Recruiting

HEPA Filtration

Sponsor:

University of Southern California

Code:

NCT05718245

Conditions

Air Pollution

Cardiometabolic Health

Eligibility Criteria

Sex: All

Age: 65 - 70+

Healthy Volunteers: Accepted

Interventions

HEPA filter

Sham filter

Study Details

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.

Conditions

Air Pollution

Cardiometabolic Health

Study ID

NCT05718245

Start date

Mar 15, 2023

Status verified date

Jul, 2025

Completion date

Dec 31, 2026

Anticipated

Primary completion date

Dec 31, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 65 - 70+

Healthy Volunteers: Accepted

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

Enrollment

52 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Prevention

Interventions and Outcome Measures

Arms

experimental: 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.

sham comparator: 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.

Interventions

HEPA filter

HEPA filters with the capacity to reduce PM2.5 levels

Sham filter

sham filters without the capacity to reduce PM2.5 levels

Primary outcome measure

  • Change in HOMA-IR [ Time Frame: At the baseline and immediately after each of the 6-month interventions ]
  • Change in HbA1c [ Time Frame: At the baseline and immediately after each of the 6-month interventions ]

Central Contacts and Locations

Central contacts

Zhanghua Chen, PhD

323-442-2109zhanghuc@usc.edu

Junfeng Zhang, PhD

919-681-7782junfeng.zhang@duke.edu

Locations

Keck School of Medicine, University of Southern California

Recruiting

Los Angeles, California, United States, 90033

Contacts

Zhanghua Chen, PhD

323-442-2109zhanghuc@usc.edu

More Information

Sponsor

University of Southern California

Last update posted

Aug 1, 2025

Last verified

Jul, 2025

Keywords

  • Air pollution
  • Particulate matter
  • Air purifier
  • HEPA filter
  • Cardiometabolic health

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by University of Southern California on 2025-08-01.