哮喘儿童中肥胖、潮气量与肺内细颗粒物沉积的关系分析
2022/04/19
摘要
背景：罹患哮喘的肥胖儿童更容易受空气污染的影响，尤其是细颗粒物（PM2.5），但原因却知之甚少。本文假设这一现象可能是由于体重指数（BMI） 升高，导致呼吸模式（潮气量、呼吸频率和分钟通气量）改变。
目的：探索 BMI 与呼吸模式和吸入 性PM2.5沉积的关系。
方法：从一项前瞻性研究中获取哮喘儿童的基线数据并进行分析（n=174）。通过皮托管流量计测量潮气呼吸情况，包括潮气量、呼吸频率和分钟通气量。采用年龄、身高、种族、性别和哮喘严重程度校正的多变量模型评估 BMI z 评分与呼吸模式的关联。基于 BMI 相关呼吸模式变化，采用颗粒剂量学模型模拟 PM2.5肺内沉积情况。
结果：高 BMI值 与高潮气量（肥胖和正常 BMI 之间的校正平均差 (aMD) 为 25 mL，95% 置信区间为 5-45 mL）和高分钟通气量（aMD 为453 mL·min-1，95% 置信区间为 123 -784 mL·min-1)。高潮气量导致肺内PM2.5沉积比例增加，这是由于肺内 PM2.5沉积增多。即表现为肥胖受试者的吸入 PM2.5的每次呼吸滞留率更高（肺泡沉积百分比的 aMD 为 3.4%，95% CI 1.3-5.5%），导致PM2.5沉积率更严重。
结论：肥胖的哮喘儿童潮气量更高，这可能会增加 PM2.5在肺内的沉积效率。这一发现可以部分解释为什么肥胖哮喘儿童对空气污染敏感性更高。
Obesity, tidal volume, and pulmonary deposition of fine particulate matter in children with asthma
Afshar-Mohajer N, Wu TD, Shade R, Brigham E, Woo H, Wood M, Koehl R, Koehler K, Kirkness J, Hansel NN, Ramchandran G, McCormack MC.
Abstract
BACKGROUND:Obese children with asthma are more vulnerable to air pollution, especially fine particulate matter (PM2.5), but reasons are poorly understood. We hypothesised that differences in breathing patterns (tidal volume, respiratory rate and minute ventilation) due to elevated body mass index (BMI) may contribute to this finding.
OBJECTIVE:To investigate the association of BMI with breathing patterns and deposition of inhaled PM2.5.
METHODS:Baseline data from a prospective study of children with asthma were analysed (n=174). Tidal breathing was measured by a pitot-tube flowmeter, from which tidal volume, respiratory rate and minute ventilation were obtained. The association of BMI z-score with breathing patterns was estimated in a multivariable model adjusted for age, height, race, sex and asthma severity. A particle dosimetry model simulated PM2.5 lung deposition based on BMI-associated changes in breathing patterns.
RESULTS:Higher BMI was associated with higher tidal volume (adjusted mean difference (aMD) between obese and normal-range BMI of 25 mL, 95%置信区间为 5-45 mL) and minute ventilation (aMD 453 mL·min-1, 95%置信区间为 123-784 mL·min-1). Higher tidal volumes caused higher fractional deposition of PM2.5 in the lung, driven by greater alveolar deposition. This translated into obese participants having greater per-breath retention of inhaled PM2.5 (aMD in alveolar deposition fraction of 3.4%, 95%置信区间为 1.3-5.5%), leading to worse PM2.5 deposition rates.
CONCLUSIONS:Obese children with asthma breathe at higher tidal volumes that may increase the efficiency of PM2.5 deposition in the lung. This finding may partially explain why obese children with asthma exhibit greater sensitivity to air pollution.
背景：罹患哮喘的肥胖儿童更容易受空气污染的影响，尤其是细颗粒物（PM2.5），但原因却知之甚少。本文假设这一现象可能是由于体重指数（BMI） 升高，导致呼吸模式（潮气量、呼吸频率和分钟通气量）改变。
目的：探索 BMI 与呼吸模式和吸入 性PM2.5沉积的关系。
方法：从一项前瞻性研究中获取哮喘儿童的基线数据并进行分析（n=174）。通过皮托管流量计测量潮气呼吸情况，包括潮气量、呼吸频率和分钟通气量。采用年龄、身高、种族、性别和哮喘严重程度校正的多变量模型评估 BMI z 评分与呼吸模式的关联。基于 BMI 相关呼吸模式变化，采用颗粒剂量学模型模拟 PM2.5肺内沉积情况。
结果：高 BMI值 与高潮气量（肥胖和正常 BMI 之间的校正平均差 (aMD) 为 25 mL，95% 置信区间为 5-45 mL）和高分钟通气量（aMD 为453 mL·min-1，95% 置信区间为 123 -784 mL·min-1)。高潮气量导致肺内PM2.5沉积比例增加，这是由于肺内 PM2.5沉积增多。即表现为肥胖受试者的吸入 PM2.5的每次呼吸滞留率更高（肺泡沉积百分比的 aMD 为 3.4%，95% CI 1.3-5.5%），导致PM2.5沉积率更严重。
结论：肥胖的哮喘儿童潮气量更高，这可能会增加 PM2.5在肺内的沉积效率。这一发现可以部分解释为什么肥胖哮喘儿童对空气污染敏感性更高。
(中日友好医院呼吸与危重症医学科 张婧媛 摘译 林江涛 审校)
(Eur Respir J. 2022;59(3):2100209. doi:10.1183/13993003.00209-2021)
(Eur Respir J. 2022;59(3):2100209. doi:10.1183/13993003.00209-2021)
Obesity, tidal volume, and pulmonary deposition of fine particulate matter in children with asthma
Afshar-Mohajer N, Wu TD, Shade R, Brigham E, Woo H, Wood M, Koehl R, Koehler K, Kirkness J, Hansel NN, Ramchandran G, McCormack MC.
Abstract
BACKGROUND:Obese children with asthma are more vulnerable to air pollution, especially fine particulate matter (PM2.5), but reasons are poorly understood. We hypothesised that differences in breathing patterns (tidal volume, respiratory rate and minute ventilation) due to elevated body mass index (BMI) may contribute to this finding.
OBJECTIVE:To investigate the association of BMI with breathing patterns and deposition of inhaled PM2.5.
METHODS:Baseline data from a prospective study of children with asthma were analysed (n=174). Tidal breathing was measured by a pitot-tube flowmeter, from which tidal volume, respiratory rate and minute ventilation were obtained. The association of BMI z-score with breathing patterns was estimated in a multivariable model adjusted for age, height, race, sex and asthma severity. A particle dosimetry model simulated PM2.5 lung deposition based on BMI-associated changes in breathing patterns.
RESULTS:Higher BMI was associated with higher tidal volume (adjusted mean difference (aMD) between obese and normal-range BMI of 25 mL, 95%置信区间为 5-45 mL) and minute ventilation (aMD 453 mL·min-1, 95%置信区间为 123-784 mL·min-1). Higher tidal volumes caused higher fractional deposition of PM2.5 in the lung, driven by greater alveolar deposition. This translated into obese participants having greater per-breath retention of inhaled PM2.5 (aMD in alveolar deposition fraction of 3.4%, 95%置信区间为 1.3-5.5%), leading to worse PM2.5 deposition rates.
CONCLUSIONS:Obese children with asthma breathe at higher tidal volumes that may increase the efficiency of PM2.5 deposition in the lung. This finding may partially explain why obese children with asthma exhibit greater sensitivity to air pollution.
