Frequency of Interruptions to Sitting Time: Benefits for Postprandial Metabolism in Type 2 Diabetes
Methods: Participants [n=23, 10 females, Age: 62±8 y (mean±SD), BMI: 32.7 ± 3.5 kg.m-2] completed a three-armed randomized crossover trial (6-14 day washout): sitting uninterrupted for 7 h (SIT); sitting with 3-minute SRAs (half-squats, calf raises, gluteal contractions, and knee raises) every 30 minutes (SRA3); and, sitting with 6-minute SRAs every 60 minutes (SRA6). Net incremental areas under the curve (iAUCnet) for glucose, insulin, and triglycerides were compared between conditions.
Results: Glucose and insulin 7 h iAUCnet were attenuated significantly during SRA6 (glucose 17.0 mmol.h.L-1, 95% CI 12.5, 21.4; insulin 1229 pmol.h.L-1, 95% CI 982, 1538) when compared to SIT (glucose 21.4 mmol.h.L-1, 95% CI 16.9, 25.8; insulin 1411 pmol.h.L-1, 95% CI 1128, 1767; P < 0.05), and compared to SRA3 ( for glucose only; 22.1 mmol.h.L-1, 95% CI 17.7, 26.6; P = 0.01) No significant differences in glucose or insulin iAUCnet were observed comparing SRA3 and SIT. There was no statistically significant effect of condition on triglyceride iAUCnet.
Conclusion: In adults with medication-controlled T2D, interrupting prolonged sitting with 6-minute SRAs every 60 minutes reduced postprandial glucose and insulin responses. Other frequencies of interruptions and potential longer-term benefits require examination to clarify clinical relevance.