Department of Clinical Epidemiology, Predictive Medicine and Public Health, and Cardiovascular Research & Development Unity, University of Porto Medical School, Porto, Portugal.
Pediatrics. 2012 Nov;130(5):e1146-54. doi: 10.1542/peds.2011-1116. Epub 2012 Oct 1.
The association between sleep and obesity has been described in different age groups. However, there are not sufficient data to clarify the inconsistent results reported in adolescents. Our objective was to study the associations between sleep duration and adiposity at 13 and at 17 years of age, with both cross-sectional and longitudinal approaches.
We evaluated, as part of an urban population-based cohort (EPITeen), 1171 adolescents at both 13 and 17 years of age. Sleep duration was estimated by self-reported bedtimes and wake-up times. Age- and gender-specific BMI z scores were calculated based on Centers for Disease Control and Prevention references. Body fat percentage (BF%) was assessed by bioelectrical impedance. Regression coefficients (β) and respective 95% confidence intervals (CIs) were used to estimate the association between sleep and BMI z scores and BF%. Additionally, a cross-lagged analysis was performed to investigate the causal relations.
In the cross-sectional analysis, at 13 years, sleep duration was inversely associated with BMI z score only in boys (β = -0.155, 95% CI: -0.267 to -0.043); at 17 years, a positive association was found among girls but was only significant for BF% (β = 0.510, 95% CI: 0.061-0.958). In the longitudinal approach, sleep duration at age 13 was inversely associated with BMI z score (β = -0.123, 95% CI: -0.233 to -0.012) and BF% (β = -0.731, 95% CI: -1.380 to -0.081) at 17 years only in boys. These significant associations disappeared after adjustment for adiposity at 13 years. These results were corroborated by those from cross-lagged analysis.
Our results showed an effect of sleep duration in adiposity at younger ages of adolescence and suggested gender differences in this association.
睡眠与肥胖的相关性在不同年龄组中已有描述。然而，对于青少年，目前还没有足够的数据来澄清报告中不一致的结果。本研究旨在通过横断面和纵向研究方法，研究 13 岁和 17 岁时的睡眠时间与肥胖的相关性。
我们评估了一个基于城市人群的队列（EPITeen）中的 1171 名青少年，他们在 13 岁和 17 岁时都接受了评估。通过自我报告的就寝时间和起床时间来估计睡眠时间。根据疾病控制和预防中心的参考标准，计算出年龄和性别特异性 BMI z 分数。通过生物电阻抗法评估体脂肪百分比（BF%）。回归系数（β）及其相应的 95%置信区间（CI）用于估计睡眠与 BMI z 分数和 BF%之间的关联。此外，还进行了交叉滞后分析以调查因果关系。
在横断面分析中，13 岁时，仅在男孩中发现睡眠时间与 BMI z 分数呈负相关（β=-0.155，95%CI：-0.267 至 -0.043）；17 岁时，女孩中发现了正相关，但仅对 BF%有统计学意义（β=0.510，95%CI：0.061-0.958）。在纵向研究中，13 岁时的睡眠时间与 17 岁时的 BMI z 分数（β=-0.123，95%CI：-0.233 至 -0.012）和 BF%（β=-0.731，95%CI：-1.380 至 -0.081）呈负相关，仅在男孩中存在统计学意义。这些显著关联在调整了 13 岁时的肥胖状况后消失。交叉滞后分析的结果证实了这些结果。
我们的结果表明，睡眠时间对青春期早期的肥胖有影响，并提示这种关联存在性别差异。
