HEPA, PM2.5, and Cardiometabolic Health

Not Applicable

Recruiting

• Conditions: Cardiometabolic Health; Air Pollution
• Interventions: Device: HEPA filter; Device: Sham filter

• Registration Number: NCT05718245
• Lead Sponsor: University of Southern California

Brief Summary

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

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.

Study Timeline

• Study First Submitted: 2023-01-24
• Study First Submitted QC: 2023-02-07
• Study First Posted: 2023-02-08
• Study Start: 2023-03-15
• Status Verified: 2024-02
• Last Update Submitted: 2024-02-01
• Last Update Posted: 2024-02-05
• Primary Completion: 2025-04-01
• Study Completion: 2025-04-01

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 52

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.

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).

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Sham first and HEPA	HEPA filter	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.
HEPA first and sham	HEPA filter	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.
Sham first and HEPA	Sham filter	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.
HEPA first and sham	Sham filter	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.

Primary Outcome Measures

Name	Time	Method
Change in HOMA-IR	At the baseline and immediately after each of the 6-month interventions	Difference between baseline and HOMA-IR measured after 6-month intervention
Change in HbA1c	At the baseline and immediately after each of the 6-month interventions	Difference between baseline and HOMA-IR measured after 6-month intervention

Secondary Outcome Measures

Name	Time	Method
Change in fasting glucose	At the baseline and immediately after each of the 6-month interventions	Difference between baseline and fasting glucose measured after 6-month intervention
Changes in lipid profiles	At the baseline and immediately after each of the 6-month interventions	Differences between baseline and LDL, HDL, VLDL, triglycerides, and total cholesterol levels measured after 6-month intervention
Change in blood pressure	At the baseline and immediately after each of the 6-month interventions	Differences between baseline and systolic and diastolic blood pressure measured after 6-month intervention
Change in fasting insulin	At the baseline and immediately after each of the 6-month interventions	Difference between baseline and fasting insulin measured after 6-month intervention
Change in continuously monitored glucose level	At the baseline and immediately after 3 months of intervention	Difference in continuously measured glucose measured using Abbott FreeStyle Libre 2 Pro Continuous Glucose Monitor (CGM) for 2 weeks between baseline and after intervention.

Trial Locations

Locations (1)

Keck School of Medicine, University of Southern California; 🇺🇸 Los Angeles, California, United States