NCT03620773CompletedPhase 1/2
Impact of Metabolic Surgery on Pancreatic, Renal and Cardiovascular Health in Youth With Type 2 Diabetes
IMPROVE-T2D Study: Impact of Metabolic Surgery on Pancreatic, Renal and Cardiovascular Health in Youth With Type 2 Diabetes
Source: ClinicalTrials.gov · Last updated 12 Jan 2026
Brief summary (registry, in English)
Type 2 diabetes (T2D) in youth is increasing in prevalence in parallel with the obesity epidemic. In the US, almost half of patients with renal failure have DKD, and ≥80% have T2D. Compared to adult-onset T2D, youth with T2D have a more aggressive phenotype with greater insulin resistance (IR), more rapid β-cell decline and higher prevalence of diabetic kidney disease (DKD), arguing for separate and dedicated studies in youth-onset T2D. Early DKD is characterized by changes in intrarenal hemodynamic function, including increased renal plasma flow (RPF) and glomerular pressure with resultant hyperfiltration, is common in Y-T2D, and predicts progressive DKD. Studies evaluating the two currently approved medications for treating T2D in youth (metformin and insulin) have shown these medications are not able to improve β-cell function over time in the youth. However, recent evidence suggests that bariatric surgery in adults is associated with improvements in diabetes outcomes, and even T2D remission in many patients. Limited data in youth also supports the benefits of bariatric surgery, regarding weight loss, glycemic control in T2D, and cardio-renal health. While weight loss is important, the acute effect of bariatric surgery on factors such as insulin resistance likely includes weight loss-independent mechanisms. A better understanding of the effects of bariatric surgery on pancreatic function, intrarenal hemodynamics, renal O2 and cardiovascular function in youth with obesity with or without diabetes is critical to help define mechanisms of surgical benefits, to help identify potential novel future non-surgical approaches to prevent pancreatic failure, DKD and cardiovascular disease. The investigators' overarching hypotheses are that: 1) Y-T2D is associated with IR, pancreatic dysfunction, intrarenal hemodynamic dysfunction, elevated renal O2 consumption and cardiovascular dysfunction which improve with bariatric surgery, 2) The early effect of bariatric surgery on intrarenal hemodynamics is mediated by improvement in IR and weight loss, 3) Some aspects of cardio-renal-metabolic complications of T2D are related to obesity and others to T2D independent of obesity. To address these hypotheses, the investigators will measure GFR, RPF, glomerular pressure and renal O2, in addition to aortic stiffness, β-cell function and insulin sensitivity in youth ages 12-21 with T2D (n=40) and in (n=up to 10) youth with similar BMI but without diabetes, before and after vertical sleeve gastrectomy (VSG). To further investigate the mechanisms of renal damage in youth with T2D, two optional procedures are included in the study prior to vertical sleeve gastrectomy: 1) kidney biopsy procedure and 2) induction of induced pluripotent stem cells (iPSCs) to assess morphometrics and genetic expression of renal tissue.
- Status (registry)
- Completed
- Phase (registry)
- Phase 1/2
- Study type
- Interventional
- Enrollment
- 24 (actual)
- First submitted
- 1 Aug 2018
- Start date
- 1 Oct 2018
- Primary completion date
- 25 Sept 2024
- Lead sponsor
- University of Colorado, Denver
- Diseases
- Chronic kidney disease, Obesity, Type 2 diabetes
- NCT number
- NCT03620773
What you commit to
- Study type: Interventional · Phase 1/2
- Participants enrolled: 24
- From 1 Oct 2018 to the primary completion date, 25 Sept 2024
- 1 site in 1 country
- Visits and tests: ask the trial team, the registry does not list them
Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.
Who cannot take part
Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.
Prior treatment
- Single kidney (either by history, documented by prior imaging or ultrasound performed prior to the biopsy)
- \> 2 cm discrepancy between left and right kidney sizes based on largest longitudinal diameter determined by ultrasound performed prior to the biopsy.
Other illness
- For participants undergoing the optional Parts 2-4 of visits 2 and 4, seafood or iodine allergy
- Other causes of diabetes other than T2D
- Evidence of bleeding disorder or complications from bleeding
- Use of aspirin, NSAIDS or other blood thinner that cannot be safely stopped for a sufficient time period before and after the biopsy so as to add no additional risk of bleeding
- Uncontrolled or difficult to control hypertension (\> 150/90 mmHg at the day of biopsy)
- Hydronephrosis or other important renal ultrasound findings such as significant stone disease
- Any evidence of a current urinary tract infection as indicated on day of biopsy
- Clinical evidence of non-diabetic renal disease
Lab values
- For participants undergoing the optional Parts 2-4 of visits 2 and 4, diuretics, sodium-glucose co-transport (SGLT) 2 or 1 blockers, daily NSAIDs or aspirin, sulfonamides, procaine, thiazolsulfone or probenecid, atypical antipsychotics or regular use of oral steroids
- Additional exclusion criteria for participants undergoing Visit 4 part 4, the optional kidney biopsy:
- INR \> 1.4
- PTT \> 35 seconds
- Hemoglobin (Hgb) \< 10 mg/dL
- Platelet count \< 100,000 / µL
- eGFR \< 40 mL/min/1.73m2
Age
- Obesity or T2D onset (diagnosis) \> 18 years of age
Other
- Prepubertal
- Anemia
- Pregnancy or breastfeeding
- Claustrophobia, implantable devices (MRI contraindications)
- Recent diabetic ketoacidosis or hyperosmolar hyperglycemia
- Blood urea nitrogen (BUN) \> 80 gm/dL
- Kidney size: One or both kidneys \< 9 cm
- Positive urine pregnancy test or pregnancy
Who the study is looking for
- Obese youth with and without T2D (≥50 kg) scheduled for VSG
- Weight \<550 lbs.
- BMI ≥ 35 kg/m2
- Age 12-21 years
- HbA1c ≤ 12% for participants with T2D, HbA1c \< 6.5% for participants with obesity
Age in the registry: 12 years to 21 years · Sex: All · Does not accept healthy volunteers
Sites (1)
Sites in registry order. Pick your city on the disease page to sort them by distance.
| Site | City | Country | Site status |
|---|---|---|---|
| Children's Hospital Colorado Coordinator of this site? Confirm its status | Aurora | United States | Unknown status |
Related publications
- Impact of Vertical Sleeve Gastrectomy in Youth-Onset Type 2 Diabetes: Changes in Glycemia, Insulin Sensitivity, and Secretion.Obesity (Silver Spring) · 2026 · PMID 41708511
This page is information, not medical advice. Discuss any trial with your doctor.