Hong Qiu

Emergency Cardiovascular Hospitalization Risk Attributable to Cold Temperatures in Hong Kong

Background—Associations between ambient temperature and cardiovascular morbidity have been well studied worldwide; however, few studies determined the cardiovascular disease burden attributable to temperature. We aimed to assess the risk attributed to temperature based on the exposure–lag–response relationship between temperature and circulatory diseases. Methods and Results—We collected daily time series data of emergency hospital admissions, mean temperature, and air pollution concentrations from January 2005 to December 2012 in Hong Kong. The association with temperature was modeled using a distributed lag nonlinear model integrated in quasi-Poisson regression. The cumulated effects of cold/hot temperature were abstracted. Attributable risk measures because of below optimal temperature (OT) were calculated to summarize the disease burden, and further separated into contributions from moderate and extreme cold temperatures. We observed significant nonlinear and delayed cold effect but no apparent hot effect lasting for 3 weeks on emergency circulatory hospitalizations. Compared with the identified OT at 23.0°C, the cumulative relative risk during 0 to 21 lag days was 1.69 (95% confidence interval, 1.56–1.82) for extreme cold (first percentile) and 1.22 (95% confidence interval, 1.15–1.29) for moderate cold temperature (10th percentile). Cold temperatures were responsible for temperature-related circulatory emergency hospitalizations, with attributable fraction of 6.33% for moderate cold and 0.82% for extreme cold while inducing 33 030 and 4257 cases, respectively. Several specific causes of cardiovascular diseases showed higher vulnerability. Conclusions—Moderate cold weather was responsible for a considerable attributable risk for cardiovascular diseases. The temperature-related hospitalizations risk found in this study may provide evidence for guiding the public health policies and preventions for cardiovascular diseases.

Major air pollutants and risk of COPD exacerbations: a systematic review and meta-analysis

Background Short-term exposure to major air pollutants (O3, CO, NO2, SO2, PM10, and PM2.5) has been associated with respiratory risk. However, evidence on the risk of chronic obstructive pulmonary disease (COPD) exacerbations is still limited. The present study aimed at evaluating the associations between short-term exposure to major air pollutants and the risk of COPD exacerbations. Methods After a systematic search up until March 30, 2016, in both English and Chinese electronic databases such as PubMed, EMBASE, and CNKI, the pooled relative risks and 95% confidence intervals were estimated by using the random-effects model. In addition, the population-attributable fractions (PAFs) were also calculated, and a subgroup analysis was conducted. Heterogeneity was assessed by I2. Results In total, 59 studies were included. In the single-pollutant model, the risks of COPD were calculated by each 10 μg/m3 increase in pollutant concentrations, with the exception of CO (100 μg/m3). There was a significant association between short-term exposure and COPD exacerbation risk for all the gaseous and particulate pollutants. The associations were strongest at lag0 and lag3 for gaseous and particulate air pollutants, respectively. The subgroup analysis not only further confirmed the overall adverse effects but also reduced the heterogeneities obviously. When 100% exposure was assumed, PAFs ranged from 0.60% to 4.31%, depending on the pollutants. The adverse health effects of SO2 and NO2 exposure were more significant in low-/middle-income countries than in high-income countries: SO2, relative risk: 1.012 (95% confidence interval: 1.001, 1.023); and NO2, relative risk: 1.019 (95% confidence interval: 1.014, 1.024). Conclusion Short-term exposure to air pollutants increases the burden of risk of COPD acute exacerbations significantly. Controlling ambient air pollution would provide benefits to COPD patients.

Using daily excessive concentration hours to explore the short-term mortality effects of ambient PM 2.5 in Hong Kong

We developed a novel indicator, daily excessive concentration hours (DECH), to explore the acute mortality impacts of ambient fine particulate matter pollution (PM2.5) in Hong Kong. The DECH of PM2.5 was calculated as daily concentration-hours >25xa0μg/m3. We applied a generalized additive models to quantify the association between DECH and mortality with adjustment for potential confounders. The results showed that the DECH was significantly associated with mortality. The excess mortality risk for an interquartile range (565xa0μg/m3*hours) increase in DECH of PM2.5 was 1.65% (95% CI: 1.05%, 2.26%) for all natural mortality at lag 02 day, 2.01% (95% CI: 0.82%, 3.21%) for cardiovascular mortality at lag 03 days, and 1.41% (95% CI: 0.34%, 2.49%) for respiratory mortality at lag 2 day. The associations remained consistent after adjustment for gaseous air pollutants (daily mean concentration of SO2, NO2 and O3) and in alternative model specifications. When compared to the mortality burden of daily mean PM2.5, DECH was found to be a relatively conservative indicator. This study adds to the evidence by showing that daily excessive concentration hours of PM2.5 might be a new predictor of mortality in Hong Kong.

Fine particulate matter exposure and incidence of stroke: A cohort study in Hong Kong

Objective: We aimed to assess the association of long-term residential exposure to fine particulate matter (PM) with aerodynamic diameter less than 2.5 μm (PM2.5) with the incidence of stroke and its major subtypes. Methods: We ascertained the first occurrence of emergency hospital admission for stroke in a Hong Kong Chinese cohort of 66,820 older people (65+ years) who enrolled during 1998–2001 (baseline) and were followed up to December 31, 2010. High-resolution (1 × 1 km) yearly mean concentrations of PM2.5 were predicted from local monitoring data and US National Aeronautics and Space Administration satellite data using linear regression. Baseline residential PM2.5 exposure was used as a proxy for long-term exposure. We used Cox proportional hazards to evaluate the risk of incident stroke associated with PM2.5 exposure adjusted for potential confounders, including individual and neighborhood factors. Results: Over a mean follow-up of 9.4 years, we ascertained 6,733 cases of incident stroke, of which 3,526 (52.4%) were ischemic and 1,175 (17.5%) were hemorrhagic. The hazard ratio for every 10 μg/m3 higher PM2.5 concentration was statistically significant at 1.21 (95% confidence interval [CI] 1.04–1.41) for ischemic and non-statistically significant at 0.90 (95% CI 0.70–1.17) for hemorrhagic stroke in fully adjusted model 3. The estimates for ischemic stroke were higher in older participants (>70 years), less educated participants, and in men for current smokers. Conclusion: Long-term PM2.5 exposure was associated with higher risk of incident ischemic stroke, but the association with incident hemorrhagic stroke was less clear.

Long-term exposure to fine particulate matter air pollution and type 2 diabetes mellitus in elderly: A cohort study in Hong Kong

BACKGROUNDnEvidence for the link between long-term air pollution exposure and occurrence of diabetes is limited and the results are mixed.nnnOBJECTIVESnWe aimed to assess the association of long-term residential exposure to fine particulate matter (PM2.5) with the prevalence and incidence of type 2 diabetes mellitus (DM).nnnMETHODSnThis is a prospective cohort study. We studied 61,447 participants of the Chinese Elderly Health Services cohort in Hong Kong enrolled 1998-2001 and followed participants without DM at baseline to 31 December 2010 to ascertain the first hospital admissions for type 2 DM. Yearly mean residential PM2.5 exposure was predicted based on satellite data. Logistic regression and time-varying Cox regression model were used to evaluate the prevalence and incidence risk of DM associated with PM2.5 while adjusting for potential individual and neighborhood confounders.nnnRESULTSnThere were 61,447 participants included in the study of prevalent DM, and in 53,905 participants without DM at baseline we studied incident type 2 DM. Over a mean follow-up of 9.8u202fyears, we ascertained 806 incident cases of type 2 DM. After adjusting for potential confounders, the odds ratio (OR) for every interquartile range (3.2u202fμg/m3) increase of PM2.5 concentration was 1.06 (95% confidence interval (CI): 1.01-1.11) for prevalent DM, while the corresponding hazard ratio (HR) was 1.15 (95% CI: 1.05-1.25) for incident type 2 DM.nnnCONCLUSIONSnLong-term exposure to high levels of PM2.5 may increase the risk of both prevalence and incidence of type 2 diabetes mellitus in Hong Kong elderly population.

Is standard deviation of daily PM2.5 concentration associated with respiratory mortality

Studies on health effects of air pollution often use daily mean concentration to estimate exposure while ignoring daily variations. This study examined the health effects of daily variation of PM2.5. We calculated daily mean and standard deviations of PM2.5 in Hong Kong between 1998 and 2011. We used a generalized additive model to estimate the association between respiratory mortality and daily mean and variation of PM2.5, as well as their interaction. We controlled for potential confounders, including temporal trends, day of the week, meteorological factors, and gaseous air pollutants. Both daily mean and standard deviation of PM2.5 were significantly associated with mortalities from overall respiratory diseases and pneumonia. Each 10xa0μg/m(3) increment in daily mean concentration at lag 2 day was associated with a 0.61% (95% CI: 0.19%, 1.03%) increase in overall respiratory mortality and a 0.67% (95% CI: 0.14%, 1.21%) increase in pneumonia mortality. And a 10xa0μg/m(3) increase in standard deviation at lag 1 day corresponded to a 1.40% (95% CI: 0.35%, 2.46%) increase in overall respiratory mortality, and a 1.80% (95% CI: 0.46%, 3.16%) increase in pneumonia mortality. We also observed a positive but non-significant synergistic interaction between daily mean and variation on respiratory mortality and pneumonia mortality. However, we did not find any significant association with mortality from chronic obstructive pulmonary diseases. Our study suggests that, besides mean concentration, the standard deviation of PM2.5 might be one potential predictor of respiratory mortality in Hong Kong, and should be considered when assessing the respiratory effects of PM2.5.

Age-dependent effect of ambient ozone on emergency asthma hospitalizations in Hong Kong

control, and increased lung function following benralizumab treatment. Together these findings suggest that targeting IL-5Ra1 cells decreases EoP cell numbers both systemically and locally within the airways, thereby attenuating potential IL-5–driven eosinophilopoietic processes that may contribute to persistent airway eosinophilia in patients with severe, prednisone-dependent asthma. This contrasts with previous findings that mepolizumab 100 mg (subcutaneous) suppressed blood eosinophils but not sputum eosinophils or EoP cells in some patients and this was associated with more modest clinical outcomes. Limitations of this study include a small size, although this study design was based on a report that showed that 6 patients per group is adequate to detect a 50% reduction in sputum eosinophil counts. In addition, the effect of benralizumab treatment on basophil counts in the airways was not investigated. However, we report a significant reduction in IL-5Ra ILC2 cells in the blood and sputum for benralizumab-treated patients. Further studies are underway to investigate the functional relevance of these cells. In conclusion, our findings indicate that targeting IL-5Ra cells interferes with and attenuates IL-5–driven eosinophilopoietic processes that may contribute to persistent airway eosinophilia in patients with severe, prednisone-dependent asthma.

Short-term effects of ambient benzene and TEX (toluene, ethylbenzene, and xylene combined) on cardiorespiratory mortality in Hong Kong

BACKGROUNDnNumerous epidemiological and experimental studies have demonstrated the detrimental effects of the criteria air pollutants on population health, including particulate matters, ozone, and nitrogen dioxide. However, evidence on health effects of benzene, toluene, ethylbenzene, and xylene (BTEX in short) is insufficient.nnnOBJECTIVESnThe present study aimed to assess the exposure-lag-response relations of ambient BTEX components with cardiorespiratory mortality in Hong Kong population.nnnMETHODSnDaily BTEX concentrations from April 2011 to December 2014 were collected from the Hong Kong Environmental Protection Department. Cause-specific mortality records were obtained from the Census and Statistics Department of Hong Kong. Generalized additive model (GAM) integrated with a distributed lag model (DLM) was used to estimate the excess risks of cardiorespiratory mortality associated with the cumulative exposure to benzene and TEX (toluene, ethylbenzene and xylene combined) over 0-9 lag days, while adjusting for time trend, seasonality, weather conditions and calendar effects.nnnRESULTSnWe observed the delayed and distributed lag effects of BTEX components on circulatory mortality. The cumulative exposures over 0-9 lag days for IQR increments of benzene (1.4u202fμg/m3) and TEX (7.9u202fμg/m3) were associated with 5.8% (95%CI: 1.0% to 10.8%) and 3.5% (95%CI: 1.0% to 6.1%) increases in circulatory mortality, respectively. The effect estimates of benzene and TEX were more delayed than that of PM2.5. We didnt observe any significant association of BTEX exposure on total and respiratory deaths.nnnCONCLUSIONSnShort-term elevations in ambient BTEX concentrations may trigger circulatory mortality in Hong Kong population.

Short-term effects of fine and coarse particles on deaths in Hong Kong elderly population: An analysis of mortality displacement

BACKGROUNDnWhile numerous studies worldwide have evaluated the short-term associations of fine and coarse particulate matter (PM) air pollution with mortality and morbidity, these studies may be susceptible to short-term harvesting effect. We aimed to investigate the short-term association between mortality and PM with aerodynamic diameter less than 2.5u202fμm (PM2.5) and those between 2.5 and 10u202fμm (PMc) within a month prior to death, and assess the mortality displacement by PM2.5 and PMc among elderly population in Hong Kong.nnnMETHODSnWe obtained air pollution data from January 2011 to December 2015 from Environmental Protection Department, and daily cause-specific mortality data from Census and Statistical Department of Hong Kong. We performed generalized additive distributed lag model to examine the acute, delayed and long-lasting effects of PM2.5 and PMc within one month on mortality.nnnRESULTSnWe observed a statistically significant association of PM2.5 and PMc exposure over lags 0-6 days with all natural mortality and cardio-respiratory mortality. The overall cumulative effect of PM2.5 over 0-30 lag days was 3.44% (95% CI: 0.30-6.67%) increase in all natural mortality and 6.90% (95% CI: 0.58-13.61%) increase of circulatory mortality, which suggested the absence of mortality displacement by PM2.5. On the other hand, no significant cumulative association with mortality was found for PMc over 0-30 lag exposure window, and thus mortality displacement by PMc cannot be ruled out. Findings remained robust in various sensitivity analyses.nnnCONCLUSIONSnWe found adverse effect of both PM2.5 and PMc exposure within one week prior to death. While there was no evidence of mortality displacement in the association of PM2.5 exposure over one month prior with all natural and circulatory mortality, mortality displacement by PMc cannot be ruled out. PM2.5 may contribute more to the longer term effect of particulate matter than PMc.

Are ambient volatile organic compounds environmental stressors for heart failure

BACKGROUNDnNumerous epidemiological studies have indicated the adverse cardiovascular effects of air pollution on heart failure (HF) risk. However, little data are available directly evaluating the association of ambient volatile organic compounds (VOCs) with HF risk. We aimed to estimate the short-term effects of ambient VOCs on HF emergency hospitalizations in Hong Kong and to evaluate whether the associations were modified by sex and age.nnnMETHODSnWe collected the daily VOCs concentrations from the Hong Kong Environmental Protection Department between April 2011 to December 2014. HF emergency hospital admission data were obtained from the Hospital Authority of Hong Kong. Generalized additive model (GAM) integrated with the distributed lag model (DLM) was used to estimate the excess risks of HF emergency hospitalizations with ambient concentrations of each VOCs groups - alkane, alkene, alkyne, benzene and substituted benzene.nnnRESULTSnWe observed short-term effects of alkyne and benzene on an increased risk of HF emergency hospitalizations. The cumulative effect over 0-6 lag days (dlm0-6) for an IQR increment of alkyne (1.17u202fppb) was associated with 4.2% (95% CI: 1.18%-7.26%) increases of HF emergency hospitalizations, while the corresponding effect estimate over dlm0-2 for benzene per IQR (0.43u202fppb) was 2.7% (95% CI: 0.39%-5.04%). Each VOCs groups was significantly associated with HF emergency hospitalizations in men.nnnCONCLUSIONSnAmbient volatile organic compounds, particularly alkyne and benzene, were associated with increased risks of heart failure in the Hong Kong population.