The effect of the fast of Ramadan on ambulatory blood pressure in treated hypertensives

Every year, millions of Moslems throughout the world fast from sunrise till sunset daily during the month of Ramadan, that is, experience repeated cyc les of fasting-refeeding. Studies in animal models have shown that repeated cycles of fasting-refeeding may cause or exacerbate hypertension. Changes in sleeping patterns as well as changes in medication timing may also influ ence ambulatory blood pressure. We undertook this study in order to examine the effect of the Ramadan fast on treated hypertensive subjects. Seventeen hypertensive subjects were examined, and 24-h blood pressure monitoring wa s carried out twice, before and during the last week of the Ramadan. All co ntinued their medications, which were all once-daily preparations. Twenty-f our hour mean blood pressure as well as average awake and average asleep bl ood pressure were compared. There was no difference between mean blood pres sure before and during the Ramadan (138.5 +/- 18.5/77.2 +/- 8.1 mm Hg vs 13 6.4 +/- 20.4/75.7 +/- 5.9 mm Hg, P-nonsignificant). Blood pressure load als o did not differ before and during Ramadan (systolic load 49% vs 44%, diast olic load 21% vs 18%, P-nonsignificant). Weight was reduced by 1.4 +/- 1.6 kg (P < 0.002). We conclude, that according to our findings, treated, hyper tensive patients may be assured that, with continuation of previous medicat ions, traditional fasting during the month of Ramadan can be safely underta ken.