Ambient temperature, seasonal influenza and risk of cardiovascular disease in a subtropical area in Southern China
Publication in refereed journal
CUHK Authors
Full Text
Digital Object Identifier (DOI) |
Times Cited
Altmetrics Information
.
Other information
AbstractBackground:
Given the regular winter recurrence of influenza epidemics and the biologically plausible association between seasonal influenza and cardiovascular events, researchers assumed a valid and reliable influenza forecast could envision the timing and burden of winter surge in cardiovascular (CVD) hospitalizations. This, however, is well justified only in temperate regions. In this study, we aim to investigate the temporal association between ambient temperature, seasonal influenza and risk of cardiovascular events in a subtropical city.
Methods:
Generalized additive model was used in conjunction with distributed-lag non-linear model of quasi-Poisson family to estimate the association of interest with daily CVD admissions as outcome and daily influenza admissions as predictor, while controlling for meteorological factors (i.e. temperature, relative humidity, wind speed and total rainfall) and respiratory pollutants (i.e. nitrogen dioxide, sulphur dioxide, ozone and PM10). Results were expressed in the form of relative risk (RR).
Results:
Using median as the reference value, a U-shaped association was observed between CVD admissions and
temperature. A slight decrease in RR was detected mainly towards the lower end of the temperature scale after
adjusting for influenza admissions. Risk of CVD admission was found to be positively associated with the number
of influenza hospitalization cases; this association remained consistent and statistically significant across subgroups
of age except for those aged 5–49 years.
Conclusion:
The slight reduction in CVD admission risk towards the lower end of the temperature scale after controlling for influenza activity might be attributed to the winter peaks of influenza, meaning that the effect of low temperature on CVD admissions might be partly mediated by influenza infection. In summary, this study reassures us that ambient temperature is independently associated with CVD hospital admissions and offers support for a positive association between seasonal influenza activity and cardiovascular events in Hong Kong.
Given the regular winter recurrence of influenza epidemics and the biologically plausible association between seasonal influenza and cardiovascular events, researchers assumed a valid and reliable influenza forecast could envision the timing and burden of winter surge in cardiovascular (CVD) hospitalizations. This, however, is well justified only in temperate regions. In this study, we aim to investigate the temporal association between ambient temperature, seasonal influenza and risk of cardiovascular events in a subtropical city.
Methods:
Generalized additive model was used in conjunction with distributed-lag non-linear model of quasi-Poisson family to estimate the association of interest with daily CVD admissions as outcome and daily influenza admissions as predictor, while controlling for meteorological factors (i.e. temperature, relative humidity, wind speed and total rainfall) and respiratory pollutants (i.e. nitrogen dioxide, sulphur dioxide, ozone and PM10). Results were expressed in the form of relative risk (RR).
Results:
Using median as the reference value, a U-shaped association was observed between CVD admissions and
temperature. A slight decrease in RR was detected mainly towards the lower end of the temperature scale after
adjusting for influenza admissions. Risk of CVD admission was found to be positively associated with the number
of influenza hospitalization cases; this association remained consistent and statistically significant across subgroups
of age except for those aged 5–49 years.
Conclusion:
The slight reduction in CVD admission risk towards the lower end of the temperature scale after controlling for influenza activity might be attributed to the winter peaks of influenza, meaning that the effect of low temperature on CVD admissions might be partly mediated by influenza infection. In summary, this study reassures us that ambient temperature is independently associated with CVD hospital admissions and offers support for a positive association between seasonal influenza activity and cardiovascular events in Hong Kong.
Acceptance Date15/04/2020
All Author(s) ListMohammad KN, Chan EYY, Wong MCS, Goggins WB, Chong KC
Journal nameEnvironmental Research
Year2020
Month7
Volume Number186
PublisherElsevier
Article number109546
ISSN0013-9351
eISSN1096-0953
LanguagesEnglish-United Kingdom
KeywordsTemperature, Seasonal influenza, Cardiovascular disease, Distributed-lag non-linear model, Subtropics
