SEASONAL-CHANGES IN HEMOSTATIC FACTORS IN YOUNG AND ELDERLY SUBJECTS

Morbidity and mortality from cardiovascular disease are more common in colder seasons, especially in elderly people. Previous studies have s hown higher fibrinogen levels in old people in the winter months. The present studies of haemostatic factors in relation to age and season h ave shown that fibrinogen, tissue plasminogen activator (tPA), protein S and protein C levels are higher in old (aged 75 years and over) tha n young (aged 25-30 years) subjects while antiplasmin levels are lower in old people. Antiplasmin and protein C levels are lower in winter i n both young and old while plasminogen activator inhibitor (PAI) is hi gher, and tPA higher in old people only. This study illustrates the co mplex interrelationships of the haemostatic system and may suggest tha t in 'successful' elderly people the fibrinolytic system may alter to maintain the delicate balance between thrombogenic and fibrinolytic ac tivity. Nevertheless, the results presented here suggest that both old age and cold weather may increase the risk of atherothrombotic diseas e.