High blood pressure and intelligence in children

Can an increasingly common childhood condition, obesity, cause untreated high blood pressure (hypertension)? And can that lead to impaired cognitive (mental) functioning, which is essential for successful school achievement and success?

Ongoing clinical research seems to suggest a qualified “yes.”

Two weeks ago, this column shared recent neuropsychological research that showed possible increased cognitive (brain) deterioration for adults with hypertension.

Research is examining similar clinical concerns for children with hypertension.

A child’s brain may be the latest body organ found to be damaged by high blood pressure.

Increased obesity rates in children have long been associated with the development of diabetes. Now there are additional concerns for the mental functioning of children in school.

Cognitive skills are essential for academic success because they help the child obtain, store and process information.

Once adolescence is reached, more obese male and female students are exhibiting hypertension and pre-hypertension. As much as one in three obese male students did so in one study. By then life-long eating habits are very established and difficult to change.

The focus on hypertension and neurocognitive brain functioning in children involved a recent neuropsychological study in The Journal of Pediatrics.  I was able to review this article and examine the neuropsychological testing results.

The study took 75 children, ages 10 to 18, from four sites. These research subjects had untreated hypertension and were compared to a control group.

The study concluded that the youth with hypertension had “significantly lower performance on neurocognitive testing.” Memory, attention and executive functions were the weakest areas measured.

I had some specific concerns about the tests administered, all of which I myself give on individual, but more comprehensive, neuropsychological examinations.

For example, take the results from their ‘intelligence’ testing component of the study. The intelligence test battery used normally consists of 10 subtests that are usually administered (with additional supplementary subtests, as needed.) This study used an abbreviated form of only two subtests, which can be completed in less than 15 minutes. Can we really call this a measure of “general intelligence” as they do? Or is it merely an estimate?

Memory tests results were also described as “worse.” However, only two tests were given, one that involved remembering a list of words. Memory is actually a complex cognitive skill, involving many areas of the brain.

In fact, the study notes that the sizes of the differences between two groups were “modest.”

Hypertension was not seen as a factor in a number of cognitive areas in this study. These areas included tests measuring paying attention (listening and looking), “working memory,” and on tests measuring executive functioning (of planning, problem-solving abilities.)

While the study states, in its abstract section, that there was a significantly lower performance on executive functioning skills, this appears to be related to a questionnaire filled out by parents on their child’s executive functioning skills, not on tests actually measuring executive functioning during the study.

Another outside factor that impacted on the testing results involved disordered sleeping problems, which, by themselves, can affect cognitive functioning. Once this factor was taken into account, even the parental importance of their rating of impaired executive functioning went away.

The study is an important preliminary one, but it is not as precise as the media coverage presented. The study does not present even the few negative findings as being statistically significant; a few scores are only “worse” than the majority of tests administered.

Perhaps, the most important thing that this study tells us is to use appropriate language to describe any neuropsychological testing result.

In such instances, where the data or testing battery are limited, one should say, “This individual scored poorly on two different measures of memory,” instead, of saying that, “This individual has a memory problem.” The public reads only the hype, which is soon forgotten.

Can the results be used to predict future impact on these children’s brains? Perhaps, with more research. Instead, this study tells us that some children and youth, particularly obese ones, should be screened and then tested for cognitive functioning deficits if hypertension is diagnosed. Such testing should be individualized and comprehensive, though initial screenings may be brief. The child’s future learning career is at stake. A specific learning disability certainly involves the brain, but terms such as brain damage and cognitive deterioration may not be exactly helpful in an educational setting.

If hypertension is diagnosed, consultation with a medical health professional may find that medication may lessen or even reverse the hypertension, if discovered early. This medical consultation and intervention may then be followed by life-style modifications that involve the entire family.

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Dr. Philip Kronk is a semi-retired, Knoxville-based child and adult clinical psychologist and clinical neuropsychologist. Dr. Kronk has a doctorate degree in Clinical Psychology and a post-doctorate degree in Clinical Psychopharmacology. His year-long internship in Clinical Psychology was served at the University of Colorado Medical School. Dr. Kronk writes a weekly, Friday online column for the Knoxville News Sentinel’s website, knoxnews.com. He can be reached at (865) 330-3633.