空气污染、道路交通噪声与绿度与青年人唾液皮质醇的关系

文献信息

中文摘要

背景： 环境暴露已被认为与压力有关，但关于其对青年人压力客观标志物唾液皮质醇影响的证据有限。
目的： 我们研究了环境暴露与唾液皮质醇水平之间的关联。
方法： 本研究在瑞典出生队列BAMSE中进行。使用经过验证的模型，在个体居住地址层面估计了临床评估前一年的空气污染物（PM2.5、PM10、黑碳、NOx）、道路交通噪声和绿度（即100 m、300 m和500 m缓冲区内归一化植被指数（NDVI）的平均值）暴露。在24岁时测量唾液皮质醇水平（n = 1148），并使用线性回归估计其与环境暴露的关联，同时校正协变量。按性别、烟草使用、体重指数、抑郁症史、哮喘、鼻炎和湿疹进行了探索性事后亚组分析。
结果： 在这项横断面分析中，未观察到环境暴露与唾液皮质醇之间的总体关联。然而，探索性事后亚组分析提示存在性别和季节特异性差异。在男性中，PM10（β = 0.058；95% CI = 0.003, 0.112）、NOx（β = 0.070；95% CI = 0.017, 0.123）和噪声（β = 0.120；95% CI = 0.024, 0.215）暴露与较高的晨间皮质醇水平相关，而绿度则呈反向关联（例如NDVI 500 m β = -0.165；95% CI = -0.263, -0.067）。晚间皮质醇也观察到类似结果。相反，女性表现出相反的趋势。夏季NDVI与较高的晚间皮质醇水平呈显著正相关，尤其是100 m范围内的NDVI（β = 0.326；95% CI = 0.063, 0.590），而空气污染物或道路交通噪声未观察到季节性模式。若干性别与暴露的交互作用在错误发现率校正后仍显著，而季节特异性模式则不显著。
影响： 本研究探讨了多种居住环境暴露——空气污染、道路交通噪声和绿度——与作为青年期压力生物标志物的唾液皮质醇之间的关系。研究使用详细的个体水平暴露建模和特征明确的人群出生队列，评估晨间和晚间皮质醇，并考察单一和联合暴露的影响。虽然总体关联大多为零，但探索性事后亚组分析提示环境暴露与唾液皮质醇之间的关联可能存在性别特异性差异，而季节性差异的证据较弱，且在校正多重检验后未保持统计学显著。研究结果强调，在评估青年期压力相关生物学机制时，应考虑多种环境暴露和易感因素。
意义： 我们在青年人中未发现环境暴露与唾液皮质醇之间的总体关联，尽管探索性亚组分析提示可能存在性别特异性差异。

英文摘要

BACKGROUND: Environmental exposures have been linked to stress, but evidence on their influence on its objective marker, salivary cortisol, in young adults is limited.
OBJECTIVE: We examined associations of environmental exposures with salivary cortisol levels.
METHODS: The study was conducted within the Swedish birth cohort BAMSE. Exposure to air pollutants (PM2.5, PM10, Black Carbon, NOx), road traffic noise, and greenness (i.e. the average Normalized Difference Vegetation Index (NDVI) within 100 m, 300 m and 500 m buffers) one year prior to clinical assessments was estimated at the individual residential address level using validated models. Salivary cortisol levels were measured at age 24 (n = 1148), and their associations with environmental exposures were estimated using linear regression, adjusted for covariates. Exploratory post hoc subgroup analyses were conducted by sex, tobacco use, body mass index, history of depression, asthma, rhinitis, and eczema.
RESULTS: In this cross-sectional analysis, no overall associations were observed between environmental exposures and salivary cortisol. However, exploratory post hoc subgroup analyses suggested sex- and season-specific differences. Among males, higher morning cortisol levels were observed in relation to exposure to PM10 (β = 0.058; 95% CI = 0.003, 0.112), NOx (β = 0.070; 95% CI = 0.017, 0.123), and noise (β = 0.120; 95% CI = 0.024, 0.215), while inverse associations were found with greenness (e.g. for NDVI 500 m β = -0.165; 95% CI = -0.263, -0.067). Similar findings were observed for evening cortisol. In contrast, females exhibited opposite trends. NDVI was significantly positively associated with higher evening cortisol levels during the summer, particularly for NDVI within 100 m (β = 0.326; 95% CI = 0.063, 0.590), while no seasonal pattern was observed in relation to air pollutants or road traffic noise. Several sex-by-exposure interactions remained significant after false discovery rate correction, whereas season-specific patterns did not.
IMPACT: This study investigates how multiple residential environmental exposures, air pollution, road traffic noise, and greenness, relate to salivary cortisol as a biomarker of stress in young adulthood. Using detailed individual-level exposure modelling and a well-characterised population-based birth cohort, we assess both morning and evening cortisol and examine single and combined exposure impact. While overall associations were largely null, exploratory post hoc subgroup analyses suggested potential sex-specific differences in the associations between environmental exposures and salivary cortisol, whereas evidence for seasonal differences was weaker and did not remain statistically significant after correction for multiple testing. The findings highlight the importance of considering multiple environmental exposures and susceptibility factors when evaluating stress-related biological mechanisms in young adults.
SIGNIFICANCE: We found no overall associations between environmental exposures and salivary cortisol in young adults, although exploratory subgroup analyses suggested potential sex-specific differences.