Innovative Approaches Helpful to Enhance Knowledge on Weather-Related Stroke Events Over a Wide Geographical Area and a Large Population

Abstract

Background and Purpose-Results on the effect of weather on stroke occurrences are still confusing and controversial.The aim of this study was to retrospectively investigate in Tuscany (central Italy) the weather-related stroke events through the use of an innovative source of weather data (Reanalysis) together with an original statistical approach to quantify the prompt/delayed health effects of both cold and heat exposures. Methods-Daily stroke hospitalizations and meteorologic data from the Reanalysis 2 Achieve were obtained for the period 1997 to 2007. Generalized linear and additive models and an innovative modeling approach, the constrained segmented distributed lag model, were applied. Results-Both daily averages and day-to-day changes of air temperature and geopotential height (a measure that approximates the mean surface pressure) were selected as independent predictors of all stroke occurrences. In particular, a 5°C temperature decrease was associated with 16.5% increase of primary intracerebral hemorrhage of people Ն65 years of age. A general short-term cold effect on hospitalizations limited to 1 week after exposure was observed and, for the first time, a clear harvesting effect (deficit of hospitalization) for cold-related primary intracerebral hemorrhage was described. Day-to-day changes of meteorologic parameters disclosed characteristic U-and J-shaped relationships with stroke occurrences. Conclusions-Thanks to the intrinsic characteristic of Reanalysis, these results might simply be implemented in an operative forecast system regarding weather-related stroke events with the aim to develop preventive health plans. (Stroke. 2011;42:593-600.)

Seasonal Blood Pressure Changes

“…This cross-sectional and observation survey indicates that health interventions targeted at better protection against cold weather (eg, improved home heating and reduced exposition to cold climate) may be particularly effective in the elderly. [16][17][18] The observation that seasonality expressed by daylight hours is positively related with nighttime SBP extends our previous observation, 19 recently confirmed by others, 20 that hot days, more frequently encountered in summer, are associated with increased nocturnal BP levels. Although subjects did not report significant restlessness in their log book, we cannot exclude that heatinduced mild perturbations in sleep quality may have played a role.…”

Effect of Seasonal and Monthly Variation in Weather and Air Pollution Factors on Stroke Incidence in Seoul, Korea

“…Similar findings were reported by a study in Italy. 22 The authors described significant negative associations between mean temperature and all stroke hospitalizations, particularly ICH, with the greatest effect in people ≥65 years of age. Furthermore, highly significant positive relationships were observed between IS and average temperature for an increment of 5°C (day to day), especially when people ≥65 years of age were considered.…”

The Health Effects of Climate Change in the WHO European Region

“…Low temperatures and extreme cold weather pose a significant risk to human health. Low temperatures have an effect on respiratory tract infections [37], myocardial infarction [38], stroke hospitalization [39] and general hospital admissions [40], and mortality [35,[41][42][43]. Extreme cold spells cause increases in morbidity [38] and mortality due to respiratory, cardio-, and cerebrovascular diseases [39,44,45].…”

“…Conversely, in the same region, mortality rates are expected to increase by up to 11.8% for each 1 °C increase above the threshold during the warm season [19]. Table 3, [19,30,35,[38][39][40][41][42][43][44][45][46] lists the search results according to the focus of the research. Most of the papers address the observed effects of low temperatures on mortality (4) and morbidity (3).…”

“…Low temperature is associated with respiratory tract infections [46] Cold weather had an effect on hospital admission in 12 cities in Europe [40] Significant negative associations between daily average air temperature and all stroke hospitalizations [39] Thermal environment inversely associated with acute myocardial infarction morbidity during winter [38] Projections [30] *…”