COPD-Related Physiology and the Brain

Determinants of Altered Brain Structure and Function in Smokers With COPD-Related Lung Pathophysiology

COPD is the third leading cause of combined morbidity, disability, and mortality in the United States and is often associated with cognitive impairment. The goal of the proposed project is to examine novel pulmonary and vascular physiological mechanisms that contribute to structural brain abnormalities and cognitive dysfunction early in the course of COPD. The project will generate information to ultimately inform the development of interventions to delay or prevent cognitive dysfunction.

Study Overview

• Status: Completed
• Conditions: Cognitive Impairment; Pulmonary Disease, Chronic Obstructive (COPD)
• Intervention / Treatment: Behavioral: Neuropsychological Assessment; Procedure: Spirometry; Procedure: Arterial Blood Gas; Procedure: Diffusion Capacity of the Lung for Carbon Monoxide; Diagnostic test: 6 Minute Walk Test; Procedure: Systemic Vascular Measures; Biological: Blood Biomarkers; Behavioral: Symptom Questionnaire Measures; Procedure: Brain MRI

Detailed Description

Chronic Obstructive Pulmonary Disease (COPD) is the 3rd leading cause of morbidity and mortality in the US with increasing prevalence in older adults. The impact of COPD on the brain is an area of expanding research interest. A staggering 40-60% of patients with COPD have cognitive impairments including deficits in executive functioning (e.g., decision making), processing speed, and memory. Intact cognition is critical for independently managing daily tasks (e.g., medication and money management). Since there are currently no treatments to fully reverse cognitive impairment once it is present, preventing and delaying onset is essential. Given the high prevalence of COPD, understanding how COPD confers an increased risk for cognitive impairment should be a top public health priority. There is an urgent need to identify potentially modifiable physiological characteristics of individuals with early COPD-related pathophysiology who are at risk of developing brain abnormalities. The earliest changes that occur in COPD are driven by an enhanced chronic inflammatory response that includes small airway disease in the lung and vascular abnormalities. COPD-related lung pathophysiology can be measured continuously and is separable from amount of smoking. These physiological changes are often present in individuals who do not meet traditional criteria for COPD diagnosis and have not yet manifested significant clinical symptoms. We propose that chronic smokers who are susceptible to COPD and show evidence of COPD-related lung pathophysiology on lung CT also experience vascular dysfunction (particularly central artery stiffness) that contributes to structural brain abnormalities and cognitive impairment. The proposed project will: 1) model the effects of novel physiological mechanisms on the brain in COPD, 2) focus on changes in brain structure and function early in the development of COPD by including smokers who have evidence of early COPD-related lung pathophysiology but do not meet traditional criteria for COPD, and 3) utilize advanced technology to assess the lung (lung CT) and brain (MRI). We will recruit participants with existing lung CT from ongoing NIH projects to complete pulmonary and vascular measures, cognitive assessment, and brain MRI. The project is highly multidisciplinary and leverages unique resources at the University of Iowa including the Institute for Clinical and Translational Science, the Translational Human Vascular Physiology Lab, the Iowa Neuroimaging Consortium, and the Iowa Comprehensive Lung Imaging Center.

• Study Type: Observational
• Enrollment (Actual): 170

Contacts and Locations

Study Locations

• United States
  • Iowa
    • Iowa City, Iowa, United States, 52242
      • University of Iowa

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 26 years to 81 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Participants will be recruited from the Iowa COPD research registry, which includes participants from several NIH funded studies with quantitative lung imaging obtained in the Iowa Comprehensive Lung Imaging Center.

Description

Inclusion Criteria:

Age 30-85, > 8th grade education, Normal/corrected hearing and vision, English Speaker, Ability to comfortably lie flat for 1 hour.

Exclusion Criteria:

Other concomitant respiratory disorder other than asthma (e.g., cystic fibrosis), Use of antibiotics or steroids for a COPD exacerbation within the past month, Use of 24-hour oxygen, Pregnancy or suspected pregnancy, Uncontrolled cancer within the last 5 years, Radiation therapy to the chest, Lung surgery (LVRS, transplant, lobectomy), Lung cancer known or suspected, Eye surgery in the last 3 months, Pulmonary Hypertension, Insulin-dependent diabetes, Inability to use albuterol, Chest or abdominal surgery in the past 3 months, Heart attack in the last 3 months, Hospitalization for any heart problem in the past month, Prior neurological condition (e.g., stroke, epilepsy, head injury with >15 mins. loss of consciousness), Previous diagnosis of dementia or learning disability, Major comorbid medical conditions with known cognitive effects (e.g., renal failure, HF), Psychotic disorder, bipolar disorder, current substance use disorder other than tobacco use, Change in psychiatric medication in last month, Claustrophobia, Metal object in body that may interfere with neuroimaging.

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Never Smoker; Neuropsychological Assessment, Spirometry, Arterial Blood Gas, Diffusion Capacity of the Lung for Carbon Monoxide, 6 Minute Walk test, Systemic Vascular Measures, Blood Biomarkers, Symptom Questionnaire Measures, Brain MRI	Behavioral: Neuropsychological Assessment; Assessments include: Paper and pencil computerized measures of Memory, Language, Visuospatial Function, Executive Functioning-Processing Speed, and Attention; Procedure: Spirometry; Pre and post bronchodilator spirometry will be administered according to the American Thoracic Society (ATS) guidelines.; Procedure: Arterial Blood Gas; Radial artery blood sample will be collected to measure gas exchange hemoglobin; arterial oxygen and carbon dioxide will be examined as potential covariates.; Procedure: Diffusion Capacity of the Lung for Carbon Monoxide; For measurement of gas exchange in the lung. DLCO adjusted for hemoglobin will be the primary variable of interest and will be examined as a potential covariate.; Other Names: (DLCO); Diagnostic test: 6 Minute Walk Test; Distance walked in 6 minutes will be the primary outcome.; Other Names: 6MWT; Procedure: Systemic Vascular Measures; Carotid artery ultrasound, pulse wave velocity, brachial artery endothelium-dependent flow mediated dilation and endothelium-independent dilation will be measured.; Biological: Blood Biomarkers; High sensitivity C-reactive protein (hs-CRP), and fibrinogen will be used as indicators of systemic inflammation, complete blood count with differential (CBC with diff) will be obtained to rule out acute infection as a cause of inflammation.; Behavioral: Symptom Questionnaire Measures; M.I.N.I Screen 7.0.0, Beck Depression Inventory-II (DBI-II), State Trait Anxiety Inventory (STAI), COPD Assessment Test (CAT), St. George's Respiratory Questionnaire (SGRQ), MMRC Dyspnea Scale (MMRC), Berlin Questionnaire; Procedure: Brain MRI; Primary neuroimaging outcomes of interest are white matter structural integrity
Smoker/Past smoker-No Airflow Limitation; Neuropsychological Assessment, Spirometry, Arterial Blood Gas, Diffusion Capacity of the Lung for Carbon Monoxide, 6 Minute Walk test, Systemic Vascular Measures, Blood Biomarkers, Symptom Questionnaire Measures, Brain MRI	Behavioral: Neuropsychological Assessment; Assessments include: Paper and pencil computerized measures of Memory, Language, Visuospatial Function, Executive Functioning-Processing Speed, and Attention; Procedure: Spirometry; Pre and post bronchodilator spirometry will be administered according to the American Thoracic Society (ATS) guidelines.; Procedure: Arterial Blood Gas; Radial artery blood sample will be collected to measure gas exchange hemoglobin; arterial oxygen and carbon dioxide will be examined as potential covariates.; Procedure: Diffusion Capacity of the Lung for Carbon Monoxide; For measurement of gas exchange in the lung. DLCO adjusted for hemoglobin will be the primary variable of interest and will be examined as a potential covariate.; Other Names: (DLCO); Diagnostic test: 6 Minute Walk Test; Distance walked in 6 minutes will be the primary outcome.; Other Names: 6MWT; Procedure: Systemic Vascular Measures; Carotid artery ultrasound, pulse wave velocity, brachial artery endothelium-dependent flow mediated dilation and endothelium-independent dilation will be measured.; Biological: Blood Biomarkers; High sensitivity C-reactive protein (hs-CRP), and fibrinogen will be used as indicators of systemic inflammation, complete blood count with differential (CBC with diff) will be obtained to rule out acute infection as a cause of inflammation.; Behavioral: Symptom Questionnaire Measures; M.I.N.I Screen 7.0.0, Beck Depression Inventory-II (DBI-II), State Trait Anxiety Inventory (STAI), COPD Assessment Test (CAT), St. George's Respiratory Questionnaire (SGRQ), MMRC Dyspnea Scale (MMRC), Berlin Questionnaire; Procedure: Brain MRI; Primary neuroimaging outcomes of interest are white matter structural integrity
Smoker/Past smoker-W/Airflow Limitation; Neuropsychological Assessment, Spirometry, Arterial Blood Gas, Diffusion Capacity of the Lung for Carbon Monoxide, 6 Minute Walk test, Systemic Vascular Measures, Blood Biomarkers, Symptom Questionnaire Measures, Brain MRI	Behavioral: Neuropsychological Assessment; Assessments include: Paper and pencil computerized measures of Memory, Language, Visuospatial Function, Executive Functioning-Processing Speed, and Attention; Procedure: Spirometry; Pre and post bronchodilator spirometry will be administered according to the American Thoracic Society (ATS) guidelines.; Procedure: Arterial Blood Gas; Radial artery blood sample will be collected to measure gas exchange hemoglobin; arterial oxygen and carbon dioxide will be examined as potential covariates.; Procedure: Diffusion Capacity of the Lung for Carbon Monoxide; For measurement of gas exchange in the lung. DLCO adjusted for hemoglobin will be the primary variable of interest and will be examined as a potential covariate.; Other Names: (DLCO); Diagnostic test: 6 Minute Walk Test; Distance walked in 6 minutes will be the primary outcome.; Other Names: 6MWT; Procedure: Systemic Vascular Measures; Carotid artery ultrasound, pulse wave velocity, brachial artery endothelium-dependent flow mediated dilation and endothelium-independent dilation will be measured.; Biological: Blood Biomarkers; High sensitivity C-reactive protein (hs-CRP), and fibrinogen will be used as indicators of systemic inflammation, complete blood count with differential (CBC with diff) will be obtained to rule out acute infection as a cause of inflammation.; Behavioral: Symptom Questionnaire Measures; M.I.N.I Screen 7.0.0, Beck Depression Inventory-II (DBI-II), State Trait Anxiety Inventory (STAI), COPD Assessment Test (CAT), St. George's Respiratory Questionnaire (SGRQ), MMRC Dyspnea Scale (MMRC), Berlin Questionnaire; Procedure: Brain MRI; Primary neuroimaging outcomes of interest are white matter structural integrity

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
White matter (WM) structural integrity from brain magnetic resonance imaging (MRI)	Fractional anisotropy from diffusion weighted imaging will be the primary WM measure	At the end of data collection in 2024
Neuropsychological test performance: average executive functioning-processing speed domain summary score	The domain summary score represents the average of the norm referenced standardized scores for the following measures: Trail Making Test Part B, Controlled Oral Word Association, Stroop Color Word Test Interference Score, and WAIS-IV (Wechsler Adult Intelligence Scale IV) Coding	At the end of data collection in 2024

Collaborators and Investigators

• Sponsor: Karin Hoth
• Collaborators: National Heart, Lung, and Blood Institute (NHLBI); National Institutes of Health (NIH)
• Investigators: Principal Investigator: Karin F Hoth, PhD, University of Iowa Department of Psychiatry

Study record dates

Study Major Dates

• Study Start (Actual): May 1, 2017
• Primary Completion (Actual): April 30, 2025
• Study Completion (Actual): April 30, 2025

Study Registration Dates

• First Submitted: August 30, 2017
• First Submitted That Met QC Criteria: August 30, 2017
• First Posted (Actual): September 1, 2017

Study Record Updates

• Last Update Posted (Estimated): December 24, 2025
• Last Update Submitted That Met QC Criteria: December 22, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: COPD; Cognition; Lung; Pulmonary
• Additional Relevant MeSH Terms: Mental Disorders; Pathologic Processes; Chronic Disease; Disease Attributes; Respiratory Tract Diseases; Neurocognitive Disorders; Lung Diseases, Obstructive; Cognition Disorders; Pathological Conditions, Signs and Symptoms; Lung Diseases; Pulmonary Disease, Chronic Obstructive; Cognitive Dysfunction; Investigative Techniques; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Inorganic Chemicals; Behavioral Disciplines and Activities; Diagnostic Techniques, Respiratory System; Oxides; Oxygen Compounds; Psychological Tests; Diagnostic Techniques, Cardiovascular; Gases; Heart Function Tests; Respiratory Function Tests; Blood Chemical Analysis; Clinical Chemistry Tests; Carbon Compounds, Inorganic; Exercise Test; Carbon Monoxide; Neuropsychological Tests; Blood Gas Analysis; Walk Test
• Other Study ID Numbers: 201404738; 1R01HL134822-01 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No