A new study from the US has found that hypertensive children are four times more likely to have learning disabilities than children with normal blood pressure. Researchers have suggested that hypertension could affect cognitive ability, in addition to causing physical harm.
The study looked at 201 patients aged between 10 and 18 years who had been referred to the hypertension clinic at the University of Rochester Medical Center's Children's Hospital (URMC). Overall, 18% of these children had learning disabilities. This proportion is far above the population average, which is 5%.
Among the 201 children, 101 had hypertension, or sustained high blood pressure. Among these children, the rate of learning disability was 28%. Among the remaining 100, 9% had learning disabilities-still well above the national average.
While previous studies have excluded children with attention deficit hyperactivity disorder (ADHD), as medications can increase blood pressure, the present research included them. This is because it is possible that the higher rate of ADHD among hypertensive children reflects neurocognitive problems caused by hypertension.
Indeed, the study found that hypertensive children are more likely to have ADHD. "Although retrospective, this work adds to the growing evidence of an association between hypertension and cognitive function", said URMC's Dr. Heater Adams.
Approximately 4% of children in the US have high blood pressure. A 2004 US working group classified children as hypertensive is they had blood pressure readings that was higher than 95% of other children with the same age, height, weight and gender.