Platelet activation and secretion in patients with major depression, thoracic aortic atherosclerosis, or renal dialysis treatment

Relatively little is known concerning the magnitude of alterations of platelet activation and secretion markers of patients with major depression when compared to patients at increased risk for, or with current, clinically significant atherosclerosis. Markers of in vivo platelet stimulation and secretion were measured under basal conditions in normal comparison subjects (n = 12) and three patient groups: patients diagnosed with DSM-IV major depression (n = 15), dialysis-dependent patients (n = 12), and patients with severe thoracic aortic atherosclerosis (n = 10). In comparison to normal comparison subjects, depressed patients and patients with thoracic aortic atherosclerosis exhibited the greatest platelet stimulation as detected by increased anti-LIBS platelet binding. Dialysis-dependent patients exhibited the highest plasma concentrations of the renally-excreted platelet-specific secretion protein, beta-thromboglobulin. This study extends previous observations of increased platelet activation in patients with major depression and documents similar alterations in patients with transesophageal echocardiography (TEE)-documented thoracic aortic atherosclerosis. Future studies will determine whether the magnitude of platelet stimulation and secretion in patients with comorbid depression and atherosclerotic aortic disease is greater than that observed in nondepressed patients with atherosclerotic aortic disease or major depression alone. These findings provide further evidence for either increased platelet activation and/or intrinsic heightened platelet reactivity as one of the biological substrates underlying the increased risk of depressed patients for cardiovascular disease.