Measurement of β-thromboglobulin in the elderly. Findings from the Rotterdam study

Objective: The platelet specific protein, β-thromboglobulin has been suggested to be a sensitive marker of in vivo platelet activation. The aim of the present study was to evaluate β-thromboglobulin levels in an elderly population and to determine to which extent β-thromboglobulin levels are associated with blood sampling procedures. Methods: This report presents baseline findings on β-thromboglobulin of the first 2,831 participants of the Rotterdam Study, a population based prospective cohort study among persons aged 55 years and over. Nonfasting blood samples were taken at varying times during the day. β-Thromboglobulin was assayed by an ELISA method. Applied stasis and quality of blood flow during sampling were registered on three grade scales. Results: The overall mean level of β-thromboglobulin was 69.2 (SD 75.5) IU/ml (range 6-612 IU/ml). In women and to a lesser extent in men, β-thromboglobulin was positively associated with age. According to increasing stasis applied during sampling mean β-thromboglobulin levels were 65.3 (SE 2.31), 74.1 (3.18), 77.6 (8.66) IU/ml. Mean β-thromboglobulin in three grades of decreasing quality of blood flow were 69.0 (1.73), 104.0 (11.5), 86.0 (23.7) IU/ml. Mean levels of β-thromboglobulin differed slightly, but significantly between the 14 laboratory technicians who collected the blood. Conclusion: In elderly women and to a lesser extent in elderly men, β-thromboglobulin is positively associated with age. A wide range in β-thromboglobulin is found in elderly subjects which is determined to a limited extent by quality of blood sampling.