Predictive Value of Nutritional and Inflammatory Indices for Postoperative Complications After Bariatric Surgery (BARI-NUTRI)

August 4, 2026 updated by: Panagiotis Chatzistavridis, G.Gennimatas General Hospital

The Predictive Value of Nutritional and Inflammatory Indices for Postoperative Complications in Bariatric Surgery Patients: A Single-Centre Retrospective Cohort Study

Bariatric surgery is an effective treatment for severe obesity, but postoperative complications remain an important cause of morbidity. Several nutritional and inflammatory biomarkers derived from routine preoperative blood tests have been proposed as predictors of postoperative outcomes; however, their comparative value in bariatric surgery has not been fully established.

This single-center retrospective cohort study will evaluate the ability of preoperative nutritional and inflammatory indices, including the Prognostic Nutritional Index (PNI), Neutrophil-to-Lymphocyte Ratio (NLR), Platelet-to-Lymphocyte Ratio (PLR), Systemic Immune-Inflammation Index (SII), Systemic Inflammation Response Index (SIRI), and C-reactive Protein-to-Albumin Ratio (CAR), to predict 30-day postoperative complications following bariatric surgery. The study aims to identify the most clinically useful biomarker for preoperative risk stratification and optimization of perioperative care.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Detailed Description

Bariatric surgery is the most effective treatment for severe obesity and obesity-related comorbidities. Despite advances in perioperative care, early postoperative complications continue to contribute to patient morbidity and healthcare utilization. Reliable preoperative risk stratification tools are therefore essential for identifying patients at increased risk and optimizing perioperative management.

Nutritional status and systemic inflammation have emerged as important determinants of surgical outcomes. Several composite indices calculated from routinely available laboratory parameters, including albumin, C-reactive protein, leukocyte subsets, and platelet counts, have demonstrated prognostic value in different surgical populations. However, evidence regarding their comparative predictive performance in bariatric surgery remains limited.

This single-center retrospective cohort study will include consecutive adult patients who underwent sleeve gastrectomy or gastric bypass procedures between 2023 and 2026. Preoperative nutritional and inflammatory indices (PNI, NLR, PLR, SII, SIRI, and CAR) will be calculated from the most recent preoperative laboratory values.

The primary outcome is the occurrence of any Clavien-Dindo grade II or higher postoperative complication within 30 days after surgery. Secondary outcomes include the Comprehensive Complication Index (CCI), length of hospital stay, intensive care unit admission, and 30-day mortality. Multivariable regression analyses will be performed to determine the independent predictive value of each index after adjustment for relevant demographic and clinical variables.

The findings of this study are expected to improve preoperative risk assessment and facilitate identification of patients who may benefit from targeted perioperative optimization strategies.

Study Type

Observational

Enrollment (Actual)

600

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Greece
      • Athens, Greece, 11526
        • General Hospital of Athens G Gennimatas

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Adult patients who underwent bariatric surgery at a single tertiary referral center between 2023 and 2026 and met the study eligibility criteria.

Description

Inclusion Criteria:

Adults aged 18 years or older.

  • Patients who underwent bariatric surgery (sleeve gastrectomy, Roux-en-Y gastric bypass, SADI, or SASI).
  • Availability of complete preoperative laboratory data required for calculation of nutritional and inflammatory indices.
  • Availability of postoperative follow-up data for assessment of 30-day complications.

Exclusion Criteria:

  • Patients younger than 18 years.

    • Missing key preoperative laboratory values required to calculate study indices.
    • Incomplete medical records or unavailable 30-day postoperative outcome data.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Bariatric Surgery Cohort
Adult patients who underwent bariatric surgery (sleeve gastrectomy or gastric bypass procedures including Roux-en-Y gastric bypass, SADI, and SASI) between 2023 and 2026. Preoperative nutritional and inflammatory indices were evaluated for their association with 30-day postoperative complications.
Procedure: Bariatric Surgery
Standard bariatric surgical procedures performed as part of routine clinical care, including sleeve gastrectomy and gastric bypass procedures (Roux-en-Y gastric bypass, SADI, and SASI). No study-specific intervention was assigned.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
30-Day Postoperative Complications (Clavien-Dindo Grade II or Higher)
Time Frame: 30 days after surgery
Occurrence of any postoperative complication classified as Clavien-Dindo grade II or higher within 30 days after bariatric surgery.
30 days after surgery

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Comprehensive Complication Index (CCI)
Time Frame: 30 days after surgery
Comprehensive Complication Index calculated from all postoperative complications occurring within 30 days after surgery.
30 days after surgery
Length of Hospital Stay
Time Frame: From surgery until hospital discharge (up to 30 days)
Total duration of hospitalization following bariatric surgery.
From surgery until hospital discharge (up to 30 days)
From surgery until hospital discharge (up to 30 days)
Time Frame: 30 days after surgery
All-cause mortality occurring within 30 days after bariatric surgery.
30 days after surgery

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

G.Gennimatas General Hospital

Investigators

  • Principal Investigator: Amalia Douma, MD PHD, G.Gennimatas General Hospital
  • Principal Investigator: Panagiotis Chatzistavridis, MD, G.Gennimatas General Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 1, 2023

Primary Completion (Actual)

May 31, 2026

Study Completion (Estimated)

December 30, 2027

Study Registration Dates

First Submitted

July 31, 2026

First Submitted That Met QC Criteria

July 31, 2026

First Posted (Actual)

August 5, 2026

Study Record Updates

Last Update Posted (Actual)

August 6, 2026

Last Update Submitted That Met QC Criteria

August 4, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 24050/28-07-2026 (Registry Identifier: Scientific Council Approval, General Hospital G. Gennimatas, Athens, Greece)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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