Amino Acid Metabolism Before and After Bariatric Surgery

Examination of Preoperative and Postoperative Serum Amino Acid Metabolism in Individuals Undergoing Bariatric Surgery

This observational study aims to investigate the changes in serum amino acid metabolism before and after bariatric surgery in obese individuals. Blood samples will be collected from 50 patients at baseline (preoperative), and at 1 and 3 months postoperatively. An additional 50 healthy individuals will serve as the control group. Amino acid profiling will be conducted using LC-MS/MS. The study seeks to determine how bariatric surgery affects metabolic pathways associated with amino acid regulation.

Study Overview

• Status: Completed
• Conditions: Obesity, Morbid
• Intervention / Treatment: Procedure: Blood sample collection for amino acid profiling

Detailed Description

Obesity is a major global health problem that significantly increases the risk of metabolic disorders. Bariatric surgery is one of the most effective interventions for sustained weight loss in morbidly obese patients. However, the metabolic effects of such surgery on amino acid profiles are not fully understood.

In this prospective observational study, a total of 100 participants will be enrolled: 50 patients undergoing bariatric surgery and 50 healthy controls. Serum samples will be collected from the patient group preoperatively, and at 1 and 3 months after surgery. The control group will provide one-time blood samples.

All serum samples will be centrifuged and stored at -80°C until analysis. Free amino acid profiles will be determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The primary outcome is to assess the change in amino acid concentrations over time in surgical patients, and to compare them with healthy controls. Secondary analyses will explore correlations between amino acid levels and body mass index (BMI). Data analysis will be performed using SPSS and MetaboAnalyst 5.0.

This study will help clarify how bariatric surgery influences amino acid metabolism and may offer insights into the metabolic mechanisms underlying postoperative recovery and weight regulation.

• Study Type: Observational
• Enrollment (Actual): 100

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Sanliurfa, Turkey (Türkiye), 63100
    • Veli Fahri Pehlivan

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Participants will include 50 patients diagnosed with obesity and undergoing bariatric surgery, and 50 healthy adults with normal BMI values. All participants will be recruited from Harran University Hospital.

Description

Inclusion Criteria:

• Age ≥18 years
• Diagnosed with obesity and scheduled for bariatric surgery (study group)
• Healthy individuals with normal BMI (control group)

Exclusion Criteria:

• Age <18 years
• History of metabolic or chronic systemic disease
• Pregnancy or lactation

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Group 1: Bariatric surgery patients (n=50); Participants in this group are adults (≥18 years old) with obesity who are scheduled to undergo bariatric surgery at Harran University Hospital. Blood samples will be collected at three time points: before surgery (baseline), and at 1 and 3 months postoperatively. Serum will be separated and stored at -80°C for subsequent amino acid profiling using LC-MS/MS.	Procedure: Blood sample collection for amino acid profiling; Blood samples (5 mL) will be collected from participants in both groups. In the bariatric surgery group, samples will be collected at three time points: preoperatively, and at 1 and 3 months postoperatively. For the control group, a single sample will be obtained. Serum will be separated, stored at -80°C, and analyzed for free amino acid profiles using LC-MS/MS.
Group 2: Healthy control participants (n=50); Participants in this group are healthy adults (≥18 years old) with no known history of obesity or chronic metabolic disease. A single blood sample will be collected at baseline. Serum samples will be analyzed using LC-MS/MS to determine amino acid profiles, which will be compared to those of the bariatric surgery group.	Procedure: Blood sample collection for amino acid profiling; Blood samples (5 mL) will be collected from participants in both groups. In the bariatric surgery group, samples will be collected at three time points: preoperatively, and at 1 and 3 months postoperatively. For the control group, a single sample will be obtained. Serum will be separated, stored at -80°C, and analyzed for free amino acid profiles using LC-MS/MS.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in serum free amino acid levels after bariatric surgery	Amino acid concentrations will be measured in serum samples collected from bariatric surgery patients at baseline, 1 month, and 3 months postoperatively using LC-MS/MS. The outcome will assess time-dependent changes in the amino acid profile within the same individuals.	Preoperative (baseline), 1 month postoperative, 3 months postoperative

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Correlation between serum amino acid levels and body mass index (BMI)	This outcome will evaluate the relationship between changes in serum amino acid concentrations and BMI values measured at baseline, 1 month, and 3 months after bariatric surgery. Pearson or Spearman correlation analyses will be performed.	Preoperative (baseline), 1 month postoperative, 3 months postoperative

Collaborators and Investigators

• Sponsor: Harran University

Study record dates

Study Major Dates

• Study Start (Actual): June 11, 2025
• Primary Completion (Actual): October 2, 2025
• Study Completion (Actual): November 3, 2025

Study Registration Dates

• First Submitted: May 29, 2025
• First Submitted That Met QC Criteria: May 29, 2025
• First Posted (Actual): June 6, 2025

Study Record Updates

• Last Update Posted (Actual): November 26, 2025
• Last Update Submitted That Met QC Criteria: November 19, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Overweight; Obesity; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Obesity, Morbid
• Other Study ID Numbers: Gerger

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No