Survey of metrological hazard effects and cardiovascular consequences in Rasht from 2005 -2015

Backgrounad and aim: Extreme events weather are known to contribute to an increase in morbidity and mortality, particularly in vulnerable groups (e.g., elderly, children, and people with chronic diseases). Many previous studies reported an increased risk of mortality associated with the variations of temperature. The purpose of this study was to investigate the effects of a metrological hazard on cardiovascular consequences in Rasht city from 2005 to 2014.Methods: This study was designed and implemented in 4 steps. In the first step, a systematic review and meta-analysis were conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Peer-reviewed studies about the temperature and cardiovascular mortality were retrieved in the MEDLINE, Web of Science, and Scopus databases from January 2000 up to the end of 2015. In the second step, the 10-year data of metrological variables were obtained from the Meteorological Organization of Guilan province. Also, data about the morbidity and mortality rate of cardiovascular patients was obtained from the only cardiovascular hospital in Rasht duration of the study. In the third phase according to data obtained from the meteorological Center of Rasht and based on systematic review, we determine the point of heat wave, cold spells. Finally, data are entered in software R and we analyzed the data basis of the dlnm package.Results: The findings of systematic review and meta-analysis showed that exposure to cold and heat increased risk of cardiovascular mortality by 5% and 1.3%, respectively. The findings also revealed that the risk of exposure to hot temperature in the elderly would increase the risk of cardiovascular mortality 8%. The results showed that the risk of cardiovascular mortality increased with each degree increased significantly in latitude and longitude in cold exposure. Result of our study indicated that the extreme hot temperatures increased risk of ACS hospitalization but the cold temperature didn’t show any effect on ACS admission. We find a significant heat effect on ACS admission in people above 65 years old in short time(lag 0 - 1). The strongest relationship between high apparent temperature and ACS was at same day. Our findings regarding the effect of temperature on the cardiovascular mortality showed that hot and cold temperatures were associated with a 9% (RR, 1.09; 95% CI, 1.02 to 1.12) and 14% (RR, 1.14; 95% CI, 1.05 to 1.23) increase in cardiovascular mortality, respectively. We observed immediate effects of hot temperatures on CVD mortality with the strongest effects on the same day (lag 0) but delayed effects of cold temperature (lag 7). Time series analyses show that the women and elderly were more vulnerable to extremely hot temperatures.Conclusion: Although cold temperature was not associated with an increase in cardiovascular disease admission, the findings showed that both cold and heat temperature increased mortality. Cold weather has a delayed effect while warm weather has had short term effects. Adaptation strategies such as using the air conditioner in summer, adequate hydration, suitable clothing in the winter in addition to a well - established early warning system and emergency service can prevent remarkably the amount of CVD mortality.

Keywords:

Climate Change , Extreme event weather , Cardiovascular disease , Mortality