Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA
Division of Sleep Medicine, Department of Medicine, Harvard Medical School, Boston, MA.
Diabetes Care. 2021 Apr;44(4):1046-1054. doi: 10.2337/dc20-2178. Epub 2021 Feb 17.
Moderate- to vigorous-intensity physical activity (MVPA) improves cardiovascular health. Few studies have examined MVPA timing. We examined the associations of timing of bout-related MVPA with cardiorespiratory fitness and cardiovascular risk in adults with type 2 diabetes.
Baseline 7-day hip-worn accelerometry data from Look AHEAD participants ( = 2,153, 57% women) were analyzed to identify bout-related MVPA (≥3 METs/min for ≥10 min). Cardiorespiratory fitness was assessed by maximal graded exercise test. Participants were categorized into six groups on the basis of the time of day with the majority of bout-related MVPA (METs × min): ≥50% of bout-related MVPA during the same time window (morning, midday, afternoon, or evening), <50% of bout-related MVPA in any time category (mixed; the reference group), and ≤1 day with bout-related MVPA per week (inactive).
Cardiorespiratory fitness was highly associated with timing of bout-related MVPA ( = 0.0005), independent of weekly bout-related MVPA volume and intensity. Importantly, this association varied by sex ( = 0.02). In men, the midday group had the lowest fitness (β = -0.46 [95% CI -0.87, -0.06]), while the mixed group in women was the least fit. Framingham risk score (FRS) was associated with timing of bout-related MVPA ( = 0.02), which also differed by sex ( = 0.0007). The male morning group had the highest 4-year FRS (2.18% [0.70, 3.65]), but no association was observed in women.
Timing of bout-related MVPA is associated with cardiorespiratory fitness and cardiovascular risk in men with type 2 diabetes, independent of bout-related MVPA volume and intensity. Prospective studies are needed to determine the impacts of MVPA timing on cardiovascular health.
中等到剧烈强度的身体活动（MVPA）可改善心血管健康。很少有研究检查过 MVPA 的时间安排。我们研究了与 2 型糖尿病成人的心肺健康和心血管风险相关的突发相关 MVPA 的时间安排。
对 LOOK AHEAD 参与者的基线 7 天髋部佩戴加速度计数据（=2153，57%为女性）进行了分析，以确定突发相关的 MVPA（≥3 MET/min 持续时间≥10 min）。心肺健康通过最大分级运动测试进行评估。参与者根据一天中进行突发相关 MVPA 的大多数时间（METs×min）分为六组：突发相关 MVPA 的≥50%发生在同一时间段（早上、中午、下午或晚上）、任何时间段都没有发生≥50%的突发相关 MVPA（混合；参考组）、每周仅有一天有突发相关 MVPA。
心肺健康与突发相关 MVPA 的时间安排高度相关（=0.0005），与每周突发相关 MVPA 的量和强度无关。重要的是，这种关联因性别而异（=0.02）。在男性中，中午组的健康状况最差（β=-0.46[95%CI-0.87，-0.06]），而女性中的混合组则是最不健康的。弗雷明汉风险评分（FRS）与突发相关 MVPA 的时间安排相关（=0.02），这也因性别而异（=0.0007）。男性早晨组的 4 年 FRS 最高（2.18%[0.70，3.65]），但女性中未观察到关联。
与 2 型糖尿病男性的心肺健康和心血管风险相关的突发相关 MVPA 的时间安排与突发相关 MVPA 的量和强度无关。需要前瞻性研究来确定 MVPA 时间安排对心血管健康的影响。
