The overall goal of this study is to develop and test a novel method involving ultrasound imaging, in order to detect the development of type 1 diabetes. In this study the investigators will first establish a standard operating procedure for measuring pancreas blood flow speed and volume in the pancreas of human subjects. The investigators will then determine 1) whether these pancreas blood flow factors differ between healthy subjects and those who have recently developed type1 diabetes; and 2) how variable measurements are in healthy subjects and subjects that recently developed type1 diabetes, both between subjects and over time. To address these aims the investigators will perform pancreas ultrasound measurements in each subject using an approved injectable 'bubble' contrast agent that allows measurement of pancreas blood flow. The investigators will compare ultrasound measurement with characteristics of the subject's type 1 diabetes, including genetic factors, glucose levels and other circulating factors, as well as other factors that may influence blood flow in the pancreas independent of type1 diabetes. The successful conclusion of this study will indicate whether measuring pancreas blood flow speed/volume will be helpful in monitoring whether type1 diabetes will emerge and thus will allow a large scale study to answer this question.
Study Design and Research Methods Part I: 5 subjects from SOP group Goal: Optimize settings for destruction-replenishment contrast-enhanced ultrasound scan 1. Subject recruited at the Barbara Davis Center 2. Subject provides written consent 3. Review medical history (exclusion if required) 4. Subject refrains from eating for \~6h prior to measurement 5. Subject visits University of Colorado Hospital CTRC echo lab 6. CTRC staff places peripheral intravenous line (PIV) 7. Research staff collects vital signs, height and weight 8. Subject received conventional ultrasound scan to locate pancreas tail (by Sonographer, verified by radiologist). 9. Subject receives DEFINITY dose 10. Subject receives destruction-replenishment contrast-enhanced ultrasound scan (adjust settings to optimize) 11. Pause for 30 minutes, allowing subject to stand and move 12. Repeat steps 9-11 (once). 13. Subject de-identified. 14. Analyze data. Part II: 30 subjects from control group (healthy controls and multiple islet autoantibody positive subjects), 15 subjects from T1D group. Goal: characterize subject variability and test whether healthy subjects and those with T1D show differing contrast measures 1. Subject recruited at the Barbara Davis Center 2. Subject provides written consent 3. Review medical history (exclusion if required) 4. Subject refrains from eating for \~6h prior to study 5. Subject visits University of Colorado Hospital CTRC echo lab 6. Subject completes questionnaire (family history of diabetes, exclusion criteria) 7. CTRC staff places peripheral intravenous line (PIV) 8. Research staff collects vital signs, height and weight 9. Subject received conventional ultrasound scan to locate pancreas tail (by Sonographer, verified by radiologist). 10. Subject receives DEFINITY dose 11. Subject receives destruction-replenishment contrast-enhanced ultrasound scan (under SOP) 12. Pause for 30 minutes, allowing subject to stand and move 13. Repeat steps 10-12 (once). 14. Subject de-identified 15. Analyze data. In part I a single repeat measurement may be made to aide in the optimization of data collection. In part II a single repeat measurement is made to assess short-term intra-subject measurement variability. In part I and part II, a subject will be asked to return on a separate date (within 1 year of the initial scan) for a repeat procedure using an additional DEFINITY delivery method (bolus or infusion, whichever was not given at the initial visit) or if data collection was not of sufficient quality during the first visit.
Study Type
OBSERVATIONAL
Enrollment
50
* DEFINITY is administered as per manufactures instructions * 1 vial of DEFINITY is allowed to warm to room temperature and activated by 45s shaking on a VIALMIX * Withdraw the activated milky white suspension using the provided Dispensing Pin, PINSYNC or 18-20 gauge syringe needle, from the middle of the liquid in the inverted vial. * Deliver a dose of 10 μl/kg of 'milky white suspension' IV as a bolus, delivered over 30seconds. * Following imaging, provide a 10 mL flush of preservative-free saline * Wait at least 30minutes until second dose (if provided).
University of Colorado Anschutz, Barbara Davis Center
Aurora, Colorado, United States
RECRUITINGPrimary outcome 1
Optimized a contrast-enhanced ultrasound 'destruction-replenishment' protocol for imaging pancreas blood flow kinetics in adult human subjects.
Time frame: End of part I (6 months)
Primary outcome 2
Comparison of pancreas blood flow kinetics (i.e. 'destruction-replenishment' k2 'reperfusion rate' parameter) between control and T1D subjects.
Time frame: End of part II (1 year)
Primary outcome 3
Determining inter-subject variability in pancreas blood flow kinetics (i.e. the 'destruction-replenishment' k2 'reperfusion rate' parameter) among control subjects and among T1D subjects
Time frame: End of part II (1 year)
Primary outcome 4
Determining reproducibility in the measurement of pancreas blood flow kinetics (i.e. the 'destruction-replenishment' k2 'reperfusion rate' parameter) within subjects. This will initially focus on short-term intra-subject measurement variability.
Time frame: End of part II (1 year)
Secondary outcome 1
Comparison between control and T1D subjects for other parameters resulting from the measurement of pancreas blood flow kinetics (i.e. the 'destruction-replenishment' 'reperfusion amplitude' A, 'destruction efficiency' 1-B and 'pre-destruction signal' parameters).
Time frame: End of part II (1 year)
Secondary outcome 2
Determining inter-subject variability among control subjects and among T1D subjects for other parameters resulting from the measurement of pancreas blood flow kinetics (i.e. the 'destruction-replenishment' 'reperfusion amplitude' A, 'destruction efficiency' 1-B and 'pre-destruction signal' parameters).
Time frame: End of part II (1 year)
Secondary outcome 3
Correlation of pancreas blood flow kinetics with blood glucose and HbA1c (to test for a link between the measurement and glucose control).
Time frame: End of part II (1 year)
Secondary outcome 4
Comparison of pancreas blood flow kinetics with HLA haplotype or whether subject has first-degree relative with T1D (to test for a link between the measurement and T1D genetic risk).
Time frame: End of part II (1 year)
Secondary outcome 5
Comparison of pancreas blood flow kinetics with subject BMI, age, heart rate, blood pressure (to test for a link between the measurement and subject characteristics)
Time frame: End of part II (1 year)
Secondary outcome 6
Assessment of subject autoantibodies, c-peptide levels (to ensure subjects free of diabetes do not have islet autoimmunity and to ensure subjects with T1D have islet autoimmunity and residual beta cell mass)
Time frame: End of part II (1 year)
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