Elevated blood pressure and decreased cognitive function among school-age children and adolescents in the United States

Abstract 

Objective

To evaluate the relationship between elevated blood pressure (BP) and cognitive test performance in a nationally representative sample of children.

Study design

The National Health and Nutrition Examination Survey III provides cross-sectional data for children 6 to 16 years, including BP and cognitive test scores. Elevated BP was defined as systolic or diastolic BP ≥90th percentile. Cognitive tests were compared for children with elevated and normal BP. Linear regression was used to evaluate the relation between elevated BP and decreased test scores.

Results

Among the 5077 children, 3.4% had systolic BP ≥90th percentile and 1.6% diastolic BP ≥90th percentile. Children with elevated systolic BP had lower average scores compared with normotensive children for digit span (7.9 vs 8.7, P=.01), block design (8.6 vs 9.5, P=.03), and mathematics (89.6 vs 93.8, P=.01). Elevated diastolic BP was associated with lower average scores on block design (9.5 vs 11, P=.01). Linear regression showed that elevated systolic BP was independently associated with lower digit span scores (P=.032).

Conclusion

Children with elevation of systolic BP are at risk for central nervous system end-organ damage, as manifested by decreased digit span test scores.

Abbreviations:  BP, Blood pressure, CNS, Central nervous system, MEC, Mobile examination center, NHANES III, Third National Health and Nutrition Examination Survey, WISC-R, Wechsler Intelligence Scale for Children, Revised, WRAT-R, Wide Range Achievement Test, Revised