Importance

Gestational exposure to particulate matter (PM) air pollution may increase the risk of childhood obesity, but the impact of reducing air pollution during pregnancy on obesity-related outcomes in childhood has not been examined.

Objective

To assess the impact of reducing gestational PM exposure on body mass index (BMI) at two years of age.

Methods

In this single-blind, parallel group randomized controlled trial in Ulaanbaatar Mongolia, we randomly assigned 540 pregnant women to receive 1–2 portable high efficiency particulate air (HEPA) filter air cleaners or no air cleaners. We measured height and weight when children were a mean age of 23.8 months. Our primary outcome was age- and sex-specific BMI z-score based on the World Health Organization 2007 Growth Charts. Secondary outcomes included age- and sex-specific weight z score, overweight/obesity (defined as BMI z-score > 2.00), and catch-up growth (defined using various cut-offs to identify children with relatively low birth weight for sex and gestational age and relatively high age- and sex-specific weight in childhood). We imputed missing outcome data using multiple imputation with chained equations and our primary analysis was by intention to treat (ITT). We estimated intervention effects on continuous and binary outcomes using linear and logistic regression, respectively.

Results

After excluding known miscarriages, still births, and neonatal deaths our analysis included 480 children (235 control and 245 intervention). The mean (SD) child BMI z score was 0.79 (1.0); 9.8% of children were overweight or obese. The mean BMI z score of children who were randomly assigned to the intervention group was 0.16-units lower (95% CI: −0.35, 0.04) than children in the control group. The intervention was also associated with reductions in overweight/obesity (odds ratio = 0.59; 95% CI: 0.31, 1.12). Catch-up growth occurred less frequently in the intervention group, but effect estimates varied depending on the specific definition of catch-up growth and confidence intervals consistently spanned no effect.

Conclusions

We found that the use of portable air cleaners during pregnancy was associated with improvements in obesity-related outcomes, although some effect estimates lacked precision. Reducing PM exposure during pregnancy may lead to improvements in cardiometabolic health in childhood.

中文翻译：

---

怀孕期间使用便携式 HEPA 过滤空气净化器和儿童两岁时的体重指数：UGAAR 随机对照试验

重要性

妊娠期暴露于颗粒物 (PM) 空气污染可能会增加儿童肥胖的风险，但尚未研究减少怀孕期间空气污染对儿童肥胖相关结果的影响。

客观的

评估减少妊娠期 PM 暴露对两岁时体重指数 (BMI) 的影响。

方法

在蒙古乌兰巴托的这项单盲、平行组随机对照试验中，我们随机分配 540 名孕妇接受 1-2 台便携式高效微粒空气 (HEPA) 过滤式空气净化器或不使用空气净化器。我们在儿童平均年龄为 23.8 个月时测量了身高和体重。我们的主要结果是基于世界卫生组织 2007 年增长图表的特定年龄和性别的 BMI z 分数。次要结果包括年龄和性别特定的体重z分数、超重/肥胖（定义为 BMI z 分数 > 2.00）和追赶生长（使用各种临界值来确定性别和胎龄出生体重相对较低以及年龄和性别特异性相对较高的儿童）小时候的体重）。我们使用链式方程的多重插补来插补缺失的结果数据，我们的主要分析是通过意向治疗 (ITT)。我们分别使用线性回归和逻辑回归来估计干预对连续和二元结果的影响。

结果

在排除已知的流产、死产和新生儿死亡后，我们的分析包括 480 名儿童（235 名对照和 245 名干预）。平均 (SD) 儿童 BMI z分数为 0.79 (1.0)；9.8% 的儿童超重或肥胖。随机分配到干预组的儿童的平均 BMI z分数比对照组的儿童低 0.16 个单位（95% CI：-0.35, 0.04）。干预还与减少超重/肥胖有关（优势比 = 0.59；95% CI：0.31, 1.12）。追赶增长在干预组中发生的频率较低，但效应估计值因追赶增长的具体定义而异，置信区间始终没有影响。

结论

我们发现在怀孕期间使用便携式空气净化器与肥胖相关结果的改善有关，尽管一些效果估计缺乏准确性。减少怀孕期间接触 PM 可能会改善儿童时期的心脏代谢健康。