Sedentary time and perceived neighborhood environment in adolescents aged 12-17 years

Abstract The environment around the residence could contribute to attenuate or increase time spent in sedentary activities, and in low energy expenditure activities (1.5 METS) in adolescents. The aim of this study was to analyze the association between sedentary time and perceived neighborhood environment in adolescents aged 12-17 years living in southern Brazil. This was an observational cross-sectional study conducted from August 2013 to May 2014, with a sample of adolescents (12-17 years), recruited from 32 census tracts in Curitiba, Brazil. All census tracts were selected according to walkability and income characteristics. Perceived environment was assessed through the NEWS-Y questionnaire, and sedentary time along seven days was obtained through accelerometers (GT1M, GT3x and GT3x+). Linear regression models were used to test the associations, and included age, nutritional status, socioeconomic level and education level as confounding variables. All analyses were performed considering p-value <0.05 through SPSS software 20.0. The analytical sample included 364 adolescents (girls=50.5%; mean age=14.7, SD=1.7) with valid accelerometry data, showing on 489.6 minutes/day (SD=99.5) spent in sedentary time activities. After adjusting for confounding variables, only the perception of places for walking and cycling remained associated with sedentary time for both boys (B=-23.402, p=0.016) and girls (B=-15.572; p=0.079). Perception of places for walking and cycling has an inverse relationship with sedentary time among adolescents living in places with extremes of walkability and income.

摘要
居住周边环境可影响青少年久坐行为及低能量消耗活动（1.5 代谢当量，MET）的时长，使其增加或减少。本研究旨在分析巴西南部地区12~17岁青少年的久坐时长与感知邻里环境之间的关联。
本研究为观察性横断面研究，于2013年8月至2014年5月在巴西库里提巴市的32个普查街区招募12~17岁青少年作为研究对象。所有普查街区均根据步行可达性与收入特征进行选取。
感知环境通过NEWS-Y问卷进行评估，连续7天的久坐时长则通过加速度计（GT1M、GT3x及GT3x+）测得。采用线性回归模型检验关联关系，并纳入年龄、营养状况、社会经济水平与受教育程度作为混杂变量。所有分析均采用SPSS 20.0统计软件完成，检验水准设定为p<0.05。
本研究的分析样本共纳入364名青少年（女性占比50.5%；平均年龄14.7岁，标准差1.7），均具备有效加速度计数据，日均久坐时长为489.6分钟（标准差99.5）。校正混杂变量后，仅步行与骑行场所的感知情况与青少年久坐时长呈负相关：男性组（B=-23.402，p=0.016），女性组（B=-15.572，p=0.079）。步行与骑行场所的感知情况，与居住在步行可达性及收入水平均处于极端区间区域的青少年久坐时长呈负相关关系。