Every year, millions of Muslims all over the world practice religious fasting, from sunrise to sunset, during Ramadan. Very few data is available about Ramadan fasting and coronary disease.

The aim of our study was to establish prevalence and particularities of patients admitted for an acute coronary syndrome (ACS) before, during and after Ramadan.

Data was collected in a descriptive and prospective cohort study within the Cardiology department of Habib Thamer Hospital. The study included all patients admitted for ACS during April, May and June of 2019 (Ramadan, one month earlier and one month later). We collected all relevant epidemiological, clinical and biological data.

Our study included 111 patients. Prevalence of ACS during each month was comparable: 19.7% (n=43) before, 18.8% (n=37) during, and 19% (n=31) after Ramadan. The epidemiological profile of patients, the prevalence of cardiovascular risk factors and their medical histories were also similar. Patient's daily lifestyle changed during the month of Ramadan. Significant decrease in smoking was noted [20±7.6 cigarettes per day vs. 10 cigarettes per day (P=0.001)]. Sleep hours were fewer [7.86±1.62hours per day vs. 6.46±1.53hours per day (P=0.001)]. There were significantly fewer meals [3.05±0.3 vs. 2.46±0.5 meals per day (P=0.001)]. Furthermore, significant metabolic changes occurring in Ramadan were revealed. HDL cholesterol decreased [73% vs. 28%(P=0.000)]. Total blood cholesterol was higher [43% vs. 14% (P=0.003)], and fasting blood sugar was also higher [43% vs. 18% (P=0,016)]. After Ramadan, prevalence of ACS decreased significantly for women: 13% (n=4) after Ramadan vs. 32% (n=12) during Ramadan (P=0.001).

There was no increase in ACS occurrence during Ramadan. Changes occurred mainly on metabolical level, affecting sugar and fat metabolism.