NCT05718245

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.

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
52

participants targeted

Target at P25-P50 for not_applicable

Timeline
8mo left

Started Mar 2023

Longer than P75 for not_applicable

Geographic Reach
1 country

1 active site

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress83%
Mar 2023Dec 2026

First Submitted

Initial submission to the registry

January 24, 2023

Completed
15 days until next milestone

First Posted

Study publicly available on registry

February 8, 2023

Completed
1 month until next milestone

Study Start

First participant enrolled

March 15, 2023

Completed
3.8 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 31, 2026

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

December 31, 2026

Last Updated

August 1, 2025

Status Verified

July 1, 2025

Enrollment Period

3.8 years

First QC Date

January 24, 2023

Last Update Submit

July 29, 2025

Conditions

Air PollutionCardiometabolic Health

Keywords

Air pollutionParticulate matterAir purifierHEPA filterCardiometabolic health

Outcome Measures

Primary Outcomes (2)

  • 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 Outcomes (5)

  • Change in fasting glucose

    At the baseline and immediately after each of the 6-month interventions

  • Change in fasting insulin

    At the baseline and immediately after each of the 6-month interventions

  • Changes in lipid profiles

    At the baseline and immediately after each of the 6-month interventions

  • Change in blood pressure

    At the baseline and immediately after each of the 6-month interventions

  • Change in continuously monitored glucose level

    At the baseline and immediately after 3 months of intervention

Study Arms (2)

HEPA first and sham

EXPERIMENTAL

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 filterDevice: Sham filter

Sham first and HEPA

SHAM COMPARATOR

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 filterDevice: Sham filter

Interventions

HEPA filterDEVICE

HEPA filters with the capacity to reduce PM2.5 levels

HEPA first and shamSham first and HEPA
Sham filterDEVICE

sham filters without the capacity to reduce PM2.5 levels

HEPA first and shamSham first and HEPA

Eligibility Criteria

Age65 Years - 84 Years
Sexall
Healthy VolunteersYes
Age GroupsOlder Adult (65+)

You may qualify if:

  • 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.

You may not qualify if:

  • 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).

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Keck School of Medicine, University of Southern California

Los Angeles, California, 90033, United States

RECRUITING

Study Officials

  • Zhanghua Chen, PhD

    University of Southern California

    PRINCIPAL INVESTIGATOR

  • Junfeng Zhang, PhD

    Duke University

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Zhanghua Chen, PhD

CONTACT

323-442-2109zhanghuc@usc.edu

Junfeng Zhang, PhD

CONTACT

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

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
DOUBLE
Who Masked
PARTICIPANT, INVESTIGATOR
Masking Details
A sham filter will be used in the control, to replace HEPA filter in the intervention group. Participants and investigators will be blinded to the intervention type, only specific investigator who will prepare air filter for intervention will be unblinded for the real air filter type.
Purpose
PREVENTION
Intervention Model
CROSSOVER
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Assistant Professor

Study Record Dates

First Submitted

January 24, 2023

First Posted

February 8, 2023

Study Start

March 15, 2023

Primary Completion (Estimated)

December 31, 2026

Study Completion (Estimated)

December 31, 2026

Last Updated

August 1, 2025

Record last verified: 2025-07

Data Sharing

IPD Sharing
Will not share

Locations

US(1)