Maternal smoking during pregnancy and childhood obesity: results from the CESAR Study.

Childhood obesity is a worldwide public health concern. Recent studies from high income countries have demonstrated associations between maternal smoking during pregnancy and children's excess body weight. We examine associations between maternal smoking during pregnancy and children's overweight or obesity, in six countries in the less affluent Central/Eastern European region. Questionnaire data were analysed, for 8,926 singleton children aged 9-12 years. Country-specific odds ratios for effects of maternal smoking during pregnancy on being overweight, and on obesity, were estimated using logistic regression. Heterogeneity between country-specific results, and mean effects (allowing for heterogeneity) were estimated. Positive associations between maternal smoking and overweight were seen in all countries but Romania. While not individually statistically significant, the mean odds ratio was 1.26 (95% CI 1.03-1.55), with no evidence of between-country heterogeneity. Obese children were few (2.7%), and associations between obesity and maternal smoking during pregnancy were more heterogeneous, with odds ratios ranging from 0.71 (0.32-1.57) in Poland to 5.49 (2.11-14.30) in Slovakia. Between-country heterogeneity was strongly related to average persons-per-room, a possible socioeconomic indicator, with stronger associations where households were less crowded. Estimates of dose-response relationships tended to be small and non-significant, even when pooled. Our results provide evidence of a link between maternal smoking in pregnancy and childhood overweight. Associations with obesity, though strong in some countries, were less consistent. Maternal smoking may confer an addition to a child's potential for obesity, which is more likely to be realised in affluent conditions

Air pollution and children's respiratory and allergic symptoms : pooled analysis across twelve countries

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Ozone, heat and mortality: acute effects in 15 British conurbations.

BACKGROUND: Acute associations between mortality and ozone are largely accepted, though recent evidence is less conclusive. Evidence on ozone-heat interaction is sparse. We assess effects of ozone, heat, and their interaction, on mortality in Britain. METHODS: Acute effects of summer ozone on mortality were estimated using data from 15 conurbations in England and Wales (May-September, 1993-2003). 2-day means of daily maximum 8-h ozone were entered into case series analyses, controlling for particulate matter with aerodynamic diameter of <10 μm, natural cubic splines of temperature, and other factors. Heat effects were estimated, comparing adjusted mortality rates at 97.5th and 75th percentiles of 2-day mean temperature. A separate model employed interaction terms to assess whether ozone effects increased on 'hot days' (where 2-day mean temperature exceeded the whole-year 95th percentile). Other heat metrics, and non-linear ozone effects, were also examined. RESULTS: Adverse ozone and heat effects occurred in nearly all conurbations. The mean mortality rate ratio for heat effect across conurbations was 1.071 (1.050-1.093). The mean ozone rate ratio was 1.003 per 10 μg/m(3) ozone increase (95% CI 1.001 to 1.005). On 'hot days' the mean ozone effect reached 1.006 (1.002-1.009) per 10 μg/m(3), though ozone-heat interaction was significant in London only. On substituting maximum for mean temperature, the overall ozone effect reduced to null, though evidence remained of effects on hot days, particularly in London. An estimated ozone effect threshold was below current guidelines in 'mean temperature' models. CONCLUSION: While heat showed robust effects on summer mortality, estimates for ozone depended upon the modelling of temperature. However, there was some evidence that ozone effects were worse on hot days, whichever temperature measure was used

Geographical variation in infant mortality, stillbirth and low birth weight in Northern Ireland, 1992-2002.

BACKGROUND: Improving the health of expectant mothers and reductions in health inequalities, are repeatedly prioritised in policy reports in England and Northern Ireland. Measurement of underlying rates, and geographical variation in rates, of adverse birth outcomes are tools in monitoring these priorities. METHODS: Northern Ireland data on stillbirths, infant mortality and low birth weight (1992-2002) were linked to board (n=4), district council (n=26) and 1991 census wards (n=568). Underlying variations in rates were estimated at each geographical level, unadjusted and controlling for year, ward-level deprivation, settlement size and higher geographical levels. Impacts on geographical variation of individual social class, maternal age, multiple birth and smoking were assessed. RESULTS: There was significant variation in underlying rates of low birth weight (<2500 g) at all three geographical levels. Controlling for smoking reduced variation between wards. Geographical variation proved more robust for medium than for very low birth weight. No variation was seen between boards for other outcomes, nor between district level rates of infant mortality. Evidence was weak for variation in district rates of neonatal deaths and stillbirths, and variation in ward-level adjusted stillbirth rates was not significant. Variation in ward-level infant death rates was robust to all adjustments, with risks tripling (infant mortality) or quadrupling (neonatal mortality) between the 10th and 90th percentile. CONCLUSIONS: Strong evidence was found of geographical variation in infant mortality and low birth weight, unexplained by individual risk factors or by area-level deprivation. Geographical targeting or area-level interventions might look beyond deprivation scores, to other environmental and social factors

Parental smoking and lung function in children: an international study.

RATIONALE: Both prenatal and postnatal passive smoking have been linked with respiratory symptoms and asthma in childhood. Their differential contributions to lung function growth in the general children's population are less clear. OBJECTIVE: To study the relative impact of pre- and postnatal exposure on respiratory functions of primary school children in a wide range of geographic settings, we analyzed flow and volume data of more than 20,000 children (aged 6-12 yr) from nine countries in Europe and North America. METHODS: Exposure information had been obtained by comparable questionnaires, and spirometry followed a protocol of the American Thoracic Society/European Respiratory Society. Linear and logistic regressions were used, controlling for individual risk factors and study area. Heterogeneity between study-specific results and mean effects were estimated using meta-analytic tools. MAIN RESULTS: Smoking during pregnancy was associated with decreases in lung function parameters between -1% (FEV1) and -6% maximal expiratory flow at 25% of vital capacity left (MEF25). A 4% lower maximal midexpiratory flow (MMEF) corresponded to a 40% increase in the risk of poor lung function (MMEF < 75% of expected). Associations with current passive smoking were weaker though still measurable, with effects ranging from -0.5% (FEV1) to -2% maximal expiratory flow (MEF50). CONCLUSIONS: Considering the high number of children exposed to maternal smoking in utero and the even higher number exposed to passive smoking after birth, this risk factor for reduced lung function growth remains a serious pediatric and public health issue

Concentration-response function for ozone and daily mortality: results from five urban and five rural U.K. populations.

BACKGROUND: Short-term exposure to ozone has been associated with increased daily mortality. The shape of the concentration-response relationship-and, in particular, if there is a threshold-is critical for estimating public health impacts. OBJECTIVE: We investigated the concentration-response relationship between daily ozone and mortality in five urban and five rural areas in the United Kingdom from 1993 to 2006. METHODS: We used Poisson regression, controlling for seasonality, temperature, and influenza, to investigate associations between daily maximum 8-hr ozone and daily all-cause mortality, assuming linear, linear-threshold, and spline models for all-year and season-specific periods. We examined sensitivity to adjustment for particles (urban areas only) and alternative temperature metrics. RESULTS: In all-year analyses, we found clear evidence for a threshold in the concentration-response relationship between ozone and all-cause mortality in London at 65 µg/m3 [95% confidence interval (CI): 58, 83] but little evidence of a threshold in other urban or rural areas. Combined linear effect estimates for all-cause mortality were comparable for urban and rural areas: 0.48% (95% CI: 0.35, 0.60) and 0.58% (95% CI: 0.36, 0.81) per 10-µg/m3 increase in ozone concentrations, respectively. Seasonal analyses suggested thresholds in both urban and rural areas for effects of ozone during summer months. CONCLUSIONS: Our results suggest that health impacts should be estimated across the whole ambient range of ozone using both threshold and nonthreshold models, and models stratified by season. Evidence of a threshold effect in London but not in other study areas requires further investigation. The public health impacts of exposure to ozone in rural areas should not be overlooked

Current and future climate- and air pollution-mediated impacts on human health.

BACKGROUND: We describe a project to quantify the burden of heat and ozone on mortality in the UK, both for the present-day and under future emission scenarios. METHODS: Mortality burdens attributable to heat and ozone exposure are estimated by combination of climate-chemistry modelling and epidemiological risk assessment. Weather forecasting models (WRF) are used to simulate the driving meteorology for the EMEP4UK chemistry transport model at 5 km by 5 km horizontal resolution across the UK; the coupled WRF-EMEP4UK model is used to simulate daily surface temperature and ozone concentrations for the years 2003, 2005 and 2006, and for future emission scenarios. The outputs of these models are combined with evidence on the ozone-mortality and heat-mortality relationships derived from epidemiological analyses (time series regressions) of daily mortality in 15 UK conurbations, 1993-2003, to quantify present-day health burdens. RESULTS: During the August 2003 heatwave period, elevated ozone concentrations > 200 microg m-3 were measured at sites in London and elsewhere. This and other ozone photochemical episodes cause breaches of the UK air quality objective for ozone. Simulations performed with WRF-EMEP4UK reproduce the August 2003 heatwave temperatures and ozone concentrations. There remains day-to-day variability in the high ozone concentrations during the heatwave period, which on some days may be explained by ozone import from the European continent.Preliminary calculations using extended time series of spatially-resolved WRF-EMEP4UK model output suggest that in the summers (May to September) of 2003, 2005 & 2006 over 6000 deaths were attributable to ozone and around 5000 to heat in England and Wales. The regional variation in these deaths appears greater for heat-related than for ozone-related burdens.Changes in UK health burdens due to a range of future emission scenarios will be quantified. These future emissions scenarios span a range of possible futures from assuming current air quality legislation is fully implemented, to a more optimistic case with maximum feasible reductions, through to a more pessimistic case with continued strong economic growth and minimal implementation of air quality legislation. CONCLUSION: Elevated surface ozone concentrations during the 2003 heatwave period led to exceedences of the current UK air quality objective standards. A coupled climate-chemistry model is able to reproduce these temperature and ozone extremes. By combining model simulations of surface temperature and ozone with ozone-heat-mortality relationships derived from an epidemiological regression model, we estimate present-day and future health burdens across the UK. Future air quality legislation may need to consider the risk of increases in future heatwaves

Effect of influenza vaccination on excess deaths occurring during periods of high circulation of influenza: cohort study in elderly people

Objective To estimate the protection against death provided by vaccination against influenza. Design Prospective cohort follow up supplemented by weekly national counts of influenza confirmed in the community. Setting Primary care. Participants 24 535 patients aged over 75 years from 73 general practices in Great Britain. Main outcome measure Death. Results In unvaccinated members of the cohort daily all cause mortality was strongly associated with an index of influenza circulating in the population (mortality ratio 1.16, 95% confidence interval 1.04 to 1.29 at 90th centile of circulating influenza). The association was strongest for respiratory deaths but was also present for cardiovascular deaths. In contrast, in vaccinated people mortality from any cause was not associated with circulating influenza. The difference in patterns between vaccinated and unvaccinated people could not easily be due to chance (P = 0.02, all causes). Conclusions This study, using a novel and robust approach to control for confounding, provides robust evidence of a protective effect on mortality of vaccination against influenza

Vulnerability to winter mortality in elderly people in Britain: population based study

Objective To examine the determinants of vulnerability to winter mortality in elderly British people. Design Population based cohort study (119 389 person years of follow up). Setting 106 general practices from the Medical Research Council trial of assessment and management of older people in Britain. Participants People aged ≥ 75 years. Main outcome measures Mortality (10 123 deaths) determined by follow up through the Office for National Statistics. Results Month to month variation accounted for 17% of annual all cause mortality, but only 7.8% after adjustment for temperature. The overall winter:non-winter rate ratio was 1.31 (95% confidence interval 1.26 to 1.36). There was little evidence that this ratio varied by geographical region, age, or any of the personal, socioeconomic, or clinical factors examined, with two exceptions: after adjustment for all major covariates the winter:non-winter ratio in women compared with men was 1.11 (1.00 to 1.23), and those with a self reported history of respiratory illness had a winter:non-winter ratio of 1.20 (1.08 to 1.34) times that of people without a history of respiratory illness. There was no evidence that socioeconomic deprivation or self reported financial worries were predictive of winter death. Conclusion Except for female sex and pre-existing respiratory illness, there was little evidence for vulnerability to winter death associated with factors thought to lead to vulnerability. The lack of socioeconomic gradient suggests that policies aimed at relief of fuel poverty may need to be supplemented by additional measures to tackle the burden of excess winter deaths in elderly people