Department of Health and Physical Activity, University of Pittsburgh, Pittsburgh, Pennsylvania.
Departments of Epidemiology, Human Genetics, and Environmental Sciences, University of Texas Health Science Center at Houston School of Public Health-Austin Campus, Austin, Texas.
Am J Prev Med. 2017 Dec;53(6):764-771. doi: 10.1016/j.amepre.2017.07.009. Epub 2017 Oct 9.
Higher sedentary time (ST) and lower moderate- to vigorous-intensity physical activity (MVPA) have each been associated with greater adiposity, but most studies are cross-sectional and measure ST and MVPA by self-report. This study evaluated associations between objective ST and MVPA with current and 5-year changes in BMI and waist circumference.
The Coronary Artery and Risk Development in Young Adults longitudinal cohort study recruited black or white young adults from four U.S. cities. This analysis (conducted in 2016) used data from 2005 to 2006 as baseline and 2010 to 2011 as 5-year follow-up. Accelerometers measured baseline ST (total and prolonged in bouts of ≥10 minutes) and MVPA (bouts of ≥10 minutes). BMI and waist circumference were assessed at baseline and repeated 5 years later. Regression models included sedentary time and MVPA simultaneously with adjustment for demographics and lifestyle factors.
Participants (n=1,826) were 57% female; 40% black; aged 38-50 years; and had a BMI of 28.7 (SD=6.3). At baseline, total and prolonged ST were directly associated with BMI and waist circumference, whereas MVPA was inversely related (all p<0.05). Longitudinally, only prolonged ST (per hour/day) was associated with greater increases in BMI (0.077, p=0.033) and waist circumference (0.198 cm, p=0.028). Associations between ST and adiposity were more apparent in less active participants. Risk of ≥5% increase in BMI across assessments increased by 8%-10% (p<0.05) per hour/day of ST.
Time spent sedentary was associated with increases in adiposity over time. Reducing sedentary time may be a novel strategy for weight control.
较高的久坐时间（ST）和较低的中等到剧烈强度体力活动（MVPA）都与更高的肥胖有关，但大多数研究都是横断面研究，通过自我报告来测量 ST 和 MVPA。本研究评估了客观 ST 和 MVPA 与当前和 5 年内 BMI 和腰围变化之间的关系。
冠状动脉和年轻人风险发展纵向队列研究从美国四个城市招募了黑人和白人年轻人。本分析（于 2016 年进行）使用了 2005 年至 2006 年的数据作为基线，2010 年至 2011 年作为 5 年随访数据。加速度计测量了基线 ST（总时间和持续时间≥10 分钟的长时间 ST）和 MVPA（持续时间≥10 分钟的时间段）。在基线和 5 年后重复测量 BMI 和腰围。回归模型同时包括久坐时间和 MVPA，并调整了人口统计学和生活方式因素。
参与者（n=1826）中，57%为女性；40%为黑人；年龄在 38-50 岁之间；BMI 为 28.7（标准差=6.3）。在基线时，总 ST 和长时间 ST 与 BMI 和腰围直接相关，而 MVPA 则呈负相关（所有 p<0.05）。纵向研究中，只有长时间 ST（每小时/天）与 BMI （0.077，p=0.033）和腰围（0.198cm，p=0.028）的增加呈正相关。在活动量较少的参与者中，ST 和肥胖之间的关联更为明显。评估时 BMI 增加≥5%的风险增加了 8%-10%（p<0.05），每小时/天的 ST 增加。
久坐时间与随时间推移的肥胖增加有关。减少久坐时间可能是控制体重的一种新策略。
