YKL-40 level and telomere length as potential biomarkers of insomnia disorder—A Case-Control Study

Abstract

Abstract Objective To explore the correlation between YKL-40 level, telomere length and different insomnia subtypes of insomnia disorder.Methods One hundred and forty-five patients with insomnia disorder were enrolled and divided into 4 group according to the insomniac subtypes: difficulty initiating sleep (DIS), early morning awakening (EMA), difficulty maintaining sleep (DMS) and mixed symptoms(MS).At the same time, eighty healthy controls were collected. Peripheral leukocyte genomic DNA was extracted, the relative telomere length was detected by real-time quantitative polymerase chain reaction method, and the level of YKL-40 was detected by enzyme-linked immunosorbent assay.Logistic regression model was used to analyze the correlation between different insomnia subtypes and YKL-40 as well as telomere length.Results Individuals within the lowest tertile of telomere showed a higher risk for difficulty initiating sleep [odds ratio 2.13, 95%CI 1.22–3.63; P = 0.004], meanwhile had a higher presence of mixed symptoms(odds ratio 1.49, 95% CI 1.30–2.81; P = 0.006).Individuals within the highest tertile of YKL-40 showed a higher risk for early morning awakening [odds ratio2.98, 95% CI 1.54–5.33; P = 0.003], meanwhile had a higher presence of mixed symptoms(odds ratio 1.47, 95% CI 1.22–2.79; P = 0.007).Conclusion The telomere length in patients with difficulty initiating sleep and mixed symptoms was significantly shortened;The level of YKL-40 in patients with early morning awakening and mixed symptoms was significantly increased.Our data provided the first evidence that YKL-40 and leukocyte telomere is independently associated with mixed symptoms.