Increasing evidence highlights the efficacy of interruptions in prolonged sitting (i.e., activity/sedentary breaks) for improving cardiometabolic health, but precise conclusions and recommendations regarding the optimal interruption frequency remain poorly defined. This systematic review and meta‐analysis aimed to directly compare the effect of different frequencies of interrupting prolonged sitting on cardiometabolic health and to determine potential moderators. Randomized crossover trials with at least two frequency interruptions compared to a prolonged sitting condition were identified via systematic review. We compared the acute effects of high‐frequency (≤ 30 min per bout, HF) versus low‐frequency (> 30 min per bout, LF) interruption protocols on various cardiometabolic health outcomes via three‐level meta‐analysis with pooled effects evaluated within a random‐effects model and exploration of potential sources of heterogeneity through subgroup analyses. The quality of evidence was assessed using Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. Thirteen studies with 211 participants (24–66 years, 41% female) were included. When comparing HF to LF condition, the HF had a significantly greater reduction in glucose (9 studies [n = 740]; Hedge's g = −0.30, 95% CI [−0.57, −0.03], p = 0.03; I2‐level 3 = 42%, PI [−1.01, 0.41]). However, there was no difference in insulin (4 studies [n = 304]; Hedge's g = −0.22, 95% CI [−0.73, 0.29], p = 0.35; I2‐level 3 = 52%, PI [−1.18, 0.74]), triglyceride (3 studies [n = 484]; Hedge's g = 0.11, 95% CI [−0.10, 0.30], p = 0.29; I2‐level 3 = 0%, PI [−0.10, 0.30]), blood pressure (5 studies [n = 352]; Hedge's g = −0.06, 95% CI [−0.41, 0.28], p = 0.69; I2‐level 3 = 35%, PI [−0.81, 0.62]), and superficial femoral flow‐mediated dilation (3 studies [n = 98]; Hedge's g = −0.42, 95% CI [−2.43, 1.60], p = 0.47; I2‐level 3 = 78%, PI [−4.09, 3.25]) between the two conditions. The quality of evidence was low GRADE for all outcomes. The present study suggests that a higher sedentary interruption frequency might be more efficacious than a lower frequency/higher duration protocol for reducing glucose levels. Based on these findings, interrupting sedentary time at least, every 30 min may be an ideal strategy to improve glucose control.

中文翻译：

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中断长时间坐姿对心脏代谢健康的最佳频率：随机交叉试验的系统评价和荟萃分析


越来越多的证据强调了长时间坐着（即活动/久坐休息）中断对改善心脏代谢健康的疗效，但关于最佳中断频率的确切结论和建议仍然定义不明确。本系统评价和荟萃分析旨在直接比较不同频率中断长时间坐着对心脏代谢健康的影响，并确定潜在的调节因素。通过系统评价确定了与长时间坐着状态相比至少有两次频率中断的随机交叉试验。我们通过三级荟萃分析比较了高频 （≤ 30 分钟/次，HF） 与低频 （> 30 分钟/次，LF） 中断方案对各种心脏代谢健康结局的急性影响，并在随机效应模型中评估了汇总效应，并通过亚组分析探索异质性的潜在来源。使用建议分级、评估、开发和评价 （GRADE） 方法评估证据质量。纳入了 13 项研究，涉及 211 名参与者 （24-66 岁，41% 为女性）。当将 HF 与 LF 条件进行比较时，HF 的葡萄糖降低幅度显着更大（9 项研究 [n = 740];Hedge's g = −0.30， 95% CI [−0.57， −0.03]，p = 0.03;I2 水平 3 = 42%，PI [-1.01， 0.41]）。然而，胰岛素没有差异 （4 项研究 [n = 304];Hedge's g = −0.22， 95% CI [−0.73， 0.29]，p = 0.35;I2 水平 3 = 52%，PI [-1.18， 0.74]），甘油三酯（3 项研究 [n = 484];Hedge's g = 0.11,95% CI [-0.10， 0.30]，p = 0.29;I2 水平 3 = 0%，PI [-0.10， 0.30]），血压（5 项研究 [n = 352];Hedge's g = −0.06,95% CI [−0.41,0.28]，p = 0.69;I2 水平 3 = 35%，PI [−0.81， 0.62]）和股浅血流介导的扩张 （3 项研究 [n = 98];Hedge's g = −0.42， 95% CI [−2.43， 1.60]，p = 0.47;I2 水平 3 = 78%，PI [-4.09， 3.25]） 在两个条件之间。所有结局的证据质量均为低 GRADE。本研究表明，较高的久坐中断频率可能比较低频率/较高持续时间的方案更有效地降低血糖水平。基于这些发现，至少每 30 分钟中断一次久坐时间可能是改善血糖控制的理想策略。