Short Term Exposure to Air Pollution and Mortality in the US: A Case-Crossover Analysis

Background: Studies examining the association of short-term air pollution exposure and daily deaths have typically been limited to cities and used citywide averages for exposure. This study aims to estimate the associations between short-term exposures to fine particulate matter (PM2.5), ozone (O3), and nitrogen dioxide (NO2) and all-cause and cause-specific mortality in multiple US states including rural areas.Methods: We conducted a time-stratified case-crossover study examining the entire population of seven US states from 2000-2015, with over 3 million non-accidental deaths. Daily predictions of PM2.5, O3, and NO2 at 1x1 km grid cells across the contiguous US were linked to mortality based on census track and residential address. For each pollutant, we used conditional logistic regression to quantify the association between exposure and the relative risk of mortality conditioning on meteorological variables and other pollutants. Results: A 10 μg/m3 increase in PM2.5 exposure at the moving average of lag 0-1 day and 10 ppb increase in NO2 exposure at lag 0-3 day were significantly associated with a 0.67% (95%CI: 0.34-1.01%) and 0.20% (95%CI: 0.00-0.39%) increase in the risk of all-cause mortality, respectively. A marginally significant association for mortality was observed with each 10 ppb increase in O3 exposure at lag 0-3 day. The adverse effects of PM2.5 on all-cause mortality persisted when restricting the analysis at lower levels.. PM2.5 was also significantly associated with respiratory mortality and cardiovascular mortality. Conclusions: Short-term exposure to PM2.5 and NO2 is associated with increased risks for all-cause mortality. Our findings delivered evidence that risks of death persisted at levels below currently permissible.

Definitions of bronchopulmonary dysplasia and long-term outcomes of extremely preterm infants in Korean Neonatal Network

New definitions for bronchopulmonary dysplasia (BPD) have recently been suggested, and an accurate diagnosis, including severity classification with proper definition, is crucial to identify high-risk infants for appropriate interventions. To determine whether recently suggested BPD definitions can better predict long-term outcomes of BPD in extremely preterm infants (EPIs) than the original BPD definition, BPD was classified with severity 1, 2, and 3 using three different definitions: definition A (original), National Institute of Child Health and Human Development (NICHD) definition in 2001; definition B, the modified NICHD 2016 definition (graded by the oxygen concentration and the respiratory support at 36 weeks’ postmenstrual age [PMA]); and definition C, the modified Jensen 2019 definition (graded by the respiratory support at 36 weeks’ PMA). We evaluated 1050 EPIs using a national cohort. Whereas EPIs with grade 2 or 3 BPD as per definition A did not show any increase in the risk, EPIs with BPD diagnosed by definition B and C showed significantly increased risk for poor outcomes, such as respiratory mortality and morbidities, neurodevelopmental delay, and growth restriction at 18–24 months of corrected age. The recently suggested definition and severity grading better reflects long-term childhood morbidities than the original definition in EPIs.

Vitamin D deficiency, impaired lung function and total and respiratory mortality in a cohort of older men: cross-sectional and prospective findings from The British Regional Heart Study

ObjectivesVitamin D deficiency is associated with chronic obstructive pulmonary disease (COPD). We examined the cross-sectional association between 25-hydroxyvitamin D (25(OH)D) and lung function impairment and assessed whether vitamin D deficiency is related to long-term mortality in those with impaired lung function.DesignProspective studySettingGeneral practices in the UK.Participants3575 men aged 60–79 years with no prevalent heart failure.Outcome measuresAirway obstruction and mortality. The Global Initiative on Obstructive Lung diseases (GOLD) spirometry criteria was used to define airway obstruction.ResultsDuring the follow-up period of 20 years, there were 2327 deaths (114 COPD deaths). Vitamin D deficiency was defined as serum 25(OH)D levels<10 ng/mL; insufficiency as 25(OH)D 10–19 ng/mL; sufficient as 25(OH)D>20 ng/mL. In cross-sectional analysis, vitamin D deficiency was more prevalent in those with moderate COPD (FEV/FVC <70% and FEV1 50 to <80%; FEV1, forced expiratory volume in 1 s and FVC, forced vital capacity) and severe COPD (FEV/FVC <70% and FEV1 <50%) but not in those with mild COPD (FEV/FVC <70% and FEV1>80%) or restrictive lung disease (FEV1/FVC >70% and FVC <80%) compared with men with normal lung function . Vitamin D deficiency was associated with increased risk of total and respiratory mortality in both men with COPD and men with restrictive lung disease after adjustment for confounders and inflammation. The adjusted HRs (95% CI) for total mortality comparing levels of 25(OH)D<10 ng/mL to 25(OH)D>=20 ng/mL were 1.39 (1.10 to 1.75), 1.52 (1.17 to 1.98), 1.58 (1.17 to 2.14) and 1.39 (0.83 to 2.33) for those with no lung impairment, restrictive lung function, mild/moderate COPD and severe COPD, respectively.ConclusionMen with COPD were more likely to be vitamin D deficient than those with normal lung function. Vitamin D deficiency is associated with increased all-cause mortality in older men with no lung impairment as well as in those with restrictive or obstructive lung impairment.

Mortality Sensitivity of Cardiovascular, Cerebrovascular, and Respiratory Diseases to Warm Season Climate in Japanese Cities

We investigated decadal (2010–2019) cardiovascular, cerebrovascular, and respiratory mortality sensitivity to annual warm temperatures in major Japanese cities: Sapporo, Tokyo (23 wards), and Osaka. The summer mortalities (June–August) increased with the monthly mean temperature for acute myocardial infarction, other acute ischemic heart diseases, cerebral infarction, and pneumonia in the three cities. Monthly mean temperatures were an indicator of these disease mortalities in Japan. However, similar responses were not found for cardiac arrhythmia and heart failure (excluding Sapporo), subarachnoid hemorrhage, and intracerebral hemorrhage. The decadal sensitivities and risk ratios between the maximum and minimum monthly mean temperatures were calculated using a linear regression model. In Sapporo, Tokyo, and Osaka, for example, the analyses of acute myocardial infarction showed summer positive responses of 0.19–0.25, 0.13–0.18, and 0.12–0.30, respectively, as the mortality rate (per 100,000 population) per 1 °C of monthly mean temperature, which estimated increased risks (between the coolest and hottest months) of 37–65% in Sapporo, 31–42% in Tokyo, and 35–39% in Osaka.

The role of absolute humidity in respiratory mortality in Guangzhou, a hot and wet city of South China

Background For the reason that many studies have been inconclusive on the effect of humidity on respiratory disease, we examined the association between absolute humidity and respiratory disease mortality and quantified the mortality burden due to non-optimal absolute humidity in Guangzhou, China. Methods Daily respiratory disease mortality including total 42,440 deaths from 1 February 2013 to 31 December 2018 and meteorological data of the same period in Guangzhou City were collected. The distributed lag non-linear model was used to determine the optimal absolute humidity of death and discuss their non-linear lagged effects. Attributable fraction and population attributable mortality were calculated based on the optimal absolute humidity, defined as the minimum mortality absolute humidity. Results The association between absolute humidity and total respiratory disease mortality showed an M-shaped non-linear curve. In total, 21.57% (95% CI 14.20 ~ 27.75%) of respiratory disease mortality (9154 deaths) was attributable to non-optimum absolute humidity. The attributable fractions due to high absolute humidity were 13.49% (95% CI 9.56 ~ 16.98%), while mortality burden of low absolute humidity were 8.08% (95% CI 0.89 ~ 13.93%), respectively. Extreme dry and moist absolute humidity accounted for total respiratory disease mortality fraction of 0.87% (95% CI − 0.09 ~ 1.58%) and 0.91% (95% CI 0.25 ~ 1.39%), respectively. There was no significant gender and age difference in the burden of attributable risk due to absolute humidity. Conclusions Our study showed that both high and low absolute humidity are responsible for considerable respiratory disease mortality burden, the component attributed to the high absolute humidity effect is greater. Our results may have important implications for the development of public health measures to reduce respiratory disease mortality.

Different Risks of Mortality and Longitudinal Transition Trajectories in New Potential Subtypes of the Preserved Ratio Impaired Spirometry: Evidence From the English Longitudinal Study of Aging

Background: Preserved ratio impaired spirometry (PRISm), characterized by the decreased forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) with a preserved FEV1/FVC ratio, is highly prevalent and heterogeneous. We aimed to identify the subtypes of PRISm and examine their differences in clinical characteristics, long-term mortality risks, and longitudinal transition trajectories.Methods: A total of 6,616 eligible subjects were included from the English longitudinal study of aging. Two subtypes of the PRISm were identified as mild PRISm (either of FEV1 and FVC &lt;80% predicted value, FEV1/FVC ≥0.7) and severe PRISm (both FEV1 and FVC &lt;80% predicted values, FEV1/FVC ≥0.7). Normal spirometry was defined as both FEV1 and FVC ≥80% predicted values and FEV1/FVC ≥0.7. Hazard ratios (HRs) and 95% CIs were calculated by the multiple Cox regression models. Longitudinal transition trajectories were described with repeated spirometry data.Results: At baseline, severe PRISm had increased respiratory symptoms, including higher percentages of phlegm, wheezing, dyspnea, chronic bronchitis, and emphysema than mild PRISm. After an average of 7.7 years of follow-up, severe PRISm significantly increased the risks of all-cause mortality (HR=1.91, 95%CI = 1.58–2.31), respiratory mortality (HR = 6.02, 95%CI = 2.83–12.84), and CVD mortality (HR = 2.11, 95%CI = 1.42–3.13) compared with the normal spirometry, but no significantly increased risks were found for mild PRISm. In the two longitudinal transitions, mild PRISm tended to transition toward normal spirometry (40.2 and 54.7%), but severe PRISm tended to maintain the status (42.4 and 30.4%) or transition toward Global Initiative for Chronic Obstructive Lung Disease (GOLD)2–4 (28.3 and 33.9%).Conclusion: Two subtypes of PRISm were identified. Severe PRISm had increased respiratory symptoms, higher mortality risks, and a higher probability of progressing to GOLD2–4 than mild PRISm. These findings provided new evidence for the stratified management of PRISm.

The Relationship Between Short-Term Exposure To Air Pollution With Hospitalization and Mortality of Cardiovascular (CVD) and Respiratory Diseases in Shahrekord, Iran

Background and objectives: Air pollution has been widely considered as an important factor in causing heart disease, respiratory disease, and death. This study sought to determine the relationship between short-term exposure to air pollutants and hospital admissions, cardiovascular and respiratory deaths and total mortality rate in Shahrekord, Iran.Procedure: This is a time series and ecological research. We collected data on hospital admissions and cardiovascular mortality and total mortality from 2012 to 2018. The study used the quasi-Poisson regression combined with linear distributed lag models, adjusted for trend, seasonality, temperature, relative humidity, weekdays and holidays.Results: Our results show a direct and significant statistical relationship between: O3 exposure in lag4 for total mortality, PM10 exposure in lag1 for total mortality and in lag4 and lag1 for respiratory death, PM2.5 exposure for total cardiovascular admissions in lag5, respiratory mortality in lag4, total respiratory admissions in lag3, NO2 exposure to respiratory mortality in lag1, and cardiovascular mortality in lag0, increased risk of death and pathogenesis.The results show a statistically significant inverse relationship between: NO and total admissions in lag3 and for respiratory mortality in lag1 between PM2.5 and cardiovascular mortality in lag1, NO with respiratory mortality in lag1 and cardiovascular admissions in lag3, NO2 with cardiovascular admissions in lag1 and NOX with respiratory death in lag0, which reduces the risk of death and pathogenesis.Conclusion: Air pollution has a significant relationship with the number of hospital admissions and mortality in Shahrekord, Iran.

Exertional ventilation/carbon dioxide output relationship in COPD: from physiological mechanisms to clinical applications

There is well established evidence that the minute ventilation (V′E)/carbon dioxide output (V′CO2) relationship is relevant to a number of patient-related outcomes in COPD. In most circumstances, an increased V′E/V′CO2 reflects an enlarged physiological dead space (“wasted” ventilation), although alveolar hyperventilation (largely due to increased chemosensitivity) may play an adjunct role, particularly in patients with coexistent cardiovascular disease. The V′E/V′CO2 nadir, in particular, has been found to be an important predictor of dyspnoea and poor exercise tolerance, even in patients with largely preserved forced expiratory volume in 1 s. As the disease progresses, a high nadir might help to unravel the cause of disproportionate breathlessness. When analysed in association with measurements of dynamic inspiratory constraints, a high V′E/V′CO2 is valuable to ascertain a role for the “lungs” in limiting dyspnoeic patients. Regardless of disease severity, cardiocirculatory (heart failure and pulmonary hypertension) and respiratory (lung fibrosis) comorbidities can further increase V′E/V′CO2. A high V′E/V′CO2 is a predictor of poor outcome in lung resection surgery, adding value to resting lung hyperinflation in predicting all-cause and respiratory mortality across the spectrum of disease severity. Considering its potential usefulness, the V′E/V′CO2 should be valued in the clinical management of patients with COPD.

Short-term effect of fine particulate matter and ozone on non-accidental mortality and respiratory mortality in Lishui district, China

Background In recent years, air pollution has become an imminent problem in China. Few studies have investigated the impact of air pollution on the mortality of the middle-aged and elderly people. Therefore, this study aims to evaluate the impact of PM2.5 (fine particulate matter) and O3 (ozone) on non-accidental mortality and respiratory mortality of the middle-aged and elderly people in Lishui District of Nanjing and provide the evidence for potential prevention and control measures of air pollution. Method Using daily mortality and atmospheric monitoring data from 2015 to 2019, we applied a generalized additive model with time-series analysis to evaluate the association of PM2.5 and O3 exposure with daily non-accidental mortality and respiratory mortality in Lishui District. Using the population attributable fractions to estimate the death burden caused by short-term exposure to O3 and PM2.5。. Result For every 10 μg/m3 increase in PM2.5, non-accidental mortality increased 0.94% with 95% confidence interval (CI) between 0.05 and 1.83%, and PM2.5 had a more profound impact on females than males. For every 10 μg/m3 increase in O3, respiratory mortality increased 1.35% (95% CI: 0.05, 2.66%) and O3 had a more profound impact on males than females. Compared with the single pollutant model, impact of the two-pollutant model on non-accidental mortality and respiratory mortality slightly decreased. In summer and winter as opposed to the other seasons, O3 had a more obvious impact on non-accidental mortality. The population attributable fractions of non-accidental mortality were 0.84% (95% CI:0.00, 1.63%) for PM2.5 and respiratory mortality were 0.14% (95% CI:0.01, 0.26%) for O3. For every 10 μg/m3 decrease in PM2.5, 122 (95% CI: 6, 237) non-accidental deaths could be avoided. For every 10 μg/m3 decrease in O3, 10 (95% CI: 1, 38) respiratory deaths could be avoided. Conclusion PM2.5 and O3 could significantly increase the risk of non-accidental and respiratory mortality in the middle-aged and elderly people in Lishui District of Nanjing. Exposed to air pollutants, men were more susceptible to O3 damage, and women were more susceptible to PM2.5 damage. Reduction of PM2.5 and O3 concentration in the air may have the potential to avoid considerable loss of lives.