CHI3L1 and Alzheimer disease: Compared to NC, YKL-40 was also increased in AD patients (386 ± 221 pg/mL, p < 0.001) but not in VaD (323 ± 96 pg/mL, p > 0.05) and DLB/PDD cases (314 ± 103 pg/mL, p > 0.05).