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Chronic Kidney DiseaseGUARDD-USNCT04191824

Genetic Testing to Understand and Address Renal Disease Disparities Across the United States

A study testing Timing of return of results in people with Chronic Kidney Disease and Hypertension, run by Duke University at 14 sites in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

GUARDD-US is a prospective, multicenter, unblinded, two arm randomized pragmatic clinical trial. Participants will be randomized in a 1:1 ratio to immediate APOL1 gene testing and return of results (ROR) to participant and provider (Intervention arm) versus delayed APOL1 gene testing and ROR to participant and… Read more about this study

Who is it for?
Ages 18 to 70 years
Conditions the study is for
Chronic Kidney Disease, Hypertension
What is being tested?
Timing of return of results
Could I receive a placebo?
No, everyone receives an active treatment
How many people
6,789 participants
Where
14 sitesUnited States
Study dates
10 Jul 2020to 17 May 2024
Phase
Interventional
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 70 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Self reported African ancestry
  • English Speaking
  • Age 18-70 years
  • Have diagnosis of hypertension: Diagnosis of hypertension is defined by either:
  • ICD10 diagnosis codes (i.e., I10; I11.x; I12.x; I13.x; I16.x) OR
  • On active antihypertensive therapy for indication of hypertension OR
Show all 12Show fewer
  • Having systolic blood pressure of 140 mm Hg or greater in at least 2 of the last 3 consecutive recorded values in the EHR OR
  • Having hypertension in the patient's medical record problem list
  • Have been seen at ≥1 time in past year at a participating primary care site
  • Either: 1) do not have diabetes and do not have CKD, or 2) have CKD; Participants with diabetes may be included as long as they also have CKD.
  • CKD is defined by either: A) ICD10 codes (i.e., N18.x; E08.22; E09.22; E10.22; E11.22;E13.22 (exclude Z94.0; N18.6; Z99.2)) OR B) Microalbumin/proteinuria level >30 mg/g for 2 time periods ≥ 3 months. Values taken within 12 months of enrollment, unless 2 values are unavailable, then review within 24 months of enrollment. OR C) 15 ≤ eGFR ≤ 60 ml/min for 2 time periods ≥ 3 months. GFRs are taken within 12 months of enrollment, unless 2 values are unavailable, then review within 24 months.
  • Diabetes is defined by: HbA1c ≥ 6.5 at least one time in the last year OR ICD10 diagnosis codes OR Having diabetes in the patient's medical record problem list.

Who cannot join

  • Have diabetes, but no CKD.
  • Are currently on dialysis (ICD 10 codes N18.6, Z99.2 and Z94.0)
  • Have ESRD (eGFR<15 ml/min)
  • Have a left ventricular assist device (LVAD)
  • Have a terminal illness
  • Have patient-reported known pregnancy at time of enrollment
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  • Have had a liver, kidney, or allogeneic bone marrow transplant
  • Too cognitively impaired to provide informed consent and/or complete the study protocol
  • Institutionalized or too ill to participate (i.e. incarcerated, psychiatric or nursing home facility)
  • Plan to move out of the area within 6 months of enrollment
  • Not a current patient seeing a provider who cares for their hypertension (i.e., family medicine, internal medicine, nephrology, HIV provider, cardiology, hypertension specialists) at a participating site
  • Previously participated in the GUARDD pilot study OR have previously undergone APOL1 testing

Trial locations and contacts

14 sites in 1 country.

14 sites in 1 country

United States14 sites
  • University of Alabama at Birmingham

    Birmingham, Alabama, 35294

  • Baylor Research Institute

    Dallas, Texas, 75210

  • University of Florida - Gainesville

    Gainesville, Florida, 32610

  • Eskenazi Health

    Indianapolis, Indiana, 46202

  • Indiana University

    Indianapolis, Indiana, 46202

  • University of Florida - Jacksonville

    Jacksonville, Florida, 32209

  • Southeastern Healthcare

    Lumberton, North Carolina, 28358

  • Meharry Medical College

    Nashville, Tennessee, 37208

  • Nashville General Hospital

    Nashville, Tennessee, 37208

  • Vanderbilt University Medical Center

    Nashville, Tennessee, 37232

  • University Medical Center New Orleans

    New Orleans, Louisiana, 70112

  • Icahn School of Medicine at Mount Sinai

    New York, New York, 10029

  • The Institute for Family Health

    New York, New York, 10035

  • University of Pittsburgh

    Pittsburgh, Pennsylvania, 15261

Other trials in United States

About this study

GUARDD-US is a prospective, multicenter, unblinded, two arm randomized pragmatic clinical trial. Participants will be randomized in a 1:1 ratio to immediate APOL1 gene testing and return of results (ROR) to participant and provider (Intervention arm) versus delayed APOL1 gene testing and ROR to participant and provider (Control arm). The main study will compare outcomes between APOL1 positive participants in the Intervention arm (i.e., early knowledge of APOL1 status) to APOL1 positive participants in the Control arm (i.e., delayed knowledge of APOL1 status). Participants that are APOL1 negative in the Intervention and Control groups will not be included in the main study analyses.

GUARDD-US also includes a substudy to determine the effect of knowledge of genetic test results that predict efficacy of various antihypertensive medications on change in SBP from baseline to 3 months in APOL1 negative individuals at participating sites.

This substudy is listed separately on clinicaltrials.gov as NCT06748040 and Unique Protocol ID - PRO00102997_A

Read the detailed description

High-risk variants in the APOL1 gene explain approximately 70% of the excess prevalence of CKD in African Americans (AAs), conferring a 5 times higher risk for hypertensive CKD and a 10 times higher risk for ESRD. A pilot study (GUARDD), showed that returning APOL1 gene test results had a statistically significant improvement in SBP at 3 months when comparing APOL1 positives to APOL1 negatives who received their genetic testing results and when comparing APOL1 positives that received their results early to overall controls who did not receive their results until after the 3 month visit. GUARDD was not however powered to evaluate the effects of having and knowing a positive APOL1 status on outcomes for those with high risk of developing CKD (i.e., comparing outcomes for APOL1 positive patients who know their genetic risk to APOL1 positive patients who do not know their genetic risk). A broader trial is needed to better determine the importance of APOL1 gene testing for improving the testing, diagnosis, and treatment of individuals at risk of CKD.

The primary aim is to determine the effect of participant and provider knowledge of a positive APOL1 status and accompanying guideline based clinical decision support (CDS) on blood pressure management on change in systolic blood pressure (SBP) from baseline to 3 months after randomization among the APOL1 positive participants. Secondary aims are to:

  1. Determine the effect of participant and provider knowledge of a positive APOL1 status on the probability of documented CKD diagnosis.
  2. Determine the effect of participant and provider knowledge of a positive APOL1 status on the probability of receiving a urine microalbumin/creatinine testing and ACE-I/ARB prescription based on results of the urine microalbumin level.
  3. Explore cost effectiveness, mediators, moderators, psychobehavioral impact of results disclosure on participants, and effects of participant and provider knowledge of APOL1 status on provider treatment recommendations.

Approximately 6,750 participants of African ancestry age 18-70 with hypertension that either: 1) do not have diabetes and do not have CKD, or 2) have CKD. Participants with diabetes may be included as long as they also have CKD.

Population for Main Study:

Participants from Randomized Population (above) who test positive for APOL1

Main Study Analyses:

  • To determine the effect of participant and provider knowledge of a positive APOL1 status on SBP, we will compare the change in SBP from baseline to 3 months of the Intervention - APOL1 positive group to the change in SBP from baseline to 3 months of the Control - APOL1 positive group using a two sided t-test, as appropriate, with an overall two-sided type I error of 0.05.
  • The effect of knowledge of a positive APOL1 status on all secondary endpoints will be compared between Intervention - APOL1 positives to Control - APOL1 positives with the proportion difference test.
  • Additional analyses will include analysis of time trends in SBP, subset analyses, and exploratory analyses of cost effectiveness, mediators, moderators, psychobehavioral impact of results disclosure on participants, and effects of knowledge of APOL1 status on provider treatment recommendations.
Being tested
Timing of return of results
Keywords
Kidney Disease, Genetic testing, APOL1, Genomics, Renal Disease
Medical subject headings
Renal Insufficiency, Chronic, Hypertension, Kidney Diseases

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Timing of return of resultsOther

    Participants will be randomized to immediate versus delayed APOL1 return of results

Study groups in NCT04191824
Study groupRoleWhat they receive
Immediate Return of ResultsActive comparatorImmediate return of results to inform participant of APOL1 status (either positive or negative).
Receives: Other: Timing of return of results
Delayed Return of ResultsActive comparatorDelayed return of results of APOL1 status (either positive or negative) after the completion of the 6 month final study visit.
Receives: Other: Timing of return of results

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in Systolic Blood Pressure From Baseline to 3 Months for APOL1 Positive Participants.

    Measured: Baseline to 3 month study visit

Secondary outcomes (6)
  1. Change in Number of Participants With Urine Microalbuminuria/Proteinuria Orders

    Measured: Baseline to 6 month study visit

  2. Number of Participants With Documented Order of Microalbuminuria/Proteinuria Tests

    Measured: From baseline to 6 month study visit

  3. Number of Participants With a Change in Documented Diagnosis for Stage 3 CKD and Above

    Measured: From baseline to 6 month study visit

  4. Number of Participants With Documented Diagnosis of CKD Stage 3 and Above

    Measured: From baseline to 6 month study visit

  5. Number of Participants With a Change in Documented Diagnosis for Any Stage CKD

    Measured: From baseline to 6 month study visit

  6. Number of Participants With Documented Diagnosis of All Stages of CKD

    Measured: From baseline to 6 month study visit

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted10 Dec 2019
  2. Study start10 Jul 2020
  3. Primary completion9 Apr 2024
  4. Study completion17 May 2024

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Model description
Immediate versus delayed return of Apolipoprotein L1 (APOL1) genetic testing results to provider and participant.
Masking
None (open label)
Enrolment
6,789 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04191824
Sponsor's protocol ID
PRO00102997
Other IDs
U01HG010225, U01HG007269, U01HG010232, U01HG010248, U01HG010231, U01HG010245
Acronym
GUARDD-US
Status last verified
Mar 2026
First submitted
5 Dec 2019
Last updated
25 Mar 2026
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: The Data Coordinating Center (DCC) will submit de-identified participant level datasets and associated documentation to the NHGRI's data repository - Genomic Analysis, Visualization and Informatics Lab-space (AnVIL), for use by other investigators. The datasets and associated documentation will be available after publication of the primary results manuscript. Documentation will include annotated case report forms, list of derived variables along with descriptions, and a description of the data model and de-identification process.

Publications

  • Eadon MT, Cavanaugh KL, Orlando LA, Christian D, Chakraborty H, Steen-Burrell KA, Merrill P, Seo J, Hauser D, Singh R, Beasley CM, Fuloria J, Kitzman H, Parker AS, Ramos M, Ong HH, Elwood EN, Lynch SE, Clermont S, Cicali EJ, Starostik P, Pratt VM, Nguyen KA, Rosenman MB, Calman NS, Robinson M, Nadkarni GN, Madden EB, Kucher N, Volpi S, Dexter PR, Skaar TC, Johnson JA, Cooper-DeHoff RM, Horowitz CR; GUARDD-US Investigators. Design and rationale of GUARDD-US: A pragmatic, randomized trial of genetic testing for APOL1 and pharmacogenomic predictors of antihypertensive efficacy in patients with hypertension. Contemp Clin Trials. 2022 Aug;119:106813. doi: 10.1016/j.cct.2022.106813. Epub 2022 Jun 1.

    PubMed 35660539
  • Eadon MT, Cavanaugh KL, She L, Steen-Burrell KA, Mohottige D, Nadkarni GN, Kitzman H, Chakraborty H, Empey PE, Limdi NA, Singh R, Beasley CM, Parker AS, Cicali EJ, Ramos MA, Clermont S, Dodgen L, Elwood EN, Robinson M, Umeukeje EM, Garcia Ortega A, Shroff N, Rosenman MB, Nguyen KA, Volpi S, Rider R, Dexter PR, Skaar TC, Peterson JF, Cavallari LH, Johnson JA, Wyatt CM, Orlando LA, Cooper-DeHoff RM, Horowitz CR; Implementing Genomics in Practice (IGNITE) Pragmatic Trials Network. Genetic Testing for APOL1 in Adults With Hypertension: The GUARDD-US Randomized Clinical Trial. JAMA Netw Open. 2026 Mar 2;9(3):e260528. doi: 10.1001/jamanetworkopen.2026.0528.

    PubMed 41784962

Questions about this trial

What is this clinical trial studying?

A study testing Timing of return of results in people with Chronic Kidney Disease and Hypertension, run by Duke University at 14 sites in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 12 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 25 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 14 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Yes. Results are posted in the registry (first posted 30 Apr 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in Systolic Blood Pressure From Baseline to 3 Months for APOL1 Positive Participants. (time frame: Baseline to 3 month study visit). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04191824, which also lists 2 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 25 Mar 2026.

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