Society of Diabetic Nephropathy Prevention Journal of Preventive Epidemiology 2476-3934 3 2 2018 07 01 Investigating the relationship between seasonal temperature changes and the referrals of patients with acute coronary syndrome e21 e21 EN Hossein Saeidi Hossein Shaker Mojtaba Chardoli Davood Saravi https://orcid.org/0000-0002-5147-9870 Journal Article 2018 08 04 2018 11 10 Introduction: Due to the relationship between climate and human health, scientists are interested in evaluating seasonal and daily changes in air temperature and risk for cardiovascular diseases. Objective: The aim of this study was to investigate the relationship between seasonal temperature changes and the rates of referring patients with acute coronary syndrome. Patients and Methods: The present case-control study was performed on all consecutive patients suffering acute coronary syndrome that were hospitalized in a great referral hospital in Tehran between 2011 and 2015. The meteorological and mortality data were first matched with each other. Then the number of patients with acute coronary syndrome was determined by region and gender. Results: Assessing the frequency of patients referred from 2011 to 2015 indicated the upward trend of referral to the hospital. Regarding the frequency of referrals in different months of the year (regardless of the year of assessment), the highest rate of referral for patients with unstable angina was in the month of October and then in November and the lowest referral was in August. The number of referees was significantly associated with the increase in minimum and maximum temperature, average air pressure, as well as with the decrease in air humidity during the years studied. Conclusion: The risk of acute coronary syndrome attacks is highest in the cold months of the year, especially in the autumn and early winter, and is the lowest in the middle of summer. Over the years, increasing air temperature with increasing air pressure and reducing humidity can increase the risk of acute coronary syndrome.