Low-level reasoning, problem-solving, and planning skills may increase the risk of heart attack and stroke, according to a study published in Neurology. The results indicate that executive function, which encompasses such high-level thinking skills, may be more closely linked to cardiovascular function than previously thought.
“While these results might not have immediate clinical translation, they emphasize that assessment of cognitive function should be part of the evaluation of future cardiovascular risk,” said study author Behnam Sabayan, MD, PhD, of Leiden University Medical Center in the Netherlands.
Sabayan and colleagues studied 3,926 people (mean age 75 years, 44% male) from the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER) study without any history of heart attack or stroke, but with a history of heart disease or increased risk of heart disease from hypertension, diabetes, or smoking. The participants were also free of dementia. Participants’ executive function scores were formed from Stroop Color-Word Test and Letter Digit Substitution Test scores, and memory scores were formed from Picture Learning Test results.
Over the course of 3.2 years of follow-up, incidence of coronary heart disease was 30.5 per 1,000 person-years, with participants in the lowest-scoring group for executive function 85% (95% confidence interval [CI] 1.39–2.45) more likely to have a heart attack than those scoring among the highest in the group. Incidence of stroke was 12.4 per 1,000 person-years, with low-scoring participants having a 51% (95% CI 0.99–2.30) higher risk of stroke than those who scored high in executive function. A total of 176 and 69 of the 1,309 participants who had low executive function scores had heart attacks and strokes, respectively, compared to 93 and 48 of the 1,308 participants who scored high in executive function. Low scores on memory testing were not associated with an increased risk of heart disease (hazard ratio 0.99, 95% CI 0.74–1.32) or stroke (hazard ratio 0.87, 95% CI 0.57–1.32).
“Performance on tests of thinking and memory are a measure of brain health. Lower scores on thinking tests indicate worse brain functioning. Worse brain functioning in particular in executive function could reflect disease of the brain vascular supply, which in turn would predict, as it did, a higher likelihood of stroke,” said Sabayan. “And, since blood vessel disease in the brain is closely related to blood vessel disease in the heart, that’s why low test scores also predicted a greater risk of heart attacks.”
Although the results were significant, the risks were small, Sabayan acknowledged. Still, low scores on executive function tests may be a useful tool in predicting vascular pathologies of the brain.