FEED-Cystic Fibrosis (FEED-CF)
- Conditions
- Cystic FibrosisCystic Fibrosis-related Diabetes
- Interventions
- Other: High-added sugar, high-fat CF dietOther: Low-added sugar, high-fat diet
- Registration Number
- NCT05766774
- Lead Sponsor
- Emory University
- Brief Summary
The goal of this study is to determine the extent to which excess dietary sugars serve as a precipitating factor in glucose intolerance in adults with cystic fibrosis (CF), a population at especially high risk for a unique form of diabetes (CF-related diabetes, CFRD) and with standard-of-care dietary recommendations (high-calorie, high-fat) that conflict with recommendations for other forms of diabetes.
This trial will investigate if the typical high-sugar, high-fat CF diet plays a role in diabetes risk and visceral fat accumulation in people with CF. A total of 30 participants will get a low-added sugar, high-fat diet and the other 30 will get a standard CF diet with no sugar restrictions. Participants will be randomized to the diet group they are assigned. All foods will be provided for 8 weeks.
- Detailed Description
Approximately half of adults with cystic fibrosis (CF), a genetic disease, will develop diabetes. Dietary strategies shown to be successful in preventing or treating other forms of diabetes in people without CF contradict current nutritional recommendations for people with CF. The nutrition standard-of-care in CF is prescription of an unrestricted high-calorie, high-fat diet because of malnutrition. However, the standard CF diet translates to low-quality diets, with excess added sugars well-above general population recommendations. Also the investigators have shown that people with CF have more fat around their abdominal organs (called visceral fat) compared to healthy controls. The hypothesis is that the typical high-sugar, high-fat CF diet plays a role in diabetes risk and visceral fat accumulation in people with CF. In this study, the investigators will test if a low-added sugar diet improves risk markers for diabetes and decreases visceral fat over 8 weeks. The study will recruit 60 participants with CF. A total of 30 participants will get a low-added sugar, high-fat diet and the other 30 will get a standard CF diet with no sugar restrictions. Participants will be randomized to the diet group they are assigned. All foods will be provided for 8 weeks. There will be a total of 4 study visits at the Emory Hospital clinical research unit. These will include: 1) a screening visit with an oral glucose tolerance test with blood draws to determine if they already have diabetes, 2) a baseline visit for an insulin secretion test (called glucose-potentiated arginine (GPA) stimulation test) to assess risk for diabetes, as well as magnetic resonance imaging (MRI) testing to measure visceral fat, 3) a 4-week visit for another oral glucose tolerance test and in-person check-in, and 4) an 8-week visit for another GPA and MRI. Blood samples will be collected and banked. In addition to all meals provided for 8 weeks, participants will be compensated for their time and effort. Participants will be recruited from patients seen at the Emory CF Clinic. Informed consent will be performed prior to any study testing. The investigators hope this study will contribute to the development of new standardized nutrition guidelines for people living with CF.
Recruitment & Eligibility
- Status
- RECRUITING
- Sex
- All
- Target Recruitment
- 60
- Confirmed CF diagnosis
- Ages 18 years and older
- Baseline estimated daily total added sugar intake >16 tsp, as estimated from the Dietary Screener Questionnaire (DSQ).
- Nocturnal tube feeds
- BMI <18.5 kg/m2
- Life expectancy < 12 months
- Confirmed diagnosis of CFRD
- Screening OGTT showing fasting hyperglycemia (ā„126 mg/dL)
- Chronic steroid use
- Current pregnancy or lactation
- Inability/unwillingness to consume the majority of foods on the menu during the study period
- MRI-incompatible metal that cannot be removed for testing
- Uncontrolled exocrine pancreatic insufficiency/malabsorption
- Clinically instability, defined as no changes in medical regimen (including medications and pulmonary exacerbations) for at least 21 days prior to study visit
- Initiation of CFTR modulator within previous 8 weeks OR unstable changes in weight and lung function due to CFTR modulator use
- Actively trying to gain or lose weight
- Any food allergies or intolerances that cannot be accommodated
- Any medical condition deemed by the a study physician or PI that may preclude completion of the study or interfere with primary end points.
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Typical CF diet Arm High-added sugar, high-fat CF diet Patients will receive a high-added sugar, high-fat CF diet for 8 weeks. Study menus will be designed by registered dietitians using the Nutrient Database System for Research (NDSR) software program with a 2-wk rotation. Total kcal provided will be individually tailored to maintain body weight and adjusted throughout as needed. All foods (including snacks and drinks) for 8 wks will be delivered to participants' homes. Menus will be designed so that food will be delivered to subjects' homes every 3-4 days. It will be expected that participants consume only the foods provided by the study. Low-added sugar, high-fat diet Arm Low-added sugar, high-fat diet Patients will receive a low-added sugar, high-fat diet for 8 weeks. Study menus will be designed by registered dietitians using the Nutrient Database System for Research (NDSR) software program with a 2-wk rotation.Total kcal provided will be individually tailored to maintain body weight and adjusted throughout as needed. All foods (including snacks and drinks) for 8 wks will be delivered to participants' homes. Menus will be designed so that food will be delivered to subjects' homes every 3-4 days. It will be expected that participants consume only the foods provided by the study.
- Primary Outcome Measures
Name Time Method Change in acute insulin response to arginine (AIRarg) from baseline Baseline and 8 weeks post intervention Participants will undergo a Glucose-Potentiated Arginine Stimulation (GPA) Test after a 10-12 hour overnight fast to measure acute insulin (AIRarg) responses during a 230 and 340 mg/dl glucose clamp. This test will measure changes in beta cell secretory capacity.
Change in acute C-peptide (ACRarg) from baseline Baseline and 8 weeks post intervention Participants will undergo a Glucose-Potentiated Arginine Stimulation (GPA) Test after a 10-12 hour overnight fast to measure acute C-peptide (ACRarg) responses during a 230 and 340 mg/dl glucose clamp. This test will measure changes in beta cell secretory capacity.
Change in visceral adipose tissue from baseline Baseline and 8 weeks post intervention Dual energy X-ray absorptiometry (DEXA)-derived measurement of visceral adipose tissue (VAT) will be assessed with a GE Lunar iDXA machine. This will enable assessment of changes in body composition over the study.
Change in fasted plasma Eh[CySS] from baseline Baseline and 8 weeks post intervention Change in plasma Cysteine/Cystine Redox Potential (Eh\[CySS\]) will be measured.
- Secondary Outcome Measures
Name Time Method Change in hepatic and pancreatic fat volume Baseline and 8 weeks post intervention Dual energy X-ray absorptiometry (DEXA)-derived measurement of visceral adipose tissue (VAT) for hepatic and pancreatic fat volume. Will be assessed with a GE Lunar iDXA machine.
Change in fasted plasma Eh[GSSG] Baseline and 8 weeks post intervention Change in plasma glutathione disulfide (GSSG) (Eh\[CySS\]) will be measured.
Change in Gastrointestinal Symptom Rating Scale (GSRS) scale Baseline and 8 weeks post intervention The GSRS is a 15 items combine into five symptom clusters: Reflux, Abdominal pain, Indigestion, Diarrhea and Constipation.
Possible score range is 0-7, with 7 being the worst and 0 being the best (no symptoms).
Trial Locations
- Locations (1)
Emory University Hospital
šŗšøAtlanta, Georgia, United States