Breaking Up Prolonged Sitting Reduces Postprandial Glucose and Insulin Responses
- David W. Dunstan, PHD1,2,3,4,5⇓,
- Bronwyn A. Kingwell, PHD1,
- Robyn Larsen, PHD1,
- Genevieve N. Healy, PHD1,3,
- Ester Cerin, PHD6,
- Marc T. Hamilton, PHD7,
- Jonathan E. Shaw, MD1,2,
- David A. Bertovic, FRACP1,
- Paul Z. Zimmet, MD1,2,
- Jo Salmon, PHD4 and
- Neville Owen, PHD1,3
- 1Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
- 2Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
- 3Cancer Prevention Research Centre, School of Population Health, The University of Queensland, Brisbane, Queensland, Australia
- 4School of Exercise and Nutrition Sciences, Deakin University, Melbourne, Victoria, Australia
- 5Edith Cowan University Health and Wellness Institute, Edith Cowan University, Perth, Western Australia, Australia
- 6Institute of Human Performance, The University of Hong Kong, Hong Kong
- 7Pennington Biomedical Research Center, Baton Rouge, Louisiana
- Corresponding author: David W. Dunstan,
OBJECTIVE Observational studies show breaking up prolonged sitting has beneficial associations with cardiometabolic risk markers, but intervention studies are required to investigate causality. We examined the acute effects on postprandial glucose and insulin levels of uninterrupted sitting compared with sitting interrupted by brief bouts of light- or moderate-intensity walking.
RESEARCH DESIGN AND METHODS Overweight/obese adults (n = 19), aged 45–65 years, were recruited for a randomized three-period, three-treatment acute crossover trial: 1) uninterrupted sitting; 2) seated with 2-min bouts of light-intensity walking every 20 min; and 3) seated with 2-min bouts of moderate-intensity walking every 20 min. A standardized test drink was provided after an initial 2-h period of uninterrupted sitting. The positive incremental area under curves (iAUC) for glucose and insulin (mean [95% CI]) for the 5 h after the test drink (75 g glucose, 50 g fat) were calculated for the respective treatments.
RESULTS The glucose iAUC (mmol/L) ⋅ h after both activity-break conditions was reduced (light: 5.2 [4.1–6.6]; moderate: 4.9 [3.8–6.1]; both P < 0.01) compared with uninterrupted sitting (6.9 [5.5–8.7]). Insulin iAUC (pmol/L) ⋅ h was also reduced with both activity-break conditions (light: 633.6 [552.4–727.1]; moderate: 637.6 [555.5–731.9], P < 0.0001) compared with uninterrupted sitting (828.6 [722.0–950.9]).
CONCLUSIONS Interrupting sitting time with short bouts of light- or moderate-intensity walking lowers postprandial glucose and insulin levels in overweight/obese adults. This may improve glucose metabolism and potentially be an important public health and clinical intervention strategy for reducing cardiovascular risk.
- Received October 5, 2011.
- Accepted December 18, 2011.
- © 2012 by the American Diabetes Association.
Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. See http://creativecommons.org/licenses/by-nc-nd/3.0/ for details.