Design and rationale of a crossover study testing the effects of increased standing and light-intensity physical activity to improve postprandial glucose in sedentary office workers (Preprint)

BACKGROUND Sedentary time (e.g., sitting with low energy expenditure) is a significant cardiometabolic disease risk factor. The modern workforce spends the majority of their workday seated at a desk. Acute (1-3 days), controlled laboratory-based studies that increase brief periods of standing or moving produce promising improvements in cardiometabolic biomarkers during the study period. It is unknown whether similar and sustained changes can be observed after a more prolonged (2 weeks) practice of increased brief standing and moving behaviors in real-world office settings. OBJECTIVE This study aims to investigate if similar or sustained cardiometabolic changes can be observed after a more prolonged (2-week) practice of increased brief standing and moving behaviors in real-world office settings METHODS This randomized crossover trial will compare the efficacy of two 2-week pilot intervention conditions designed to interrupt sitting time in sedentary office workers (N=15) to a control condition. The intervention conditions utilize a mobile application (app) to deliver real-time prompts to increase standing (STAND) or moving (MOVE) time by an additional 6 minutes each hour during work hours. Our primary aim is to assess intervention-associated improvements to daily postprandial glucose using continuous glucose monitors. Our secondary aim is to determine whether the interventions successfully evoked substantive positional changes and light-intensity physical activity (LPA). Other outcomes include the feasibility and acceptability of the intervention conditions, fasting blood glucose concentration, femoral artery flow-mediated dilation (f-FMD), and systolic and diastolic blood pressure. RESULTS The trial is ongoing at the time of submission. CONCLUSIONS Results of this study will extend our knowledge of the acute and chronic effects of increasing standing and LPA in sedentary office workers and establish the feasibility and acceptability of real-time prompt-based interventions to reduce sitting. CLINICALTRIAL NCT04239070