Dose-response between frequency of breaks in sedentary time and glucose control in type 2 diabetes: A proof of concept study

Objectives: This study aimed to investigate dose-response between frequency of breaks in sedentary time and glucose control. Design: Randomised three-treatment, two-period balanced incomplete block trial. Methods: Twelve adults with type 2 diabetes (age, 60 +/- 11 years; body mass index, 30.2 +/- 4.7 kg/m(2)) participated in two of the following treatment conditions: sitting for 711 interrupted by 3 min light-intensity walking breaks every (1) 60 min (Condition 1), (2) 30 min (Condition 2), and (3) 15 min (Condition 3). Postprandial glucose incremental area under the curves (iAUCs) and 21-h glucose total area under the curve (AUC) were measured using continuous glucose monitoring. Standardised meals were provided. Results: Compared with Condition 1 (6.7 +/- 0.8 mmol L-1 x 3.5 h(-1)), post-breakfast glucose iAUC was reduced for Condition 3 (3.5 +/- 0.9 mmol L-1 x 3.5 h(-1), p <0.04). Post-lunch glucose iAUC was lower in Condition 3 (1.3 +/- 0.9 mmol L-1 x 3.5 h(-1), p <0.03) and Condition 2 (2.1 +/- 0.7 mmol L-1 x 3.5 h(-1), p <0.05) relative to Condition 1 (4.6 +/- 0.8 mmol L-1 x 3.5 h(-1)). Condition 3 (1.0 +/- 0.7 mmol L-1 x 3.5 h(-1), p= 0.02) and Condition 2 (1.6 +/- 0.6 mmol L-1 x 3.5 h(-1), p <0.04) attenuated post-dinner glucose iAUC compared with Condition 1 (4.0 +/- 0.7 mmol L-1 x 3.5 h(-1)). Cumulative 10.5-h postprandial glucose iAUC was lower in Condition 3 than Condition 1 (p =0.02). Condition 3 reduced 21-11 glucose AUC compared with Condition 1 (p < 0.001) and Condition 2 (p = 0.002). However, post-breakfast glucose iAUC, cumulative 10.5-h postprandial glucose iAUC and 21-h glucose AUC were not different between Condition 2 and Condition 1 (p square 0.05). Conclusions: There could be dose-response between frequency of breaks in sedentary time and glucose. Interrupting sedentary time every 15 min could produce better glucose control. (C) 2019 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.