Are circadian variations of acute myocardial infarction related to regional differences?

40 SUMMARY An obvious circadian variation (CV) is observed in patients of acute myocardial infarction (AMI) which is affected by plenty of factors such as daily homeostatic processes of the organism itself, the psycho-social structure, habits,traditions of the society he or she lives in oc seasonal or environmental changes. Current study was designed to include 442 patients (357 males,85 fameles) with a range between 23-100 years admitted to Cardiology Department of Dicle University Hospital that is a referral center giving service for ten provinces in the southeastern part of Turkey, with a diagnosis of AMI beetwen. January 1995-January 1997 and to interrogate pain initation (PI) hour, risk factors (sex, age, smoking, hypertension, Diabetes Mellitus, hypercholesterolemia, family history, obesity, pre-infarction stress) and seasonal distribution of the disease, localization of the infarction, in-hospital mortality. Daily, monthly, seasonal CV was studied as well as hourly and six-hourly intervals (Group 1-24:01-06:00; GroupII- 06:01-12:00; Group 111-12:01-18:00; Group IV- 18: 01 -24:00), HI wa.s race at night hours whereas it had two peaks at 06:00 and 18:00. From the point of six hourly analysisthe highest incidence was 31% between 18:01-24:00 and the lowest was 17.4% 1>etween 24:01-06:00. AMI incidences were highest in January (13.1%),in winter (32.1%) and lowest in August (3.1%) and in summer (14.9%). In six-hourly analysis smoking and pre-infarction stress rates were remarkably higher in Group III and IV (p<0.01,p<0.01). Smoking was notably higher in patients younger than 40 years (p<0.01) and saturated fat consumption was significantly increased in all age groups (p<0.05), whereas no other significant variables were identified among the risk factors. Conclusively we observed both an early morning peak and a significantly higher evening peak and a higher PI between 18:01-24:00 and 06:01-12:0.0,be$ides higher incidences of^AMl in January and in Winter and lower incidences in August and in Summer were detected.We suggested the need to wake up at very early times to perform ritual worship, resulting with changing actual daily CV in Islamic population who are the leading religional community in our country and in this region, gives rise to the morning peak to be earlier compared to the literature, whereas precipitated mental stress at the end of the day of being lived in a region with specific demographic and sociopolitical characteristics including increased intensity of socioeconomic problems would explain the significantly increased evening peak.