Purpose: This study aimed to examine whether reductions in sitting time through alternating 30-min bouts of sitting and standing can reduce postprandial glucose, insulin, and triglyceride responses.
Methods: Twenty-three overweight/obese sedentary office workers (17 males and six females; mean ± SD: age, 48.2 ± 7.9 yr; body mass index, 29.6 ± 4.0 kg·m−2) undertook two short-term (5 d) experimental conditions in an equal, randomized (1:1) order. In a simulated office environment, participants performed typical occupational tasks for 8 h·d−1 while in a 1) seated work posture (control condition) or 2) interchanging between a seated and standing work posture every 30 min using an electric, height-adjustable workstation (intervention condition). Fasting and postprandial blood samples after a mixed test drink were collected hourly for 4 h on days 1 and 5 of each condition to assess serum insulin, plasma glucose, and triglycerides. Dietary intake (kJ·d−1) and physical activity were standardized during each condition. The trial was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12611000632998).
Results: After adjustment for time (days 1 and 5), incremental area under the analyte time curve differed significantly between conditions for plasma glucose (P = 0.007) but not for serum insulin or plasma triglycerides. Adjusted mean glucose incremental area under the analyte time curve was lowered by 11.1% after the intervention condition (6.38 mM·h−1 (confidence interval, 5.04–7.71)) relative to the control condition (7.18 mM·h−1 (confidence interval, 5.85–8.52)). No temporal changes (days 1 vs 5) between conditions were observed.
Conclusions: Alternating standing and sitting in 30-min bouts results in modest beneficial effects on postprandial glucose responses in overweight/obese office workers.
1Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, AUSTRALIA; 2School of Public Health and Preventive Medicine, Monash University, Melbourne, AUSTRALIA; 3Department of Physiology, Monash University, Melbourne, AUSTRALIA; 4School of Population Health, University of Queensland, Brisbane, AUSTRALIA; 5School of Population and Global Health, Melbourne University, Melbourne, AUSTRALIA; 6School of Sport Science, Exercise and Health, University of Western Australia, Perth, AUSTRALIA; and 7School of Exercise and Nutrition Sciences, Deakin University, Melbourne, AUSTRALIA
Address for correspondence: Alicia Ann Thorp, Ph.D., R.Nutr., Neurovascular Hypertension and Kidney Disease, Baker IDI Heart and Diabetes Institute, Level 4, 99 Commercial Road, Melbourne, Victoria, Australia 3004; E-mail: Alicia.Thorp@bakeridi.edu.au.
Submitted for publication December 2013.
Accepted for publication March 2014.