Calcification but also risk stratification of patients by the changes in vascular calcification may be important for clinicians to manage dialysis patients. To date, a number of techniques are available to detect vascular calcification. Electron beam computed tomography (EBCT), multi-slice CT (MSCT), planar X-ray (such as plain X-ray of lateral abdomen, pelvis, and hands), 2D ultrasonography, and echocardiography have been used to assess vascular calcification [6,9,10,13,14,15,16,17]. Among these, EBCT and MSCT are well-validated noninvasive imaging methods that are considered the golden standard for quantifying vascular calcification. However, EBCT and MSCT cannot be routinely performed due to the relatively high cost of testing and exposure to a high radiation dose . Recently, aortic arch calcification (AoAC) in plain chest Xrays was found to reflect the magnitude of whole aortic calcification in general population and dialysis patients [15,16]. In addition, several previous studies showed that AoAC was an independent predictor of cardiovascular events and that AoAC progression was significantly associated with increased cardiovascular mortality in patients with ESRD [3,11,18,19]. However, since the majority of subjects included in most previous studies were ESRD patients on hemodialysis (HD), little is known about the prevalence, natural history, and prognostic value of vascular calcification in peritoneal dialysis (PD) patients. In the present study, we investigated the prevalence of AoAC at PD initiation and the frequencies of AoAC progression or regression during the first year after PD. The impact of AoAC progression on all-cause and cardiovascular mortality was also determined.tion procedure. Patients were weighed in light clothing and height 18055761 was measured with no shoes. Body mass index (BMI) was calculated as weight/height2 (kg/m2). Blood was drawn after a 12-hour overnight fasting, and the following laboratory data were measured from blood samples: hemoglobin, blood urea nitrogen, creatinine, calcium, phosphorus, albumin, total cholesterol, triglyceride, low density lipoprotein (LDL)-cholesterol, high density lipoprotein (HDL)-cholesterol, and intact parathyroid hormone (iPTH) concentrations. In addition, high sensitivity Creactive protein (hs-CRP) levels were determined by a latexenhanced immunoephelometric method using a BN II analyzer (Dade Behring, Newark, DE, USA). To reflect the actual situation, usual overnight dialysate volume and glucose concentrations were not changed for this study. Kt/V urea was determined from the total loss of urea nitrogen in spent dialysate using PD Adequest 2.0 for Windows software (Baxter Healthcare, Deerfield, Illinois, USA). The modified peritoneal equilibration test was performed with 4.25 glucose dialysis solution as described previously  and the dialysate-to-plasma creatinine (D/P Cr) and glucose (D/ D0 glucose) concentration ratios at 4 hours of dwell were used to describe the peritoneal transport characteristics; high, high average, low average, and low.Assessment of AoAC by Chest X-rayTo determine AoAC extent, two trained medical doctors blinded to the patients’ clinical data reviewed posterior-anterior plain chest X-rays taken at the start of PD using a specific scale developed by Ogawa et al . This scale, which divides the aortic arch into 16 sections by circumference, was attached to the aortic arch on chest X-rays and the number of sectors was divided by 16. AoAC score.