The inflammatory biomarker YKL‐40 at admission is a strong predictor of overall mortality

• Published in: Journal of internal medicine Vol. 273; no. 2; pp. 205 - 216
• Main Authors: Mygind, N. D., Iversen, K., Køber, L., Goetze, J. P., Nielsen, H., Boesgaard, S., Bay, M., Johansen, J. S., Nielsen, O. W., Kirk, V., Kastrup, J.
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell 01.02.2013
• Subjects: Adipokines - blood; Adult; Aged; Aged, 80 and over; Biological and medical sciences; biomarker; Biomarkers - blood; Chitinase-3-Like Protein 1; CRP; Denmark - epidemiology; Epidemiology; Female; General aspects; Hospitalization; Humans; inflammation; Lectins - blood; Male; Medical sciences; Middle Aged; Mortality; Predictive Value of Tests; Public health. Hygiene; Public health. Hygiene-occupational medicine; YKL‐40; CRP; YKL40 protein; Mortality; Prediction; Biological marker; Biological indicator; Inflammation; YKL-40; biomarker; Epidemiology; Medicine; Secretory protein; Predictive factor; C reactive protein
• ISSN: 0954-6820; 1365-2796; 1365-2796
• DOI: 10.1111/joim.12006

Objectives YKL‐40 is an inflammatory biomarker associated with disease activity and mortality in patients with diseases characterized by inflammation and tissue remodelling. The aim of this study was to describe the prognostic value of YKL‐40 in an unselected patient population. Design In consecutive patients admitted to hospital during a 1‐year period, blood was collected and information regarding final diagnosis and mortality was collected. Median follow‐up time was 11.5 years. Setting District hospital, Copenhagen, Denmark. Patients A total of 1407 patients >40 years of age were admitted acutely. Main outcome measure All‐cause mortality. Results Median YKL‐40 was increased in patients (157 μg L−1, range 13–7704 μg L−1) compared to healthy controls (40 μg L−1, range 29–58 μg L−1; P < 0.001). Patients with YKL‐40 in the highest quartile had a hazard ratio (HR) of 7.1 [95% confidence interval (CI) 4.2–12.0] for all‐cause mortality in the first year and 3.4 (95% CI 2.8–4.2) in the total study period, compared to those in the lowest quartile (HR = 1). The HR for death for all patients with YKL‐40 above the normal age‐corrected 95th percentile was 2.1 (95% CI 1.6–2.7) after 1 year and 1.5 (95% CI 1.3–1.7) during the total study period, compared to patients with YKL‐40 below the age‐corrected 95th percentile. The results of multivariable analysis showed that YKL‐40 was an independent biomarker of mortality; this was most significant in the first year. YKL‐40 was a marker of prognosis in all disease categories. The HR for death was increased in patients with YKL‐40 above the normal age‐corrected 95th percentile in healthy subjects independent of type of disease (all P < 0.001). Conclusion The level of YKL‐40 at admission is a strong predictor of overall mortality, independent of diagnosis and could be useful as a biomarker in the acute evaluation of all patients.