Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia.
Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Victoria, Australia.
Am J Physiol Heart Circ Physiol. 2021 Jan 1;320(1):H393-H403. doi: 10.1152/ajpheart.00422.2020. Epub 2020 Nov 8.
In healthy and overweight/obese adults, interrupting prolonged sitting with activity bouts mitigates impairment in vascular function. However, it is unknown whether these benefits extend to those with type 2 diabetes (T2D), nor whether an optimal frequency of activity interruptions exist. We examined the acute effects on vascular function in T2D of interrupting prolonged sitting with simple resistance activities (SRA) at different frequencies. In a randomized crossover trial, 24 adults with T2D (35-70 yr) completed three 7-h conditions: ) uninterrupted sitting (SIT), ) sitting with 3-min bouts of SRA every 30 min (SRA3), and ) sitting with 6 min bouts of SRA every 60 min (SRA6). Femoral artery flow-mediated dilation (FMD), resting shear rate, blood flow, and endothelin-1 were measured at 0, 1, 3.5, 4.5, and 6.5-7 h. Mean femoral artery FMD over 7 h was significantly higher in SRA3 (4.1 ± 0.3%) compared with SIT (3.7 ± 0.3%, = 0.04) but not in SRA6. Mean resting femoral shear rate over 7 h was increased significantly for SRA3 (45.3 ± 4.1/s, < 0.001) and SRA6 (46.2 ± 4.1/s, < 0.001) relative to SIT (33.1 ± 4.1/s). Endothelin-1 concentrations were not statistically different between conditions. Interrupting sitting with activity breaks every 30 min, but not 60 min, significantly increased mean femoral artery FMD over 7 h, relative to SIT. Our findings suggest that more frequent and shorter breaks may be more beneficial than longer, less frequent breaks for vascular health in those with T2D. This is the first trial to examine both the effects of interrupting prolonged sitting on vascular function in type 2 diabetes and the effects of the frequency and duration of interruptions. Brief, simple resistance activity bouts every 30 min, but not every 60 min, increased mean femoral artery flow-mediated dilation over 7 h, relative to uninterrupted sitting. With further supporting evidence, these initial findings can have important implications for cardiovascular health in type 2 diabetes.
在健康和超重/肥胖成年人中，通过活动打断长时间的静坐可以减轻血管功能障碍。然而，目前尚不清楚这些益处是否适用于 2 型糖尿病（T2D）患者，也不知道活动中断的最佳频率是否存在。我们研究了在 T2D 患者中，通过不同频率的简单抵抗活动（SRA）打断长时间静坐对血管功能的急性影响。在一项随机交叉试验中，24 名 T2D 成年人（35-70 岁）完成了三种 7 小时的条件：）不间断静坐（SIT），）每 30 分钟进行 3 分钟 SRA 运动（SRA3），和）每 60 分钟进行 6 分钟 SRA 运动（SRA6）。在 0、1、3.5、4.5 和 6.5-7 小时测量股动脉血流介导的扩张（FMD）、静息剪切率、血流和内皮素-1。7 小时内平均股动脉 FMD 在 SRA3 中显著高于 SIT（4.1±0.3%， = 0.04），但在 SRA6 中则没有。7 小时内平均股动脉静息剪切率在 SRA3（45.3±4.1/s， < 0.001）和 SRA6（46.2±4.1/s， < 0.001）相对于 SIT（33.1±4.1/s）显著增加。在条件之间，内皮素-1浓度没有统计学差异。与 SIT 相比，活动中断间隔 30 分钟而不是 60 分钟，显著增加了 7 小时内平均股动脉 FMD。我们的研究结果表明，与 T2D 患者的血管健康相比，更频繁和更短的休息可能比更长、更不频繁的休息更有益。这是第一项研究打断长时间静坐对 2 型糖尿病患者血管功能的影响以及中断频率和持续时间对血管功能的影响的试验。与不间断静坐相比，每 30 分钟进行一次短暂的简单抵抗活动，而不是每 60 分钟进行一次，可以使 7 小时内平均股动脉血流介导的扩张增加。有了进一步的支持证据，这些初步发现可能对 2 型糖尿病的心血管健康具有重要意义。
