The Dallas Asthma Brain and Cognition (ABC) Study
1 other identifier
observational
130
1 country
2
Brief Summary
Asthma is a chronic inflammatory airway disease that leads to episodic symptom exacerbations, which exerts a substantial burden on quality of life and can influence other health domains if not adequately controlled. Asthma prevalence rates have increased in the past decade, affecting 8.4% (25.7 million people) of the United States population. The economic costs of asthma have been estimated annually with $56 billion in the US alone. Despite progress in pharmacological treatment, overall asthma control remains unsatisfactory and treatment non-adherence is extremely high. Asthma is particularly under diagnosed and understudied in aging adults. This problem will increase in coming decades given demographic trends and will disproportionally contribute to the societal and personal economic costs associated with asthma treatment and management. In the proposed 4-year project we will evaluate, in a two-session assessment recruiting a total of 126 asthma patients and 66 healthy controls aged 40-69 years, the extent to which asthma and aging are associated with changes in cognition and brain chemistry, structure, and function.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P50-P75 for all trials
Started Feb 2019
Longer than P75 for all trials
2 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
Click on a node to explore related trials.
Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
December 12, 2018
CompletedFirst Posted
Study publicly available on registry
January 7, 2019
CompletedStudy Start
First participant enrolled
February 21, 2019
CompletedPrimary Completion
Last participant's last visit for primary outcome
May 28, 2025
CompletedStudy Completion
Last participant's last visit for all outcomes
May 28, 2025
CompletedJuly 9, 2025
July 1, 2025
6.3 years
December 12, 2018
July 3, 2025
Conditions
Keywords
Outcome Measures
Primary Outcomes (8)
Examine processing speed of middle- to late-age adults with asthma with the Wechsler Adult Intelligence Scale (WAIS) Symbol Search Test.
The Wechsler Adult Intelligence Scale (WAIS) Symbol Search test is a subtest of the WAIS, a scale widely used to measure intelligence. The examinee scans a search group of symbols and indicates whether one of the symbols matches a symbol in the target group. The time limit for this subtest is 120 seconds. The total raw score is the sum of the number of correct responses minus the number of incorrect responses. A higher score indicates better performance. The maximum total raw score is 60. If the total raw score is equal to or less than 0, then the total raw score is recorded as 0.
From date of baseline until the date of second session, approximately one week after baseline.
Examine executive functioning of middle- to late-age adults with asthma with the Trails A&B test.
The Trails A\&B test is a neuropsychological assessment. The task requires a subject to connect a sequence of 25 circles on a sheet of paper as quickly as possible. The test has 2 parts, with the first part of the test requiring the subject to connect circles that are all numbers (1, 2, 3, etc.) in order. The second part of the test requires that the subject alternates between numbers and letters (1, A, 2, B, etc.). The time taken for each part, measured in seconds, is the raw score. The score is then converted to a scaled score and a T score, both based on sex (male, female), race, and age. A higher score indicates better performance.
From date of baseline until the date of second session, approximately one week after baseline.
Examine working memory of middle- to late-age adults with asthma with the National Institute of Health (NIH) Sorting Working Memory Test.
The National Institute of Health Sorting Working Memory Test is a computerized test that requires the subject to sequence sets of visually and auditorily presented stimuli (pictures of animals and food) in size order from smallest to biggest. There are two lists, with the 1-list version requiring sequencing among a single category (either animals or food), and the 2-list version (requiring sequencing of both food and animals within a series). The raw score is based on the sum of the correct across both lists, which comprise the List Sorting "Total Score". The raw score is converted into a t-score (mean = 50, standard deviation = 10). A higher score indicates better performance.
From date of baseline until the date of second session, approximately one week after baseline.
Examine episodic memory of middle- to late-age adults with asthma with the Rey Auditory Verbal Learning Test (RAVLT).
The examiner reads a list of 15 nouns aloud at the rate of one per second. The subject is asked to repeat all words they recall over 5 trials. An interference list (List B) is then read and subject is asked to recall. Immediately following the interference trial, the subject is asked to recall words from List A (Trial 6). After a 20 minute delay the subject is asked to recall as many words as possible from the first list (delayed recall). A list of 50 words is presented containing all words from List A and the subject is asked to indicate whether each word was on List A (recognition task). The total score (Trials 1-5) is calculated by summing the correct number of words for each trial. List B, Trial 6 and Delayed Recall are calculated by summing the correct number of words. Recognition task is scored by taking the number of correct words and subtracting the number of false positive words. Scores are converted into t-scores with higher score indicating better performance.
From date of baseline until the date of second session, approximately one week after baseline.
Examine reasoning of middle- to late-age adults with asthma with the National Adult Reading Test (NART).
The National Adult Reading Test is a commonly used test to measure intellectual ability in English-speaking patients. A list of 50 words, whose pronunciation cannot be determined from their spelling, are given to the subject and the subject is asked to read down the list. The examiner marks whether the subject pronounced the word correctly and the NART is scored by summing the number of words pronounced correctly.
From date of baseline until the date of second session, approximately one week after baseline.
Examine brain function of adult asthma patients from age 40-69 with functional magnetic resonance imaging (fMRI)
We will assess brain functioning by measuring default brain network connectivity using functional magnetic resonance imaging (fMRI)
From date of baseline until the date of second session, approximately one week after baseline.
Examine brain structure of adult asthma patients from age 40-69 with structural magnetic resonance imaging (sMRI)
We will assess brain structure, hippocampal gray matter volume, using structural magnetic resonance imaging (sMRI)
From date of baseline until the date of second session, approximately one week after baseline.
Examine brain chemistry of adult asthma patients from age 40-69 with proton magnetic resonance spectroscopy (1H-MRS)
We will assess brain chemistry, specifically differences in hippocampal metabolite levels, using proton magnetic resonance spectroscopy (1H-MRS)
From date of baseline until the date of second session, approximately one week after baseline.
Study Arms (2)
Asthma patients
Asthma patients will undergo behavioral testing and imaging at a single timepoint.
Healthy Volunteers
Healthy volunteers will undergo behavioral testing and imaging at a single timepoint.
Interventions
Brain structure and function will be compared in middle to late-age adults with asthma compared to healthy adults.
Multiple domains of cognitive functioning will be investigated, including processing speed, executive functioning/working memory and episodic memory.
Participants will fill out asthma and psychological questionnaires (non-diagnostic)
Eligibility Criteria
Subjects will be recruited from the larger Dallas/ Fort Worth community. We will recruit both healthy controls and subjects with asthma through local flyers, online advertisements, at community allergy and pulmonary clinics, and databases. Individuals who appear eligible will be invited to participate.
You may qualify if:
- For asthma patients: diagnosis of asthma (verified by a medical documentation) for at least 2 years; for healthy volunteers: no significant medical or psychiatric history.
- Ages 40 to 69 years old.
- Proficient in English.
- Education level of at least 10th grade level.
You may not qualify if:
- Treatment with oral corticosteroids in the previous 6 weeks, because of the potent effects of this drug on airway reactivity.
- Spirometry: Peak expiratory flow (PEF) below 60% of predicted.
- Diagnosis of vocal cord dysfunction (identified by abnormalities in spirometric flow-volume curves), clinically significant chronic obstructive pulmonary disease, or emphysema.
- Presence or history of medical or neurological disorder that may affect brain function and the physiological systems of interest (e.g. angina, myocardial infarction, congestive heart failure, transient ischemic attacks, cerebrovascular accidents, emphysema, or chronic obstructive pulmonary disease, history of seizures or head trauma, endocrine disorders or renal disease, chemotherapy or radiation presently or in the past 5 years, uncontrolled diabetes, blood pressure above 160/90 (self-reported or measured at session 1).
- Corrected vision poorer than 20/30 on Snellen Eye Chart.
- Presence or history of Schizophrenia, Psychosis, Dementia, Bipolar I, Bipolar II, PTSD or Acute Stress Disorder
- Current or recent history (within 1 year) of Substance Related Disorders, current recreational drug use (defined as past 30 days) or consuming more than 20 alcoholic drinks per week.
- Current treatment with anti-psychotics, sedatives, benzodiazepines with a half-life longer than 6 hours.
- Previous electroconvulsive therapy.
- Presence of history of orthopaedic circumstances and metallic inserts interfering with MR scanning (prior surgeries and/or implant pacemakers, pacemaker wires, artificial heart value, brain aneurysm surgery, middle ear implant, non-removable hearing aid or jewelry, braces or extensive dental work, cataract surgery or lens implant, implanted mechanical or electrical device, artificial limb or joint, foreign metallic objects in the body such as bullets, BB's, shrapnel, or metalwork fragments, pregnancy, claustrophobia, uncontrollable shaking, or inability to lie still for one hour.
- Not proficient in English.
- In the opinion of the principal investigator, participant is otherwise unsuitable for this study.
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (2)
Southern Methodist University
Dallas, Texas, 75206, United States
The University of Texas Southwestern Medical Center
Dallas, Texas, 75390, United States
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Intervention Hierarchy (Ancestors)
Study Officials
- PRINCIPAL INVESTIGATOR
E. Sherwood Brown, MD, PhD
University of Texas Southwestern Medical Center
Study Design
- Study Type
- observational
- Observational Model
- CASE CONTROL
- Time Perspective
- CROSS SECTIONAL
- Sponsor Type
- OTHER
- Responsible Party
- PRINCIPAL INVESTIGATOR
- PI Title
- Professor of Medicine
Study Record Dates
First Submitted
December 12, 2018
First Posted
January 7, 2019
Study Start
February 21, 2019
Primary Completion
May 28, 2025
Study Completion
May 28, 2025
Last Updated
July 9, 2025
Record last verified: 2025-07
Data Sharing
- IPD Sharing
- Will not share