Transcriptional changes in blood from metabolic syndrome patients after a period of high intensity interval training

Abstract The metabolic syndrome is a cluster of conditions that predispose for diabetes and cardiovascular disease. Nine metabolic syndrome patients were recruited to 48 workouts of interval training. At the end of the study, all patients significantly reduced their risk of cardiovascular disease (in terms of VO2max, blood pressure and plasma lipid). Exercise-induced transcriptional changes may provide new mechanistically insights in the area of improved health by exercise. Aim: Determine whether transcriptional changes occurred in the blood cells of patients after the exercise program. We hypothesized that significantly altered biological processes in blood would include a set of genes at least partly responsible for the improvement seen in this patient group after the exercise programme. Methods: Blood from five patients were collected in PAXgene tubes pre and post the exercise period. RNA was extracted and run on microarrays. Results: Gene set enrichment analysis revealed twelve significantly enriched biological processes and molecular functions that were up-regulated post exercise. Seven processes and functions were down-regulated (nom p-value <0.05). Exercise induced a down-regulation of plasma mRNA- and protein levels of arginase-I and vWf, which might explain improved risk profile and endothelial function of the metabolic syndrome patients. Conclusion: After the exercise period was completed, the metabolic syndrome patients had decreased transcription of genes associated with blood clotting and steroid metabolism. Arginase-I was decreased post exercise, which may explain the previous reported improved NO-availability and endothelial function. Keywords: aerobic capacity, cardiovascular disease, microarray, arginase, blood clotting Patient group The patients included in this study were randomly selected from a population of patients described in our recently published study of the metabolic syndrome. Briefly, nine patients diagnosed with the metabolic syndrome, according to the WHO-criteria were recruited for aerobic interval training. All subjects provided written, informed consent, and the regional committee for medical research ethics approved the protocol. The participants’ diet was registered during the study period. The blood from 5 of these patients were analyzed for whole-genome gene expression pre and post the exercise period, to study transcriptional alterations in blood that might be able to explain.