HEPA, PM2.5, and Cardiometabolic Health

NCT ID: NCT05718245

Last Updated: 2025-08-01

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 52 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2023-03-15
• Study Completion Date: 2026-12-31

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.

Conditions

Air Pollution; Cardiometabolic Health

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: PREVENTION
• Blinding Strategy: DOUBLE

Study Groups

HEPA first and sham

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.

Group Type: EXPERIMENTAL

HEPA filter

Intervention Type: DEVICE

HEPA filters with the capacity to reduce PM2.5 levels

Sham filter

Intervention Type: DEVICE

sham filters without the capacity to reduce PM2.5 levels

Sham first and HEPA

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.

Group Type: SHAM_COMPARATOR

HEPA filter

Intervention Type: DEVICE

HEPA filters with the capacity to reduce PM2.5 levels

Sham filter

Intervention Type: DEVICE

sham filters without the capacity to reduce PM2.5 levels

Interventions

HEPA filter

HEPA filters with the capacity to reduce PM2.5 levels

Intervention Type: DEVICE

Sham filter

sham filters without the capacity to reduce PM2.5 levels

Intervention Type: DEVICE

Eligibility Criteria

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).

• Minimum Eligible Age: 65 Years
• Maximum Eligible Age: 84 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Duke University

OTHER

Sponsor Role: collaborator

University of Southern California

OTHER

Sponsor Role: lead

Responsible Party

Zhanghua Chen

Assistant Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Zhanghua Chen, PhD

Role: PRINCIPAL_INVESTIGATOR

University of Southern California

Junfeng Zhang, PhD

Role: PRINCIPAL_INVESTIGATOR

Duke University

Locations

Keck School of Medicine, University of Southern California

Los Angeles, California, United States

Site Status: RECRUITING

Countries

United States

Central Contacts

Zhanghua Chen, PhD

Role: CONTACT

zhanghuc@usc.edu

323-442-2109

Junfeng Zhang, PhD

Role: CONTACT

junfeng.zhang@duke.edu

919-681-7782

Facility Contacts

Zhanghua Chen, PhD

Role: primary

zhanghuc@usc.edu

323-442-2109

Other Identifiers

UL2_Study

Identifier Type: -

Identifier Source: org_study_id