Obesity is in constant increase all over the world and affects 35% of the global population according to the World Health Organisation. It is associated with other cardiovascular risk factors (particularly hypertension and diabetes) and with high morbi-mortality. It is also responsible for an increase of the risk of developing chronic kidney diseases (CKD). In fact, obese patients represent 25% of the dialysis population and Picardy is one of the most affected areas. However, their access to kidney transplant is still restricted and the reasons are not completely understood.

Inclusion Criteria:

• Age over 18 years old.
• Patients with BMI≥30 kg/m2 (for study population) and 25≤BMI≤30 kg/m2(for control population) one month after dialysis initiation.
• Patients agree with their data collection.

Exclusion Criteria:

• Patients with bariatric surgery history.
• Patients needed dialysis for graft dysfunction.
• Data loss.

Patients will be included in the study one month after the dialysis initiation. All clinical (obesity history, comorbidities, nephropathy aetiology and treatment…) and biological (nutrition markers, hemoglobin, brain natriuretic peptide (BNP)…) informations after one month and during the two years of follow-up (weight evolution, obesity complications, transplant path...) will be collected.