Objective Evidence on the relationship between ambient temperature and morbidity of different stroke subtypes in China is limited. This study aimed to assess the influence of ambient temperature on stroke risk in Shenzhen, China.
Methods From 1 January 2003 to 31 December 2014, 114 552 stroke cases in Shenzhen were collected. A generalised additive model with quasi-Poisson regression combined with a distributed lag non-linear model was applied to evaluate the temperature effects on stroke subtypes. Furthermore, this study explored the variability of the effects across sex, age and education.
Results The immediate heat effects on ischaemic stroke (IS) and the persistent effects of ambient temperature on intracerebral haemorrhage (ICH) were significant. Overall, the cold-related relative risks (RRs) of IS, ICH and subarachnoid haemorrhage (SAH) were 1.02 (0.97–1.07), 1.16 (1.04–1.30) and 1.12 (0.61–2.04), whereas the heat-related RRs were 1.00 (0.97–1.04), 0.80 (0.73–0.88) and 1.05 (0.63–1.78), respectively. For IS, a weakly beneficial cold effect was found among men while a detrimental heat effect among both men and women, the elderly and higher-educated population at lag0. However, regarding ICH, the temperature effects in men, the young and higher-educated population are stronger at lag0–4, lag0–7 as cold reveals threat and heat reveals protection.
Conclusion Responses of diverse stroke subtypes to ambient temperature varied. Effective measures should be taken to increase public awareness about the effects of ambient temperature on stroke attack and to educate the public about self-protection.
- public health
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JP, JC and PY contributed equally.
Contributors LL, JP, SH, JC and PY contributed to the conception and design of the study. LL led the data analysis with support from JP, SH. PL, LL and JC contributed to data collection and data quality control. YD, YT and MX contributed to literature review. YD supervised the analysis and generation of results. LL drafted, finalised and modified the paper with inputs from JP, JC and PY. All authors contributed to data interpretation, and reviewed and approved the final version of the manuscript. PY, JC and JP had full access to all the data in the study and had the final responsibility of the decision to submit the manuscript for publication.
Funding The study was supported by two grants from the National Natural Science Foundation of China (No. 81573262 and No.81973004), the Sanming Project of Medicine in Shenzhen (No: SZSM201511007) as well as the Shenzhen Key Medical Discipline (No: SZXK067).
Competing interests None declared.
Patient consent for publication Not required.
Data availability statement No data are available.
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