Background: Serum YKL-40 is an inflammatory biomarker associated with disease activity and mortality in diseases characterized by inflammation such as coronary artery disease (CAD). Exercise has a positive effect on CAD, possibly mediated by a decreased inflammatory activity. This study aimed to compare serial measurements of serum YKL-40 before and after exercise in patients with stable CAD versus controls.
Materials and methods: Eleven patients with stable CAD verified by coronary angiography (>70% stenosis) and 11 patients with a computer tomography angiography with no stenosis or calcification (calcium score=0) (controls) performed a standard clinical maximal exercise test. Serum YKL-40 was measured before exercise, immediately after exercise, and every hour for 6 h.
Results: Cardiovascular risk factors were more prevalent among the CAD patients compared with the controls. CAD patients had higher serum concentration of YKL-40 at baseline compared with controls, median (interquartile range) 94 (52–151) versus 57 (45–79) μg/l. Serum YKL-40 decreased stepwise after exercise, with a median decrease of 16 (13–39) μg/l for the CAD patients and 13 (10–22) μg/l for the controls from baseline to the lowest value. Thereafter, values increased again toward baseline level. Time after exercise was a significant factor for decrease in serum YKL-40 (P<0.0001), but no difference in YKL-40 decrease over time could be demonstrated between the groups (P=0.12).
Conclusion: Serum YKL-40 is elevated in patients with documented CAD compared with controls, and it decreases stepwise after exercise in both groups, indicating an anti-inflammatory effect of exercise independent of the presence of coronary atherosclerosis.
aDepartment of Cardiology, Copenhagen University Hospital Rigshospitalet
bDepartment of Cardiology, Copenhagen University Hospital Hillerød
Departments of cCardiology
dMedicine and Oncology, Copenhagen University Hospital Herlev
eDepartment of Cardiology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark
Correspondence to Naja Dam Mygind, MD, Department of Cardiology, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen Ø, Denmark Tel: +45 3545 1783; fax: +45 3545 2705; e-mail: firstname.lastname@example.org
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Received December 1, 2015
Accepted January 6, 2016