Lowe Samuel A J, Hunter Stephen, Patte Karen A, Leatherdale Scott T, Pabayo Roman
School of Public Health, University of Alberta, Edmonton, AB, Canada.
Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, Canada.
SSM Popul Health. 2023 Sep 21;24:101519. doi: 10.1016/j.ssmph.2023.101519. eCollection 2023 Dec.
Income inequality is a structural determinant of health linked to increased risk of overweight and obesity, although its links to the health of adolescent populations are not well understood. This study investigated the longitudinal associations between census-division-level (CD) income inequality and BMI trajectories among Canadian adolescents, and determine if these associations vary by gender.
Study data are from the Cannabis use, Obesity, Mental health, Physical Activity, Alcohol use, Smoking, and Sedentary behaviour (COMPASS) cohort of adolescents attending secondary schools in Canada. Our sample included 14,675 adolescents who were followed up across three waves of the COMPASS study (2016-2017, 2017-2018, and 2018-2019) and linked to 30 CDs. Measures of income inequality and other area-level covariates were derived and linked to COMPASS participants using data from the 2016 Canadian Census. We utilized multilevel mixed-effects linear regression modelling to quantify the associations between income inequality and BMI and test for effect modification by gender. Sensitivity analyses were run excluding those with BMI scores in the range considered overweight or obesity at baseline.
Higher CD income inequality was significantly associated with higher z-transformed BMI scores (β = 0.11, 95% CI = 0.034 to 0.19). The interaction term between income inequality and time was not statistically significant, indicating that this association remained constant over time. Once stratified by gender, the association between inequality and BMI became stronger for males (β = 0.14, 95% CI = 0.060 to 0.022) and attenuated for females (β = 0.063, 95% CI = -0.047 to 0.17).
Attending schools in CDs with higher income inequality was associated with higher BMI scores among male but not female adolescents. Further work is needed to investigate this discrepancy and identify the structural mechanisms that mediate the relationship between inequality and adolescent health.
收入不平等是健康的一个结构性决定因素，与超重和肥胖风险增加相关，尽管其与青少年人群健康的联系尚未得到充分理解。本研究调查了加拿大青少年中普查分区（CD）层面的收入不平等与体重指数（BMI）轨迹之间的纵向关联，并确定这些关联是否因性别而异。
研究数据来自加拿大中学青少年的大麻使用、肥胖、心理健康、身体活动、酒精使用、吸烟和久坐行为（COMPASS）队列。我们的样本包括14675名青少年，他们在COMPASS研究的三个阶段（2016 - 2017年、2017 - 2018年和2018 - 2019年）接受了随访，并与30个普查分区相关联。使用2016年加拿大人口普查数据得出收入不平等和其他地区层面协变量的测量值，并将其与COMPASS参与者相关联。我们利用多层次混合效应线性回归模型来量化收入不平等与BMI之间的关联，并检验性别对效应的修正作用。进行敏感性分析时排除了基线时BMI分数处于超重或肥胖范围内的人群。
较高的普查分区收入不平等与较高的z变换BMI分数显著相关（β = 0.11，95%置信区间 = 0.034至0.19）。收入不平等与时间之间的交互项无统计学意义，表明这种关联随时间保持不变。按性别分层后，不平等与BMI之间的关联在男性中变得更强（β = 0.14，95%置信区间 = 0.060至0.22），而在女性中减弱（β = 0.063，95%置信区间 = -0.047至0.17）。
在收入不平等较高的普查分区上学与男性青少年而非女性青少年较高的BMI分数相关。需要进一步开展工作来研究这种差异，并确定介导不平等与青少年健康之间关系的结构机制。
