1. Frequent interruptions of sedentary time modulates contraction- and insulin-stimulated glucose uptake pathways in muscle: Ancillary analysis from randomized clinical trials
- Author
-
Bergouignan, A, Latouche, C, Heywood, S, Grace, MS, Reddy-Luthmoodoo, M, Natoli, AK, Owen, N, Dunstan, David, Kingwell, BA, Bergouignan, A, Latouche, C, Heywood, S, Grace, MS, Reddy-Luthmoodoo, M, Natoli, AK, Owen, N, Dunstan, David, and Kingwell, BA
- Abstract
Epidemiological studies have observed associations between frequent interruptions of sitting time withphysical activity bouts and beneficial metabolic outcomes, even in individuals who regularly exercise.Frequent interruptions to prolonged sitting reduce postprandial plasma glucose. Here we studiedpotential skeletal muscle mechanisms accounting for this improved control of glycemia in overweightadults under conditions of one day uninterrupted sitting and sitting interrupted with light-intensity ormoderate-intensity walking every 20-min (n = 8); and, after three days of either uninterrupted sitting orlight-intensity walking interruptions (n = 5). Contraction- and insulin-mediated glucose uptake signalingpathways as well as changes in oxidative phosphorylation proteins were examined. We showed that 1)both interventions reduce postprandial glucose concentration, 2) acute interruptions to sitting overone day stimulate the contraction-mediated glucose uptake pathway, 3) both acute interruptions tositting with moderate-intensity activity over one day and light-intensity activity over three days inducea transition to modulation of the insulin-signaling pathway, in association with increased capacity forglucose transport. Only the moderate-intensity interruptions resulted in greater capacity for glycogensynthesis and likely for ATP production. These observations contribute to a mechanistic explanationof improved postprandial glucose metabolism with regular interruptions to sitting time, a promisingpreventive strategy for metabolic diseases.
- Published
- 2016