Lower ambient temperature was associated with an increased risk of hospitalization for stroke and acute myocardial infarction in young women

Objective: Results of investigations into the impact of seasonal variation on the incidence of cardiovascular diseases (CVD) have been inconsistent. Using the WHO Collaborative Study of CVD and Steroid Hormone Contraception database, we attempted to examine the relationship between variation in three climatic variables and risk of hospitalization for venous thromboembolism (VTE), arterial stroke, and acute myocardial infarction (AMI). Study Design and Setting: We compared the monthly mean temperature, rainfall, and humidity with rates of hospitalized VTE, stroke, and AMI among young women aged 15-49 from 17 different countries in Africa, Asia, Europe, Latin America, and the Caribbean by using a negative binomial regression model. Results: The study included 1146, 2,269, and 369 cases of VTE, stroke, and AMI, respectively. Significant associations between temperature and hospital admission rates of stroke and AMI, but not VTE, were apparent. Lagging the effects of temperature suggested that these effects were relatively acute, within a period of a month. Conclusion: These data may help in understanding the mechanisms whereby stroke and AMI events are triggered. (C) 2004 Elsevier Inc. All rights reserved.