THE EFFECT OF CHANGE IN THE RHYTHM OF FOOD-INTAKE AND SLEEPING TIME DURING RAMADAN ON THE DIURNAL-VARIATION OF FIBRINOLYTIC-ACTIVITY

Consecutive measurements of blood coagulation and fibrinolytic parameters were undertaken at 9.00 am, 4.00 pm, 9.00 pm and 4.00 am in eleven healthy subjects, observing the dawn to sunset fast of the holy Muslim fasting month of Ramadan. Measurements were repeated in an ordinary 'non-fasting' day. No statistically significant fluctuations were noted in prothrombin time, activated partial thromboplastin time, thrombin time, plasma fibrinogen, plasminogen, and tissue plasminogen activator (t-PA) either during Ramadan or in a non-fasting day. However, markedly elevated levels of the plasminogen activator inhibitor (PAI) activity were noted at 9.00 am in Ramadan and at 4.00 am on a non-fasting da Both increases were determined after several hours overnight sleep; the waking time in Ramadan being 8.30 am and 4.30 am in non-Ramadan day. Thus the circadian variation in PAI activity levels are influenced more by sleep pattern rather than food intake or the normal activities of a working day.