Abstract
Fasting is a part of many world religions and in Islam fasting is obligatory for every adult Muslim during the month of Ramadan. Islam has exempted sick people from fasting; however, many people still partake in this activity. We investigated how Islamic fasting affects patients with heart failure with preserved ejection fraction (HFpEF). We enrolled 938 patients (fasting n = 456; non-fasting = 482) in this prospective observational study. The fasting group showed a decrease in NYHA functional class III (23.36% vs. 17.77%; p-value < 0.05) and IV (3.76% vs. 2.19%; p-value < 0.05), and an increase in class I(35.57% vs. 43.64%; p-value < 0.05). symptoms. This is an important area for physicians to advise patients with HFpEF to fast in the month of Ramadan as it can have a favorable effect on their symptoms and quality of life.