Obesity medicine, or bariatric medicine, focuses not only on the biological and behavioral aspects, but also on the environmental and social factors that contribute to the development of obesity. Many diseases are associated with obesity, such as type 2 diabetes, hypertension, cardiovascular diseases, numerous cancers, gynecological disorders, etc. Focusing on obesity medicine is crucial for improving patients' quality of life, reducing healthcare costs, and developing effective prevention strategies. The Quebec Heart and Lung Institute - Laval University (IUCPQ-ULaval) maintains a clinical database and biological material bank for studying the multidisciplinary management of obesity and its complications.

A biobank is a collection of information, clinical or biochemical data (including radiological, cardiac, and genetic data), and blood samples concerning donors. The information that can be collected includes, for example, age, sex, diagnosis, progression or treatment of a medical condition, medications, DNA, etc. DNA is a molecule present in all cells and contains all the information necessary for the development and functioning of our body.

This bank aims to better characterize patients' profile receiving follow-up care in obesity medicine, identify predictive factors of success or failure of interventions and adapt management strategies according to specific needs. The collected data and blood samples will be used in several research projects with the following objectives:

1. To document the socioeconomic, demographic, clinical, radiological, genetic, and biochemical characteristics of patients living with obesity and requiring medical follow-up at the bariatric medicine clinic at the IUCPQ-ULaval
2. To explore the effects or associations of genetic and biochemical determinants on health in the context of obesity
3. To gain a better understanding of the pathophysiology and genes involved in obesity and associated metabolic abnormalities
4. To evaluate the clinical utility of non-invasive biomarkers in the screening of preclinical obesity and its comorbidities and/or
5. To evaluate the effectiveness of medications, health behavior changes, and bariatric surgery in order to develop optimal interventions aimed at improving the health and medical management of people with obesity.

To be included in the registry (database + biobank), a person must first be referred to the Bariatric Medicine Clinic at the IUCPQ-ULaval and meet several criteria:

1. Be over 18 years of age

2. Meet at least one of the following five criteria:

   1. Body mass index ≥30 kg/m2 with or without comorbidities (preclinical or clinical obesity);
   2. Require weight loss related to a transplant, bariatric surgery, or another type of surgery (e.g., hernia repair, orthopedic surgery, neurosurgery, etc.);
   3. History of bariatric surgery resulting in weight regain of at least 15% of the total weight lost;
   4. History of bariatric surgery resulting in weight loss deemed insufficient by the treating medical team;
   5. Having undergone bariatric surgery with complications related to it (i.e., flushing syndrome or hypoglycemia, nephrolithiasis, return of comorbidities in remission, abnormalities in phosphocalcic balance and vitamin deficiencies).

Patient starting follow-up at the Bariatric Medicine Clinic of the IUCPQ-ULaval.