Acute effects of active breaks during prolonged sitting on subcutaneous adipose tissue gene expression

Breaking up prolonged periods of time spent sitting has a range of beneficial impacts on cardiometabolic risk biomarkers. The molecular mechanisms include regulation of skeletal muscle gene and protein expression controlling metabolic, inflammatory and cell development pathways. An active communication network exists between adipose and muscle tissue, but the effect of active breaks in prolonged sitting on adipose tissue have yet to be investigated. This study characterised the acute transcriptional events induced in adipose tissue by regular active breaks during prolonged sitting. In a subset of 8 overweight/obese adults participating in an acute randomised three-intervention crossover trial, subcutaneous adipose tissue biopsies were obtained after each condition. The three experimental conditions were conducted in the postprandial state and included: i) prolonged uninterrupted sitting; or prolonged sitting interrupted with 2-minute bouts of ii) light- or iii) moderate-intensity treadmill walking every 20 minutes. Microarrays identified 36 differentially expressed genes between the three conditions (fold change≥0.5 in either direction; p<0.05). Pathway analysis indicated that breaking up of prolonged sitting led to differential regulation of adipose tissue metabolic networks and inflammatory pathways, increased insulin signalling, increased adipocyte turnover, and facilitated cross-talk between adipose tissue and other organs. This study provides insight into the adipose tissue regulatory systems and transcriptional processes that contribute to the physiological benefits of interrupting prolonged sitting. Total RNA was extracted from abdominal subcutaneous adipose tissue at the 3 different experimental condition from 8 participants.