Sardinha Luís B, Magalhães João P, Santos Diana A, Júdice Pedro B
Exercise and Health Laboratory, CIPER, Faculdade de Motricidade Humana, Universidade de LisboaCruz-Quebrada, Portugal.
Front Physiol. 2017 Apr 28;8:262. doi: 10.3389/fphys.2017.00262. eCollection 2017.
Sedentary behavior has been considered an independent risk factor for type-2 diabetes (T2D), with a negative impact on several physiological outcomes, whereas breaks in sedentary time (BST) have been proposed as a viable solution to mitigate some of these effects. However, little is known about the independent associations of sedentary pursuits, physical activity, and cardiorespiratory fitness (CRF) variables with glycemic control. We investigated the independent associations of total sedentary time, BST, moderate-to-vigorous physical activity (MVPA), and CRF with glycemic outcomes in patients with T2D. Total sedentary time, BST, and MVPA were assessed in 66 participants (29 women) with T2D, using accelerometry. Glucose and insulin were measured during a mixed meal tolerance test, with the respective calculations of HOMA-IR and Matsuda index. Glycated hemoglobin (HbA1c) was also analyzed. CRF was measured in a maximal treadmill test with breath-by-breath gases analysis. Multiple regressions were used for data analysis. Regardless of CRF, total sedentary time was positively associated with HbA1c (β = 0.25, = 0.044). Adjusting for MVPA, total sedentary time was related to fasting glucose (β = 0.32, = 0.037). No associations between total sedentary time and the remaining glycemic outcomes, after adjusting for MVPA. BST had favorable associations with HOMA-IR (β = -0.28, = 0.047) and fasting glucose (β = -0.25, p = 0.046), when adjusted for MVPA, and with HOMA-IR (β = -0.25, = 0.036), Matsuda index (β = 0.26, = 0.036), and fasting glucose (β = -0.22, = 0.038), following adjustment for CRF. When adjusting for total sedentary time, only CRF yielded favorable associations with HOMA-IR (β = -0.29, = 0.039), fasting glucose (β = -0.32, = 0.012), and glucose at 120-min (β = -0.26, = 0.035), and no associations were found for MVPA with none of the metabolic outcomes. The results from this study suggest that sedentary time and patterns are relevant for the glycemic control in patients with T2D. Still, MVPA and CRF counteracted most of the associations for total sedentary time but not for the BST. MVPA was not associated with metabolic outcomes, and CRF lost some of the associations with glycemic indicators when adjusted for total sedentary time. Future interventions aiming to control/improve T2D must consider reducing and breaking up sedentary time as a viable strategy to improve glycemic control.
久坐行为被认为是2型糖尿病（T2D）的一个独立危险因素，对多种生理指标有负面影响，而中断久坐时间（BST）被认为是减轻其中一些影响的可行方法。然而，关于久坐行为、身体活动和心肺适能（CRF）变量与血糖控制的独立关联，我们所知甚少。我们研究了T2D患者的总久坐时间、BST、中度至剧烈身体活动（MVPA）和CRF与血糖结果之间的独立关联。使用加速度计对66名T2D患者（29名女性）的总久坐时间、BST和MVPA进行了评估。在混合餐耐量试验期间测量血糖和胰岛素，并分别计算胰岛素抵抗指数（HOMA-IR）和松田指数。还分析了糖化血红蛋白（HbA1c）。通过最大跑步机测试和逐次呼吸气体分析来测量CRF。使用多元回归进行数据分析。无论CRF如何，总久坐时间与HbA1c呈正相关（β = 0.25，P = 0.044）。在调整MVPA后，总久坐时间与空腹血糖相关（β = 0.32，P = 0.037）。在调整MVPA后，总久坐时间与其余血糖结果之间无关联。在调整MVPA后，BST与HOMA-IR（β = -0.28，P = 0.047）和空腹血糖（β = -0.25，P = 0.046）呈有利关联，在调整CRF后，BST与HOMA-IR（β = -0.25，P = 0.036）、松田指数（β = 0.26，P = 0.036）和空腹血糖（β = -0.22，P = 0.038）呈有利关联。在调整总久坐时间后，只有CRF与HOMA-IR（β = -0.29，P = 0.039）、空腹血糖（β = -0.32，P = 0.012）和120分钟时的血糖（β = -0.26，P = 0.035）呈有利关联，而MVPA与任何代谢结果均无关联。本研究结果表明，久坐时间和模式与T2D患者的血糖控制相关。尽管如此，MVPA和CRF抵消了总久坐时间的大部分关联，但对BST的关联没有影响。MVPA与代谢结果无关，在调整总久坐时间后，CRF与血糖指标的一些关联消失。未来旨在控制/改善T2D的干预措施必须考虑将减少和打破久坐时间作为改善血糖控制的可行策略。
