Spontaneous platelet aggregation and coagulation parameters as risk factors for arterial occlusions in diabetics. Results of the PARD-study.

PARD is a prospective study sponsored by the German Research Council with the aim to establish whether spontaneously enhanced platelet aggregation or changes of other hemostatic parameters are risk factors for new vascular occlusions in diabetic patients. 363 diabetic patients (aged 45-65, 232 men, 131 women) were observed for 5 years. Of the 232 men, 53 were on diet, 104 on oral antidiabetic drugs and 75 on insulin. Of 131 women 16 were on diet, 46 on oral antidiabetic drugs and 69 on insulin. At entry clinical examination and laboratory tests were performed, covering the known risk factors for cardiovascular complications. Hemostatic tests and clinical examination were performed at 3 months' intervals. The life status was followed for all patients. Endpoints were carefully defined. Until December 31, 1984, 42 patients died, 23 from cardiovascular disease and 19 from other causes. 13 patients suffered a myocardial infarction, 10 a stroke and 53 peripheral arterial occlusions. The occurrence of new vascular occlusions was significantly higher in those men with enhanced spontaneous platelet aggregation measured by PAT III angle alpha above 40 degrees at entry as compared to those with lower values. This was not the case for women. Other hemostatic parameters, which had also some relation to cardiovascular complications, in men were fibrinogen and F. VIII R:Ag. Established risk factors for which a significant relation to cardiovascular complications was observed in this study, were smoking, duration of diabetes, diastolic blood pressure, cholesterol, triglycerides and also HbA1. The results of the PARD-study have verified the hypothesis that spontaneous aggregation is a major risk factor for future vascular occlusions in diabetic men. They also lead to the hypothesis that high levels of F. VIII R:Ag and fibrinogen are further indicators of progressive vascular disease and may be useful as predictors of new vascular occlusions in combination with such established risk factors as smoking, duration of diabetes, diastolic blood pressure, cholesterol, and triglycerides.