Cystic Fibrosis

Cystic Fibrosis (CF) Systematic Review Research Questions (2018)

Based on the findings from the scoping review, the Nutritional Genomics systematic review will address the following research questions (subject to change):

Assessment Research Questions 
  1. In patients with cystic fibrosis, which nutrition assessment parameters (see list below) are valid and reliable compared to reference standards, as measured by validity and/or reliability studies? 
    • Composite nutrition scores (ex: SGA) (assessment and screening tools)
    • Nutrition Focused Physical Exam (NFPE)
    • Weight and growth parameters
      • Adults (20 and over): BMI, BMI change, weight change
      • Pediatrics (2-19 years): BMI percentile, weight percentile, height percentile, height-for-age, weight-for-age, change in any of the above
      • Pediatrics (<2 years): weight percentile, length percentile, weight-for-length, weight-for-age, change in any of the above (specify WHO vs CDC)
    • Body composition (skinfold measurements, MUAC, BIA, DEXA)
    • Handgrip Strength
       
  2. In patients with cystic fibrosis, which nutrition assessment parameters (see list below) predict hard outcomes (FEV1, Quality of Life or mortality) after ≥3 months? 
    • Composite nutrition scores
    • Nutrition Focused Physical Exam (NFPE)
    • Weight and growth parameters
      • Adults (20 and over): BMI, BMI change, weight change
      • Pediatrics (2-19 years): BMI percentile, weight percentile, height percentile, height-for-age, weight-for-age, change in any of the above
      • Pediatrics (<2 years): weight percentile, length percentile, weight-for-length, weight-for-age, changes in any of the above (specify WHO vs CDC)
    • Body Composition (skinfold measurements, MUAC, BIA, DEXA)
    • Handgrip strength
    • Micronutrient Deficiencies (vitamins A, D, E, Zinc)
    • EFA Deficiencies
    • Lipid Profile
    • Cystic Fibrosis-related diabetes
       
  3. In patients with cystic fibrosis, what is the accuracy of using energy requirement formulas to determine REE, compared to indirect calorimetry?
    • Which REE equations include adjustment for physical activity level?
       
Intervention Research Questions
  1. In patients with cystic fibrosis, how does Medical Nutrition Therapy (MNT/nutrition counseling) provided by a registered dietitian or international equivalent, compared to an alternative intervention or control, affect nutrition-related outcomes? 
     
  2. In patients with cystic fibrosis, what is the effect of dietary intake on nutrition-related outcomes?
    • high or low in dietary fat </> 40%,
    • fat type (SFAs, PUFAs, MUFAs, EFAs)
    • high or low dietary protein (>20% or <10%)
    • dietary protein type (plant vs animal)
    • high or low dietary carbohydrates (>65% or <45%)
    • specific dietary patterns
      • mediterranean diet
      • vegetarian or vegan diet
      • low glycemic index/load diet
    • food groups
      • ≥5 servings of fruits and vegetables per day
      • ≥3 servings of  whole grains per day
      • ≥8 oz of fish/seafood per week
      • ≥3 servings of dairy products per day
      • </>10% of calories from added sugars
    • eating at least 3 times each day
    • In infants with CFRD, what is the effect  refined carbohydrates, including juice, soda and candy, on glycemic control (HbA1C)?
    • Infants with cystic fibrosis: exclusive breastfeeding, mixed feeding or formula feeding
       
  3. Effect of CFTR Therapy
    • In patients with CF, what is the effect of CFTR modulation therapy on weight/growth parameters (BMI, BMI change, weight change, BMI z-score, height-for-age z-score, weight-for-age z-score) and body composition (fat mass and fat free mass)?  
    • How is this relationship modified by dietary intake?

Nutrition Related Outcomes: Primary Outcomes
  1. Mortality/survival
  2. Quality of Life
  3. Lung/pulmonary function 
  4. Anthropometric Measures and Growth
  5. Morbidities 
  6. GI symptoms
  7. Lab measures

 Project Timeline
The systematic review is in the question development phase and will soon start the data extraction phase. The anticipated publication date of the systematic review and guideline is spring 2019. Please continue to check for updates.
  • Learn more about the EAL systematic review process. Visit Policy and Process
  • Question or input on the cystic fibrosis scoping review and/or systematic review research questions, please email: eal@eatright.org


updated: 5/22/2018