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

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

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

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

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

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
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

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
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

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
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

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
G.Gennimatas General Hospital

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • 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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2023

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 31, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 30, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 31, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 31, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 5, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 6, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 4, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant 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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