Abstract
Asthma is a chronic inflammatory airway disease, with an increasing prevalence, that is associated with a
substantial burden on quality of life for patients and financial burden on society. Despite progress in the
pharmacological treatment, overall asthma control remains unsatisfactory and treatment non-adherence is
extremely high. The available research, much of which was conducted by investigators on this proposal,
suggests that asthma may be associated with changes in brain structure and biochemistry, as well as
increased risk for cognitive impairment and dementia. However, little is known about the impact of asthma on
cognitive function and associated central nervous system processes, especially for in middle- to older age
patients. Prior research has also not characterized the relationship between key domains of cognitive function
and possible changes in brain structure, chemistry, and function specific to asthma. Additionally, the role of
biobehavioral factors (such as mood, sleep, or inflammation) and asthma-specific factors (severity, duration,
medication, airway inflammation) in explaining some of these deficits in asthma and aging has not been
explored. We therefore propose to compare 126 adults 40-69 years old, diagnosed with asthma, and stratified
for age (three decades) and asthma severity, with 66 age-matched non-asthmatic controls using cognitive tests
that include processing speed, episodic memory, and executive function. Participants will also undergo
neuroimaging. Structural magnetic resonance imaging (MRI) will focus on hippocampal volume. Diffusion
tensor imaging (DTI) will be used to measure integrity of white matter integrity, which is associated with
processing speed. Proton magnetic resonance spectroscopy (1HMRS) will measure metabolites linked to
neuronal degeneration (N-acetyl aspartate, NAA) and glial inflammation (myo-inositol, mI). Three functional
MRI scans will measure brain activity under different cognitive conditions: (a) a resting state scan to examine
functional connectivity of brain networks; (b) a subsequent memory task to assess the role of hippocampal
activation in the service of memory encoding, and (c) a modulation task that measures the ability of the
cognitive control network to increase brain activity in fronto-parietal regions as task demands increase. We will
also examine whether cognitive impairments are mediated by distinct brain changes extrapolated from prior
research on aging and pilot research on respiratory disease. In addition, we will study a potential role of
depressive mood, sleep quality and systemic inflammation, as well as asthma-relevant variables in mediating
these associations. We hypothesize that asthma patients, compared to controls, will demonstrate accelerated
brain aging as demonstrated by cognitive deficits and brain changes, which increase in magnitude with older
age. Thus, this proposal will provide fundamental information to develop future preventative and intervention
efforts to mitigate the potentially adverse effects of asthma on brain and cognition. A multidisciplinary research
team with extensive experience in mental health in asthma patients, as well as neuroimaging across the
lifespan will conduct the study.