NCT02202876.

Study name	Redox Imbalance and the Development of Cystic Fibrosis Diabetes (Redoxy).
Methods	RCT; parallel design; single blind (participant); single centre USA.
Participants	Estimated enrolment: 98 participants. Age: over 1 year. Includes healthy age‐matched controls.
Interventions	Group 1: children with CF aged 1 ‐ 9 years with normal glucose tolerance to receive 1.75 g/kg to a maximum of 75 gm of an oral glucose solution for OGTT. Group 2: age‐matched control children (1 ‐ 9 years) to receive 1.75 gm/kg to a maximum of 75 g of an oral glucose solution for OGTT. Group 3: teenagers (12 years and over) with CF with normal glucose tolerance to eat a high GI meal i.e. isocaloric breakfasts with GI of 80, the nutrient composition of each meal will be 10 kcal/kg, 50% kcal from carbohydrates, 20% kcal from protein, and 30% kcal from fat. Group 4: teenagers (12 years and over) with CF with normal glucose tolerance to eat a low GI meal i.e. isocaloric breakfasts with GI of 30, the nutrient composition of each meal will be 10 kcal/kg, 50% kcal from carbohydrates, 20% kcal from protein, and 30% kcal from fat.
Outcomes	Primary outcome: acute oxidation (cysteine/cysteine ratio) [Time Frame: Up to 3 hours]
Starting date	Start date: November 2014. Estimated primary completion date: September 2019. Estimated study completion date: September 2019.
Contact information	Principal Investigator: Arlene Stecenko MD (astecen@emory.edu), Children's Healthcare of Atlanta and Emory University, Atlanta, Georgia, USA. Contact: Joy Dangerfield (jdanger@emory.edu).
Notes	Data from healthy controls not eligible for inclusion in the review.

CF: cystic fibrosis
CFRD: cystic fibrosis‐related diabetes
GI: glycemic index
GIP: glucose‐dependent insulinotropic polypeptide
GLP‐1: glucagon‐like‐peptide‐1
GPA: glucose‐potentiated arginine
IGT: impaired glucose tolerance
Ind‐GT: indeterminate glucose tolerance
OGTT: oral glucose tolerance test
RCT: randomized controlled trial