Researchers have found that cognitive processes and mood grow stronger with more effective blood pressure regulation - and, by contrast, can suffer in both children and adults who fail to show an adequate blood pressure increase in response to standing. Next, is there a link to ADHD?
A simple variation to the tried and true method of checking blood pressure can reveal startling information about both older and younger persons, new research suggests.
The standard method of checking blood pressure – taking one measurement while a patient relaxes – can identify hypertension. But health professionals can learn even more by checking pressure while a patient is lying down and again, a couple minutes after they stand up. That’s how to measure for orthostatic hypotension, a form of low blood pressure.
Primarily seen in the elderly, orthostatic hypotension is characterized by a decrease in systolic blood pressure as a patient shifts from lying down to standing. It is associated with dizziness, problems with gait and even diminished cognition. Orthostatic hypotension is also associated with several complications associated with chronic illnesses such as diabetes and Parkinson’s disease.
Lawrence Perlmuter, PhD, a psychologist at Chicago’s Rosalind Franklin University of Medicine and Science, has found that both adults and children who show an inadequate increase in blood pressure in response to standing also perform more poorly on neuropsychological tests and may be at higher risk for depression.
“If a person fails to adequately adjust to the switch from supine to standing, one can expect to find some adverse effects that may be behavioral, cognitive and affective,” says Dr. Perlmuter.
“When we stand, gravity pulls down on the blood flow. A complex set of processes, including a response by the nervous system, must occur almost immediately to prevent the blood from flowing downward, instead of upward toward the brain.”
Hospitalizations related to clinical orthostatic hypotension numbered slightly more than 80,000 in the United States in 2004 and these rates increased with age, according to the American Journal of Medicine.
About 20% of participants in research conducted by Rosalind Franklin University show measurable subsyndromal effects, or very mild symptoms not considered severe enough for clinical diagnosis.
Dr. Perlmuter first studied orthostatic hypotension in 1982 among diabetic patients at Massachusetts General Hospital in association with the Harvard University School of Dental Medicine. He later explored the relationship between orthostatic blood pressure and Alzheimer’s patients under a grant from the Illinois Department of Public Health. The condition’s broader implications soon captured his interest.
• “Blood pressure changes in response to standing are so multifaceted and can be a clinical problem in older people,” Dr. Perlmuter said.
• “But the latest research shows that children and adolescents are not immune to these very mild blood pressure changes, affecting their thinking and behaviors as well as depression and anxiety.”
Dr. Perlmuter found that poor orthostatic blood pressure regulation is a factor in poor academic performance, decreased concentration and lowered motivation. “And it’s a psychosocial educational issue,” he said. “Even though the magnitude is subclinical in orthostasis, its effect on depression and other behaviors are nevertheless measurable.”
But poor systolic blood pressure regulation can have important behavioral implications, particularly for children.
“When a person stands from a lying position, several processes are in need of correction,” Dr. Perlmuter said. “For example, if the brain chemical dopamine is not released in a sufficient amount this indicates that measurable cognitive problems as well as elevations in depression may be evident.
In a study published in 2008 in the International Journal of Psychology, Dr. Perlmuter examined systolic blood pressure regulation in children ages 7 to 11 in relation to teacher evaluations of those students’ grades and classroom effort. Forty-five students at a Waukegan elementary school took part in the study, which found a correlation between weak systolic blood pressure response to orthostatic challenge and reduced academic effort. The teachers were blind to these findings.
Researchers found that cognitive processes grew stronger as blood pressure regulation proved more effective.
“When we’re studying blood pressure change, this simple procedure provides a marker of what’s going on underneath,” Dr. Perlmuter said. “If the blood pressure increase isn’t adequate, that’s a reflection of some underlying problem that can affect a child’s learning and personality, possibility resulting in inappropriately acting out.”
In another study published in the same journal in 2009, Dr. Perlmuter and fellow researchers looked at 3- to 5-year-olds from a local Head Start program. They examined the relationship between the preschoolers’ orthostatic blood pressure regulation and their performance on a screening test used to uncover developmental delays.
Children who exhibited an appropriate increase in systolic blood pressure upon standing scored best in terms of composite motor skills, an index of cognitive function.
Checking for orthostatic hypotension in early childhood could help identify children at risk for depression and learning difficulties. Such children could then be offered an early academic intervention.
Maternal anxiety, low birth weight, and suboptimal BP regulation linked.
Rosalind Franklin University researchers are also examining the relationship between maternal anxiety and blood pressure regulation. Anxiety in mothers not only correlated with anxiety scores in their children, but also predicted poor blood pressure regulation in their children. Dr. Perlmuter’s research has also found that low birth weight can predict orthostatic hypotension in children.
However, his latest study revisits the other end of life’s spectrum. The report, “Cognition and Hopelessness in Association with Subsyndromal Orthostatic Hypotension,” published in the August issue of the Journal of Gerontology, examined men and women ages 30 to 75.
• Poor blood pressure regulation in response to standing was associated with decreased verbal memory, decreased concentration and higher hopelessness scores.
• The study concludes that “routine assessment and identification of orthostatic hypotension may provide an opportunity to reduce the risk for cognitive and affective decline through positive lifestyle changes and physical exercise.”
Next, Research to Determine if There’s a Link with ADHD
With regard to future implications, Dr. Perlmuter hopes his research succeeds in “identifying one of the antecedents” to Attention Deficit Hyperactivity Disorder (ADHD) as well to aggressive and impulsive behaviors. This research is getting underway with Head Start children in September.
“A question is whether we view this topic as a clinical phenomenon,” Dr. Perlmuter said. “It nevertheless has broad health and psychosocial implications. Finally, it should be recognized that since subclinical orthostatic hypotension is a phenomenon crossing physiological, cognitive and emotional boundaries with people, we weren’t expecting these relationships – thus researchers have not until now looked for them.”
Source: Rosalind Franklin University of Medicine and Science (Chicago) news release, Aug 3, 2010