Serum YKL-40 Levels are Increased in Patients with Diabetes Mellitus and Coronary Artery Diseases: A Meta-analysis

Background: YKL-40 also named as chitinase-3-like protein 1 (CHI3L1) is a novel inflammatory biomarker found to be elevated in inflammatory and chronic diseases. This meta-analysis was done to estimate the pooled SMD of serum YKL-40 and evaluate its use as a diagnostic biomarker for Diabetes Mellitus (DM) and Coronary artery disease (CAD).

Methods: Through searching the following electronic databases: Google scholar, PubMed, Scopus among others, related articles were extracted in English language. Stata (Version 12.0) was used for statistical analysis. Newcastle–Ottawa Scale was used for quality assessment. Standard mean difference (SMD) and its corresponding 95% confidence interval (95% CI) were calculated. Heterogeneity was assessed by I2 statistic.

Results: Fourteen CAD studies with 1400 patients, 1685 controls and Thirteen DM studies with 1103 patients, 982 controls were selected for statistical analysis. The results showed that serum YKL-40 level in both CAD and DM patients was significantly higher than that in control subjects (SMD = 1.76 (95% CI 0.96-2.57) and (SMD=1.89 (95% CI 0.79-3.00) respectively. In both studies, stratified analysis showed that, studies which did not control for smoking had higher SMD compared to those controlled. Besides, CAD patients from developed countries had higher serum YKL-40 levels compared to those from developing countries.

Conclusion: This meta-analysis suggests that an elevated serum YKL-40 level may be used as a promising diagnostic tool for early identification of CAD and DM. However patients’ age, history of smoking, and comorbidities should be put into consideration.