Frequency of interruptions to sitting time: benefits for postprandial metabolism in type 2 diabetes

Abstract

OBJECTIVE: To determine whether interrupting sitting with brief bouts of simple resistance activities (SRAs) at different frequencies improves postprandial glucose, insulin, and triglycerides in adults with medication-controlled type 2 diabetes (T2D). RESEARCH DESIGN AND METHODS: Participants (n = 23, 10 of whom were female, with mean ± SD age 62 ± 8 years and BMI 32.7 ± 3.5 kg · m−2) completed a three-armed randomized crossover trial (6- to 14-day washout): sitting uninterrupted for 7 h (SIT), sitting with 3-min SRAs (half squats, calf raises, gluteal contractions, and knee raises) every 30 min (SRA3), and sitting with 6-min SRAs every 60 min (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 1,229 pmol · h · L−1, 95% CI 982, 1,538) in comparison with SIT (glucose 21.4 mmol · h · L−1, 95% CI 16.9, 25.8; insulin 1,411 pmol · h · L−1, 95% CI 1,128, 1,767; P < 0.05) and in comparison with 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 in comparison of SRA3 and SIT. There was no statistically significant effect of condition on triglyceride iAUCnet. CONCLUSIONS: In adults with medication-controlled T2D, interrupting prolonged sitting with 6-min SRAs every 60 min reduced postprandial glucose and insulin responses. Other frequencies of interruptions and potential longer-term benefits require examination to clarify clinical relevance.