ozone air pollution and ischaemic stroke occurrence: a case-crossover study in nice, france - ozone air purifier

Relationship between low goals
The degree of air pollution and stroke is contradictory.
The study was conducted to record the relationship between outdoor air pollution and stroke occurrence. Design Time-Layered case
Cross-analysis.
University Hospital in Nice, France.
Participants in all consecutive patients with ischemic stroke who lived in the University Hospital of Nice (France)
From January 2007 to December 2011.
Association for measurement of main results (adjusted OR)
Between the daily levels of outdoor pollutants (ozone (O3)
Nitrogen (NO2)
Particulate matter (PM10)
And sulfur dioxide (SO2))
And the occurrence of stroke.
Results 1729 stroke patients (mean age: 76. 1±14. 0u2005years; men: 46. 7%)were enrolled.
No significant association was found between stroke occurrence and short duration
Long-term effects of all contaminants tested.
In stratified analysis, we only observed recurrence (n=280)
Major artery ischemia stroke (n=578)
Short onset time
Long-term effects of ozone exposure.
Increased ozone levels by 10g/m3, risk of recurrent stroke (mean D-1, D-2 and D-3 lag)
An increase of 12. 1% (95% CI 1. 5% to 23. 9%)
Risk of major artery stroke (mean D-3 and D-4 lag)
Increased by 8% (95% CI 2. 0% to 16. 6%).
Linear dose-response relationships were found in the two subgroups.
Conclusion our results confirm the low
Independent of other contaminants and meteorological parameters, ozone exposure levels and ischemia stroke in high vascular risk subgroups with linear exposure-response relationships.
The physiological and pathological process of this association between ischemia stroke and ozone exposure remains to be studied.
Relationship between goals
The degree of air pollution and stroke is contradictory.
The study was conducted to record the relationship between outdoor air pollution and stroke occurrence. Design Time-Layered case
Cross-analysis.
University Hospital in Nice, France.
Participants in all consecutive patients with ischemic stroke who lived in the University Hospital of Nice (France)
From January 2007 to December 2011.
Association for measurement of main results (adjusted OR)
Between the daily levels of outdoor pollutants (ozone (O3)
Nitrogen (NO2)
Particulate matter (PM10)
And sulfur dioxide (SO2))
And the occurrence of stroke.
Results 1729 stroke patients (mean age: 76. 1±14. 0u2005years; men: 46. 7%)were enrolled.
No significant association was found between stroke occurrence and short duration
Long-term effects of all contaminants tested.
In stratified analysis, we only observed recurrence (n=280)
Major artery ischemia stroke (n=578)
Short onset time
Long-term effects of ozone exposure.
Increased ozone levels by 10g/m3, risk of recurrent stroke (mean D-1, D-2 and D-3 lag)
An increase of 12. 1% (95% CI 1. 5% to 23. 9%)
Risk of major artery stroke (mean D-3 and D-4 lag)
Increased by 8% (95% CI 2. 0% to 16. 6%).
Linear dose-response relationships were found in the two subgroups.
Conclusion our results confirm the low
Independent of other contaminants and meteorological parameters, ozone exposure levels and ischemia stroke in high vascular risk subgroups with linear exposure-response relationships.
The physiological and pathological process of this association between ischemia stroke and ozone exposure remains to be studied.
Outdoor air pollution is considered a major environmental health problem, causing excessive deaths worldwide.
It is defined as any adverse changes in air by substances that are toxic or may have adverse effects on health.
Outdoor air pollutants are known to increase the incidence and mortality of respiratory diseases.
However, in the 1960 s and 1950 s, epidemiology studies of acute serious pollution events also showed an increased risk of cardiovascular mortality.
The December 1952 London fog incident study first reported a link between acute air pollution and stroke mortality.
2 in the past few decades, the consequences of low
The effects of air pollution on cardiovascular mortality and morbidity have been clearly described.
3-6 by analogy, some studies have studied the role of short time
Air pollution is a term for stroke, but there is actually no conclusion to generalize.
3, 5-24 the purpose of this study was to record the relationship between the features of outdoor air pollution and the occurrence of an ischemic stroke.
We did a study of materials and methods-year (2007–2011)case-
Cross-analysis of Nice, France.
We reviewed consecutive stroke patients admitted to University of Nice hospital from January 2007 to December 2011.
Query FrenchBased on database (
PMSI: integrated scheme of information system)
I60-I69 code with International Classification of Diseases (10th revision)
We screened all patients hospitalized for stroke.
We filter the samples to patients living in Nice (
Geographic area defined by Zip code: 06000, 06100, 06200 and 06300).
A team of neurologists reviewed and confirmed the diagnosis of an ischemic stroke using clinical and radiological data from medical records.
Other diagnostic patients other than stroke were excluded.
Demographic data and vascular risk factors (WHO definition)
In addition, clinical and radiological features of stroke were collected from medical records.
Outdoor air pollution and meteorological data are a city in the South.
Eastern France on the Mediterranean coast.
According to the latest census, Nice had a population of 340735 in 2009.
Mild climate, Mediterranean.
Surrounded by mountains (south Alps)
The city of Nice sheltered from the wind in the constant winds.
Outdoor air pollution mainly comes from traffic with High Road density and international airports (
France's first airport after Paris Airport).
Obtaining air pollution data from air quality monitoring regional agencies (AirPACA).
During the study, exposure measurements were performed at 2 of the 13 permanent monitoring stations in the study area. Measures (µg/m3)
Perform at the City station (
Ladumeg)
The following atmospheric pollutants: particulate matter (PM10;
Oscillating micro-balance of cone element)
Nitrogen (NO2)(
Chemical glow
Sulfur dioxide (SO2;
Ultraviolet light measurementand ozone (O3;
Ultraviolet light measurement.
The missing values were replaced by measures taken by observation stations at Nice airport.
We calculated each pollutant during the 24-hour average period, especially ozone during the 8-hour day period.
Daily meteorological data, including temperature, are obtained from the nice National Meteorological Administration (°C)and humidity (%).
In addition, data on the flu epidemic (weekly count)
In Provence-Alpes-Cote-
D'Azur was obtained from the Sentiweb network.
Continuous variables are represented as mean (SD)or median (IQR)
, And classification variables expressed in percentages.
Correlation coefficient (r)
The relationship between atmospheric pollutants and atmospheric parameters is calculated. The time-Layered case
Cross design is used to test short-
Long-term effects of outdoor air contaminants and strokes.
In this design, each participant is his own control.
The day of the case is defined as a windy day.
The control day is defined as the same day on the same level as the case day.
Study time is layered on a monthly basis.
Therefore, the level of explanatory variables for the case day is compared to the same level of variables for the control day.
This approach has a major advantage in controlling individual factors, a certain day of the week, seasons, and time trends.
24 conditional logistic regression was performed to estimate the short-
The long-term effects of each type of air pollutant and stroke attack measured.
OR and 95% CI adjusted for 10g/m3 increase in pollutant levels to 1-
There is no delay in the day, the flu epidemic and holidays.
Pollutant exposure was tested in a 1-1 modelday, 2-day or 3-day lag.
According to age, gender, risk vascular factors (
Smoking, diabetes, high cholesterol and high blood pressure)
According to the trial of ORG 10 stroke 172 in the treatment of acute stroke, the etiology subtype of stroke (TOAST).
We evaluated the dose-response relationship of the exposure levels of the four pollutants studied and used the first four-point position as a reference group.
P value less than 0.
05 is considered important.
Analyze data using Stata V. 10. 0 SE software.
We did a population study-year (2007–2011)case-
Cross-analysis of Nice, France.
We reviewed consecutive stroke patients admitted to University of Nice hospital from January 2007 to December 2011.
Query FrenchBased on database (
PMSI: integrated scheme of information system)
I60-I69 code with International Classification of Diseases (10th revision)
We screened all patients hospitalized for stroke.
We filter the samples to patients living in Nice (
Geographic area defined by Zip code: 06000, 06100, 06200 and 06300).
A team of neurologists reviewed and confirmed the diagnosis of an ischemic stroke using clinical and radiological data from medical records.
Other diagnostic patients other than stroke were excluded.
Demographic data and vascular risk factors (WHO definition)
In addition, clinical and radiological features of stroke were collected from medical records.
Outdoor air pollution and meteorological data are a city in the South.
Eastern France on the Mediterranean coast.
According to the latest census, Nice had a population of 340735 in 2009.
Mild climate, Mediterranean.
Surrounded by mountains (south Alps)
The city of Nice sheltered from the wind in the constant winds.
Outdoor air pollution mainly comes from traffic with High Road density and international airports (
France's first airport after Paris Airport).
Obtaining air pollution data from air quality monitoring regional agencies (AirPACA).
During the study, exposure measurements were performed at 2 of the 13 permanent monitoring stations in the study area. Measures (µg/m3)
Perform at the City station (
Ladumeg)
The following atmospheric pollutants: particulate matter (PM10;
Oscillating micro-balance of cone element)
Nitrogen (NO2)(
Chemical glow
Sulfur dioxide (SO2;
Ultraviolet light measurementand ozone (O3;
Ultraviolet light measurement.
The missing values were replaced by measures taken by observation stations at Nice airport.
We calculated each pollutant during the 24-hour average period, especially ozone during the 8-hour day period.
Daily meteorological data, including temperature, are obtained from the nice National Meteorological Administration (°C)and humidity (%).
In addition, data on the flu epidemic (weekly count)
In Provence-Alpes-Cote-
D'Azur was obtained from the Sentiweb network.
Continuous variables are represented as mean (SD)or median (IQR)
, And classification variables expressed in percentages.
Correlation coefficient (r)
The relationship between atmospheric pollutants and atmospheric parameters is calculated. The time-Layered case
Cross design is used to test short-
Long-term effects of outdoor air contaminants and strokes.
In this design, each participant is his own control.
The day of the case is defined as a windy day.
The control day is defined as the same day on the same level as the case day.
Study time is layered on a monthly basis.
Therefore, the level of explanatory variables for the case day is compared to the same level of variables for the control day.
This approach has a major advantage in controlling individual factors, a certain day of the week, seasons, and time trends.
24 conditional logistic regression was performed to estimate the short-
The long-term effects of each type of air pollutant and stroke attack measured.
OR and 95% CI adjusted for 10g/m3 increase in pollutant levels to 1-
There is no delay in the day, the flu epidemic and holidays.
Pollutant exposure was tested in a 1-1 modelday, 2-day or 3-day lag.
According to age, gender, risk vascular factors (
Smoking, diabetes, high cholesterol and high blood pressure)
According to the trial of ORG 10 stroke 172 in the treatment of acute stroke, the etiology subtype of stroke (TOAST).
We evaluated the dose-response relationship of the exposure levels of the four pollutants studied and used the first four-point position as a reference group.
P value less than 0.
05 is considered important.
Analyze data using Stata V. 10. 0 SE software.
Results during the study (
January 2007-December 2011)
, 2067 patients lived in Nice and were included in the stroke center of the University Hospital according to the backroot festival database.
Following a review by neurologists of medical records, 1729 patients with ischemia stroke were included in the final analysis.
620 (35. 9%)
Some of these patients were hospitalized in the stroke ward.
According to the last census in 2009, the incidence of stroke per year (by 100u2005000)
From 2007 to 2011, the study areas were 100, 98, 96 and 112, respectively.
The average age is 76. 1±14. 0 yarears, 46. 7% were men (table 1).
View this table: View baseline features of stroke patients (
Events and repetitions)
From 2007 to 2011 were hospitalized at the University of Nice hospital. The distribution of air pollutants and meteorological variables is shown in Table 2.
Correlation coefficient (r)
Are between 0. 01 to 0.
25 except between ozone and no 2, between the contaminants of each study (r=−0. 54).
The correlation coefficient r = 0 between the lowest temperature and ozone. 67 (
See online supplementary form 1).
View this table: View the inline View pop-up table 2 Distribution of nice air pollution concentration and meteorological parameters (France)
Between 2007 and 2012, no significant association was found between stroke occurrence and short duration
Long-term effects of all contaminants tested.
In addition, we performed a stratified subgroup analysis based on gender, age, event/recurrent stroke status, vascular risk factors, atrial fibrillation, and stroke etiology.
We only measured the significant association between stroke and short stroke
Long-term effects of ozone on the following two groups: recurrence (n=280)
Stroke of great arteries (n=578)(table 3).
03 levels increased by 10g/m3 in the recurrent stroke subgroup (mean D-1, D-2 and D-3 lag)
The risk of stroke increased significantly by 12. 1% (95% CI 1. 5% to 23. 9%).
Adjust or between ozone exposure (mean D-3 and D-4)
The large artery stroke subgroup was 1. 080 (95% CI 1. 002 to 1. 166).
No significant association was observed with other contaminants other than O3.
Two adjustments
A model of pollution, or not affected.
Use four bricks of ozone (
1st four points as reference group)
, The linear dose-response relationship between the two subgroups was observed (figure 1).
Baseline features of recurrent stroke and arterial stroke subgroups are shown in figure 2.
View this table: View the adjusted or (s) of the inline View popuptable 3 between the increased ischemia stroke and outdoor pollutant exposure in Nice 10 µg/m3 (France)
Between 2007 and 2011, download the dose relationship between figureOpen ozone and ischemia stroke events in the new tabDownload powerpoint Figure 1 ((A)
, A subgroup of recurrent ischemia stroke and (B)
Subgroup of major artery ischemia stroke).
According to the recurrent stroke group, download figureOpen in the new tabDownload powerpoint figure 2 baseline feature (A)
Subgroup of great artery stroke (B)(*p