HEPA, PM2.5, and Cardiometabolic Health

Study Overview
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Brief Summary
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The goal of this randomized, double-blind, crossover trial is to test the hypothesis that a longer-term indoor HEPA filtration intervention can improve cardiometabolic profiles by reducing indoor PM2.5 exposures in at-risk individuals.

Detailed Description
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This randomized, double-blind, crossover trial will recruit 52 non-diabetic adults and will investigate potential benefits of HEPA air purifiers on improving cardiometabolic profiles. Participants will be contacted and recruited to the study based on inclusion and exclusion criteria. After consenting, participants will be block randomized to HEPA and control groups for 6-month interventions by sex. After 6-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 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 body weight and blood pressure, and collect biospecimen. In aim 1, the researcher will assess the effect of a 6-month residential HEPA intervention on changes of type 2 diabetes-related metabolic outcomes in 52 adults. In aim 2, the researchers will examine the association between reduction in indoor PM2.5 exposure brought by the intervention and changes in metabolic outcomes adjusting for ambient PM2.5 exposure. In aim 3, the researchers will explore major pathophysiologic changes pertinent to the cardio-metabolic profile of type 2 diabetes relevance in response to the intervention and changes in PM2.5 exposure.

Official Title
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Using Indoor Air Filtration to Reduce PM2.5 Cardiometabolic Effects in At-risk Individuals

Conditions
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Air Pollution, Cardiometabolic Health

Intervention / Treatment
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* Device: HEPA filter
* Device: Sham filter


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age between 65 and 84 years old; Nonsmoker for at least 1 year; History of BMI ≥ 25 kg/m2 in the past based on EMR information; Either an English or Spanish speaker; Live in the Los Angeles County; Have Wi-Fi installed in residential house. Exclusion Criteria: History of diabetes (both type 1 and type 2) or degenerative disease of the nervous system (Alzheimer's disease or dementia); Currently have active cancer treatment; The residential house has already had HEPA filters; Participants will move out of the current house in the next 2 years; Participants will spend more than one month living outside the primary home; Have any health conditions that prohibit collecting health and covariate data and biospecimen; The residential houses are not feasible for setting up air purifiers and air pollutants monitors; Have high blood glucose from finger stick test (> 200 mg/dL).

Ages Eligible for Study
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Minimum Age: 65 Years
Maximum Age: 84 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: HEPA first and sham<br>This group of participants will be assigned an intervention of HEPA filters with the capacity to reduce PM2.5 levels at their residence for 6 months. After 6-month wash-out period, will be assigned to sham filters for 6 months. | Device: HEPA filter<br>* HEPA filters with the capacity to reduce PM2.5 levels<br>Device: Sham filter<br>* sham filters without the capacity to reduce PM2.5 levels<br>|
| Sham Comparator: Sham first and HEPA<br>This group of participants will be assigned an intervention of sham filters without the capacity to reduce PM2.5 levels at their residence for 6 months. After 6-month wash-out period, will be assigned to HEPA filters for 6 months. | Device: HEPA filter<br>* HEPA filters with the capacity to reduce PM2.5 levels<br>Device: Sham filter<br>* sham filters without the capacity to reduce PM2.5 levels<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in HOMA-IR | Difference between baseline and HOMA-IR measured after 6-month intervention | At the baseline and immediately after each of the 6-month interventions | 
| Change in HbA1c | Difference between baseline and HOMA-IR measured after 6-month intervention | At the baseline and immediately after each of the 6-month interventions | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in fasting glucose | Difference between baseline and fasting glucose measured after 6-month intervention | At the baseline and immediately after each of the 6-month interventions | 
| Change in fasting insulin | Difference between baseline and fasting insulin measured after 6-month intervention | At the baseline and immediately after each of the 6-month interventions | 
| Changes in lipid profiles | Differences between baseline and LDL, HDL, VLDL, triglycerides, and total cholesterol levels measured after 6-month intervention | At the baseline and immediately after each of the 6-month interventions | 
| Change in blood pressure | Differences between baseline and systolic and diastolic blood pressure measured after 6-month intervention | At the baseline and immediately after each of the 6-month interventions | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Air pollution, Particulate matter, Air purifier, HEPA filter, Cardiometabolic health