Association between stroke occurrence and changes in atmospheric circulation

Abstract

Background The impact of weather on morbidity from stroke has been analysed in previous studies. As the risk of stroke was mostly associated with changing weather, the changes in the daily stroke occurrence may be associated with changes in atmospheric circulation. The aim of our study was to detect and evaluate the association between daily numbers of ischaemic strokes (ISs) and haemorrhagic strokes (HSs) and the teleconnection pattern. Methods The study was performed in Kaunas, Lithuania, from 2000 to 2010. The daily numbers of ISs, subarachnoid haemorrhages (SAHs), and intracerebral haemorrhages (ICHs) were obtained from the Kaunas Stroke Register. We evaluated the association between these types of stroke and the teleconnection pattern by applying Poisson regression and adjusting for the linear trend, month, and other weather variables. Results During the study period, we analysed 4038 cases (2226 men and 1812 women) of stroke. Of these, 3245 (80.4%) cases were ISs, 533 (13.2%) cases were ICHs, and 260 (6.4%) cases were SAHs. An increased risk of SAH was associated with a change in mean daily atmospheric pressure over 3.9 hPa (RR = 1.49, 95% CI 1.14–1.96), and a stronger El Niño event had a protective effect against SAHs (RR = 0.34, 95% CI 0.16–0.69). The risk of HS was positively associated with East Atlantic/West Russia indices (RR = 1.13, 95% CI 1.04–1.23). The risk of IS was negatively associated with the Arctic Oscillation index on the same day and on the previous day (RR = 0.97, p < 0.033). During November–March, the risk of HS was associated with a positive North Atlantic Oscillation (NAO) (RR = 1.29, 95% CI 1.03–1.62), and the risk of IS was negatively associated with the NAO index (RR = 0.92, 95% CI 0.85–0.99). Conclusions The results of our study provide new evidence that the North Atlantic Oscillation, Arctic Oscillation, East Atlantic/West Russia, and El Niño-Southern Oscillation pattern may affect the risk of stroke. The impact of these teleconnections is not identical for various types of stroke. Emergency services should be aware that specific weather conditions are more likely to prompt calls for more severe strokes.

Association between El Niño-Southern Oscillation events and stroke: a case-crossover study in Kaunas city, Lithuania, 2000–2015

“…We found a different and significant effect of strong and moderate ENSO on stroke. Our findings provide additional insight into a similar association in Lithuania where some evidence was found on a link between atmospheric circulation and health (Venclovienė et al 2021 ). The weather conditions during the period of a strong El Niño were different as compared to the period of a moderate El Niño.…”

“…Furthermore, it is thought that changes in atmospheric pressure may lead to a plaque rupture in the carotid arteries (Houck et al 2005). Studies on thrombosis in air travel suggest that prothrombin fragments and the thrombin-antithrombin complex are activated in hypobaric conditions (Gungor and Onar 2007;Schreijer et al 2006), which could be another clue to the underlying mechanism (Vencloviene et al 2021). The results obtained in previous studies showed different and controversial effects of atmospheric pressure on HS and IS.…”

“…To indicate the ENSO events (La Nina and El Nino), we used the daily NIÑO 3.4 index interpolated from weekly data (Equatorial Pacific Sea Surface Temperature) from the Climate Explorer database ( http://climexp.knmi.nl/data/inino34_weekly.dat ). Other weather variables having an effect on stroke occurrence (Vencloviene et al 2021 ) were obtained from databases ftp://ftp.cpc.ncep.noaa.gov/cwlinks/ (the daily North Atlantic Oscillation and Arctic Oscillation Indices) and https://www.cpc.ncep.noaa.gov/data/teledoc/telecontents.shtml (the monthly East Atlantic/West Russia pattern and Scandinavian pattern indices). Data on the ambient temperature (°C), atmospheric pressure (hPa), relative humidity (%), and wind speed (m/s) were obtained from Kaunas Meteorological Station.…”

“…The associations between the ENSO categories and the risk of stroke occurrence were evaluated by using the multivariate Poisson regression model, which was specified as: where X (1) was the vector of predictors such as categorical variables (months and week days), the linear trend, population volume, and weather variables set out in our previous work (Vencloviene et al 2021 ). For all stroke types, the East Atlantic/West Russia pattern index and a change in daily atmospheric pressure of over 8 hPa from the previous day were additionally included, and for the IS model, a strongly negative East Atlantic/West Russia pattern was additionally included (Breiman et al 1984 ).…”

“…Previous evidence shows that during the second half of autumn, the NIÑO 3.4 > 1.14 period was characterized by a lower mean atmospheric pressure, more precipitation and relative humidity, and a very significantly lower diurnal temperature range. In winter, the NIÑO 3.4 > 1.14 period was characterized by lower ambient temperature, wind speed, and cloud cover and a higher atmospheric pressure and diurnal temperature range (Venclovienė et al 2021 ).…”