The Causal Effect of Bariatric Surgery on Cardiovascular Disease and Mortality

The association between weight, and cardiovascular disease and mortality is well established, however, the causal effect of weight-loss in midlife on these outcomes is less clear. Bariatric surgery results in substantial weight-loss and is an ideal candidate to study the causal effects of weight-loss. The investigators propose a project that will use causal inference and machine learning methods to answer two important questions:

1. Is bariatric surgery effective for reducing cardiovascular disease and mortality, and if so, for who?
2. Which type of bariatric surgery (gastric bypass or sleeve gastrectomy) is most effective, and for who? The investigators will use data from various Swedish registers to identify individuals with obesity who are eligible for bariatric surgery. We will then compare cardiovascular and mortality outcomes among those undergoing different types of bariatric surgery with those receiving non-surgical obesity management using causal inference methods. The investigators will use causal forests and expert knowledge to estimate indiviual treatment effects, and identify the groups of patients who benefit the most from these surgeries.

Study Overview

• Status: Recruiting
• Conditions: Cardiovascular Diseases; Bariatric Surgery Candidate; Morality
• Intervention / Treatment: Procedure: Bariatric surgery

• Study Type: Observational
• Enrollment (Estimated): 100000

Contacts and Locations

• Study Contact: Name: Conor MacDonald, PhD; Phone Number: 000 0000; Email: conor.macdonald@ki.se
• Study Contact Backup: Name: Anita Berglund, PhD; Phone Number: 000 0000; Email: anita.berglund@ki.se

Study Locations

• Sweden
  • Stockholm, Sweden
    • Recruiting
    • Karolinska Institutet
    • Contact: Conor MacDonald, PhD; Phone Number: 000 0000; Email: conor.macdonald@ki.se
    • Contact: Anita Berglund, PhD; Phone Number: 000 0000; Email: anita.berglund@ki.se

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

A cohort of individuals eligible for bariatric surgery in Sweden

Description

Inclusion Criteria:

• Men and women of reproductive age with a diagnosis of obesity, no prior history of cardiovascular disease or cancer, and no contraindications for surgery after 1982

Exclusion Criteria:

• Contraindications to bariatric surgery

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cardiovascular disease	myocardial infarction, stroke, and death from cardiovascular causes	20 year

Secondary Outcome Measures

Outcome Measure	Time Frame
Death from any cause	20 year

Collaborators and Investigators

• Sponsor: Karolinska Institutet

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2024
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2027

Study Registration Dates

• First Submitted: May 14, 2024
• First Submitted That Met QC Criteria: May 14, 2024
• First Posted (Actual): May 20, 2024

Study Record Updates

• Last Update Posted (Actual): June 17, 2024
• Last Update Submitted That Met QC Criteria: June 13, 2024
• Last Verified: June 1, 2024

More Information

Terms related to this study

• Keywords: Cardiovascular Diseases; bariatric surgery; Mortality
• Additional Relevant MeSH Terms: Cardiovascular Diseases
• Other Study ID Numbers: 2024-00558-01

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