Division of Cardiology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas.
Department of Internal Medicine, University of Minnesota School of Medicine, Minneapolis.
JAMA Cardiol. 2016 Aug 1;1(5):575-83. doi: 10.1001/jamacardio.2016.1567.
Prior studies suggest that higher sedentary time is associated with a greater risk for cardiovascular disease (CVD). However, the quantitative, dose-response association between sedentary time and CVD risk is not known.
To determine the categorical and quantitative dose-response association between sedentary time and CVD risk.
Two independent investigators searched the MEDLINE and EMBASE databases for all studies published before July 6, 2015, that evaluated the association between sedentary time and incident CVD.
Prospective cohort studies with participants 18 years or older that reported the association between sedentary time and incident CVD were included.
Two independent investigators performed the data extraction and collection using a standardized form. The study quality was assessed using the Newcastle-Ottawa Scale. The categorical dose-response association was evaluated by comparing the pooled hazard ratio (HR) for incident CVD associated with different levels of sedentary time (vs lowest sedentary time) across studies. The continuous dose-response association was assessed using random-effects generalized least squares spline models. Data were collected from April 5 to July 6, 2015.
Incident CVD (coronary heart disease, including nonfatal myocardial infarction, stroke, and cardiovascular mortality).
Nine prospective cohort studies with 720 425 unique participants (57.1% women; 42.9% men; mean age, 54.5 years) and 25 769 unique cardiovascular events and a median follow-up of 11 years were included. In categorical analyses, compared with the lowest sedentary time category (median, 2.5 h/d), participants in the highest sedentary time category (median, 12.5 h/d) had an increased risk for CVD (HR, 1.14; 95% CI, 1.09-1.19). However, no apparent risk associated with intermediate levels of sedentary time (HR for 7.5 h/d, 1.02; 95% CI, 0.96-1.08) was found. In continuous analyses, a nonlinear association between sedentary time and incident CVD was found (P for nonlinearity < .001), with an increased risk observed for more than 10 hours of sedentary time per day (pooled HR, 1.08; 95% CI, 1.00-1.14).
The association between sedentary time and the risk for CVD is nonlinear with an increased risk only at very high levels. These findings could have implications for guideline recommendations regarding the risks related to sedentary behavior.
先前的研究表明，久坐时间越长与心血管疾病（CVD）的风险越高相关。然而，久坐时间与 CVD 风险之间的定量、剂量反应关联尚不清楚。
确定久坐时间与 CVD 风险之间的分类和定量剂量反应关联。
两位独立的研究员在 2015 年 7 月 6 日之前，通过搜索 MEDLINE 和 EMBASE 数据库，检索了所有评估久坐时间与新发 CVD 之间关联的前瞻性队列研究。
纳入参与者年龄在 18 岁或以上，且报告久坐时间与新发 CVD 之间关联的前瞻性队列研究。
两位独立的研究员使用标准化表格进行数据提取和收集。使用纽卡斯尔-渥太华量表评估研究质量。通过比较不同水平（相对于最低久坐时间）的久坐时间与心血管疾病发生率（vs 最低久坐时间）之间的汇总风险比（HR）来评估分类剂量反应关联。使用随机效应广义最小二乘样条模型评估连续剂量反应关联。数据收集时间为 2015 年 4 月 5 日至 7 月 6 日。
新发 CVD（冠心病，包括非致死性心肌梗死、中风和心血管死亡率）。
纳入 9 项前瞻性队列研究，共有 720425 名独特的参与者（57.1%为女性；42.9%为男性；平均年龄为 54.5 岁）和 25769 例独特的心血管事件，中位随访时间为 11 年。在分类分析中，与最低久坐时间类别（中位数 2.5 h/d）相比，最高久坐时间类别（中位数 12.5 h/d）的参与者 CVD 风险增加（HR 1.14；95%CI，1.09-1.19）。然而，并未发现与中等水平久坐时间（HR 7.5 h/d，1.02；95%CI，0.96-1.08）相关的明显风险。在连续分析中，发现久坐时间与新发 CVD 之间存在非线性关联（P ＜.001），每天久坐时间超过 10 小时时风险增加（汇总 HR，1.08；95%CI，1.00-1.14）。
久坐时间与 CVD 风险之间的关联是非线性的，仅在极高水平时风险增加。这些发现可能对与久坐行为相关的指南建议产生影响。
