Insulin Resistance, Obesity & Overweight, Pancreatic Steatosis, Type 2 Diabetes Mellitus (T2DM)
Conditions
Keywords
Bariatric Surgery, Sleeve Gastrectomy, Pancreatic Fat, MRI, Dixon Imaging, Islet Function, Insulin Secretion, Metabolic Surgery, Diabetes Remission
Brief summary
This study evaluates changes in pancreatic fat and recovery of pancreatic function in obese patients undergoing laparoscopic sleeve gastrectomy (LSG), a weight-loss surgery. Obesity can cause fat to accumulate in the pancreas, which may impair insulin production and lead to type 2 diabetes. This study uses magnetic resonance imaging (MRI) to measure pancreatic fat before and after surgery to understand how weight loss affects pancreatic function. About 50 obese patients (BMI \> 32 kg/m²) aged 16-60 years who are scheduled for LSG will be enrolled. Participants will undergo MRI scans of the pancreas and blood tests before surgery and at 1, 3, and 6 months after surgery. The MRI uses a safe, non-invasive technique called Dixon imaging to measure fat content in different parts of the pancreas (head, body, and tail). Blood tests will measure fasting glucose, insulin, C-peptide, and HbA1c to assess pancreatic function. The study aims to determine whether reduction in pancreatic fat after weight-loss surgery is associated with improved insulin secretion and reduced insulin resistance. This information may help doctors better understand how bariatric surgery improves metabolic health and guide postoperative patient management. Participation involves no additional risk beyond routine clinical care. All MRI scans and blood tests are part of standard postoperative monitoring for bariatric surgery patients.
Detailed description
See attached protocol for detailed study design, eligibility criteria, and outcome measures.
Interventions
Standard laparoscopic sleeve gastrectomy performed by experienced surgeons. This is the routine clinical procedure for weight loss, not an experimental intervention. The study observes pancreatic fat changes and metabolic outcomes following this standard surgery.
Sponsors
yu li，MD
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
16 Years to 60 Years
Healthy volunteers
No
Inclusion criteria
* Age between 16 and 60 years * BMI \> 32 kg/m² * Preoperative auxiliary examination supports diagnosis of pancreatic fat infiltration * Willing to undergo pancreatic MRI examination * Previous attempts at other weight loss methods have been ineffective * Complete medical records available * Voluntary signed informed consent * Scheduled to undergo laparoscopic sleeve gastrectomy (LSG) at Qingdao University Affiliated Hospital
Exclusion criteria
* Secondary obesity * Previous major gastrointestinal surgery * Diagnosed gastric or duodenal ulcer * Gastrointestinal diseases associated with malabsorption * Other diseases causing abnormal pancreatic function * BMI \< 32 kg/m² * Poor compliance or self-control, unable to follow dietary guidance after surgery * Unable to complete follow-up visits * Contraindications for MRI examination * Pregnancy or lactation
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Pancreatic Fat Content | Baseline (preoperative), 1 month, 3 months, and 6 months postoperatively | Pancreatic fat fraction will be measured using MRI Dixon imaging at pancreatic head, body, and tail. Fat fraction (%) = \[(SI in-phase - SI opposed-phase) / (2 × SI in-phase)\] × 100. |
| Change in Insulin Resistance Index (HOMA-IR) | Baseline (preoperative), 1 month, 3 months, and 6 months postoperatively | Insulin resistance will be assessed using the Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) calculated as: \[fasting plasma glucose (mmol/L) × fasting insulin (μU/mL)\] / 22.5. Fasting plasma glucose will be measured by glucose oxidase method and fasting insulin will be measured by chemiluminescence immunoassay. Higher HOMA-IR values indicate greater insulin resistance. |
| Change in Pancreatic Beta-cell Function | Baseline (preoperative), 1 month, 3 months, and 6 months postoperatively | Pancreatic beta-cell function will be assessed using HOMA-%β (Homeostasis Model Assessment for beta-cell function) calculated as: HOMA-%β = \[20 × fasting insulin (μU/mL)\] / \[fasting glucose (mmol/L) - 3.5\] (%). Fasting blood glucose, fasting insulin, C-peptide, and HbA1c will be measured at each time point. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Body Weight and BMI | Baseline (preoperative), 1 month, 3 months, and 6 months postoperatively | Body weight will be measured using calibrated electronic scales with subjects wearing light clothing and no shoes. Height will be measured using a stadiometer. BMI will be calculated as weight (kg) divided by height squared (m²). Percentage of total weight loss (%TWL) and percentage of excess weight loss (%EWL) will also be calculated to assess surgical efficacy. |
| Change in Pancreatic Fat Distribution (Head, Body, Tail) | Baseline (preoperative), 1 month, 3 months, and 6 months postoperatively | Regional pancreatic fat content will be measured separately at pancreatic head, body, and tail using MRI Dixon imaging. Three regions of interest (ROI) will be drawn at the maximal cross-sectional area of each pancreatic segment. Fat fraction (%) = \[(SI in-phase - SI opposed-phase) / (2 × SI in-phase)\] × 100. This allows assessment of differential fat reduction patterns across pancreatic regions and correlation with regional islet function recovery. |
| Correlation Between Pancreatic Fat Reduction and Islet Function Recovery | Baseline to 6 months postoperatively (change scores will be calculated) | Correlation analysis between the magnitude of pancreatic fat reduction (measured by MRI Dixon) and improvement in islet function parameters (HOMA-%β, HOMA-IR, fasting insulin, C-peptide). This will identify whether pancreatic fat reduction is an independent predictor of beta-cell function recovery after laparoscopic sleeve gastrectomy. |
Countries
China
Contacts
STUDY_CHAIRYu Lu, MD, PhD
The Affiliated Hospital of Qingdao University
Outcome results
None listed