A Pilot Study of a Low Glycemic Load Diet in Adults With Cystic Fibrosis

NCT ID: NCT04519853

Last Updated: 2023-08-14

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

11 participants

Study Classification

INTERVENTIONAL

Study Start Date

2021-10-25

Study Completion Date

2023-07-01

Brief Summary

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This pilot study will evaluate the safety and tolerability of a low glycemic load dietary intervention in adult patients with cystic fibrosis (CF) in a rigorous feeding study. Specific emphasis will be placed on changes in weight, body composition, and glycemic measures obtained via continuous glucose monitor (CGM) usage.

Detailed Description

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Non-pulmonary complications of cystic fibrosis (CF) are becoming increasingly prevalent with the changing landscape of CF care. CF related diabetes mellitus (CFRD) and CF related gastrointestinal (GI) complications have significant effects on morbidity and mortality. Treatment options are limited to insulin therapy for CFRD and symptom control for most GI complications.

BMI is a well-established marker of morbidity and mortality in patients with CF. Many patients consume a high carbohydrate intake to meet their increase caloric needs, potentially leading to complications including post-prandial hyperglycemia, increased inflammation, and abnormal GI motility. Dietary recommendations for children and adults with CF are limited and based entirely on consensus and expert opinion. As patients with CF live longer with highly effective modulator therapy, it is important to understand the effects of dietary composition on short and long-term endocrine, GI, and pulmonary outcomes.

The investigators will conduct a prospective, open-label pilot study in adults with CF and impaired glucose tolerance or indeterminate glycemia to establish the safety and tolerability of a low glycemic load (LGL) diet. Subjects will initially follow their standard diet for a 2-week run-in period, then transition to a LGL diet provided by a food delivery service for the remaining 8 weeks. The investigators will also investigate potential short-term outcomes of dietary carbohydrate manipulation, including glycemic variability measured by continuous glucose monitor (CGM), body composition via DXA, GI symptoms, and quality of life measures.

The investigators hypothesize that a diet lower in carbohydrate content will be safe, tolerable, and associated with weight maintenance or gain, and that a LGL diet will result in decreased glycemic variability via CGM, improved GI symptoms, increased lean to fat mass ratio, and improved quality of life measures over an 8-week period.

Conditions

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Cystic Fibrosis Cystic Fibrosis-related Diabetes Cystic Fibrosis With Intestinal Manifestations

Study Design

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Allocation Method

NA

Intervention Model

SINGLE_GROUP

Single dietary treatment arm with run-in period as a control
Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

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Low Glycemic Load Diet

Feeding study with dietary composition (approximately) 50% fat, 30% carbohydrate, 20% protein.

Group Type EXPERIMENTAL

Low Glycemic Load Diet

Intervention Type BEHAVIORAL

Food delivery service will provide a low glycemic load diet for 8 weeks

Interventions

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Low Glycemic Load Diet

Food delivery service will provide a low glycemic load diet for 8 weeks

Intervention Type BEHAVIORAL

Eligibility Criteria

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Inclusion Criteria

1. Diagnosis of CF
2. Diagnosis of pancreatic insufficiency, requiring pancreatic enzyme replacement
3. Oral glucose tolerance test within the past three years showing impaired glucose tolerance (2-hour glucose ≥140 mg/dL) or indeterminate glycemia (1-hour glucose ≥200), HbA1c 5.7-6.4% in the past one year, and/or or documented random glucose ≥200 in the past one year
4. BMI 21-25 kg/m2
5. 18 years and above

Exclusion Criteria

1. Current use of insulin
2. Most recent HbA1c ≥6.5%
3. History of solid organ transplant or currently listed for solid organ transplant
4. FEV1 \<50% predicted on most recent pulmonary function testing
5. Currently receiving enteral nutrition support
6. Current or anticipated pregnancy in the next 1 year
7. Hospitalization for CF exacerbation within 1 month of enrollment
8. Started or stopped treatment with Trikafta or other CFTR modulator within 3 months of enrollment
9. Currently adhering to a low glycemic index or other carbohydrate restricted diet
Minimum Eligible Age

18 Years

Maximum Eligible Age

70 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Boston Children's Hospital

OTHER

Sponsor Role lead

Responsible Party

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Melissa Putman

Assistant Professor of Pediatrics, Attending in Endocrinology

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Melissa S Putman, MD,MS

Role: PRINCIPAL_INVESTIGATOR

Boston Children's Hospital; Massachusetts General Hospital

Locations

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Boston Children's Hospital

Boston, Massachusetts, United States

Site Status

Countries

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United States

References

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Moran A, Brunzell C, Cohen RC, Katz M, Marshall BC, Onady G, Robinson KA, Sabadosa KA, Stecenko A, Slovis B; CFRD Guidelines Committee. Clinical care guidelines for cystic fibrosis-related diabetes: a position statement of the American Diabetes Association and a clinical practice guideline of the Cystic Fibrosis Foundation, endorsed by the Pediatric Endocrine Society. Diabetes Care. 2010 Dec;33(12):2697-708. doi: 10.2337/dc10-1768. No abstract available.

Reference Type BACKGROUND
PMID: 21115772 (View on PubMed)

Gabel ME, Galante GJ, Freedman SD. Gastrointestinal and Hepatobiliary Disease in Cystic Fibrosis. Semin Respir Crit Care Med. 2019 Dec;40(6):825-841. doi: 10.1055/s-0039-1697591. Epub 2019 Oct 28.

Reference Type BACKGROUND
PMID: 31659728 (View on PubMed)

Prentice BJ, Ooi CY, Strachan RE, Hameed S, Ebrahimkhani S, Waters SA, Verge CF, Widger J. Early glucose abnormalities are associated with pulmonary inflammation in young children with cystic fibrosis. J Cyst Fibros. 2019 Nov;18(6):869-873. doi: 10.1016/j.jcf.2019.03.010. Epub 2019 Apr 26.

Reference Type BACKGROUND
PMID: 31036487 (View on PubMed)

Brennan AL, Gyi KM, Wood DM, Johnson J, Holliman R, Baines DL, Philips BJ, Geddes DM, Hodson ME, Baker EH. Airway glucose concentrations and effect on growth of respiratory pathogens in cystic fibrosis. J Cyst Fibros. 2007 Apr;6(2):101-9. doi: 10.1016/j.jcf.2006.03.009. Epub 2006 Jul 17.

Reference Type BACKGROUND
PMID: 16844431 (View on PubMed)

Balzer BW, Graham CL, Craig ME, Selvadurai H, Donaghue KC, Brand-Miller JC, Steinbeck KS. Low glycaemic index dietary interventions in youth with cystic fibrosis: a systematic review and discussion of the clinical implications. Nutrients. 2012 Apr;4(4):286-96. doi: 10.3390/nu4040286. Epub 2012 Apr 18.

Reference Type BACKGROUND
PMID: 22606371 (View on PubMed)

Other Identifiers

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P00034904

Identifier Type: -

Identifier Source: org_study_id

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