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

Abstract

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±11years; body mass index, 30.2±4.7kg/m²) participated in two of the following treatment conditions: sitting for 7h interrupted by 3min light-intensity walking breaks every (1) 60min (Condition 1), (2) 30min (Condition 2), and (3) 15min (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±0.8mmolL^-1×3.5h^-1), post-breakfast glucose iAUC was reduced for Condition 3 (3.5±0.9 mmolL^-1×3.5h^-1, p˂0.04). Post-lunch glucose iAUC was lower in Condition 3 (1.3±0.9mmolL^-1×3.5h^-1, p˂0.03) and Condition 2 (2.1±0.7mmolL^-1×3.5h^-1, p˂0.05) relative to Condition 1 (4.6±0.8mmolL^-1×3.5h^-1). Condition 3 (1.0±0.7mmolL^-1×3.5h^-1, p=0.02) and Condition 2 (1.6±0.6mmolL^-1×3.5h^-1, p˂0.04) attenuated post-dinner glucose iAUC compared with Condition 1 (4.0±0.7mmolL^-1×3.5h^-1). Cumulative 10.5-h postprandial glucose iAUC was lower in Condition 3 than Condition 1 (p=0.02). Condition 3 reduced 21-h 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˃0.05).

Conclusions: There could be dose-response between frequency of breaks in sedentary time and glucose. Interrupting sedentary time every 15min could produce better glucose control.

Keywords: Diabetes mellitus; Exercise; Glucose; Sedentary lifestyle.