8-Year Outcomes After Sleeve Gastrectomy

NCT07348822 | Active Not Recruiting

• 1 other identifier: MUDU-SBE-SS-02
• Study Type: observational
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

Obesity is a major global public health concern, and bariatric surgery is recognized as the most effective treatment for achieving sustained weight loss and improving obesity-related comorbidities. Sleeve gastrectomy (SG) is one of the most commonly performed bariatric procedures; however, long-term outcomes vary considerably among individuals. While some patients maintain satisfactory weight loss, others experience suboptimal weight loss or weight regain several years after surgery. Evidence suggests that long-term weight trajectories after SG may be influenced by metabolic changes, dietary habits, and lifestyle factors, highlighting the need for extended follow-up studies. This observational cohort study aims to evaluate the long-term outcomes of individuals who underwent sleeve gastrectomy approximately 8 years ago. Anthropometric measurements, biochemical parameters, and nutritional status will be reassessed at an 8-year follow-up visit and compared with data obtained during the preoperative period and at postoperative 6 months. By examining within-subject changes over time, this study seeks to provide insight into the long-term sustainability of weight loss after sleeve gastrectomy and to identify metabolic and nutritional factors associated with long-term outcomes.

Conditions

Sleeve Gastrectomy; Obesity & Overweight

Keywords

long-term follow-up; sleeve gastrectomy; obesity; metabolic outcomes; nutritional status; anthropometric measurements

Outcome Measures

Primary Outcomes (9)

• Change in Fat Mass

  Changes in fat mass measured using multi-frequency bioelectrical impedance analysis (BIA).

  Preoperative, postoperative 6 months, and postoperative 8 years

• Change in Body Weight

  Body weight measured using a calibrated digital scale with participants wearing light clothing and no shoes.

  Preoperative, postoperative 6 months, and postoperative 8 years

• Change in Body Mass Index (BMI)

  BMI calculated as weight in kilograms divided by height in meters squared (kg/m²), measured using a wall-mounted stadiometer.

  Preoperative, postoperative 6 months, and postoperative 8 years

• Change in Waist Circumference

  Waist circumference measured in centimeters at the midpoint between the subcostal margin and the iliac crest with participants standing upright.

  Preoperative, postoperative 6 months, and postoperative 8 years

• Change in Hip Circumference

  Hip circumference measured in centimeters at the level of maximum gluteal protrusion.

  Preoperative, postoperative 6 months, and postoperative 8 years

• Percent Total Weight Loss (TWL%)

  Calculated as \[(preoperative weight - postoperative weight) / preoperative weight\] × 100.

  Postoperative 6 months and postoperative 8 years

• Percent Excess Weight Loss (EWL%)

  Calculated as \[(preoperative weight - postoperative weight) / (preoperative weight - ideal body weight)\] × 100, where ideal body weight corresponds to a BMI of 25 kg/m².

  Postoperative 6 months and postoperative 8 years

• Change in Body Fat Percentage

  Changes in body fat percentage measured using multi-frequency bioelectrical impedance analysis (BIA).

  Preoperative baseline, postoperative 6 months, and postoperative 8 years

• Change in Skeletal Muscle Mass

  Changes in skeletal muscle mass measured using multi-frequency bioelectrical impedance analysis (BIA).

  Preoperative baseline, postoperative 6 months, and postoperative 8 years

Secondary Outcomes (15)

• Change in Fasting Plasma Glucose

  Preoperative, postoperative 6 months, and postoperative 8 years

• Change in Fasting Insulin Levels

  Preoperative, postoperative 6 months, and postoperative 8 years

• Change in Glycated Hemoglobin (HbA1c)

  Preoperative, postoperative 6 months, and postoperative 8 years

• Change in Lipid Profile Parameters

  Preoperative, postoperative 6 months, and postoperative 8 years

• Change in Liver Enzyme Levels

  Preoperative, postoperative 6 months, and postoperative 8 years

Study Arms (1)

Sleeve Gastrectomy Long-Term Follow-up Cohort

This cohort includes adults who underwent sleeve gastrectomy between 2016 and 2017 and were re-evaluated approximately 8 years after surgery. Participants are followed observationally, with anthropometric measurements, biochemical parameters, and nutritional status assessed preoperatively, at postoperative 6 months, and at long-term (8-year) follow-up. No intervention is assigned as part of the study protocol; all surgical procedures were performed as part of routine clinical care.

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

The study population includes adults aged 18-65 years who underwent sleeve gastrectomy approximately eight years prior to enrollment and completed standard postoperative follow-up. Participants had available preoperative and 6-month postoperative anthropometric, biochemical, and nutritional data and were re-evaluated at 8 years after surgery to assess long-term outcomes.

You may qualify if:

• Adults aged 18-65 years
• Patients who underwent sleeve gastrectomy approximately 8 years prior to study enrollment
• Patients with available postoperative follow-up data at 6 months, including anthropometric measurements, biochemical parameters, and nutritional status assessments
• Patients willing to participate in long-term follow-up and attend in-person evaluations

You may not qualify if:

• Pregnancy or lactation
• Presence of acute illness or active infection at the time of evaluation
• Presence of acute illness, infection, or comorbid conditions that may limit study safety or validity, including malignancy, type 1 diabetes mellitus, renal or hepatic failure, recent stroke or myocardial infarction, nephrolithiasis, drug or alcohol abuse, eating disorders, severe depression or other major psychiatric disorders, inflammatory bowel disease, cardiac arrhythmias or heart failure, respiratory failure, or chronic systemic corticosteroid therapy.
• Professional athletes

Sponsors & Collaborators

• Medipol University: lead

Study Sites (1)

Mudanya Univesity

Bursa, Mudanya, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Obesity; Overweight

Condition Hierarchy (Ancestors)

Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Seher Şen

  Mudanya University

  STUDY DIRECTOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assist. Prof. Dr.

Study Record Dates

• First Submitted: December 18, 2025
• First Posted: January 16, 2026
• Study Start: June 12, 2025
• Primary Completion: January 10, 2026
• Study Completion: March 10, 2026
• Last Updated: February 3, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)