Abstract: Objective To investigate the prevalence, severity and related factors of vascular calcification in maintenance peritoneal dialysis (PD) patients. Methods This cross-section study enrolled the PD patients at stable status and treated in Peking University People’s Hospital for more than 6 months. We used plain X-ray films of abdomen, pelvis and hands to quantitatively evaluate vascular calcification of large artery (abdominal aorta), medium arteries (iliac arteries, femoral arteries), and small arteries (radial arteries and digital arteries). Two radiologists blindly read and scored the vascular calcification. Demographic data, clinical characteristics, Charlson comorbidity index (CCI), baseline and time- averaged laboratory indexes including parameters of calcium phosphorus metabolism, serum albumin and PD adequacy were collected. The factors related to vascular calcification were analyzed by logistic regression. The factors relating to the degree of vascular calcification were analyzed by multiple linear regression method. Results ①A total of 154 PD patients (78 male patients, mean age 60.41±13.88 years, average PD duration 30.63±20.74 months) were enrolled in this study. The major primary disease was diabetic nephropathy (39%). ② A total of 111 patients (72.07%) were found to have vascular calcifications, including abdominal aorta calcification (83.78%), medium artery calcification (61.26%) and small artery calcification (35.13%). Moderate to severe degree of vascular calcifications were detected in 45.04% patients. ③ Logistic regression showed that diabetes (OR 12.982, 95% CI 3.258～51.722, P＜0.001), older age (OR 1.092, 95% CI 1.047～1.139, P＜0.001), longer dialysis duration (OR 1.049, 95% CI 1.017～1.081, P=0.002), and lower baseline intact parathyroid hormone (iPTH) (OR 0.996, 95% CI 0.992～0.999, P=0.010) were the independent risk factors for vascular calcification. (d) Compared to patients with mild calcification, patients with moderate to severe degree of calcification had higher proportion of diabetes (χ²=9.617, P=0.002), higher CCI ( t=- 4.575, P＜0.001) and higher baseline alkaline phosphatase (t=-2.018, P=0.047). Multiple linear regression results demonstrated that CCI (Β =0.258, P=0.003), gender (Β=1.136, P=0.042), and diabetes (Β=0.242, P=0.008) were the independent factors for calcification severity. Conclusions Vascular calcification is commonly present in maintenance PD patients. Vascular calcification in abdominal aorta is most frequently seen. It is more likely to occur in patients with diabetes, older age, male, longer dialysis duration, and lower baseline iPTH. In patients with vascular calcification, the degree of vascular calcification is severer in male patients and the patients with diabetes and more comorbidities.

Key words: Peritoneal dialysis, Vascular calcification, X-ray films, Abdominal aorta calcification