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Copeptin in Adolescent Participants With Type 1 Diabetes and Early Renal Hemodynamic Function (CASPER)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT03618420
Recruitment Status : Completed
First Posted : August 7, 2018
Results First Posted : August 31, 2021
Last Update Posted : April 20, 2022
Information provided by (Responsible Party):
University of Colorado, Denver

Brief Summary:

Over 1.25 million Americans have type 1 diabetes (T1D), increasing risk for early death from cardiorenal disease. The strongest risk factor for cardiovascular disease (CVD) and mortality in T1D is diabetic kidney disease (DKD). Current treatments, such as control of hyperglycemia and hypertension, are beneficial, but only partially protect against DKD.

Hyperfiltration is common in youth with T1D, and predicts progressive DKD. Hyperfiltration is also associated with early changes in intrarenal hemodynamic function, including increased renal plasma flow (RPF) and glomerular pressure. Intrarenal hemodynamic function is strongly influenced by the renin-angiotensin-aldosterone system (RAAS), which is also considered a key player in the pathogenesis of DKD. Preliminary data demonstrate differences in intrarenal hemodynamic function and RAAS activation in early and advanced DKD in T1D. However, the pathophysiology contributing to the differences observed in RAAS activation and intrarenal hemodynamic function in T1D are poorly defined Animal research demonstrates that arginine vasopressin (AVP) acts directly to modify intrarenal hemodynamic function, but also indirectly by activating RAAS. Preliminary data suggest that elevated copeptin, a marker of AVP, which predicts DKD in T1D adults, independently of other risk factors. However, no human studies to date have examined how copeptin relates to intrarenal hemodynamic function in early DKD in T1D. A better understanding of this relationship is critical to inform development of new therapies targeting the AVP system in T1D. Accordingly, in this study, the investigators propose to define the relationship between copeptin and intrarenal hemodynamics in early stages of DKD, by studying copeptin levels, renal plasma flow, and glomerular filtration in youth (n=50) aged 12-21 y with T1D duration < 10 y.

Condition or disease Intervention/treatment Phase
Diabetes Mellitus, Type 1 Nephropathy Diabetic Nephropathies Juvenile Diabetes Diabetes Mellitus Complication Autoimmune Diabetes Type 1 Diabetes Mellitus Drug: Aminohippurate Sodium Inj 20% Drug: Iohexol Inj 300 mg/mL Phase 1 Phase 2

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 50 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Intervention Model Description: All study participants will receive the same intervention.
Masking: None (Open Label)
Primary Purpose: Diagnostic
Official Title: CASPER Study: Copeptin in Adolescent Participants With Type 1 Diabetes and Early Renal Hemodynamic Function
Actual Study Start Date : October 1, 2018
Actual Primary Completion Date : October 19, 2019
Actual Study Completion Date : August 1, 2021

Arm Intervention/treatment
Clinical Investigation
All participants will undergo assessment of Glomerular Filtration Rate, (Iohexol Inj 300 mg/mL) and Effective Renal Plasma Flow (Aminohippurate Sodium Inj 20%). In addition, participants will undergo imaging assessment that includes Dual X-Ray Absorptiometry (DXA), renal Blood Oxygen Level Dependent (BOLD) and Arterial Spin Labeling (ASL) MRI.
Drug: Aminohippurate Sodium Inj 20%
Diagnostic aid/agent used to measure effective renal plasma flow (ERPF)
Other Names:
  • Aminohippuric acid
  • Para-aminohippurate (PAH)
  • Sodium 4-amino hippurate (PAH) inj 20% 2g/10 mL

Drug: Iohexol Inj 300 mg/mL
Diagnostic aid/agent used to measure glomerular filtration rate (GFR)
Other Name: omnipaque 300

Primary Outcome Measures :
  1. Copeptin Levels [ Time Frame: 4 hours ]
    Measured by fasting blood draw; Copeptin will be measured by ultrasensitive assays on KRYPTOR Compact Plus analyzers using the commercial sandwich immunoluminometric assays (Thermo Fisher Scientific, Waltham, MA). The copeptin assay has a lower limit of detection of 0.9 pmol/L, and a sensitivity of <2pmol/L. Elevated copeptin will be defined as >13pmol/L, which is >97.5th percentile for healthy adults (68).

  2. Effective Renal Plasma Flow (ERPF) [ Time Frame: 4 hours ]
    Measured by para-aminohippurate (PAH) clearance; An intravenous (IV) line was placed, and participants were asked to empty their bladders. Spot plasma and urine samples were collected prior PAH infusion. PAH (2 g/10 mL, prepared at the University of Minnesota, with a dose of [weight in kg]/75 × 4.2 mL; IND #140129) was given slowly over 5 min followed by a continuous infusion of 8 mL of PAH and 42 mL of normal saline at a rate of 24 mL/h for 2 h. After an equilibration period, blood was drawn at 90 and 120 min, and ERPF was calculated as PAH clearance divided by the estimated extraction ratio of PAH, which varies by the level of GFR (13). We report absolute ERPF (mL/min) in the main analyses because the practice of indexing ERPF for body surface underestimates hyperperfusion, and body surface area (BSA) calculations introduce noise into the clearance measurements.

  3. Glomerular Filtration Rate (GFR) [ Time Frame: 4 hours ]
    Measured by iohexol clearance; An intravenous (IV) line was placed, and participants were asked to empty their bladders. Spot plasma and urine samples were collected prior to iohexol infusion. Iohexol was administered through bolus IV injection (5 mL of 300 mg/mL; Omnipaque 300, GE Healthcare). An equilibration period of 120 min was used and blood collections for iohexol plasma disappearance were drawn at +120, +150, +180, +210, +240 min (11). Because the Brøchner-Mortensen equation underestimates high values of GFR, the Jødal-Brøchner-Mortensen equation was used to calculate the GFR (12). We report absolute GFR (mL/min) in the main analyses because the practice of indexing GFR for body surface underestimates hyperfiltration, and body surface area (BSA) calculations introduce noise into the clearance measurements.

Secondary Outcome Measures :
  1. Renal Perfusion [ Time Frame: 10 min ]
    Measured by Arterial Spin Labeling (ASL) MRI; ASL MRI: ROI analysis will be used to estimate (delta) M (difference in signal intensity between non-selective and selective inversion images). Using the same ROI, M0 will be estimated from the proton density image. T1 measurements from the same ROI will be obtained by fitting the signal intensity vs. inversion time data as described previously (104) using XLFit (ID Business Solutions Ltd., UK) or T1 maps created using MRI Mapper (Beth Israel Deaconess Medical Center, Boston). Partition coefficient will be assumed to be 0.8 ml/gm (105, 106). These values will then be used to estimate regional blood flow.

  2. Renal Oxygenation [ Time Frame: 60 min ]
    Measured by Blood Oxygen Level Dependent (BOLD) MRI; Regions of interest (ROI) analysis for BOLD MRI will be performed on a Leonardo Workstation (Siemens Medical Systems, Germany). Typically, 1 to 3 regions in each, cortex and medulla, per kidney per slice will be defined leading to a total of about 10 ROIs per region (cortex and medulla) per subject. The mean and standard deviation of these 10 measurements will be used a R2* measurement for the region, for the subject and for that time point. These data are used to calculate kidney oxygen availability (R2*), which is the BOLD-MRI outcome.

Information from the National Library of Medicine

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Ages Eligible for Study:   12 Years to 21 Years   (Child, Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Antibody+ T1D with <10 yr duration
  • Age 12-21 years
  • BMI ≥ 5%ile
  • Weight<350 lbs and > 57 lbs.
  • No anemia
  • HbA1c <12%

Exclusion Criteria:

  • Severe illness, recent diabetic ketoacidosis (DKA)
  • Estimated Glomerular Filtration Rate (eGFR) <60ml/min/1.73m2 or creatinine > 1.5mg/dl or history of ACR≥300mg/g
  • Anemia or allergy to shellfish or iodine
  • Pregnancy or nursing
  • MRI scanning contraindications (claustrophobia, implantable devices, >350 lbs)
  • Angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARB), diuretics, sodium-glucose co-transport (SGLT) 2 or 1 blockers, daily NSAIDs or aspirin, sulfonamides, procaine, thiazolsulfone or probenecid, atypical antipsychotics and steroids

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03618420

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United States, Colorado
Children's Hospital Colorado
Aurora, Colorado, United States, 80045
Sponsors and Collaborators
University of Colorado, Denver
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Principal Investigator: Petter Bjornstad, MD University of Colorado School of Medicine
  Study Documents (Full-Text)

Documents provided by University of Colorado, Denver:
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: University of Colorado, Denver Identifier: NCT03618420    
Other Study ID Numbers: 17-0820
First Posted: August 7, 2018    Key Record Dates
Results First Posted: August 31, 2021
Last Update Posted: April 20, 2022
Last Verified: March 2022
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided

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Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
Additional relevant MeSH terms:
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Kidney Diseases
Diabetic Nephropathies
Diabetes Mellitus
Diabetes Mellitus, Type 1
Diabetes Complications
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Autoimmune Diseases
Immune System Diseases
Urologic Diseases