The Effects of the CF Carrier State on the Kidneys and Pancreas

NCT ID: NCT05474417

Last Updated: 2026-01-07

Basic Information

• Recruitment Status: RECRUITING
• Total Enrollment: 1250 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2021-12-20
• Study Completion Date: 2026-07-31

Brief Summary

The overarching hypothesis is that CF carriers are at increased risk for developing most of the extrapulmonary conditions associated with CF compared to the general population. Specifically, it is hypothesized that this pilot data will detect subclinical evidence of pancreatic and kidney disorders among CF carriers. This will be determined by bringing CF carriers and controls to the CRU for one visit where they will answer survey questions and undergo laboratory testing. Additionally, they will collect urine and stool samples at home that will be sent to outside laboratories for testing.

Detailed Description

There are 2 main study components- a clinic visit (all participants) and at-home specimen collections (volunteer subsample only). Each procedure is described below.

Clinic Visit Procedures (all participants):

Height- Height will be measured to the nearest 0.5 cm. Shoes should be removed.

Weight- Weight will be measured to the nearest 0.5 kg. Shoes and any extra jackets/sweaters/layers should be removed.

Blood Pressure- Blood pressure will be measured using the following procedures- Make sure that the participant hasn't smoked for 20 minutes prior to the BP measurement. Remove all clothing that covers the location of the cuff placement. Have the participant sit comfortably in a chair, with back supported, legs uncrossed and feet flat on the floor, arm supported at the level of the heart on a table, palm facing upward. Be sure to choose a cuff that correctly fits the participant's arm size. The lower end of the cuff should be ½ to 1 inch above the inner side of the elbow joint. The middle of the cuff should be at the level of the right atrium. Place the cuff snugly around the bare upper arm so that you can only insert one finger between the cuff and the arm.

Blood Draws/2-Hour OGTT- The participant should be active and eat a regular diet for three days prior to the test. They should be instructed not to eat or drink anything except water for at least 8 hours before the test. Someone trained in phlebotomy will insert an IV into the patient's arm so that blood draws can occur before and after the oral glucose tolerance test (OGTT). They will draw 2 tubes of blood (one 3 ml lavender top tube for HbA1C and one 4.5 ml green plasma separator tube for glucose, insulin, c-peptide, and lipid values). Then, a team member will provide the participant with a chilled Fisherbrand Glucose Tolerance Test Beverage (10 oz beverage, 75 g concentration) to drink. The participant must drink the entire beverage within 5 minutes. The patient should remain seated during the 2-hours of the test. They should not eat or drink anything except for plain water during the test (no mints, cough drops, chewing gum, or smoking).

At the 1-hour mark, 1 tube of blood (4.5 ml green plasma separator tube for glucose and insulin values) will be drawn.

Once the 2 hours have passed, 2 more tubes of blood (one 3 ml lavender top tube for c-reactive protein, calprotectin, and lactoferrin and one 4.5 ml green plasma separator tube for glucose and insulin values) will be drawn.

During the downtime between blood draws, the participant will answer the questions from the baseline survey and report their current medications interview-style with the research team member.

This visit is expected to last 3-4 hours.

Home Specimen Collection (volunteer subsample only; volunteers may do urine and/or stool samples):

Participants will be given specimen collection containers and instructions on collecting the 24-hour urine sample and/or stool sample, whichever they volunteer to collect. Finally, a date, time, and meeting location will be scheduled to return the samples to the research team.

Conditions

Carrier State; Pancreatic Disease; Kidney Diseases

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: CROSS_SECTIONAL

Study Groups

Cystic Fibrosis Carrier Group

Participants who have been identified as Cystic Fibrosis Carriers via previous genetic testing.

No interventions assigned to this group

Control Group

Participants who have been identified as not being Cystic Fibrosis Carriers via previous genetic testing.

No interventions assigned to this group

Eligibility Criteria

Inclusion Criteria

• A CF Carrier identified via genetic testing

• No previous CF carrier test results

Exclusion Criteria

• CF patient status
• Unable to speak English
• Currently pregnant
• Unable to provide written informed consent
• Prisoner status
• Currently taking any medications for the treatment of diabetes

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 100 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

National Institutes of Health (NIH)

NIH

Sponsor Role: collaborator

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

NIH

Sponsor Role: collaborator

Philip Polgreen

OTHER

Sponsor Role: lead

Responsible Party

Philip Polgreen

Professor, Internal Medicine

Responsibility Role: SPONSOR_INVESTIGATOR

Principal Investigators

Philip M Polgreen, MD

Role: PRINCIPAL_INVESTIGATOR

University of Iowa

Locations

University of Iowa Hospitals and Clinics

Iowa City, Iowa, United States

Site Status: RECRUITING

Countries

United States

Central Contacts

Philip M Polgreen, MD

Role: CONTACT

philip-polgreen@uiowa.edu

(319) 384-6194

Shelby L Francis, PhD

Role: CONTACT

shelby-francis@uiowa.edu

319-678-8037

Facility Contacts

Shelby L Francis, PhD

Role: primary

shelby-francis@uiowa.edu

319-678-8037

Other Identifiers

5P30DK054759

Identifier Type: NIH

Identifier Source: secondary_id

View Link

202012447

Identifier Type: -

Identifier Source: org_study_id