**Serum** *P***-Cresyl Sulfate Is a Predictor of Central Arterial Sti** ff**ness in Patients on Maintenance Hemodialysis**

### **Yu-Hsien Lai 1,2, Chih-Hsien Wang 1,2, Chiu-Huang Kuo 1,2, Yu-Li Lin 1,2, Jen-Pi Tsai 1,3,\* and Bang-Gee Hsu 1,2,\***


Received: 30 October 2019; Accepted: 19 December 2019; Published: 21 December 2019

**Abstract:** Arterial sti ffness (AS) has an important impact on the outcomes of patients on hemodialysis (HD), and *p*-cresyl sulfate (PC) can mediate the process of vascular damage. We aimed to investigate the relationship between carotid–femoral pulse wave velocity (cfPWV) and the level of PCs in HD patients. Serum PCs were quantified using liquid chromatography mass spectrometry. Patients who were on standard HD for more than 3 months were enrolled and categorized according to the cfPWV into the high AS (>10 m/s) and control (≤10 m/s) groups. Forty-nine (41.5%) patients belonged to the high AS group and had a higher incidence of diabetes mellitus (DM) and increased systolic blood pressure, serum C-reactive protein, and PC levels but had lower creatinine, compared with those in the control group. In HD patients, the risk for developing high AS increased in the presence of DM (OR 4.147, 95% confidence interval (CI) 1.497–11.491) and high PCs (OR 1.067, 95% CI 1.002–1.136). Having DM (r = 0.446) and high PC level (r = 0.174) were positively associated with cfPWV. The most optimal cuto ff value of PC for predicting AS was 18.99 mg/<sup>L</sup> (area under the curve 0.661, 95% CI 0.568–0.746). We concluded that DM and PCs were promising predictors of high AS in patients on maintenance HD.

**Keywords:** arterial sti ffness; carotid–femoral pulse wave velocity; hemodialysis; *p*-cresyl sulfate

**Key Contribution:** Serum PC level was positively associated with cfPWV and was a risk factor for developing AS in HD patients.
