An interventional study of Low Glycemic Load Diet in Cystic Fibrosis, Cystic Fibrosis-related Diabetes and Cystic Fibrosis With Intestinal Manifestations, sponsored by Boston Children's Hospital. Completed at 1 site in United States. Open to participants aged 18 Years to 70 Years. Per ClinicalTrials.gov, last updated 2023-08-14.
Sponsored by Boston Children's Hospital · Not applicable, Interventional, and Treatment
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.
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.
1,581 studies on the registry are indexed under Cystic Fibrosis; 190 are open to participants now.
This study's enrollment of 11 is below the median of 36 across 1,034 interventional studies indexed under Cystic Fibrosis.
Browse Cystic Fibrosis studies →Boston Children's Hospital is the lead sponsor of 598 studies on the registry; 151 are open to participants now.
Of its 31 completed or terminated interventional studies of FDA-regulated products, 18 (58%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Feeding study with dietary composition (approximately) 50% fat, 30% carbohydrate, 20% protein.
Behavioral: Low Glycemic Load Diet
Food delivery service will provide a low glycemic load diet for 8 weeks
Change in weight from baseline and 10 weeks
Anthropometric measure
Time frame: Baseline and 10 weeks
Change in percent time <54 mg/dL
Continuous glucose monitoring
Time frame: Baseline and 10 weeks
Patient reported tolerability of dietary intervention, Likert scale
Single Likert scale question of overall diet tolerability, ranging from 1 (intolerable) to 10 (completely tolerable)
Time frame: Single measurement at 10 weeks after diet completion
Change in percent time >140 mg/dL
Continuous glucose monitoring
Time frame: Baseline to 10 weeks
Change in CGM average glucose
Continuous glucose monitoring
Time frame: Baseline to 10 weeks
Change in CGM glucose management indicator (GMI)
Continuous glucose monitoring
Time frame: Baseline to 10 weeks
Change in CGM standard deviation (SD)
Continuous glucose monitoring
Time frame: Baseline to 10 weeks
Change in CGM coefficient of variation (CV)
Continuous glucose monitoring
Time frame: Baseline to 10 weeks
Change in percent time less than 50 mg/dL on CGM
Continuous glucose monitoring
Time frame: Baseline to 10 weeks
Change in percent time less than 70 mg/dL on CGM
Continuous glucose monitoring
Time frame: Baseline to 10 weeks
Change in percent time 70-180 mg/dL on CGM
Continuous glucose monitoring
Time frame: Baseline to 10 weeks
Change in percent time greater than 180 mg/dL on CGM
Continuous glucose monitoring
Time frame: Baseline to 10 weeks
Change in percent time greater than >250 mg/dL on CGM
Continuous glucose monitoring
Time frame: Baseline to 10 weeks
Number of episodes of symptomatic hypoglycemia
Survey
Time frame: Baseline and 10 weeks
Change in lean and fat mass
DXA body composition measures
Time frame: Baseline and 10 weeks
Change in Patient Assessment of Constipation (PAC) questionnaire score
Likert scale questionnaire with 12 items, each item scored 0-4, total score ranging from 0-48 with higher scores related to worse outcomes
Time frame: Baseline and 10 weeks
Change in Patient Assessment of Gastrointestinal Symptom (PAGI-SYM) questionnaire score
Likert scale questionnaire with 20 items, each item scored 0-5, total score ranging from 0-100 with higher scores related to worse outcomes
Time frame: Baseline and 10 weeks
Change in Modified Activity Questionnaire (MAQ) score
Questionnaire, units of total hours of exercise over past 12 months, no min or max scores, higher value related to better outcome
Time frame: Baseline and 10 weeks
Change in Cystic Fibrosis Questionnaire Revised (CFQ-R) score
Likert scale questionnaire, 50 items, each scored 0-4, total score ranging from 0-100 with higher value reflecting better outcome
Time frame: Baseline and 10 weeks
Change in erythrocyte sedimentation rate (ESR)
Laboratory test, measured in mm/hr
Time frame: Baseline and 10 weeks
Change in c-reactive protein (CRP)
Laboratory test, measured in mg/L
Time frame: Baseline and 10 weeks
Change in intestinal fatty acid binding protein (I-FABP)
Laboratory test, measured in ng/mL
Time frame: Baseline and 10 weeks
Plan to share: No — There is no plan to share IPD data with other researchers.
This study is completed, as verified in Aug 2023. You cannot join it, but the record below documents what was studied.
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Boston Children's Hospital