The Dallas Asthma Brain and Cognition (ABC) Study

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.

This study will implement a cross-sectional design, conducted across two sessions. The first session will capture cognitive performance, health history, and relevant social, behavioral, and emotional processes. The second session approximately one week later will capture neural structure, function, and chemistry. In the first session, participants will undergo screening for psychological disorders, neuropsychological testing and pulmonary function assessment at the Southern Methodist University (SMU) or UT Southwestern site. They will then participate in a second session at University of Texas Southwestern Medical Center (UTSW) Advanced Imaging Research Center (AIRC) with structural and functional magnetic resonance imaging (MRI), diffusion tensor imaging (DTI), and brain metabolic activity with spectroscopy. Blood draws and additional pre- and post-neuroimaging spirometry will also be performed at the second session. Potential participants identified by brief phone screen will be invited for two assessment sessions 1 week apart. At the first session, they will be consented, interviewed about their asthma and/or general health status, and pulmonary function tests will be performed. They will then fill in questionnaires and will be screened for psychological disorders by standardized psychiatric interview. After that, they will complete the neuropsychological test battery. The second session will entail spirometry (to ascertain adequate lung function for imaging), the 1 ½ hour neuroimaging protocol, saliva samples, and blood sampling. Spirometry will be repeated at the end of the imaging session. We will also offer patients a brief optional session before the imaging session to get acquainted to the scanning environment in a mock scanner.

Eligibility Criteria:
Inclusion Criteria:

* 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.

Exclusion Criteria:

* 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.