Ambient air pollution and markers of fetal growth: A retrospective population-based cohort study of 2.57 million term singleton births in China

The associations of particulate matters with fetal growth in utero and birth weight: A birth cohort study in Beijing, China.

Background: small birth size may be associated with increased risk of cardiovascular diseases (CVD), whereas large birth size may predict increased risk of obesity and some cancers. The net effect of birth size on long-term mortality has only been assessed in individual studies, with conflicting results. Methods: the Meta-analyses of Observational Studies in Epidemiology (MOOSE) guidelines for conducting and reporting meta-analysis of observational studies were followed. We retrieved 22 studies that assessed the association between birthweight and adult mortality from all causes, CVD or cancer. The studies were systematically reviewed and those reporting hazard ratios (HRs) and 95% confidence intervals (95% CIs) per kilogram (kg) increase in birthweight were included in generic inverse variance meta-analyses. Results: for all-cause mortality, 36 834 deaths were included and the results showed a 6% lower risk (adjusted HR¼0.94, 95% CI: 0.92–0.97) per kg higher birthweight for men and women combined. For cardiovascular mortality, the corresponding inverse association was stronger (HR¼0.88, 95% CI: 0.85–0.91). For cancer mortality, HR per kg higher birthweight was 1.13 (95% CI: 1.07–1.19) for men and 1.04 (95% CI: 0.98–1.10) for women (Pinteraction¼0.03). Residual confounding could not be eliminated, but is unlikely to account for the main findings. Conclusion: these results show an inverse but moderate association of birthweight with adult mortality from all-causes and a stronger inverse association with cardiovascular mortality. For men, higher birthweight was strongly associated with increased risk of cancer deaths. The findings suggest that birthweight can be a useful indicator of processes that influence long-term health.

Birthweight and mortality in adulthood: a systematic review and meta-analysis

The literature shows associations between maternal exposures to PM2.5 and adverse pregnancy outcomes. There are few data from Latin America. We have examined PM2.5 and pregnancy outcomes in Lima. The study included 123,034 births from 2012 to 2016, at three public hospitals. We used estimated daily PM2.5 from a newly created model developed using ground measurements, satellite data, and a chemical transport model. Exposure was assigned based on district of residence (n = 39). Linear and logistic regression analyzes were used to estimate the associations between air pollution exposure and pregnancy outcomes. Increased exposure to PM2.5 during the entire pregnancy and in the first trimester was inversely associated with birth weight. We found a decrease of 8.13 g (−14.0; −1.84) overall and 18.6 g (−24.4, −12.8) in the first trimester, for an interquartile range (IQR) increase (9.2 µg/m3) in PM2.5. PM2.5 exposure was positively associated with low birth weight at term (TLBW) during entire pregnancy (OR: 1.11; 95% CI: 1.03–1.20), and at the first (OR: 1.11; 95% CI: 1.03–1.20), second (OR: 1.09; 95% CI: 1.01–1.17), and third trimester (OR: 1.10; 95% CI: 1.02–1.18) per IQR (9.2 µg/m3) increase. Higher exposure to PM2.5 was also associated with increased risk of small for gestational age (SGA). There were no statistically significant associations between PM2.5 exposure and preterm births (PTB). Exposure to higher concentrations of PM2.5 in Lima may decrease birth weight and increase the frequency of TLBW and SGA. Our study was inconsistent with the literature in finding no associations with preterm birth.

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Association between maternal exposure to particulate matter (PM2.5) and adverse pregnancy outcomes in Lima, Peru.

Previous studies have suggested that maternal exposure to air pollution might affect term birth weight. However, the conclusions are controversial. Birth data of all term newborns born in Xi'an city of Shaanxi, China, from 2015 to 2018 and whose mother lived in Xi'an during pregnancy were selected form the Birth Registry Database. And the daily air quality data of Xi'an city was collected from Chinese Air Quality Online Monitoring and Analysis Platform. Generalized additive models (GAM) and 2-level binary logistic regression models were used to estimate the effects of air pollution exposure on term birth weight, the risk term low birth weight (TLBW), and macrosomia. Finally, 321521 term newborns were selected, including 4369(1.36%) TLBW infants and 24,960 (7.76%) macrosomia. The average pollution levels of PM2.5, PM10, and NO2 in Xi'an city from 2015 to 2018 were higher than national limits. During the whole pregnancy, maternal exposure to PM2.5, PM10, SO2, and CO all significantly reduced the term birth weight and increased the risk of TLBW. However, NO2 and O3 exposure have significantly increased the term birth weight, and O3 even increased the risk of macrosomia significantly. Those effects were also observed in the first and second trimesters of pregnancy. But during the third trimester, high level of air quality index (AQI) and maternal exposure to PM2.5, PM10, SO2, NO2, and CO increased the term birth weight and the risk of macrosomia, while O3 exposure was contrary to this effect. The findings suggested that prenatal exposure to air pollution might cause adverse impacts on term birth weight, and the effects varied with trimesters and pollutants, which provides further pieces of evidence for the adverse effects of air pollution exposure in heavy polluted-area on term birth weight.

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Impact of air pollution exposure during various periods of pregnancy on term birth weight: a large-sample, retrospective population-based cohort study.

Association of ambient air pollutants and birth weight in Ningbo, 2015-2017.

The PD-1/PD-L1 immune checkpoint blockade therapy has shown revolutionary efficacy in the treatment of multiple cancers including gastric cancer. Isothiocyanates play important roles in cancer cell suppression and immunomodulation. However, the effects of isothiocyanates on immune checkpoint inhibitors are poorly understood in gastric cancer. The influence of three major isothiocyanates (sulforaphane, phenylethyl isothiocyanate, and benzhydryl isothiocyanate) on gastric cancer cell growth and PD-L1 expression was investigated. Syngeneic mouse models were administered by isothiocyanates and anti-PD-L1 monoclonal antibody, and the anti-tumor effects were assessed. The expression of PD-L1, proportion of lymphocytes and serum cytokine levels were detected to explore the underlying mechanisms. We found that PD-L1 expression was significantly induced by isothiocyanates which was associated with TAp63α up-regulation. We further revealed that TAp63α promoted PD-L1 through transcriptional activation. Combination treatment of isothiocyanates and anti-PD-L1 therapy weakened the sensitivity of gastric cancer cells to anti-PD-L1 drug. Moreover, in vivo studies illustrated that the interference effects of isothiocyanates on anti-PD-L1 antibody were related to PD-L1 expression and decreased infiltrating T lymphocytes in tumor bearing mouse hosts. Our findings provide novel insights as isothiocyanates could interfere with the successful application of immunotherapy in gastric cancer. 

Lixia Hong

Papers

Association of ambient air pollutants and birth weight in Ningbo, 2015-2017.

Isothiocyanates attenuate immune checkpoint blockage therapy in gastric cancer via induction of PD-L1 expression.