This pilot study will be conducted in adolescents with cystic fibrosis (CF) without diabetes but with abnormal glucose tolerance, and will assess the effects of sitagliptin on glucose regulation. An oral glucose tolerance test (OGTT) and a mixed meal tolerance test (MMTT), will be performed at baseline and again \~4 weeks after treatment with study drug. We will also look at blood sugars throughout the day using a continuous glucose monitor (CGM) before each time the MMTT/OGTT are performed. Several hormones that may affect the way the body regulates blood sugars will be measured in blood when the OGTT and MMTT are done. We will assess the effect this medicine has on blood sugars (using CGM) and the effect the medicine has on the hormones measured during the OGTT and MMTT.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
6
Nemours Children's Clinic
Jacksonville, Florida, United States
Response to sitagliptin
Baseline and stimulated C-peptide levels (using mixed meal tolerance test) before and after treatment with sitagliptin.
Time frame: Change from baseline to ~4 weeks of study drug
Response to sitagliptin
Change in glycemic variability using continuous glucose monitoring data before and after treatment with dipeptidyl peptidase-4 inhibitor.
Time frame: Change from baseline to ~4 weeks of study drug
Response to sitagliptin
Change in incretins concentrations (glucagon like peptide 1; glucose-dependent insulinotropic polypeptide) in response to study drug.
Time frame: Change from baseline to ~4 weeks of study drug
Response to sitagliptin
Change in incretin (glucagon like peptide 1; glucose-dependent insulinotropic polypeptide) concentrations in response to study drug.
Time frame: Change from baseline to ~4 weeks of study drug
Beta-cell function
Beta-cell function will be measured using mixed meal tolerance tests (MMTT) and oral glucose tolerance tests (OGTT), assessing maximum concentration and area under the curve (AUC) of glucose, insulin and c-peptide for both OGTT and MMTT.
Time frame: Change from baseline to ~4 weeks of study drug
Continuous glucose monitoring (CGM)
Baseline and post-treatment changes in glycemic variability using CGM, including mean amplitude of glycemic excursion (MAGE), peak post-prandial blood sugars, and glucose area under the curve.
Time frame: change from baseline to ~4 weeks of study drug
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.