This double-blind, randomized, crossover trial aims to test the hypothesis that longer-term indoor air filtration intervention can slow atherothrombosis progression by reducing indoor fine particulate matter (PM2.5) exposure in adults with ischemic heart disease history.
This double-blind, randomized, crossover trial will recruit 112 adults with ischemic heart disease history and will investigate potential benefits of indoor high efficiency particulate air (HEPA) filtration on ameliorating the progression of atherothrombosis. Participants will be contacted and recruited to the study based on inclusion and exclusion criteria. After consenting, participants will go through a total of 21-month study period comprised of true HEPA filtration and sham filtration, each of 9-month in duration, and a 3-month wash-out period. After 3-month wash-out period, participants will be switched to the other arm of the intervention. During the trial, project specialists will complete a series of home visits before, in the middle, and after each intervention session to set up air purifiers and indoor and outdoor air pollution monitors, as well as conduct interview to collect questionnaire data, measure vascular function, blood pressure, and collect biospecimens. Participants will self-monitor their daily blood pressure through out the intervention periods. In aim 1, researchers will assess the effect of a 9-month residential HEPA intervention on atherothrombosis progression in 112 participants. In aim 2, the researchers will examine the association between reduction in indoor PM2.5 exposure brought by the intervention and the changes in atherothrombosis progression indicators adjusting for outdoor PM2.5 exposure. In aim 3, researchers will examine atherothrombosis responses (both levels and slopes of change) to the HEPA intervention within four subgroups of participants: 1) non-Hispanics, 2) Hispanics, 3) females, and 4) males.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
DOUBLE
Enrollment
112
HEPA filters with the capacity to reduce PM2.5 levels
Sham filtration use the same appearance of air purifier but with HEPA filter removed.
Keck School of Medicine, University of Southern California
Los Angeles, California, United States
RECRUITINGChange in blood pressure
Differences between baseline and systolic and diastolic blood pressure measured during and after intervention
Time frame: Blood pressure will be monitored daily during each of the 9-month intervention
Change in carotid-femoral pulse wave velocity
Differences between baseline and carotid-femoral pulse wave velocity measured with Vicorder device during and after intervention
Time frame: At the baseline, in the middle (4.5 month after intervention) and immediately after each of the 9-month interventions
Change in augmentation index
Differences between baseline and augmentation index measured with Vicorder device during and after intervention
Time frame: At the baseline, in the middle (4.5 month after intervention) and immediately after each of the 9-month interventions
Change in von Willebrand factor
Differences between baseline and von Willebrand factor measured during and after intervention
Time frame: At the baseline, in the middle (4.5 month after intervention) and immediately after each of the 9-month interventions
Change in P-selectin
Differences between baseline and P-selectin measured during and after intervention
Time frame: At the baseline, in the middle (4.5 month after intervention) and immediately after each of the 9-month interventions
Change in fasting glucose
Differences between baseline and fasting glucose measured during and after intervention
Time frame: At the baseline, in the middle (4.5 month after intervention) and immediately after each of the 9-month interventions
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Change in fasting insulin
Differences between baseline and fasting insulin measured during and after intervention
Time frame: At the baseline, in the middle (4.5 month after intervention) and immediately after each of the 9-month interventions
Changes in lipid profiles
Differences between baseline and low-density lipoprotein, high-density lipoprotein, very-low-density lipoprotein, triglycerides, and total cholesterol levels measured during and after intervention
Time frame: At the baseline, in the middle (4.5 month after intervention) and immediately after each of the 9-month interventions
Change in C-reactive protein
Differences between baseline and C-reactive protein measured during and after intervention
Time frame: At the baseline, in the middle (4.5 month after intervention) and immediately after each of the 9-month interventions
Change in interleukin 6
Differences between baseline and interleukin 6 measured during and after intervention
Time frame: At the baseline, in the middle (4.5 month after intervention) and immediately after each of the 9-month interventions
Changes in 384 kinds of targeted cardiovascular disease-related proteomic markers
Differences between baseline and the relative abundance of 384 kinds of targeted cardiovascular disease-related proteomic markers, such as tumor necrosis factor, E-selectin, intercellular adhesion molecule 1, vascular cell adhesion molecule 1, and leptin, measured with Olink's Explore 384 cardiometabolic panel 1 during and after intervention. The Olink kit is a relative quantification assay and there are no units for the measurements.
Time frame: At the baseline, in the middle (4.5 month after intervention) and immediately after each of the 9-month interventions