Hildebrand Maria, Kolle Elin, Hansen Bjørge H, Collings Paul J, Wijndaele Katrien, Kordas Katarzyna, Cooper Ashley R, Sherar Lauren B, Andersen Lars Bo, Sardinha Luis B, Kriemler Susi, Hallal Pedro, van Sluijs Esther, Ekelund Ulf
From the Department of Sports Medicine, Norwegian School of Sport Sciences, Oslo, Norway (MH, EK, BHH, LBA, and UE); the Medical Research Council Epidemiology Unit, University of Cambridge, Cambridge, United Kingdom (PJC, KW, EvS, and UE); the School of Social and Community Medicine (KK) and the Centre for Exercise, Nutrition & Health Sciences, School for Policy Studies (ARC), University of Bristol, Bristol, United Kingdom; the School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom (LB Sherar); the Institute of Sport Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark (LBA); the Department of Sport and Health, University of Lisbon, Lisbon, Portugal (LB Sardinha); the Institute of Social and Preventive Medicine, University of Zürich, Zürich, Switzerland (SK); and the Department of Physical Education, Federal University of Pelotas, Pelotas, Brazil (PH).
Am J Clin Nutr. 2015 May;101(5):983-90. doi: 10.3945/ajcn.114.103648. Epub 2015 Apr 1.
Birth weight is an early correlate of disease later in life, and animal studies suggest that low birth weight is associated with reduced activity and increased sedentary time. Whether birth weight predicts later sedentary time in humans is uncertain.
We examined the relation between birth weight and sedentary time in youth and examined whether this association was mediated by central adiposity.
We used pooled cross-sectional data from 8 observational studies conducted between 1997 and 2007 that consisted of 10,793 youth (boys: 47%) aged 6-18 y from the International Children's Accelerometry Database. Birth weight was measured in hospitals or maternally reported, sedentary time was assessed by using accelerometry (<100 counts/min), and abdominal adiposity (waist circumference) was measured according to WHO procedures. A mediation analysis with bootstrapping was used to analyze data.
The mean (±SD) time spent sedentary was 370 ± 91 min/d. Birth weight was positively associated with sedentary time (B = 4.04, P = 0.006) and waist circumference (B = 1.59, P < 0.001), whereas waist circumference was positively associated with sedentary time (B = 0.82, P < 0.001). Results of the mediation analysis showed a significant indirect effect of birth weight on sedentary time through waist circumference (B: 1.30; 95% bias-corrected CI: 0.94, 1.72), and when waist circumference was controlled for, the effect of birth weight on sedentary time was attenuated by 32% (B = 2.74, P = 0.06).
The association between birth weight and sedentary time appears partially mediated by central adiposity, suggesting that both birth weight and abdominal adiposity may be correlates of sedentary time in youth.
出生体重是日后疾病的早期关联因素，动物研究表明低出生体重与活动减少和久坐时间增加有关。出生体重是否能预测人类日后的久坐时间尚不确定。
我们研究了出生体重与青少年久坐时间之间的关系，并探讨这种关联是否由中心性肥胖介导。
我们使用了1997年至2007年间进行的8项观察性研究的汇总横断面数据，这些数据来自国际儿童加速度计数据库，包括10793名6至18岁的青少年（男孩占47%）。出生体重在医院测量或由母亲报告，久坐时间通过加速度计（每分钟计数<100次）评估，腹部肥胖（腰围）根据世界卫生组织的程序测量。采用自抽样法进行中介分析以分析数据。
久坐的平均（±标准差）时间为370±91分钟/天。出生体重与久坐时间呈正相关（B = 4.04，P = 0.006）和腰围呈正相关（B = 1.59，P < 0.001），而腰围与久坐时间呈正相关（B = 0.82，P < 0.001）。中介分析结果显示，出生体重通过腰围对久坐时间有显著的间接影响（B：1.30；95%偏差校正CI：0.94，1.72），当控制腰围时，出生体重对久坐时间的影响减弱了32%（B = 2.74，P = 0.06）。
出生体重与久坐时间之间的关联似乎部分由中心性肥胖介导，这表明出生体重和腹部肥胖都可能是青少年久坐时间的相关因素。
