Nassikas Nicholas J, Ni Wenli, Rifas-Shiman Sheryl L, Luttmann-Gibson Heike, Synn Andrew, Oken Emily, Gold Diane R, Rice Mary B
Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts.
Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts.
Environ Epidemiol. 2025 Feb 10;9(2):e371. doi: 10.1097/EE9.0000000000000371. eCollection 2025 Apr.
Extremes in humidity can induce bronchoconstriction and trigger breathing symptoms in people with asthma. Less is known about how humidity influences measurements of lung health in children and adolescents. Our objective was to assess the extent to which short-term exposures to high and low relative humidity (RH) are associated with lung function and fractional exhaled nitric oxide (FeNO) in adolescents.
We included adolescents (mean age 13.2 y, SD: 0.9) from a northeast US prospective prebirth cohort (n = 1019). We assigned daily RH levels to geocoded participant addresses. We defined low or high RH as ≤10 or ≥90 internal percentiles, respectively, of the cohort-specific RH distribution and the reference RH as the median. We evaluated the linearity of associations of RH in the 1-7 days before assessment with forced expiratory volume in 1 s (FEV), forced vital capacity (FVC), and FeNO using generalized additive models with penalized splines (df = 3). We log-transformed FeNO due to non-normality. For nonlinear relationships, we used distributed lag nonlinear models to explore the cumulative effects of lag 1-7 day RH on FEV, FVC, and FeNO.
Median RH was 65.6% (interquartile range [IQR] = 19.8%), 10th percentile 47.2%, 90th percentile 86.6%. Mean FeNO (SD) was 25.9ppb (26.9ppb). High (vs. median) RH was associated with 38.0% higher FeNO (95% CI = 10.3, 72.7). Exposure to low (vs. median) RH was associated with 186.2 ml lower FEV (95% CI = -299.2, -73.3) and -130.2 ml lower FVC (95% CI = -251.9, -8.5).
Short-term exposures to extremes of RH were associated with lower lung function and higher FeNO, a measure of airway inflammation, in adolescents.
湿度极端情况可诱发哮喘患者支气管收缩并引发呼吸症状。关于湿度如何影响儿童和青少年肺健康测量的了解较少。我们的目的是评估青少年短期暴露于高、低相对湿度（RH）与肺功能及呼出一氧化氮分数（FeNO）之间的关联程度。
我们纳入了来自美国东北部一个前瞻性出生队列的青少年（平均年龄13.2岁，标准差：0.9）（n = 1019）。我们根据地理编码的参与者住址分配每日RH水平。我们将低或高RH分别定义为队列特定RH分布的≤10或≥90百分位数内，将参考RH定义为中位数。我们使用带惩罚样条的广义相加模型（自由度 = 3）评估评估前1 - 7天的RH与1秒用力呼气量（FEV）、用力肺活量（FVC）和FeNO之间关联的线性。由于FeNO呈非正态分布，我们对其进行对数转换。对于非线性关系，我们使用分布滞后非线性模型来探讨滞后1 - 7天RH对FEV、FVC和FeNO的累积影响。
RH中位数为65.6%（四分位间距[IQR] = 19.8%），第10百分位数为47.2%，第90百分位数为86.6%。平均FeNO（标准差）为25.9ppb（26.9ppb）。高（相对于中位数）RH与FeNO升高38.0%相关（95%置信区间 = 10.3，72.7）。暴露于低（相对于中位数）RH与FEV降低186.2ml（95%置信区间 = -299.2，-73.3）和FVC降低130.2ml（95%置信区间 = -251.9，-8.5）相关。
青少年短期暴露于极端RH与较低的肺功能和较高的FeNO（一种气道炎症指标）相关。
