From the Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI.
Department of Environmental and Occupational Health Sciences, University of Washington School of Public Health, Seattle, WA.
Epidemiology. 2018 Nov;29(6):756-764. doi: 10.1097/EDE.0000000000000910.
With climate change, temperatures are increasing. Heat-associated health events disproportionately affect certain subpopulations. However, prior research has often lacked information on individual-level health and air conditioning and neighborhood stressors/protections.
To assess whether (1) heat (2-day mean temperature above local 75th percentiles) is associated with increased heart rate and decreased blood pressure, controlling for age, time, season, daily ozone, and daily particulate matter (PM2.5) and (2) associations differ by antihypertensive medication use, renal function, fasting glucose, emotional support, air conditioning ownership and use, normalized difference vegetation index, neighborhood safety, and residence- specific oxides of nitrogen and PM2.5.
Health and behavioral characteristics were obtained repeatedly on participants of the Multi-Ethnic Study of Atherosclerosis in six US sites (2000-2010). These were linked with airport temperature, air quality, and satellite- and survey-derived neighborhood characteristics. We used a fixed-effects design, regressing health outcomes on linear temperature splines with knots at the 75th percentiles, interaction terms for each characteristic, and adjustment for month of year, age, PM2.5, and ozone.
Overall, heat was not associated with heart rate. However, for a 2°C increase in heat, systolic blood pressure decreased by 1.1 mmHg (95% CI = -1.6, -0.6) and diastolic blood pressure by 0.3 mmHg (95% CI = -0.6, -0.1). Among nonusers of antihypertensive medications, heat-associated decreases in SBP were 2.1 mmHg greater among individuals with central air conditioning versus those without. Confidence intervals around the remaining modifiers were wide after multiple-comparisons corrections or sensitivity analyses.
Outdoor heat is associated with decreasing blood pressure, and cardiovascular vulnerability may vary primarily by ownership of central air conditioning.
随着气候变化，气温不断升高。与热相关的健康事件不成比例地影响某些亚人群。然而，先前的研究往往缺乏个体健康和空调以及邻里压力源/保护因素的信息。
评估（1）热（2 天平均温度高于当地第 75 个百分位数）是否与心率增加和血压降低有关，同时控制年龄、时间、季节、每日臭氧和每日颗粒物（PM2.5），以及（2）与降压药物使用、肾功能、空腹血糖、情感支持、空调拥有和使用、归一化差异植被指数、邻里安全以及特定于居住地的氮氧化物和 PM2.5 相关的关联是否不同。
在美国六个地点（2000-2010 年）的多民族动脉粥样硬化研究中，多次获取健康和行为特征。这些特征与机场温度、空气质量以及卫星和调查衍生的邻里特征相关联。我们使用固定效应设计，通过在第 75 个百分位数处的线性温度样条上回归健康结果，为每个特征的交互项，并根据月份、年龄、PM2.5 和臭氧进行调整。
总体而言，热与心率无关。然而，对于 2°C 的热增加，收缩压降低了 1.1mmHg（95%CI=-1.6，-0.6），舒张压降低了 0.3mmHg（95%CI=-0.6，-0.1）。在未使用降压药物的人群中，与没有中央空调的人相比，中央空调使用者的 SBP 与热相关的下降幅度大 2.1mmHg。在多次比较校正或敏感性分析后，剩余修饰符的置信区间很宽。
室外热与血压降低有关，心血管脆弱性可能主要取决于中央空调的拥有情况。
