Obesity is a serious public health problem around the world. According to data from the World Health Organization, 39% of people over eighteen are overweight, of which over 650 million were obese in 2016. Among the most notable consequences of this “21st century epidemic”, as described by the specialists, are cardiovascular diseases, diabetes musculoskeletal diseases and some types of cancer.
To work towards a solution for this problem, in 2005 an international team of scientists launched the project DiOGenes with the aim of understanding how to prevent and treat obesity integrating genetic, dietetic or psychological factors The pan-European study compiled data from 500 overweight individuals, who were put on a low-calorie replacement diet, followed by a weight maintenance period.
One important piece of research within DiOGenes has sought to identify the set of proteins involved in reducing and maintaining healthy weight. In other words, scientists of the Institute for Bioengineering of Catalonia (IBEC) and the Nestlé Institute of Health Sciences have analyzed the part of the proteome related with body mass index, fat mass and insulin resistance and sensitivity. Their results, which have been published in the journal Proteomics – Clinical Applications—the cover of which highlights this study—have enabled researchers to identify potential biomarkers for weight loss and maintenance.
To perform their work, the researchers put together different profiles of the plasma proteome of the cohort included in the DiOGenes project. In recent years, many research groups have focused on analyzing complete proteomes through mass spectrometry. Nevertheless, as the authors of the article state, “much less attention has been given to the ‘sample number race’ that can ultimately lead to sufficient statistical power and deliver robust and reproducible biological findings, by taking into account diversity and variability of human populations.”
Their longitudinal research effort has determined the changes in the proteome before and after the dietetic interventions of DiOGenes participants. The samples from 525 individuals—of which 473 were ultimately used—were analyzed on two independent but identical systems composed of a linear ion trap‐Orbitrap Elite and an Ultimate 3000 RSLCnano system (Thermo Scientific). The data gathered were later deposited in the ProteomeXchange database, under the dataset identifier PXD005216.
Many of the proteins identified in the research had already been related with weight loss in obese individuals. Specifically, as the study researchers state, “proteins with largest changes were sex hormone‐binding globulin, adiponectin, C‐reactive protein, calprotectin, serum amyloid A, and proteoglycan 4 (PRG4).” The researchers also propose that this kind of proteomic analysis based on mass spectrometry in large cohorts of overweight or obese individuals who do not suffer diabetes can help determine new biomarkers. Their work, which goes beyond other approaches in different models, is the first to use this focus in such a large sample in clinical research.