1 Department of Health and Human Physiology College of Liberal Arts & Sciences University of Iowa Iowa City IA.
2 Department of Epidemiology College of Public Health University of Iowa Iowa City IA.
J Am Heart Assoc. 2019 Jan 8;8(1):e010212. doi: 10.1161/JAHA.118.010212.
Background Isotemporal substitution examines the effect on health outcomes of replacing sedentary time with light-intensity physical activity or moderate-to-vigorous intensity physical activity; however, existing studies are limited by cross-sectional study designs. Methods and Results Participants were 1922 adults from the CARDIA (Coronary Artery Risk Development in Young Adults) study. Linear regression examined the associations of sedentary, light-intensity physical activity, and moderate-to-vigorous intensity physical activity at year 20 (2005-2006) with waist circumference, blood pressure, glucose, insulin, triglycerides, high-density lipoprotein cholesterol, and a composite risk score at year 30 (2015-2016). Models then examined change in activity with change in cardiometabolic risk over the same 10-year period. Replacing 30 min/day of sedentary time with 30 min/day of light-intensity physical activity at year 20 was associated with a lower composite risk score (-0.01 SD [95% CI, -0.02, -0.00]) at year 30, characterized by lower waist circumference (0.15 cm [95% CI, -0.27, 0.02]), insulin (0.20 μU/mL [95% CI, -0.35, -0.04]), and higher high-density lipoprotein cholesterol (0.20 mg/dL [95% CI, 0.00, 0.40]; all P<0.05). An increase of 30 min/day in MVPA from year 20 to year 30, when replacing an equivalent increase in sedentary time, was associated with a decrease in the composite risk score (-0.08 [95% CI, -0.13, -0.04]) over the same 10 years, characterized by a decrease in waist circumference (1.52 cm [95% CI, -2.21, -0.84]), insulin (-1.13 μU/mL [95% CI, -1.95, -0.31]), triglycerides (-6.92 mg/dL [95% CI, -11.69, -2.15]), and an increase in high-density lipoprotein cholesterol (1.59 mg/dL [95% CI, 0.45, 2.73]; all P<0.05). Conclusions Replacement of sedentary time with light-intensity physical activity or moderate-to-vigorous intensity physical activity is associated with improved cardiometabolic health 10 years later.
等时替代研究考察了将久坐时间替换为低强度身体活动或中高强度身体活动对健康结果的影响；然而，现有研究受到横断面研究设计的限制。
参与者为来自 CARDIA（年轻人冠状动脉风险发展）研究的 1922 名成年人。线性回归分析了 20 年（2005-2006 年）时的久坐时间、低强度身体活动和中高强度身体活动与腰围、血压、血糖、胰岛素、甘油三酯、高密度脂蛋白胆固醇和 30 年（2015-2016 年）时的综合风险评分之间的关联。然后，模型检验了在同一 10 年期间，活动量的变化与心血管代谢风险的变化之间的关系。与 20 年时每天久坐 30 分钟相比，每天用 30 分钟的低强度身体活动替换 30 分钟的久坐时间与 30 年时的综合风险评分降低有关（-0.01SD[95%CI，-0.02，-0.00]），其特征为腰围（0.15cm[95%CI，-0.27，0.02]）、胰岛素（0.20μU/mL[95%CI，-0.35，-0.04]）降低和高密度脂蛋白胆固醇（0.20mg/dL[95%CI，0.00，0.40]）升高（均 P<0.05）。与以同等幅度增加久坐时间相比，20 年至 30 年期间每天增加 30 分钟的中高强度身体活动与相同 10 年内的综合风险评分降低有关（-0.08[95%CI，-0.13，-0.04]），其特征为腰围（1.52cm[95%CI，-2.21，-0.84]）、胰岛素（-1.13μU/mL[95%CI，-1.95，-0.31]）、甘油三酯（-6.92mg/dL[95%CI，-11.69，-2.15]）降低和高密度脂蛋白胆固醇（1.59mg/dL[95%CI，0.45，2.73]）升高（均 P<0.05）。
用低强度身体活动或中高强度身体活动替换久坐时间与 10 年后心血管代谢健康状况的改善有关。
