PHILADELPHIA – Children and young adults with increased systolic and diastolic indices and decreased nocturnal dipping on ambulatory blood pressure monitoring are at increased risk for cognitive dysfunction, according to findings from a cross-sectional study.
In 152 subjects aged 8-25 years, systolic index and diastolic indices – after controlling for chronic kidney disease (CKD) versus control group, race, and maternal education – were negatively associated with performance in several domains, including attention, inhibitory control, and verbal memory. For the attention domain, there was a 0.02 increase in z score for every 1% increase in diastolic dip. For the verbal memory and inhibitory control domains, there was a decrease of 0.14 and 0.06 in z score, respectively, for every 10% increase in diastolic load, Nina Laney of Children’s Hospital of Philadelphia reported.
Systolic dipping was negatively associated with set shifting, with a decrease of 0.03 in z score (P = .04) for every 1% decrease in systolic dipping.
“Hypertension is a well known risk factor for cognitive dysfunction in adults both with and without kidney disease. There are fewer studies that look at this in children, but those that have identify many of the same areas of dysfunction, including executive function, attention, memory, and verbal and visual skills,” Ms. Laney said at the meeting sponsored by the American Society of Nephrology.
The current findings suggest that hypertension affects cognitive function in younger patients, particularly given the decreased rate of comorbidities in children, compared with adults, and this has important implications for early detection and treatment, she said.
Study subjects were 96 patients with CKD and 56 healthy controls. Those with CKD had a mean age of 15.7 years and mean estimated glomerular filtration rate (eGFR) of 48.6 mL/min/1.73m2. The healthy controls had a mean age of 15.1 years and mean eGFR of 103.1 mL/min/1.73m2.
Each patient completed the ambulatory blood pressure measurement as well as a neurocognitive battery consisting of measures of language, attention, inhibitory control, problem solving, set shifting, visuospatial memory (verbal and visual), working memory (verbal and visual), and executive function.
Among the proposed mechanisms for the relationship between hypertension and cognitive dysfunction are impaired cerebral blood flow, autoregulation, decreased microvascular reactivity, and brain volume reduction in gray matter, she noted.
She noted, however, that the study is limited by relatively small sample size, the use of some assumptions while grouping tests into domains, and assessments only once for both the blood pressure and neuropositive assessments. Also, the results were not adjusted for multiple comparisons.
“For future analyses, we will use neuropositive results, blood pressure results, and neuroimaging to look at specific regions of interest in the brain and correlate them with performance in our neurocognitive testing,” she said.
This study was funded by the Pennsylvania Department of Health. Ms. Laney reported having no disclosures.