Abstract: 【Abstract】Objective To investigate the association between serum chitinase-3-like protein 1(CHI3L1) and vascular calcification in peritoneal dialysis (PD) patients of different genders. Methods In this cross-sectional study, a total of 116 patients with chronic renal failure treated with PD over 6 months were recruited. Lateral plain X-ray films of abdomen were used to evaluate the abdominal aortic calcification (AAC) score according to the Kauppila scoring system. Patients were divided into the low AAC score group (AAC score＜4) and the high AAC score group (AAC score≥4). Demographic data and laboratory measurements were collected. Bioelectrical impedance analysis was applied to examine the body composition of these PD patients. Serum CHI3L1 was measured by enzyme-linked immunosorbent assay. Results Fifty- six males and 60 females were recruited. The mean age was 57.0±13.7 years and 61 patients (52.6%) had an AAC score≥4. Serum CHI3L1 of the female patients was significantly higher than that of the male patients (Z=− 3.435，P=0.001). Among male patients, there was a trend that serum CHI3L1 of the high AAC score group was higher than that of the low AAC score group, but the result was not significant (285.9±100.3ng/ml versus. 238.4±106.8ng/ml，t=−1.701,P=0.095). Among female patients, serum CHI3L1 of the high AAC score group was significantly higher than that of the low AAC score group [437.7(314.2,459.2) ng/ml versus. 273.4 (177.6,368.6)ng/ml，Z=−3.600，P＜0.001]. Serum CHI3L1 was positively correlated with the AAC score in the female patients (r=0.590, P＜0.001), but not in the male patients (r=0.194, P=0.155). Multivariate logistic regression analysis showed that serum CHI3L1 (OR=1.012, 95% CI 1.005～1.019, P=0.001) and serum phosphate (＞1.45mmol/L or not) (OR=5.596, 95%CI 1 .345～23.278, P=0.018) were independent related factors of high AAC score (AAC score ≥4) in the female patients. However, age (OR=1.138, 95% CI 1.026～1.262, P=
0.014), diastolic blood pressure (OR=0.927, 95%CI 0.861～0.997, P=0.042), serum high-sensitivity C-reactive protein (OR=1.169, 95%CI 1.003～1.361, P=0.046), and skeletal muscle mass (OR=0.829, 95% CI 0.696～0.987, P=0.035) were the independent related factors of high AAC score (AAC score ≥4) in the male patients. Conclusions There are gender differences in the correlation between serum CHI3L1 and AAC among PD patients. Higher serumCHI3L1 is an independent marker of AAC score in female but not male PD patients.

Key words: chitinase-3-like protein 1, Peritoneal dialysis, Vascular calcification, Body composition