An international multi-centre study has shown that the drug semaglutide, administered to treat diabetes and obesity, protects the kidney in obese patients with chronic kidney disease.

The SMART (SeMaglutide and Albuminuria Reduction Trial in obese individuals without diabetes) trial, which was carried out in non-diabetic patients with kidney disease and obesity, involved several centres in four different countries: Spain, which was the main recruiter, the Netherlands, Germany and Canada. The trial was coordinated by the Department of Pharmacy and Clinical Pharmacology of the University of Groningen (Netherlands).

The SMART trial involved various institutions, including the INCLIVA Health Research Institute of the Hospital Clínic Universitari de València, the Universitat de València, the Vall d'Hebron Research Institute (VHIR), the Vall d'Hebron University Hospital, the Hospital de Bellvitge, the Bellvitge Biomedical Research Institute (IDIBELL) and the Hospital Ribera-Polusa in Lugo, along with other Spanish centres. The findings of this study were presented at the American Society of Nephrology's Kidney Week 2024 meeting, which was held in San Diego (United States) from 24 to 26 October, and simultaneously published in the prestigious journal Nature Medicine.

These institutions were represented by the doctors José Luis Górriz and María Jesús Puchades, both researchers from INCLIVA and the Nephrology Service of the Hospital Clínic Universitari de València; doctors María José Soler and Marina López-Martínez from the Nephrology Service of Vall d'Hebron University Hospital and the Vall d'Hebron Research Institute's Nephrology and Renal Transplantation Group; doctor Josep Maria Cruzado from the Nephrology Service of the Hospital de Bellvitge and head of the IDIBELL Nephrology and Renal Transplantation Research Group; and doctor Secundino Cigarrán, nephrologist in charge of the Research Unit at the Hospital Ribera-Polusa in Lugo.

Other centres from the Netherlands, Germany and Canada also took part in the study.

Obesity and chronic kidney disease

Obesity and overweight are now a global health problem. This extra weight is considered abnormal or excessive when the accumulation of fat poses a health risk to the individual. Overweight and obesity are diagnosed by measuring a person's weight and height and then using the formula weight (kg)/height² (m²) to calculate their body mass index (BMI). A person is considered to be overweight when their BMI is equal to or greater than 25; and they are considered to be obese when their BMI is equal to or greater than 30.

The rate of global obesity has tripled since 1975, with 650 million adults (13%) and 340 million children (18%) currently considered obese. In Spain, almost 40% is overweight and 22% is obese. Furthermore, 3 out of every 10 patients with chronic kidney disease suffer from obesity.

More than 850 million people worldwide are currently suffering from some form of kidney disease. In Spain, 15% of the adult population suffers from some type of kidney disease. The mortality rate of patients with chronic kidney disease in Spain, meanwhile, has increased by 30% in recent years, accounting for 10,700 deaths in 2016.

There is a relationship between obesity and chronic kidney disease, and the pathophysiological mechanisms underlying this interaction are complex. Therapies with antidiabetic drugs and others have been used to reduce body weight in patients with and without diabetes, without inducing hypoglycaemia. However, its specific effect on obese patients with chronic kidney disease was not known until now.

The current randomised, double-blind, placebo-controlled clinical trial involved 125 patients who had chronic kidney disease but not diabetes. These subjects were randomly assigned to receive either semaglutide 2.4 mg per week or a placebo.

The study was funded by a research grant from Novo Nordisk to the Groninger Medical Centre University.  Link to the article.