 to 20.
“Increasing BMI in adults has been linked to an elevated risk of both hemorrhagic and ischemic stroke, independent of hypertension, diabetes, and cholesterol,” wrote Dr. Hills and colleagues. “Although attention has recently focused on childhood obesity, no studies have formally addressed its potential role as a risk factor for stroke. Our goal was to study the relationship between childhood stroke and BMI in a population-based cohort.”
The researchers identified 173 stroke patients and pair-matched each subject with three randomly selected controls. BMIs were calculated using height and weight measurements taken within two years of the stroke date for subjects and within three years of the index date for controls. Cases were 60% male, compared with 50% male for controls, and the median age for both groups was 14.
Using a conditional logistic regression analysis to account for matching and adjusted for traditional adult risk factors, such as hypertension and diabetes, and known risk factors for childhood stroke, including trauma and congenital heart disease, Dr. Hill and colleagues found that children with a BMI in the 40th or lower percentile for their age had a twofold increased risk for stroke. Thirty percent of subjects had lower BMI percentiles, compared with 18.6% of controls.
“This association remained even after adjustments for etiologic risk factors, [including] head/neck trauma, congenital heart disease, and hypertension, and was observed in patients with both hemorrhagic and ischemic stroke,” the researchers noted. “Because trauma could be potentially on the causal pathway between BMI and stroke (if lower-weight children are more active and therefore more susceptible to trauma, which is associated with stroke), we repeated analyses excluding all subjects who had experienced trauma within 12 weeks preceding their stroke, or the index date for controls. BMI at or below the 40th percentile remained significantly associated with stroke.”
Previous studies have linked a high BMI in childhood to an increased risk of stroke as an adult, but no studies have been published correlating childhood BMI to childhood stroke risk, the authors noted.
—Rebecca K. Abma