CIRCADIAN VARIATION IN THE ONSET OF ACUTE CRITICAL LIMB ISCHEMIA

Research has identified a circadian rhythm for several acute thromboti c cardiovascular and cerebrovascular diseases. We investigated the pos sible existence of a circadian variation in the onset of acute critica l limb ischemia. Out of a consecutive series of 198 cases, precise det ermination (within 30 minutes) of the time of symptom onset was possib le in 156 (78.8%). Partial Fourier series were applied to hourly data and the best-fitting curves for circadian rhythmicity were calculated. Both in the total population and in subgroups by gender and location of ischemia, a highly significant circadian pattern of occurrence was demonstrated with peak in the morning (approximately 0800) and nocturn al minimum around midnight. This study is the first demonstration of t he circadian pattern of acute arterial occlusion of the limbs, in agre ement with several studies showing a circadian pattern to the time of onset of acute myocardial infarction and other unfavorable acute event s related to thrombosis. This opens up the potential for therapeutic i mplications, suggesting the need to adjust the dose of drugs based on the time of day. Further studies dealing with circadian variation in t he efficacy of thrombolytic agents are so needed. (C) 1998 Elsevier Sc ience Ltd.