Differences in gene expression related to the outcomes of obesity treatment, peak oxygen uptake, and fatty acid metabolism measured in a cardiopulmonary exercise test.

Abstract

INTRODUCTION Theobesity pandemic requires development of methods that could be used on alarge scale, such as thecardiopulmonary exercise test (CPET). Gene expression may explain CPET results on themolecular level. OBJECTIVES The aim of this study was to compare gene expression in obesity, depending on CPET results. PATIENTS AND METHODS Thestudy group consisted of 9 obese patients and 7 controls. Thetreatment encompassed diet, rehabilitation, and behavioral therapy. Diet was based on the body composition analyzed by bioelectrical impedance, resting metabolic rate, and subjective patient preferences. Therehabilitation depended on theCPET results: maximal oxygen uptake and fatty acid metabolism. Behavioral intervention focused on thediagnosis of health problems leading to obesity, lifestyle modification, training in self‑assessment, and development of healthy habits. The intensive treatment lasted for 12 weeks and consisted of consultations with a physician, dietitian, and medical rehabilitation specialist. RNA was isolated from the whole blood. A total of 47 323 transcripts were analyzed, of which 32 379 entities were confirmed to havehigh quality of RNA. RESULTS We observed differences in gene expression related to the CPET results indicating abnormalities in fat oxidation and maximal oxygen uptake. The genes with major differences in expression were: CLEC12A, HLA‑DRB1, HLA‑DRB4, HLA‑A29.1, IFIT1, and LOC100133662. CONCLUSIONS Thedifferences in gene expression may account for theoutcomes of treatment related to inflammation caused by obesity, which affects the muscles, fat tissue, and fatty acid metabolism.