Temperature and ischemic heart disease mortality in cities of tropical, Mexico

摘要

Background The temperature in the Guadalajara Metropolitan Area (GMA, the second-largest in Mexico) has increased from 22 degrees (1996-2000) to 26oC (1996-2009); 2005 was a critical year with respect to temperature increase, ischemic heart disease mortality was the second cause of death in the GMA. Aims To analyze the relation between an increase in temperature and ischemic heart disease mortality in GMA during 2005. Methodology Observational, retrospective and longitudinal study of the year 2005. The maximum observed daily temperature and daily ischemic heart disease mortality were analyzed. Days on which temperatures were equal to or above 32oC were identified. Daily ischemic heart disease mortality was analyzed with respect to the relation between the maximum observed daily temperature on such days or on the days following the temperature increase. Temperature data was obtained from the GMA Automatic Atmospheric Monitoring Network and information related to daily mortality was obtained from Jalisco's Public Health Department (SSJ). Results In the GMA, during 2005, the highest number of days (124) with temperatures equal or above 32oC was recorded. Seventy-percent occurred during April to June. During the 124 days, there were 305 deaths due to ischemic heart disease, 53.4% of such deaths occurred when the temperature range was 33 to 36 oC, concentrated (72.4%) during the months from April to June. With respect to the increase in the number of deaths, it was found that on days after exposure to such temperatures, there was an increase of 22 deaths three days after exposure.No significant differences between groups. Conclusions In 2005, 32.51% of deaths due to ischemic heart disease occur when temperatures are equal or above 32.4oC. It was also observed that ischemic heart disease mortality is high in zones which historically register higher maximum temperatures, at a rate of 4.19/10,000 inhabitants.