Effect of intermittent fasting and chronotherapy on blood pressure control in hypertensive patients during Ramadan

Introduction: During Ramadan, repeated cycles of fasting, associated with alterations in the daily patterns of sleep, activities and medication timing might contribute to changes in blood pressure (BP) and heart rate among hypertensive patients. Studies on the effects of fasting on blood pressure of hypertensive patients are rare, and have provided inconclusive results. The aim of this study was to examine the effect of medication timing during Ramadan on blood pressure and heart rate in hypertensive subjects taking their treatment once daily. Methods: The study prospectively recruited 44 hypertensive patients between April and June 2019, followed up at the cardiology department of Habib Thameur Hospital of Tunis. A 24-hour pressure monitoring was carried out during two periods: prior to Ramadan and during the last ten days of Ramadan. We compared the average values of 24 hour, awake and asleep systolic and diastolic blood pressure and 24 hour, awake and asleep heart rate. Results: We studied 29 women and 15 men, mean age was 58.7 years. 34% of the patients were diabetics, 46% dyslipidemics and 16% had coronaropathy. 46% of the patients were on monotherapy, 43% on dual therapy and 11% on a triple antihypertensive therapy. During Ramadan, 57% of the patients took their treatment during the dinner (group1), whereas 43% took their treatment during the Shour (group 2). Average 24hour blood pressure in the whole group was 129±18/74±10 mmHg before Ramadan and 129±19/74±10 mmHg during Ramadan (p > 0.05). Daytime and nighttime mean values of systolic and diastolic blood pressure as well as mean values of heart rate were not different between both periods regardless of age and gender. However, during Ramadan, those who took their treatment after dinner had significant higher values of 24 hour systolic BP, awake systolic and diastolic BP, asleep systolic and diastolic BP than those who took their treatment with the shour (p < 0.05). Conclusions: In this study, there were no significant changes in systolic and diastolic blood pressures as well as heart rate during the 2 periods. However, during Ramadan, a slight superiority of taking the treatment with the shour is observed.