Circadian pattern of acute coronary syndrome patients in Ramadan fasting

Background Over one billion Muslims fast worldwide during the month of Ramadan. The impact of fasting on circadian presentation with acute cardiac events is unknown. Objectives This study aims to determine whether fasting during Ramadan has any effect on the circadian pattern of acute coronary syndromes (ACS) or not. Patients and methods This is a prospective observational study that included all patients with ACS. Patients were divided into two groups based on the history of fasting. Information about age, sex, cardiovascular risk factor profiles, and outcome was collected. The relationship of time of presentation of initial symptoms with fasting and time of seeking medical advice was evaluated and statistically analyzed. Results Of the 494 patients with ACS hospitalized during the study period, 85 patients were fasting during Ramadan. Fasting patients were more likely to have their symptoms between 3 a.m. and 4 a.m. (15.3%), whereas nonfasting patients were more likely to have their symptoms between 7 a.m. and 8 a.m. (16.6%) (P 0.005). In addition, fasting patients were more likely to present to the hospital early within the first hour of onset of symptoms (35.3%), whereas nonfasting patients were less likely to present to the hospital early within the first hour (23.7%). These differences were also statistically significant (P 0.04). Conclusion The changes in food intake and/or sleep timings affect the circadian rhythm and influence the timing of presentation of ACS.