[Changes in the number and volume of platelets in male elderly persons, and effects of various factors on them].

Platelets are deeply involved in the onset of thrombosis, such as cerebral thrombosis and myocardial infarction. In large-sized platelets, the enzyme activity is increased, and adhesion and release potential as well as coagulability are also increased, resulting in particularly active involvement in thrombogenesis. This indicates that changes in the platelet count (PLT) and mean platelet volume (MPV) reflect the state of thrombogenesis. However, there have been only a relatively few reports on PLT and MPV in the elderly, although thrombosis frequently occurs in this population. Therefore, we measured platelet parameters in men without thrombotic diseases, hematological diseases, hepatic diseases, or malignant tumors, in order to determine changes in PLT and MPV in aged men and the effects of various factors (hypertension, hyperlipidemia, diabetes, obesity, and smoking/drinking) on these changes. A total of 2,061 men, aged 30-83 (264 cases in their 30s, 810 cases in their 40s, 742 cases in their 50s, 209 cases in their 60s, 32 cases in their 70s and 3 cases in their 80s), were used as subjects. In addition, 36 men aged 30-34 (mean age 32.6 +/- 1.2 years) and 35 men aged over 70 (mean age 73.0 +/- 3.5 years) were designated as the young and aged groups, respectively. Compared with the young group, the frequency of hypertension and that of diabetes were significantly higher or tended to be higher in the aged group, whereas the frequency of smoking tended to be smaller in the aged group.(ABSTRACT TRUNCATED AT 250 WORDS)