Breaking up prolonged sitting with standing or walking attenuates the postprandial metabolic response in post-menopausal women: a randomised acute study

Objective To determine whether breaking up prolonged sitting with short bouts of standing or walking improves post-prandial markers of cardio-metabolic health in women at high risk of type 2 diabetes. Research Design and Methods Twenty-two overweight/obese, dysglycaemic, postmenopausal women (mean age ± SD: 66.8±4.6 years) each participated in two of the following treatments; prolonged, unbroken sitting (7.5 hours) or prolonged sitting broken up with either standing or walking at a self-perceived light-intensity (for 5 minutes every 30 minutes). Both allocation and treatment order were randomised. The incremental area under the curves (iAUC) for glucose, insulin, non-esterified fatty acids (NEFA) and triglycerides were calculated for each treatment condition (mean ± SEM). The following day, all participants underwent the 7.5 hours sitting protocol. Results Compared to a prolonged bout of sitting (iAUC 5.3±0.8mmol/L•h), both standing (3.5±0.8) and walking (3.8±0.7) significantly reduced the glucose iAUC (both p<0.05). When compared with prolonged sitting (548.2±71.8mU/L•h), insulin was also reduced for both activity conditions (standing: 437.2±73.5; walking: 347.9±78.7; both p<0.05). Both standing (-1.0±0.2mmol/L•h) and walking (-0.8±0.2) attenuated the suppression of the NEFA compared with prolonged sitting (-1.5±0.2); both p<0.05. There was no significant effect on triglyceride iAUC. The effects on glucose (standing and walking) and insulin (walking only) persisted into the following day. Conclusions Breaking up prolonged sitting with 5-minute bouts of standing or walking at a self-perceived light-intensity reduced postprandial glucose, insulin and NEFA responses in women at high risk of type 2 diabetes. This simple, behavioural approach could inform future public health interventions aimed at improving the metabolic profile of post-menopausal, dysglycaemic women.