Bariatric Surgery, Bariatric Surgery (Gastric Bypass), Insulin Resistance, Obesity (BMI>30), Obesity (BMI > 35)
Conditions
Keywords
FABP4, Roux-en-Y gastric bypass, adipokine, bariatric surgery, weight loss, adipose tissue remodeling, GLP-1, PYY, inflammation
Brief summary
This retrospective observational cohort study examined serum fatty acid-binding protein 4 (FABP4) dynamics in 28 adults who underwent Roux-en-Y gastric bypass (RYGB), followed at baseline, 3 months, and 6 months. Anthropometric, metabolic, and inflammatory parameters were assessed alongside FABP4, fasting GLP-1, and PYY. Patients were classified as FABP4 responders (decrease from baseline to 6 months) or rebound/non-responders. The study investigated whether FABP4 trajectory after RYGB is associated with the magnitude of weight loss, systemic inflammation, and fasting incretin change.
Detailed description
Sixteen of the 28 participants had previously been enrolled in the control (probiotic-only, non-prebiotic) arm of a completed, registered randomized trial of pre-/probiotic supplementation after RYGB at the same institution (ClinicalTrials.gov Identifier: NCT03517345); these participants received no prebiotic intervention. The remaining 12 participants underwent RYGB by the same surgeon during a comparable period and were not enrolled in that trial. Blood samples from both subgroups had originally been collected and stored at -80°C as part of their respective prospective clinical follow-up. FABP4 concentrations were subsequently measured in these banked, single freeze-thaw samples using a commercial ELISA assay, blinded to patients' weight-loss and inflammatory outcomes, and merged with the anthropometric and biochemical data collected at the corresponding original visits. Because FABP4 assay and the present statistical analysis were performed after clinical follow-up had already been completed for both subgroups, this study is registered retrospectively.
Interventions
None listed
Sponsors
Istanbul University
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
* Adults who underwent Roux-en-Y gastric bypass (RYGB), performed by a single surgeon * Completed baseline, 3-month, and 6-month clinical and anthropometric assessments
Exclusion criteria
* Use of GLP-1 receptor agonists at any study time point * Use of insulin at any study time point * Missing 6-month FABP4 measurement (excluded from FABP4-based longitudinal/group analyses; n=1)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Measure: Change in serum FABP4 level from baseline to 6 months after RYGB | Time Frame: Baseline, 3 months, 6 months | Description: FABP4 measured by ELISA; patients classified as responders (decrease) vs. rebound/non-responders (no decrease or increase) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in BMI from baseline to 3 and 6 months | Baseline, 3 months, 6 months | Change in BMI from baseline to 3 and 6 months |
| Change in body weight from baseline to 3 and 6 months | Baseline, 3 months, 6 months | Change in body weight from baseline to 3 and 6 months |
| Change in fat mass (bioelectrical impedance) from baseline to 3 and 6 months | Baseline, 3 months, 6 months | Change in fat mass and fat-free mass (bioelectrical impedance) from baseline to 3 and 6 months |
| Change in fat-free mass (bioelectrical impedance) from baseline to 3 and 6 months | Baseline, 3 months, 6 months | Change in fat mass and fat-free mass (bioelectrical impedance) from baseline to 3 and 6 months |
| Change in HOMA-IR from baseline to 3 and 6 months | Baseline, 3 months, 6 months | Change in HOMA-IR from baseline to 3 and 6 months |
| Change in IL-6 from baseline to 3 and 6 months | Baseline, 3 months, 6 months | Change in hsCRP and IL-6 from baseline to 3 and 6 months |
| Change in hsCRP from baseline to 3 and 6 months | Baseline, 3 months, 6 months | Change in hsCRP and IL-6 from baseline to 3 and 6 months |
| Change in fasting GLP-1 from baseline to 3 and 6 months | Baseline, 3 months, 6 months | Change in fasting GLP-1 and PYY from baseline to 3 and 6 months |
| Change in fasting PYY from baseline to 3 and 6 months | Baseline, 3 months, 6 months | Change in fasting GLP-1 and PYY from baseline to 3 and 6 months |
| Baseline-Adjusted 6-Month Change in Body Mass Index (BMI) by FABP4 Response Group | Baseline, 3 months, 6 months | 6-month change in BMI (kg/m²) was compared between FABP4 responder and rebound (non-responder) groups using an ANCOVA model adjusted for baseline (preoperative) serum FABP4 concentration (log-transformed). FABP4 response group was defined by the direction of change in serum FABP4, measured by enzyme-linked immunosorbent assay (ELISA), from baseline to 6 months after Roux-en-Y gastric bypass. |
| Odds Ratios for Predictors of 6-Month FABP4 Rebound: Early (0-3-Month) BMI Change, Age, and Sex | Baseline, 3 months, 6 months | Odds ratios (OR) with 95% confidence intervals were estimated using a multivariable logistic regression model to identify predictors of FABP4 rebound status at 6 months after Roux-en-Y gastric bypass. Covariates included early (0-3-month) percentage change in body mass index (BMI), age (years), and sex (male/female). FABP4 rebound was defined as an increase in serum FABP4 concentration, measured by enzyme-linked immunosorbent assay (ELISA), from baseline to 6 months postoperatively. |
Contacts
PRINCIPAL_INVESTIGATORBedia Fulya Calikoglu, M.D., PhD.
Istanbul University, Istanbul Medical Faculty
Outcome results
None listed