Breaking Up Prolonged Sitting Reduces Postprandial Glucose and Insulin Responses

Abstract

OBJECTIVEObservational 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 METHODSOverweight/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.RESULTSThe 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]).CONCLUSIONSInterrupting 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.

Breaking sitting with light activities vs structured exercise: a randomised crossover study demonstrating benefits for glycaemic control and insulin sensitivity in type 2 diabetes

“…3c), from 211 (44) min/day in the Sitting regimen to 118 (32) (Fig. 3d) Insulin resistance (HOMA2-IR) and plasma lipids Fasting insulin levels in the Exercise regimen were similar to those in the Sitting regimen (102 [14] vs 108 [13] pmol/l, respectively; p = 0.117). In contrast, compared with Sitting, Sit Less significantly (p = 0.001) reduced fasting insulin levels to 95 [14] pmol/l).…”

“…Recent evidence from observational studies shows an association between sedentary time and an increased risk of type 2 diabetes, independent of the time spent exercising [8,10]. Experimental studies under laboratory conditions suggest that regular interruption of sitting using small bouts of walking may be effective in lowering glucose and insulin levels in healthy and overweight/obese adults and in individuals with type 2 diabetes [11][12][13][14][15]. We recently showed that replacing sitting time with standing and light-intensity walking in free-living conditions was more efficient at improving insulin action than replacement with one bout of moderate-to vigorous-intensity exercise (cycling) in healthy sedentary participants [16].…”

Acceptability of smartphone technology to interrupt sedentary time in adults with diabetes

“…and wear the intervention accelerometer around their waist during waking hours for 1 month. When 20 min of consecutive sedentary time was detected from the intervention accelerometer [13], the NEAT! application initiated a noise or vibration prompt based on the participant's preference, encouraging him/her to stand up ( Fig.…”

“…Increased levels of 2 h plasma glucose are seen not only in those with increased total sedentary time but also in those who have fewer interruptions in sedentary time [10][11][12]. Recent experimental findings suggest that breaking up prolonged bouts (≥20 min) of sedentary behavior with either light-or moderateintensity physical activity for 2 min reduces postprandial glucose and insulin responses [13]. With the increased prevalence and rising economic costs of diagnosed diabetes in the USA, targeting sedentary time among this population may be an appropriate strategy to intervene and reduce the substantial economic burden and health consequences of diabetes [14].…”

“…works in conjunction with a wireless accelerometer (Shimmer, Dublin, Ireland) that measures physical activity. When a sedentary bout, defined as ≥20 min based on the experimental findings by Dunstan et al [13], is detected from the accelerometer, the smartphone application triggers a reminder prompt to the user encouraging him/her to engage in light-intensity physical activity for at least 2 min. The purpose of this feasibility study was to examine the acceptability of using NEAT!…”