Pathophysiology and Natural HistoryC-reactive protein levels increase after exercise testing in patients with increased platelet reactivityGulmez, Oyku; Ertan, Cagatay; Yildirir, Aylin; Konas, Didem; Bal, Ugur; Aydinalp, Alp; Demir, Ozlem; Ozin, Bulent; Muderrisoglu, HaldunAuthor Information Department of Cardiology, Baskent University Faculty of Medicine, Ankara, Turkey Correspondence to Dr Oyku Gulmez, MD, Baskent Universitesi Istanbul Saglýk, Uygulama ve Arastýrma Merkezi Hastanesi, Kardiyoloji Anabilim Dalý, Oymacý sokak, No: 7, 34662, Altunizade, Ýstanbul, Turkey Tel: +90 216 5541500; fax: +90 216 6519858; e-mail: firstname.lastname@example.org Received 2 December 2006 Revised 28 March 2007 Accepted 29 April 2007 Coronary Artery Disease: September 2007 - Volume 18 - Issue 6 - p 437-442 doi: 10.1097/MCA.0b013e328258fe2a Buy Metrics Abstract Aspirin has the potential to influence C-reactive protein (CRP) levels, an inflammatory marker, by its anti-inflammatory activity. Persistently increased platelet reactivity, however, can be detected with different laboratory methods despite aspirin therapy in some patients. The aim of this study was to investigate the effects of increased platelet reactivity on CRP levels at rest and after exercise in patients with documented or suspected coronary artery disease. Blood samples were collected from 100 patients (age, 58.1±8.5 years; 63.0% men) who were treated with 100 or 300 mg/day enteric-coated aspirin for at least 7 days, before and immediately after treadmill test for CRP analyses. Platelet reactivity was measured by the standardized platelet function analyzer-100, and increased platelet reactivity was defined as a normal collagen/epinephrine closure time (<165 s). Of the 100 patients, 82 had normal platelet reactivity (group A) and 18 had increased platelet reactivity (group B). The CRP levels increase was statistically significant after exercise in patients with increased platelet reactivity [group A: 2.3 (1.4–4.3) to 2.8 (1.6–4.9) mg/l, P=0.09; group B: 3.3 (2.0–4.5) to 4.7 (2.9–8.5) mg/l, P=0.02]. Detecting increased platelet reactivity is associated with an increase in CRP levels. The clinical significance of this finding needs to be further investigated. © 2007 Lippincott Williams & Wilkins, Inc.