Prolonged standing reduces fasting plasma triglyceride but does not influence postprandial metabolism compared to prolonged sitting

Prolonged periods of sedentary behavior are linked to cardiometabolic disease independent of exercise and physical activity. This study examined the effects of posture by comparing one day of sitting (14.4 +/- 0.3 h) to one day of standing (12.2 +/- 0.1 h) on postprandial metabolism the following day. Eighteen subjects (9 men, 9 women; 24 +/- 1 y) completed two trials (sit or stand) in a crossover design. The day after prolonged sitting or standing the subjects completed a postprandial high fat/glucose tolerance test, during which blood and expired gas was collected immediately before and hourly for 6 h after the ingestion of the test meal. Indirect calorimetry was used to measure substrate oxidation while plasma samples were analyzed for triglyceride, glucose, and insulin concentrations. Standing resulted in a lower fasting plasma triglyceride concentration (p = 0.021) which was primarily responsible for an 11.3% reduction in total area under the curve (p = 0.022) compared to sitting. However, no difference between trials in incremental area under the curve for plasma triglycerides was detected (p>0.05). There were no differences in substrate oxidation, plasma glucose concentration, or plasma insulin concentration (all p>0.05). These data demonstrate that 12 h of standing compared to 14 h of sitting has a small effect the next day by lowering fasting plasma triglyceride concentration, and this contributed to a 11.3% reduction in postprandial plasma triglyceride total area under the curve (p = 0.022) compared to sitting.