Middle-term nitrogen dioxide exposure and electrocardiogram abnormalities: A nationwide longitudinal study.

Area of Science:

• Environmental Health
• Cardiovascular Research
• Public Health

Background:

• Nitrogen dioxide (NO2) is a significant urban air pollutant linked to cardiorespiratory issues.
• While short- and long-term effects are known, middle-term NO2 exposure's cardiovascular impact is unclear.
• Recent WHO recommendations highlight the need for stricter NO2 standards.

Purpose of the Study:

• To investigate the association between middle-term NO2 exposure and cardiovascular risks.
• To identify cardiovascular risks using electrocardiogram (ECG) abnormalities as indicators.
• To examine NO2 exposure's link to subclinical cardiovascular system changes.

Main Methods:

• Longitudinal data from 61,094 subjects (132,249 visits) from the China National Stroke Screening Survey (CNSSS).
• Monthly average NO2 concentrations in the 6 months preceding ECG measurements were used.
• Generalized estimation equation models assessed the association between NO2 exposure and ECG abnormalities.

Main Results:

• A 10 µg/m³ increase in monthly average NO2 was associated with a 1.10 odds ratio for ECG abnormalities.
• Significant associations were observed in both urban and rural populations.
• The link remained robust even after adjusting for PM2.5, showing a nearly linear exposure-response relationship.

Conclusions:

• Middle-term NO2 exposure increases the risk of cardiovascular issues, indicated by ECG variations.
• ECG signal changes can serve as a reversible indicator of subclinical cardiovascular risk.
• Policies to control NO2 concentrations are crucial for preventing cardiovascular diseases in Chinese adults.