Critical Windows of Maternal Exposure to Biothermal Stress and Birth Weight for Gestational Age in Western Australia

BACKGROUND

There is limited and inconsistent evidence on the risk of ambient temperature on small for gestational age (SGA) and there are no known related studies for large for gestational age (LGA). In addition, previous studies used temperature rather than a biothermal metric.

OBJECTIVES

Our aim was to examine the associations and critical susceptible windows of maternal exposure to a biothermal metric [Universal Thermal Climate Index (UTCI)] and the hazards of SGA and LGA.

METHODS

We linked 385,337 singleton term births between 1 January 2000 and 31 December 2015 in Western Australia to daily spatiotemporal UTCI. Distributed lag nonlinear models with Cox regression and multiple models were used to investigate maternal exposure to UTCI from 12 weeks preconception to birth and the adjusted hazard ratios (HRs) of SGA and LGA.

RESULTS

Relative to the median exposure, weekly and monthly specific exposures showed potential critical windows of susceptibility for SGA and LGA at extreme exposures, especially during late gestational periods. Monthly exposure showed strong positive associations from the 6th to the 10th gestational months with the highest hazard of 13% for SGA (HR = 1.13 ; 95% CI: 1.10, 1.14) and 7% for LGA (HR = 1.07 ; 95% CI: 1.03, 1.11) at the 10th month for the 1st UTCI centile. Entire pregnancy exposures showed the strongest hazards of 11% for SGA (HR = 1.11 ; 95% CI: 1.04, 1.18) and 3% for LGA (HR = 1.03 ; 95% CI: 0.95, 1.11) at the 99th UTCI centile. By trimesters, the highest hazards were found during the second and first trimesters for SGA and LGA, respectively, at the 99th UTCI centile. Based on estimated interaction effects, male births, mothers who were non-Caucasian, smokers, ≥ 35 years of age, and rural residents were most vulnerable.

CONCLUSIONS

Both weekly and monthly specific extreme biothermal stress exposures showed potential critical susceptible windows of SGA and LGA during late gestational periods with disproportionate sociodemographic vulnerabilities. https://doi.org/10.1289/EHP12660.

Predicting fine-scale daily NO2 over Mexico City using an ensemble modeling approach

In recent years, there has been growing interest in developing air pollution prediction models to reduce exposure measurement error in epidemiologic studies. However, efforts for localized, fine-scale prediction models have been predominantly focused in the United States and Europe. Furthermore, the availability of new satellite instruments such as the TROPOsopheric Monitoring Instrument (TROPOMI) provides novel opportunities for modeling efforts. We estimated daily ground-level nitrogen dioxide (NO2) concentrations in the Mexico City Metropolitan Area at 1-km2 grids from 2005 to 2019 using a four-stage approach. In stage 1 (imputation stage), we imputed missing satellite NO2 column measurements from the Ozone Monitoring Instrument (OMI) and TROPOMI using the random forest (RF) approach. In stage 2 (calibration stage), we calibrated the association of column NO2 to ground-level NO2 using ground monitors and meteorological features using RF and extreme gradient boosting (XGBoost) models. In stage 3 (prediction stage), we predicted the stage 2 model over each 1-km2 grid in our study area, then ensembled the results using a generalized additive model (GAM). In stage 4 (residual stage), we used XGBoost to model the local component at the 200-m2 scale. The cross-validated R2 of the RF and XGBoost models in stage 2 were 0.75 and 0.86 respectively, and 0.87 for the ensembled GAM. Cross-validated rootmean-squared error (RMSE) of the GAM was 3.95 μg/m3. Using novel approaches and newly available remote sensing data, our multi-stage model presented high cross-validated fits and reconstructs fine-scale NO2 estimates for further epidemiologic studies in Mexico City.

Particulate Air Pollution Exposure and Stroke among Adults in Israel

Stroke is the second most common cause of death and disability in the world. Many studies have found fine particulate matter (PM2.5) exposure to be associated with an increased risk of atherosclerotic cardiovascular disease, mostly focusing on ischemic heart disease and acute myocardial infarction. In a national analysis conducted in Israel-an area with unique climate conditions and high air pollution levels, we estimated the association between short-term PM2.5 exposure and ischemic stroke, intracerebral hemorrhage (ICH), or transient ischemic attacks (TIA). Using the Israeli National Stroke Registry, we obtained information on all stroke cases across Israel in 2014-2018. We obtained daily PM2.5 exposures from spatiotemporally resolved exposure models. We restricted the analytical data to days in which PM2.5 levels did not exceed the Israeli 24 h standard (37.5 µg/m3). We repeated the analysis with a stratification by sociodemographic characteristics and comorbidities. For all outcomes, the exposure-response curves were nonlinear. PM2.5 exposure was associated with a higher ischemic stroke risk, with larger effect estimates at higher exposure levels. Although nonsignificant, the exposure-response curve for TIA was similar. The associations with ICH were nonsignificant throughout the PM2.5 exposure distribution. The associations with ischemic stroke/TIA were larger among women, non-Jewish individuals, older adults, and individuals with diabetes, hypertension, and ischemic heart disease. In conclusion, short-term PM2.5 exposure is associated with a higher risk for ischemic stroke and possibly TIA, even when PM2.5 concentrations do not exceed the Israeli air quality guideline threshold. Vulnerability to the air pollution effects differed by age, sex, ethnicity, and comorbidities.

Intermediate- and long-term associations between air pollution and ambient temperature and glycated hemoglobin levels in women of child bearing age

BACKGROUND

Air pollution has been linked to obesity while higher ambient temperatures typically reduce metabolic demand in a compensatory manner. Both relationships may impact glucose metabolism, thus we examined the association between intermediate- and long-term exposure to fine particulate matter (PM2.5) and ambient temperature and glycated hemoglobin(HbA1c), a longer-term marker of glucose control.

METHODS

We assessed 3-month, 6-month, and 12-month average air pollution and ambient temperature at 1-km2 spatial resolution via satellite remote sensing models (2013-2019), and assessed HbA1c at four, six, and eight years postpartum in women enrolled in the Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS) cohort based in Mexico City. PM2.5 and ambient temperature were matched to participants' addresses and confirmed by GPS tracker. Using linear mixed-effects models, we examined the association between 3-month, 6-month, and 12-month average PM2.5 and ambient temperature with repeated log-transformed HbA1c values. All models included a random intercept for each woman and were adjusted for calendar year, season, and individual-level confounders (age, marital status, smoking, alcohol consumption level, and education level).

RESULTS

We analyzed 1,265 HbA1c measurements of 484 women. Per 1 µg/m3 increase in 3-month and 6-month PM2.5, HbA1c levels increased by 0.28% (95% confidence interval (95 %CI): 0.14, 0.42%) and 0.28% (95 %CI: 0.04, 0.52%) respectively. No association was seen for 12-month average PM2.5. Per 1 °C increase in ambient temperature, HbA1c levels decreased by 0.63% (95 %CI: -1.06, -0.21%) and 0.61% (95 %CI: -1.08, -0.13%), while the 12-month average again is not associated with HbA1c.

CONCLUSIONS

Intermediate-term exposure to PM2.5 and ambient temperature are associated with opposing changes in HbA1c levels, in this region of high PM2.5 and moderate temperature fluctuation. These effects, measurable in mid-adult life, may portend future risk of type 2 diabetes and possible heart disease.

The effect of prenatal temperature and PM2.5 exposure on birthweight: Weekly windows of exposure throughout the pregnancy

BACKGROUND

Birthweight is a strong predictor of normal growth, healthy development, and survival. Several studies have found associations between temperature, fine particulate matter (PM_2.5), and birth weight. However, the relevant timing of exposures varies between studies and is yet unclear. Therefore, we assessed the difference in term birthweight (TBW) associated with weekly exposure to temperature and PM_2.5 throughout 37 weeks of gestation.

METHODS

We included all singleton live term births in Massachusetts, U.S between 2004 and 2015 (n = 712,438). Weekly PM_2.5 and temperature predictions were estimated on a 1 km grid from satellite-based models. We utilized a distributed lag nonlinear model (DLNM) to estimate the difference in TBW associated with weekly exposures from the last menstrual period to 37 weeks of gestation.

RESULTS

We found a nonlinear association with prenatal temperature exposure. Larger effects were observed in warmer temperatures, where higher temperatures were negatively associated with TBW. Temperature effects were larger in the first and final weeks of gestation. We observed a negative difference in TBW associated with PM_2.5 exposure. Overall, a 1 µg/m³ increase in prenatal exposure was associated with 3.9 g lower TBW (95% CI -5.0 g; -2.9 g). PM_2.5 effects were larger in the final weeks of gestation.

CONCLUSION

We found heat and PM_2.5 exposure to be related to lower TBW. Our findings suggest that women are more susceptible to both exposures towards the end of pregnancy. Susceptibility to heat was higher in the initial weeks of pregnancy as well. These critical windows of susceptibility can be communicated to pregnant women during routine prenatal visits to increase awareness and target interventions to reduce exposures.

Differences in environmental factors contributing to preterm labor and PPROM - Population based study

BACKGROUND

Previous reports indicate an association between ambient temperature (Ta) and air pollution exposure during pregnancy and preterm birth (PTB). Nevertheless, information regarding the association between environmental factors and specific precursors of spontaneous preterm birth is lacking. We aimed to determine the association between Ta and air pollution during gestation and the precursors of spontaneous preterm parturition, i.e. preterm labor (PTL) and preterm prelabor rupture of membranes (PPROM).

METHODS

From 2003 to 2013 there were 84,476 deliveries of singleton gestation that comprised the study cohort. Exposure data during pregnancy included daily measurements of temperature and particulate matter <2.5 μm and <10 μm, PM_2.5 and PM₁₀, respectively. Deliveries were grouped into PPROM, PTL and non-spontaneous preterm and term deliveries. Exposure effect was tested in windows of a week and two days prior to admission for delivery and adjusted to gestational age and socio-economic status. Poisson regression models were used for analyses.

RESULTS

There is an association of environmental exposure with the precursors of spontaneous preterm parturition; PPROM was more sensitive to Ta fluctuations than PTL. This effect was modified by the ethnicity, Bedouin-Arabs were susceptible to elevated Ta, especially within the last day prior to admission with PPROM (Relative Risk (RR) =1.19 [95% CI, 1.03; 1.37]). Jews, on the other hand, were susceptible to ambient pollutants, two (RR=1.025 [1.010; 1.040]) and one (RR= 1.017 [1.002; 1.033]) days prior to spontaneous PTL with intact membranes resulting in preterm birth.

CONCLUSION

High temperature is an independent risk factor for PPROM among Bedouin-Arabs; ambient pollution is an independent risk factor for spontaneous PTL resulting in preterm birth. Thus, the precursors of spontaneous preterm parturition differ in their association with environmental factors.

Modeling the impact of exposure reductions using multi-stressor epidemiology, exposure models, and synthetic microdata: an application to birthweight in two environmental justice communities

BACKGROUND

Many vulnerable populations experience elevated exposures to environmental and social stressors, with deleterious effects on health. Multi-stressor epidemiological models can be used to assess benefits of exposure reductions. However, requisite individual-level risk factor data are often unavailable at adequate spatial resolution.

OBJECTIVE

To leverage public data and novel simulation methods to estimate birthweight changes following simulated environmental interventions in two environmental justice communities in Massachusetts, USA.

METHODS

We gathered risk factor data from public sources (US Census, Behavioral Risk Factor Surveillance System, and Massachusetts Department of Health). We then created synthetic individual-level data sets using combinatorial optimization, and probabilistic and logistic modeling. Finally, we used coefficients from a multi-stressor epidemiological model to estimate birthweight and birthweight improvement associated with simulated environmental interventions.

RESULTS

We created geographically resolved synthetic microdata. Mothers with the lowest predicted birthweight were those identifying as Black or Hispanic, with parity > 1, utilization of government prenatal support, and lower educational attainment. Birthweight improvements following greenness and temperature improvements were similar for all high-risk groups and were larger than benefits from smoking cessation.

SIGNIFICANCE

Absent private health data, this methodology allows for assessment of cumulative risk and health inequities, and comparison of individual-level impacts of localized health interventions.

Maternal metal concentration during gestation and pediatric morbidity in children: an exploratory analysis

Background

The majority of studies linking exposure to metals with certain health outcomes focus on known toxic metals. Alternatively, this study assesses the extent to which exposure to a wider range of metals during gestation is associated with childhood morbidity.

Methods

We analyzed the concentrations of 25 metals found in urine samples of 111 pregnant women of Arab-Bedouin origin collected prior to birth. In addition, we collected medical records on their offspring for six years following birth, including every interaction with HMOs, local hospitals, and pharmacies.

Results

The main types of morbidities diagnosed and treated during this period were preterm births, malformations, asthma-like morbidity, cardiovascular and behavioral problems, and obesity. Multivariable analysis showed that offspring born before term were more likely to have been exposed to elevated maternal concentrations of zinc, thallium, aluminum, manganese, and uranium, all with adjusted relative risk above 1.40 for an increase by each quintile. Likewise, children with asthma had been exposed to higher levels of magnesium, strontium, and barium at gestation, while behavioral outcomes were associated with elevated biometals, i.e., sodium, magnesium, calcium, selenium, and zinc, as well as higher levels of lithium, cobalt, nickel, strontium, cadmium, vanadium, arsenic, and molybdenum. A heatmap of adjusted relative risk estimates indicates the considerable implications that exposure to metals may have for preterm birth and developmental outcomes.

Conclusions

The current study shows that perinatal exposure to metals is adversely associated with pediatric morbidity. Further such analyses on additional samples are warranted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12199-021-00963-z.

PM2.5 and hospital admissions among Medicare enrollees with chronic debilitating brain disorders

BACKGROUND

Although long-term exposure to particulate matter<2.5 μm (PM_2.5) has been linked to chronic debilitating brain disorders (CDBD), the role of short-term exposure in health care demand, and increased susceptibility for PM_2.5-related health conditions, among Medicare enrollees with CDBD has received little attention. We used a causal modeling approach to assess the effect of short-term high PM_2.5 exposure on all-cause admissions, and prevalent cause-specific admissions among Medicare enrollees with CDBD (Parkinson's disease-PD, Alzheimer's disease-AD and other dementia).

METHODS

We constructed daily zipcode counts of hospital admissions of Medicare beneficiaries older than 65 across the United-States (2000-2014). We obtained daily PM_2.5 estimates from a satellite-based model. A propensity score matching approach was applied to match high-pollution (PM_2.5 > 17.4 μg/m³) to low-pollution zip code-days with similar background characteristics. Then, we estimated the percent change in admissions attributable to high pollution. We repeated the models restricting the analysis to zipcode-days with PM_2.5 below of 35 μg/m³.

RESULTS

We observed significant increases in all-cause hospital admissions (2.53% in PD and 2.49% in AD/dementia) attributable to high PM_2.5 exposure. The largest observed effect for common causes was for pneumonia and urinary tract infection. All the effects were larger in CDBD compared to the general Medicare population, and similarly strong at levels of exposure considered safe by the EPA.

CONCLUSION

We found Medicare beneficiaries with CDBD to be at higher risk of being admitted to the hospital following acute exposure to PM_2.5 levels well below the National Ambient Air Quality Standard defined as safe by the EPA.

Estimating the Combined Effects of Natural and Built Environmental Exposures on Birthweight among Urban Residents in Massachusetts

Intrauterine growth has health implications both in childhood and adulthood. Birthweight is partially determined by prenatal environmental exposures. We aim to identify important predictors of birthweight out of a set of environmental, built environment exposures, and socioeconomic environment variables during pregnancy (i.e., fine particulate matter (PM2.5), temperature, greenness, walkability, noise, and economic indices). We included all singleton live births of mothers who resided in urban census block-groups and delivered in Massachusetts between 2001 and 2011 (n = 640,659). We used an elastic-net model to select important predictors of birthweight and constructed a multivariate model including the selected predictors, with adjustment for confounders. We additionally used a weighted quantile sum regression to assess the contribution of each exposure to differences in birthweight. All exposures were selected as important predictors of birthweight. In the multivariate model, lower birthweight was significantly associated with lower greenness and with higher temperature, walkability, noise, and segregation of the "high income" group. Treating the exposures individually, nighttime noise had the highest weight in its contribution to lower birthweight. In conclusion, after accounting for individual confounders, maternal environmental exposures, built environment exposures, and socioeconomic environment during pregnancy were important predictors of birthweight, emphasizing the role of these exposures in fetal growth and development.

The effect of exposure to particulate matter during pregnancy on lower respiratory tract infection hospitalizations during first year of life

BACKGROUND

Lower respiratory tract infections (LRTI) in early life, including pneumonia, bronchitis and bronchiolitis, can lead to decreased lung function, persistent lung damage and increased susceptibility to various respiratory diseases such as asthma. In-utero exposure to particulate matter (PM) during pregnancy may disrupt biological mechanisms that regulate fetal growth, maturation and development. We aimed to estimate the association between intrauterine exposure to PM of size < 2.5 μm in diameter (PM_2.5) and incidence of LRTIs during the first year of life.

METHODS

A retrospective population-based cohort study in a population of mothers and infants born in Soroka University Medical Center (SUMC) in the years 2004-2012. All infants < 1 year old that were hospitalized due to LRTIs were included. The main exposure assessment was based on a hybrid model incorporating daily satellite-based predictions at 1 km² spatial resolution. Data from monitoring stations was used for imputation of main exposure and other pollutants. Levels of environmental exposures were assigned to subjects based on their residential addresses and averaged for each trimester. Analysis was conducted by a multivariable generalized estimating equation (GEE) Poisson regression. Data was analyzed separately for the two main ethnic groups in the region, Jewish and Arab-Bedouin.

RESULTS

The study cohort included 57,331 deliveries that met the inclusion criteria. Overall, 1871 hospitalizations of infants < 1 year old due to pneumonia or bronchiolitis were documented. In a multivariable analysis, intrauterine exposure to high levels of PM_2.5 (> 24 μg/m³) in the first and second trimesters was found to be adversely associated with LRTIs in the Arab-Bedouin population (1st trimester, RR = 1.31, CI 95% 1.08-1.60; 2nd trimester: RR = 1.34, CI 95% 1.09-1.66).

CONCLUSION

Intrauterine exposure to high levels of PM_2.5 is associated with a higher risk of hospitalizations due to lower respiratory tract infections in Arab-Bedouin infants.

Race or racial segregation? Modification of the PM2.5 and cardiovascular mortality association

BACKGROUND

Many studies have identified an inequitable distribution of exposure to PM2.5 (particulate matter less than 2.5 microns) by race. We investigated the association of PM2.5 and cardiovascular mortality considering both the decedents' race and neighborhood racial composition as potential modifiers.

METHODS

We obtained geocoded cardiovascular mortality records of all black and white decedents from urban block-groups in Massachusetts between 2001 and 2011 (n = 130,863). We examined the association between PM2.5 and cardiovascular mortality, and assessed effect modification by three types of racial modifiers: decedents' race, census block-group percent black and white, and two novel measures of racial segregation. The Racial Residential Segregation (RRS) quantifies the concentration of non-Hispanic blacks and whites in each block-group. The Index of Racial Dissimilarity measures dissimilarity in non-Hispanic black and white racial distribution between the smaller census block-group and larger tract.

RESULTS

We found a 2.35%(95%CI: 0.92%;3.79%) increase in mortality for each 10μg/m3 increase in two-day average exposure to PM2.5. The effect was modified by the block-group racial composition, with higher risks in block-groups with the highest percentage of black residents (interaction p-value = 0.04), and in block-groups with the lowest RRS (i.e. higher black to white resident ratio, interaction p-value = 0.072). Racial dissimilarity did not modify the associations.

CONCLUSION

Current levels of PM2.5 are associated with increased cardiovascular deaths in Massachusetts, with different risks between areas with different racial composition and segregation. This suggests that pollution reductions in neighborhoods with the highest percentage of non-Hispanic blacks would be most beneficial in reducing cardiovascular mortality and disparities.

Temperature and preeclampsia: Epidemiological evidence that perturbation in maternal heat homeostasis affects pregnancy outcome

INTRODUCTION

This study aims to determine the association between temperature and preeclampsia and whether it is affected by seasonality and rural/urban lifestyle.

METHODS

This cohort study included women who delivered at our medical center from 2004 to 2013 (31,101 women, 64,566 deliveries). Temperature values were obtained from a spatiotemporally resolved estimation model performing predictions at a 1×1km spatial resolution. In "Warm" pregnancies >50% of gestation occurred during the spring-summer period. In cold pregnancies >50% of gestation occurred during the fall and winter. Generalized estimating equation multivariable models were used to estimate the association between temperature and incidence of preeclampsia.

RESULTS

1) The incidence of preeclampsia in at least one pregnancy was 7% (2173/64,566); 2) during "warm" pregnancies, an elevation of one IQR of the average temperature in the 1st or the 3rd trimesters was associated with an increased risk to develop preeclampsia [patients with Jewish ethnicity: 1st trimester: relative risk (RR) of 2.38(95%CI 1.50; 3.80), 3rd trimester 1.94(95%CI 1.34;2.81); Bedouins: 1st trimester: RR = 2.91(95%CI 1.98;4.28), 3rd trimester: RR = 2.37(95%CI 1.75;3.20)]; 3) In "cold" pregnancies, an elevation of one IQR of average temperature was associated with a lower risk to develop preeclampsia among patients with Bedouin-Arab ethnicity RR = 0.68 (95% CI 0.49-0.94) for 1st trimester and RR = 0.62 (95% CI 0.44-0.87) for 3rd trimester.

CONCLUSIONS

1) Elevated averaged temperature during the 1st or 3rd trimesters in "warm" pregnancies confer an increased risk for the development of preeclampsia, especially in nomadic patients; 2) Of interest, during cold pregnancies, elevated averaged temperature was associated with a lower risk to develop preeclampsia for nomadic patients. 3) These findings suggest temperature might be associated with perturbations in maternal heat homeostasis resulting in reallocation of energy resources and their availability to the fetus that may increase the risk for preeclampsia. This observation is especially relevant in the context of global warming and its effects on maternal/fetal reproductive health.

Racial Disparities in Associations between Neighborhood Demographic Polarization and Birth Weight

Neighborhood demographic polarization, or the extent to which a privileged population group outnumbers a deprived group, can affect health by influencing social dynamics. While using birth records from 2001 to 2013 in Massachusetts (n = 629,675), we estimated the effect of two demographic indices, racial residential polarization (RRP) and economic residential polarization (ERP), on birth weight outcomes, which are established predictors of the newborn's future morbidity and mortality risk. Higher RRP and ERP was each associated with higher continuous birth weight and lower odds for low birth weight and small for gestational age, with evidence for effect modification by maternal race. On average, per interquartile range increase in RRP, the birth weight was 10.0 g (95% confidence interval: 8.0, 12.0) higher among babies born to white mothers versus 6.9 g (95% CI: 4.8, 9.0) higher among those born to black mothers. For ERP, it was 18.6 g (95% CI: 15.7, 21.5) higher among those that were born to white mothers versus 1.8 g (95% CI: -4.2, 7.8) higher among those born to black mothers. Racial and economic polarization towards more privileged groups was associated with healthier birth weight outcomes, with greater estimated effects in babies that were born to white mothers than those born to black mothers.

Improvement of Blood Samples Preanalytic Management Alters the Clinical Results of Glucose Values: Population Study

BACKGROUND

Prolonged time elapsing between the blood drawing and separation of the cell mass may result in decreased sample glucose levels due to continuous glycolysis. This can lead to underdiagnoses of hyperglycemic states and overdiagnosis of hypoglycemia. We aimed to evaluate the clinical impact of shortened transit time and earlier centrifugation of laboratory specimens on reported glucose results and diagnosis of clinically significant hypoglycemia (<50 mg/dL) or elevated glucose levels (>100 mg/dL).

METHODS

We assessed all fasting-serum glucose tests from the adult population (190 767 subjects) without known diabetes residing in Southern Israel. Before and after intervention periods were compared: 268 359 blood tests were performed during 2009-2010, and 317 336 during 2012-2013.

RESULTS

While glucose levels were 94.17 mg/dL ± 14.12 in 2012-2013 versus 83.53 mg/dL ± 14.50 in 2009-2010 (12.75% ± 0.88 increase, P < .001), the difference in glycated hemoglobin levels was statistically significant but clinically negligible: 5.84% ± 0.56 in 2012-2013 versus 5.88% ± 0.56 in 2009-2010 (0.53% ± 0.78 decrease, P < .01). There was an increased likelihood of a glucose result to be above 100 mg/dL following intervention: 9.80% versus 25.90%, P < .001. For clinics distanced over 40 km from the laboratory, age-adjusted odds ratio value was 1.26 (95% CI 1.13, 1.41). The proportion of samples with hypoglycemia values decreased from 0.33% to 0.03% (P < .001).

CONCLUSIONS

We demonstrated an important change in glucose values over a two-year period following an improvement of the preanalytic processes. The intervention was related to an increase in the frequency of hyperglycemia results and a decrease in the number of hypoglycemia results. Future administrative projects should consider clinical consequences with involvement of all relevant stakeholders.

Alive and Ventilator Free: A Hierarchical, Composite Outcome for Clinical Trials in the Acute Respiratory Distress Syndrome

OBJECTIVES

Survival from acute respiratory distress syndrome is improving, and outcomes beyond mortality may be important for testing new treatments. The "ventilator-free days" score, is an established composite that equates ventilation on day 28 to death. A hierarchical outcome treating death as a worse than prolonged ventilation would enhance face validity, but performance characteristics and reporting of such an outcome are unknown. We therefore evaluated the performance of a novel hierarchical composite endpoint, the Alive and Ventilator Free score.

DESIGN

Using data from four Acute Respiratory Distress Syndrome Network clinical trials, we compared Alive and Ventilator Free to the ventilator-free days score. Alive and Ventilator Free compares each patient with every other patient in a win-lose-tie for each comparison. Duration of mechanical ventilation is only compared if both patients survived. We evaluated power of Alive and Ventilator Free versus ventilator-free days score under various circumstances.

SETTING

ICUs within the Acute Respiratory Distress Syndrome Network.

PATIENTS

Individuals enrolled in four Acute Respiratory Distress Syndrome Network trials.

INTERVENTIONS

None for this analysis.

MEASUREMENTS AND MAIN RESULTS

Within the four trials (n = 2,410 patients), Alive and Ventilator Free and ventilator-free days score had similar power, with Alive and Ventilator Free slightly more powerful when a mortality difference was present, and ventilator-free days score slightly more powerful with a difference in duration of mechanical ventilation. Alive and Ventilator Free less often found in favor of treatments that increased mortality and increased days free of ventilation among survivors.

CONCLUSIONS

A hierarchical composite endpoint, Alive and Ventilator Free, preserves statistical power while improving face validity. Alive and Ventilator Free is less prone to favor a treatment with discordant effects on survival and days free of ventilation. This general approach can support complex outcome hierarchies with multiple constituent outcomes. Approaches to interpretation of differences in Alive and Ventilator Free are also presented.

County-level radon exposure and all-cause mortality risk among Medicare beneficiaries

BACKGROUND

Radon is an inert gas formed from the decay of naturally-occurring materials in the earth's crust. It infiltrates into homes from soil, water, and construction materials. Its decay products are radionuclides, which attach to ambient particles. Residential radon is one of the leading risk factors for lung cancer. The scarce evidence for associations with other mortality causes originates mostly from occupational studies.

METHODS

In a cohort study with 14 years of follow-up (2000-2013), we evaluated the association between chronic radon exposure and all-cause mortality, and explored whether there are subpopulations who are more vulnerable to radon effects. We included 87,296,195 person-years of follow-up from all Medicare beneficiaries in the Mid-Atlantic and Northeastern U.S. states. We examined the association between the logarithm of county-averaged radon (ln(Rn)) and mortality and assessed effect modification by chronic conditions.

RESULTS

An interquartile range increase in the ln(Rn) was associated with a 2·62% increase (95% CI 2·52%; 2·73%) in mortality, independent of PM2.5 exposure. Larger mortality risks were observed among individuals with respiratory, cardiovascular and metabolic diseases, with the highest associations observed among those with diabetes (4·98% increase), heart failure (4·58% increase), and chronic obstructive pulmonary disease (4·49% increase).

CONCLUSION

We found an increased risk for all-cause mortality associated with increased radon exposure. The risk was enhanced among susceptible individuals with chronic conditions. We believe this is the first cohort study to identify populations at higher risk for non-malignant health consequences of radon exposure. Due to the limitations in exposure assessment and availability of individual confounders, these findings should be interpreted with caution.

Neighborhood Greenness Attenuates the Adverse Effect of PM2.5 on Cardiovascular Mortality in Neighborhoods of Lower Socioeconomic Status

Features of the environment may modify the effect of particulate matter ≤2.5 µm in aerodynamic diameter (PM2.5) on health. Therefore, we investigated how neighborhood sociodemographic and land-use characteristics may modify the association between PM2.5 and cardiovascular mortality. We obtained residence-level geocoded cardiovascular mortality cases from the Massachusetts Department of Public Health (n = 179,986), and PM2.5 predictions from a satellite-based model (2001⁻2011). We appended census block group-level information on sociodemographic factors and walkability, and calculated neighborhood greenness within a 250 m buffer surrounding each residence. We found a 2.54% (1.34%; 3.74%) increase in cardiovascular mortality associated with a 10 µg/m³ increase in two-day average PM2.5. Walkability or greenness did not modify the association. However, when stratifying by neighborhood sociodemographic characteristics, smaller PM2.5 effects were observed in greener areas only among cases who resided in neighborhoods with a higher population density and lower percentages of white residents or residents with a high school diploma. In conclusion, the PM2.5 effects on cardiovascular mortality were attenuated by higher greenness only in areas with sociodemographic features that are highly correlated with lower socioeconomic status. Previous evidence suggests health benefits linked to neighborhood greenness may be stronger among lower socioeconomic groups. Attenuation of the PM2.5⁻mortality relationship due to greenness may explain some of this evidence.

The association between short and long-term exposure to PM2.5 and temperature and hospital admissions in New England and the synergistic effect of the short-term exposures

BACKGROUND

Particulate matter < 2.5 μm in diameter (PM2.5) and heat are strong predictors of morbidity, yet few studies have examined the effects of long-term exposures on non-fatal events, or assessed the short and long-term effect on health simultaneously.

OBJECTIVE

We jointly investigated the association of short and long-term exposures to PM2.5 and temperature with hospital admissions, and explored the modification of the associations with the short-term exposures by one another and by temperature variability.

METHODS

Daily ZIP code counts of respiratory, cardiac and stroke admissions of adults ≥65 (N = 2,015,660) were constructed across New-England (2001-2011). Daily PM2.5 and temperature exposure estimates were obtained from satellite-based spatio-temporally resolved models. For each admission cause, a Poisson regression was fit on short and long-term exposures, with a random intercept for ZIP code. Modifications of the short-term effects were tested by adding interaction terms with temperature, PM2.5 and temperature variability.

RESULTS

Associations between short and long-term exposures were observed for all of the outcomes, with stronger effects of long-term exposures to PM2.5. For respiratory admissions, the short-term PM2.5 effect (percent increase per IQR) was larger on warmer days (1.12% versus -0.53%) and in months of higher temperature variability (1.63% versus -0.45%). The short-term temperature effect was higher in months of higher temperature variability as well. For cardiac admissions, the PM2.5 effect was larger on colder days (0.56% versus -0.30%) and in months of higher temperature variability (0.99% versus -0.56%).

CONCLUSIONS

We observed synergistic effects of short-term exposures to PM2.5, temperature and temperature variability. Long-term exposures to PM2.5 were associated with larger effects compared to short-term exposures.

Assessment of the Association Between Post-tonsillectomy Hemorrhage and Weather Conditions

BACKGROUND

The most common complication after tonsillectomy is bleeding. We investigated whether performing the procedure during the summer or the winter affects the bleeding rate.

OBJECTIVES

To investigate whether there is an association between meteorological conditions and the occurrence of post-tonsillectomy hemorrhage (PTH) in the southern Israel Negev region.

METHODS

All patients who underwent tonsillectomy from 2001-2013 at the Soroka Medical Center were included. We collected patient demographic data and indications for surgery. Meteorological data were obtained from a weather station operated by the Israel Ministry of Environmental Protection.

RESULTS

Of 4438 patients who underwent tonsillectomy, with or without adenoidectomy, 432 (9.73%) experienced hemorrhage. Patients who suffered from PTH were significantly older: median age 9.61 years vs.4.7 years, P < 0.0001. When comparing patients without PTH to those who bled within 0-3 days after surgery, there was a higher risk for bleeding during the warmer seasons: relative risk (RR) 1.38, 95% confidence interval ([95%CI] 1.07-1.77), RR 1.45 (95%CI 1.17-1.80), and 1.62 (95%CI 1.27-2.06) comparing the winter to spring, summer, and fall, respectively. A statistically significant positive association was also found with the average temperature on the day of surgery. Bleeding more than 3 days after surgery was less likely in summer: RR 0.82, 95%CI 0.69-0.97. We found no association with temperature on the day of surgery and PTH after postoperative day 3.

CONCLUSIONS

Seasonality, and to an extent temperature, seem to play only a minor role in PTH.

Increase in Ischemic Stroke Incident Hospitalizations Among Bedouin Arabs During Ramadan Month

Background

Previous studies have not shown any significant effect on stroke incidence during Ramadan. We aimed to investigate the association between ischemic stroke incident hospitalizations and Ramadan, accounting for seasonality and temperature.

Methods and Results

This retrospective cohort study included all patients admitted with acute ischemic stroke to Soroka University Medical Center from June 2012 to June 2016. We obtained daily mean temperatures and relative humidity rates from 2 monitoring stations in South Israel. We analyzed the association between stroke incidence and Ramadan month, adjusting for weekly temperature and seasonality using Poisson regression models. We compared the first versus the last Ramadan fortnight. We performed an effect specificity analysis by assessing stroke incidence in the non‐Bedouin population. We identified 4727 cases of ischemic stroke, 564 cases of which were Bedouin Arabs. Fifty‐one cases occurred during Ramadan. Ramadan was significantly associated with an increased risk for ischemic stroke (RR 1.48; 95% confidence interval, 1.04–2.09), mainly during the first fortnight (RR 1.73, 95% confidence interval, 1.13–2.66) when compared with non‐Ramadan periods. Mean weekly temperatures and the summer season were not associated with stroke incidence among Bedouin Arabs (RR 0.98; 95% confidence interval, 0.82–1.18 and RR 0.77; confidence interval 0.56–1.06 accordingly). Such association was not observed in the non‐Bedouin population.

Conclusion

The Ramadan month, particularly in its first 2 weeks, is an independent and ethnicity specific risk factor for ischemic stroke hospitalizations among the Bedouin Arab fasting population.

Neonatal Risk Factors for Colonization with Extended-Spectrum Beta-Lactamase-Producing Bacteria in the Neonatal Intensive Care Unit

BACKGROUND

Extended-spectrum beta-lactamase (ESBL) production is the most common antimicrobial resistance mechanism in the neonatal intensive care unit (NICU), with colonization and blood stream infections being a major threat to this population. Since 2013, all NICU admissions at our facility were screened twice weekly for ESBL colonization.

OBJECTIVES

To determine independent risk factors for colonization of infants with ESBL-producing bacteria in the NICU.

METHODS

A retrospective case study of ESBL-colonized infants vs. controls (matched by date of birth and gestational age) was conducted in the NICU of Soroka University Medical Center, Israel, between 2013 and 2014. Epidemiological, laboratory, and clinical data were extracted from medical files. Univariable and multivariable analyses were used to assess associations between ESBL colonization and possible clinical risk factors.

RESULTS

Of 639 admissions during the study period, 87 were found to be ESBL-colonized (case infants) and were matched to 87 controls. Five case infants became infected (5.7%) with ESBL strains. Klebsiella pneumoniae was the most common isolated bacteria. The mean time from admission to colonization was 15 days. Univariable analysis showed an association of male gender and highest Apgar score at 1 and 5 minutes with ESBL colonization (P < 0.05). Multivariable analysis yielded only a possible association of higher Apgar score at 1 and 5 minutes (hazard ratio [HR] 1.515, 95% confidence interval [95%CI] 0.993-2.314; HR 1.603, 95%CI 0.958-2.682, respectively) with ESBL colonization.

CONCLUSIONS

Future studies should focus on maternal colonization and possible strategies for preventing vertical transmission of ESBL strains to high-risk neonates.

Medically indicated late preterm delivery and its impact on perinatal morbidity and mortality: a retrospective population-based cohort study

Objective: In the last few decades, attention has been focused on morbidity and mortality associated with late preterm delivery (34-36 + 6/7 weeks), accounting for 60-70% of all preterm births. This study is aimed to determine (1) the prevalence of late preterm deliveries (spontaneous and medically indicated) in our population; and (2) the rate of neonatal morbidity and mortality as well as maternal complications associated with the different phenotypes of late preterm deliveries. Study design: This retrospective population-based cohort study, included 96,176 women who had 257,182 deliveries, occurred between 1988 and 2011, allocated into three groups: term (n = 242,286), spontaneous (n = 10,063), and medically indicated (n = 4833) late preterm deliveries. Results: (1) Medically indicated late preterm deliveries were associated with increased maternal morbidity, as well as neonatal morbidity and mortality, in comparison with other study groups (p < .01 for all comparisons); (2) medically indicated late preterm delivery was an independent risk factor for composite neonatal morbidity (low Apgar score at 5', seizures, asphyxia, acidosis) after adjustment for confounding factors (maternal age and ethnicity and neonatal gender) and stratification according to gestational age at delivery; and (3) the proportion of medically indicated late preterm deliveries affected the neonatal mortality rate. Below 35% of all late preterm deliveries, indicated late preterm birth were associated with a reduction in neonatal mortality; however, above this threshold medically indicated late preterm deliveries were associated with an increased risk for neonatal death. Conclusions: (1) Medically indicated late preterm deliveries were independently associated with adverse composite neonatal outcome; and (2) to benefit in term of neonatal outcome from the tool of medically indicated late preterm birth, their proportion should be kept below 35% of all late preterm deliveries, while exceeding this threshold increases the risk of neonatal mortality.

The Association Between Heat Waves and Other Meteorological Parameters and Snakebites: Israel National Study

BACKGROUND

Published annual estimates report a global burden of 2.5 million snakebite cases and >100,000 deaths. In Israel, envenomations are the third most frequent cause of poisonings that are of moderate to major clinical severity. Most studies focus on the clinical descriptions of snakebites in tropical climates, and we sought to investigate the association between snakebite frequency and meteorological parameters.

OBJECTIVE

We sought to investigate the seasonality of snakebites and evaluate the association between increasingly common heat waves and other meteorological parameters and snakebite frequency in a semiarid nontropical climate.

METHODS

We obtained data for all medical evacuations (2008-2015) because of snakebites in Israel. Climate data included daily 24-hour average temperature (°C) and relative humidity (%). We used a time-stratified case crossover method, in which a conditional logistic regression was applied to estimate the association, and we also stratified our analysis by season and by region.

RESULTS

We identified 1234 snakebite cases over 8 years, of which most (74.2%) occurred in hot seasons and between 6 pm and 9 pm. The risk of snakebite was positively associated with temperature >23°C (odds ratio [OR] 1.24, 95% confidence interval [CI] 1.01-1.53) and inversely with humidity >40% (OR 0.74, 95% CI 0.57-0.97). We also found an association with heat waves both in cold (OR 1.62, 95% CI 1.01-2.60) and hot seasons (OR 1.50, 95% CI 1.18-1.92).

CONCLUSIONS

In a semiarid nontropical climate, we observed an association between an increase in the number of snakebite cases and higher temperatures and lower humidity. Moreover, heat waves increased the frequency of snakebites in both cold and hot seasons.

Do air pollution and neighborhood greenness exposures improve the predicted cardiovascular risk?

BACKGROUND

Numerous studies show associations between exposure to Particulate Matter and Cardiovascular disease (CVD). Current cardiovascular equations incorporate the major risk factors for CVD. The patients' environment, however, is not incorporated in these equations.

METHODS

In a retrospective analysis, we assessed the contribution of neighborhood greenness and particulate matter (coarse-PM and PM<2.5μm-PM_2.5) to the development of CVD by analyzing the change in prediction abilities. We included members of the largest health-care provider in Southern-Israel, who had at least one cardiovascular risk factor (dyslipidemia, diabetes, hypertension or smokers). PM exposure and neighborhood greenness (Normalized Difference Vegetation Index-NDVI) were assessed by satellite-based models. We used pooled logistic mixed regressions to obtain the CVD risks including conventional risk factors (i.e. age, gender, blood-pressure, etc.) and measured the model performance with and without PM and NDVI.

RESULTS

We included 23,110 subjects, of whom 12% had CVD. Coarse-PM exposure was associated with stroke and Myocardial-Infarction (MI) (OR 1.02,p<0.01 for both). NDVI was associated with MI: OR 0.72(p<0.01) for NDVI 0.1-0.2; and OR 0.52(p=0.270) for NDVI >0.2. The c-statistics slightly improved from 77.30%-77.40% for the prediction of MI (p=0.004) and from 75.60%-75.76% for the prediction of stroke (p=0.027). Calibration was fair in all models. The associations were partially mediated through the patients' comorbidities.

CONCLUSION

The negligible improvement in the prediction performance, despite significant associations with PM and NDVI, may be due to partial mediation of these associations through the conventional cardiovascular risk factors, suggesting the importance in assessing the environmental effects on more basic physiological pathways when addressing the contribution to the cardiovascular risk.

Is the association between hip fractures and seasonality modified by influenza vaccination? An ecological study

Osteoporotic hip fractures in 4344 patients were more common during winter. Lower temperatures were associated with higher rates of fracture only in those not vaccinated for influenza. Influenza outbreaks increased the risk of hip fractures. Further studies are needed to assess whether influenza vaccination can prevent hip fractures.

INTRODUCTION

Winter seasonality of osteoporotic hip fracture incidence has been demonstrated, yet the explanation for the association is lacking. We hypothesize that the seasonality of osteoporotic hip fracture can be explained by an association between hip fractures and seasonal influenza outbreaks.

METHODS

This retrospective cohort study included all patients admitted to Soroka University Medical Center with a diagnosis of osteoporotic hip fracture (ICD-9 code 820) between the years 2001 and 2013. Patients with malignancies, trauma, and age under 50 were excluded. In a time series analysis, we examined the association between hip fracture incidence and seasonality adjusted for meteorological factors, and population rates of influenza infection and vaccination using Poisson models.

RESULTS

Four thousand three hundred forty-four patients with a hip fracture were included (69% females, mean age 78). Daily fracture rates were significantly higher in winter (1.1 fractures/day) compared to summer, fall, and spring (0.79, 0.90, and 0.91; p < 0.001). In analysis adjusted for seasons and spline function of time, temperatures were associated with hip fractures risk only in those not vaccinated for influenza (n = 2939, for every decrease of 5 °C, RR 1.08, CI 1.02-1.16; p < 0.05). In subgroup analysis during the years with weekly data on national influenza rates (2010-2013), the risk for hip fracture, adjusted for seasons and temperature, was 1.26 2 weeks following a week with high infection burden (CI 1.05;1.51 p = 0.01), while the temperature was not significantly associated with the fracture risk.

CONCLUSIONS

Under dry and warm desert climate, winter hip fracture incidence increase might be associated with influenza infection, and this effect can be negated by influenza vaccination.

Association between ambient air pollution and proliferation of umbilical cord blood cells

It has been established as a common knowledge that ambient air pollution (AAP) has an adverse effect on human health. The pathophysiological mechanism of this impact is likely to be related to the oxidative stress. In the current study we estimate the association between AAP and cell proliferation (CP) of umbilical cord blood cells, representing maternal organism most proximal to the fetal body. Blood samples were tested for proliferation in 292 enrolled Arab-Bedouin women at delivery (July 2012-March 2013). The estimates of AAP were defined by a hybrid satellite based model predicting both PM_2.5 (particles<2.5µm in diameter) and PM₁₀ (particles<10µm in diameter) as well as monitoring stations for gaseous air pollutants. Risk estimates of pollution exposure were adjusted to medical history, household risk factors and meteorological factors on the day of delivery or one week prior. Ambient ozone (O₃) levels on 1, 2, 3and 4 days prior to delivery were associated with lower CP (Prevalence ratio (PR)=0.92, 0.92, 0.93, 0.93, respectively). Increase in inter-quartile range (IOR) of PM_2.5 one day before delivery was associated with 9% increase in CP levels (PR=1.09). The positive direction in association was changed to negative association with CP for PM_2.5 levels measured at more distant time periods (PR=0.90 and 0.93 for lags 5 and 6 days, respectively). Investigation of PM₁₀ levels indicated a similar pattern (PR=1.05 for pollution values recorded one day before delivery and 0.93 and 0.95 for lags of 5 and 6 days, respectively). Carbon monoxide (CO) levels were associated with lower CP on the day of delivery and 1day prior (PR=0.92 and PR=0.94). To conclude, the levels of cell proliferation of umbilical cord blood cells appear to be associated with the AAP. More studies are needed to support our findings.

Relationship of ambient air pollutants and hazardous household factors with birth weight among Bedouin-Arabs

BACKGROUND

Air pollution and meteorology exposures during pregnancy have been suggested to be associated with Birth Weight (BW). Yet, the individual medical background and close household environment is rarely addressed. We aimed to evaluate the independent association of BW with meteorological and air pollution exposures during pregnancy, in addition to individual, parental and household risk factors, among the Bedouin-Arab population in Southern Israel; a semi nomadic population, featured by low socio-economic levels and poor housing and household environment.

METHODS

In a retrospective cohort study we enrolled pregnant women upon their arrival in the local hospital for delivery during December 2011-April 2013. We interviewed the women and collected data on socio-demographic characteristics, medical history and household environmental hazards. Air pollution (NO2, SO2, CO, Ozone and Particulate Matter <2.5 μ and 10 μ in diameter) and meteorological data (temperature, relative humidity), retrieved from 13 monitoring sites, were linked to each woman based on the proximity of her residential address.

RESULTS

A total of 959 women were eligible for the study, half of them resided in temporary tribal localities. Ozone IQR elevation in the 3rd trimester was associated with 0.119 gr decrease in BW (95%CI -0.127 gr; -0.112 gr); temperature IQR elevation in the 3rd trimester was associated with 0.002 gr (95%CI -0.004 gr; -0.001 gr) decrease in BW. Waste in the house surroundings was associated with a decrease of 117.27 gr in BW (95%CI -209.19 gr; -25.34 gr).

CONCLUSION

Although exposure to high levels of temperature and O3 were associated with lower BW, the contribution of poor household environment indicators to BW reduction was substantially higher.

Ethnicity and immunization coverage among schools in Israel

OBJECTIVE

Recent years have seen a global trend of declining immunization rates of recommended vaccines that is more pronounced among school-age children. Ethnic disparities in child immunization rates have been reported in several countries. We investigated an effect of ethnicity on the vaccination rates of immunizations routinely administered within schools in Israel.

DESIGN

Data were collected from the Ministry of Health database regarding immunization coverage for all registered Israeli schools (3736) in the years 2009-2011. Negative binomial regression was used to assess the association between school ethnicity and immunization coverage while controlling for school characteristics.

RESULTS

The lowest immunization coverage was found in Bedouin schools (median values of 75.1%, 81.5% and 0% for the first, second and eighth grades, respectively) in 2011. During this year, vaccination coverage in the first and second grades in Jewish schools was 1.51 and 1.35 times higher, respectively, compared to Bedouin schools. In the years 2009 and 2010, no significant increase in risk for lower vaccination rate was observed in Bedouin schools, and children in Arab and Druze schools were more likely to have been vaccinated.

CONCLUSION

The lower vaccination refusal rate found in Bedouin schools supports the hypothesis that difficulties related to accessibility constitute the main problem rather than noncompliance with the recommended vaccination protocol for school-age children, featuring higher socio-economic status groups. Our study emphasizes the importance of identifying, beyond the national-level data, subpopulation groups at risk for non-vaccination. This knowledge is essential to administrative-level policy-makers for the allocation of resources and the planning of intervention programs.

Early onset preeclampsia and cerebral palsy: a double hit model?

BACKGROUND

Cerebral palsy (CP) is a late sequel of pregnancy, and the role of preeclampsia is debatable.

OBJECTIVE

The aims of this study were to determine the association between preeclampsia and cerebral palsy and to determine the risk factors for the development of cerebral palsy in these patients.

STUDY DESIGN

A retrospective population-based cohort study was designed that included 229,192 singleton pregnancies. The study population was divided into 2 groups: (1) patients with preeclampsia (n = 9749) and (2) normotensive gestations (n = 219,443). Generalized Estimating Equation multiple logistic regression models were performed to study the associations among preeclampsia, small for gestational age, gestational age at delivery, and the risk factors for the development of cerebral palsy in neonates of women with preeclampsia.

RESULTS

The rate of cerebral palsy was double in patients with preeclampsia than in the normotensive group (0.2% vs 0.1%; P = .015); early onset preeclampsia and small for gestational age were independent risk factors for the subsequent development of cerebral palsy (odds ratio, 8.639 [95% confidence interval, 4.269-17.480]; odds ratio, 2.737 [95% confidence interval, 1.937-3.868], respectively). A second model was conducted to determine the risk factors for the development of cerebral palsy in women with preeclampsia. Birth asphyxia, complications of prematurity, and neonatal infectious morbidity, but not small for gestational age or gestational age at delivery, were independent risk factors for the development of cerebral palsy.

CONCLUSION

In a comparison with normal pregnant women, the rate of cerebral palsy is double among patients with preeclampsia, especially those with early-onset disease. Early-onset preeclampsia is an independent risk factor for cerebral palsy. Among women with preeclampsia, the presence of neonatal infectious morbidity, birth asphyxia, and complications of prematurity are independent risk factors for the development of cerebral palsy, which further supports the role of a multi-hit model in the pathogenesis of this syndrome.

Nitrogen Dioxide pollution and hazardous household environment: what impacts more congenital malformations

Nitrogen Dioxide (NO2) is a product of fuel combustion originating mainly from industry and transportation. Studies suggest an association between NO2 and congenital malformations (CM). We investigated an independent effect of NO2 on CM by adjusting to individual factors and household environment in 1024 Bedouin-Arab pregnant women in southern Israel. This population is characterised by high rates of CMs, frequent consanguineous marriages, paternal smoking, temporary housing and usage of open fire for heat cooking. Information on household risk factors was collected during an interview. Ambient measurements of 24-h average NO2 and meteorological conditions were obtained from 13 local monitors. Median value of daily NO2 measured in the area was 6.78ppb. CM was diagnosed in 8.0% (82) of offspring. Maternal NO2 exposure during the 1st trimester >8.6ppb was significantly associated with minor CM (RR=2.68, p=0.029). Major CM were independently associated with maternal juvenile diabetes (RR=9.97, p-value=0.002) and heating by open fire (RR=2.00, p-value=0.049), but not NO2 exposure. We found that NO2 emissions had an independent impact only on minor malformations, whereas major malformations depended mostly on the household environment. Antepartum deaths were associated by maternal morbidity.

Effects of changes in copayment for obstetric emergency room visits on the utilization of obstetric emergency rooms

In view of the growing proportion of "non-urgent" admissions to obstetric emergency rooms (OERs) and recent changes in copayment policies for OER visits in Israel, we assessed factors contributing to OER overcrowding. The changes investigated were (a) exemption from copayment for women with birth contractions, (b) allowing phone referrals to the OER and (c) exemption from copayment during primary care clinic closing hours. We analyzed data of a large tertiary hospital with 37 deliveries per day. Counts of women discharged to home from the OER were an indicator of "non-urgent" visits. The annual number of non-urgent visits increased at a higher rate (3.4%) than the natural increase in deliveries (2.1%). Exemption from copayment for visits during non-working hours of primary care clinics was associated with increases in OER admissions (IRR=1.22) and in non-urgent OER visits (IRR=1.54). Younger and first-time mothers with medically unjustified complaints were more likely to be discharged to home. We showed that the changes in the policy for OER copayment meant to attract new clients to the HMO had an independent impact on OER utilization, and hence, added to the workload of medical personnel. The change in HMO policy regulating OER availability requires rigorous assessment of possible health system implications.

Prenatal exposure to H2 blockers and to proton pump inhibitors and asthma development in offspring

Fetal exposure to H2 blockers (H2 Bs) or proton pump inhibitors (PPIs) has been reported to be associated with asthma in children. We evaluated the risk of asthma in offspring following prenatal H2 Bs. We enrolled 91 428 children and their mothers who resided in southern Israel during 1998-2011. The computerized medications database was linked with records from the district hospital. Of the eligible children, 11 227 developed asthma, and overall 5.5% had been exposed to H2 Bs or PPIs prenatally. The risk of developing asthma was slightly higher in the group exposed to H2 Bs or PPIs (RR, 1.09; P = .023). At greater risk were children whose mothers purchased these medications more than 3 times (RR, 1.22; P = .038) or exposed to >20 defined daily doses or prenatally exposed to lansoprazole. The statistical association was significant and depended on magnitude of exposure and specific medication, but the absolute risk was low. The association between maternal consumption of H2 Bs or PPIs and asthma and childhood remained statistically significant 2 years after delivery, raising the possibility of confounding by the indication phenomenon. In view of the findings, a causal relationship could not be ascertained, and an unidentified etiological factor could be operative.

Can cell proliferation of umbilical cord blood cells reflect environmental exposures?

Environmental hazards were shown to have an impact on cell proliferation (CP). We investigated CP of lymphocytes in umbilical cord blood in relation to prenatal environmental exposures in a sample of 346 Arab-Bedouin women giving birth in a local hospital. Information on subjects' addresses at pregnancy, potential household exposures and demographical status was collected in an interview during hospitalization. This population is usually featured by high rates of neonatal morbidity and multiple environmental exposures, originating from the local industrial park (IP), household hazards and frequent male smoking. A geometric mean CP ratio 2.17 (2.06; 2.29), and was high in women residing in a direction of prevailing winds from the local IP (p value = 0.094) and who gave birth during fall-winter season (p value = 0.024). Women complaining on disturbing exposure to noise had lower CP (p value = 0.015), compared to other women. CP was not indicative of neonatal morbidity. However, our findings suggest that CP of umbilical cord might be modified by environmental exposures. A long-term follow-up of the children is required to assess their developmental outcomes.

Air Pollution and Serum Glucose Levels: A Population-Based Study

Recent studies demonstrated an adverse effect of chronic exposure to air pollution (AP) on metabolic syndrome and its components. In a population-based study, we investigated the association between exposure to ambient AP and serum glucose (SG), among subjects with normal glucose, impaired fasting glucose (IFG), and diabetes mellitus (DM).We included 1,063,887 SG tests performed in 131,882 subjects (years 2001-2012). Exposure data included daily levels of SO2, NO2 and other pollutants of industrial, traffic, and nonanthropogenic sources. Demographical, clinical, and medications purchase data were assessed. Log-transformed SG levels were analyzed by linear mixed models adjusted for seasonal variables and personal characteristics.SG increases (%increase [95% CI]), among subjects with normal glucose, IFG, and DM, respectively, were associated with 6.36 ppb increase of NO2 measured 24 to 72 hours before the test (0.40% [0.31%; 0.50%], 0.56% [0.40%; 0.71%], and 1.08% [0.86%; 1.29%]); and with 1.17 ppb increase of SO2 measured 24 hours before the test (0.29% [0.22%; 0.36%], 0.20% [0.10%; 0.31%], and 0.33% [0.14%; 0.52%]). Among DM population, weakest association was observed among patients treated with Metformin (0.56% increase in SG [0.18%; 0.95%]).In conclusion, NO2 and SO2 exposure is associated with small but significantly increased levels of SG. Although DM patients were found to be more susceptible to the AP induced SG variations, Metformin treatment seem to have a protective effect. Given the chronic lifetime exposure to AP and the broad coverage of the population, even small associations such as those found in our study can be associated with detrimental health effects and may have profound public health implications.

Exposure to metals and congenital anomalies: a biomonitoring study of pregnant Bedouin-Arab women

BACKGROUND

The Bedouin-Arab population in Israel comprises a low socio-economic society in transition. Smoking among males and consanguineous marriages are frequent. A previous study showed elevated rates of major malformations within groups from this population residing near an industrial park, where high ambient values of arsenic (As) and nickel (Ni) were detected, compared to groups living in remote localities.

OBJECTIVES

We estimated the extent of exposure to metals in pregnant Bedouin-Arab women in relation to congenital malformations.

METHODS

We collected maternal urine samples from 140 Bedouin women who gave birth in a local hospital. Patient medical history, type of marriage (consanguineous or non-consanguineous), and parental exposure history were collected by interview and medical records.

RESULTS

Aluminum (Al) was detected in 37 women (26.4%), cadmium (Cd) in 2 (1.4%), As in 10 (7.1%), and Ni in 1 woman (0.7%). The detected rate of Cd exposure was low, though more than 92% of the fathers reported smoking. Concentrations of Al were higher for women residing within 10 km of the local industrial park (Prevalence Ratio (PR)=1.12, p-value=0.012) or who reported using a wood burning stove (PR=1.37, p-value=0.011) and cooking over an open fire (PR=1.16, p-value=0.076). Exposure to Al was adversely associated with minor anomalies (OR=3.8, p-value=0.046) after adjusting for history of abortions (OR=6.1, p-value=0.007). Fetuses prenatally exposed to As were born prematurely (p-value=0.001) and at lower weights (pv=0.023).

CONCLUSIONS

The study population of pregnant women is exposed to high levels of metals mainly of household origin. Our findings may be generalized to similar populations in developing countries.

Non-anthropogenic dust exposure and asthma medication purchase in children

Air pollution has been shown to increase frequency of asthma attacks, as usually measured by hospitalisation rates. We hypothesise that purchase of asthma reliever medications will reflect a broader association between the environmental exposure and asthma exacerbations. In a time series analysis, we estimated the association of dust storms with mild asthma manifestations, as indicated by medication purchases, during 2005-2011. We compared our results with the estimation of the association of dust storms with hospitalisations due to asthma and asthma-like symptoms. We detected 289 dust storms characterised by high levels of particulate matter <10 μm in diameter. We identified 42,920 children with asthma, wheezing or asthma-like symptoms, of whom 2418 were hospitalised. We observed a higher risk of asthma medication purchase on the day of a mild dust storm (relative risk 1.05, 95% CI 1.00-1.10). The next peak in drug purchases was 3 days later and was more pronounced among Bedouin-Arab children. Stratified analyses showed higher risks for hospitalisation among Bedouin-Arab children; especially among children living in temporary houses (relative risk 1.33, 95% CI 1.04-1.71). We observed an increased risk of asthma medication purchase associated with mild dust storms. The risk observed for hospitalisation was more pronounced among the rural Bedouin-Arab population.

Association between prenatal exposure to metals and neonatal morbidity

An association between prenatal exposure to (semi-)metals and of neonatal morbidity was assessed by introducing an oxidative stress as a possible intermediate step. An oxidative stress was measured by cell proliferation (CP) ratio in umbilical cord blood cells. Urine samples of 18 out of 58 enrolled women (31%) were positive for (semi-)metals; 25.9% of women were positive for aluminum (Al). The CP ratio was higher (1) in subjects with Al, (2) in mothers to newborns diagnosed as small-for-gestational age (p value = .052), (3) neonates that weighed less (p value = .079), and (4) in women who experienced repeated abortions (p value = .049). Our findings suggest the possibility of metal-induced oxidative stress.