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

Background: 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 hyper-tensive patients. Studies on the effects of fasting on the 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 individuals taking their treatment once daily.Material and methods: The study prospectively recruited 44 hypertensive patients between April and June 2019, followed up at the cardiology department of Habib Thameur Hospital in Tunis. A 24-hour blood pressure monitor-ing 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. Fifteen patients were diabetics, 20 had dys-lipidemia and 7 patients had coronaropathy. Twenty patients were on monotherapy, 19 on dual therapy and 5 on a triple antihypertensive therapy. During Ramadan, 25 patients took their treatment during the dinner (group1), whereas 19 took their treatment during the S'hour (group 2). Average 24-hour blood pressure in the whole group was 129 +/- 18/74 +/- 10 mm Hg before Ramadan and 129 +/- 19/74 +/- 10 mm Hg during Ramadan (p > 0.05). Day-time and night-time 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 significantly 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 S'hour (p < 0.05).Conclusions: In this study, there were no significant changes in systolic and diastolic blood pressures or in heart rate during the 2 periods. However, during Ramadan, a slight superiority of taking the treatment with the S'hour is observed.