Serial Platelet Survival Half-Life (PS) In Peripheral Vascular Disease And Diabetes Mellitus

Abstract

Mayo Clinic, Mayo Foundation, Rochester, MinnesotaPlatelets are believed to play an important role in the pathogenesis of atherosclerosis and thrombotic occlusive arterial disease. As part of a prospective study of peripheral occlusive arterial disease in diabetes mellitus, platelet survival half-life (PS) was determined in years 1 and 2 from the disappearance pattern of 51cr-labeled platelets obtained by measuring radioactivity in serial samples over 8 days in four groups of patients age 50-70. Using computer assisted least-square analysis, a single exponent is fitted to the data and half-life determined.Groups included (1) normal subjects (NC); (2) subjects with clinical and objective evidence (transcutaneous doppler ultrasound and treadmill exercise) of peripheral arterial occlusive disease (AS0); (3) subjects with diabetes mellitus without AS0 (DM); (A) subjects with both diabetes mellitus and AS0 (DM+AS0). 112 subjects were tested in year 1 and 75 of these were available for retesting in year 2.In year 1, there is a difference in the distribution of platelet survival (PS) for the four groups (p=.002). PS is significantly short in groups AS0 and DM+AS0 compared with controls (NC), Year 2 values for PS (75 subjects) were compared to year 1. Using the t test on mean differences PS for each group was not significantly different year 2 vs year 1; mean percent differences year 2 vs year 1 were 1.2% (NC), 0.2% (ASO), 3.2% (DM), and -9.3% (9-3% lower than year 1 for DM+ ASO).Platelet survival half-life (PS) does distinguish popula tion groups and is reproducible when repeated.