Gastrointestinal-related uremic toxins in peritoneal dialysis: a pilot study with a 5-year follow-up.
OBJECTIVE
P-cresyl sulfate (PCS) and indoxyl sulfate (IS) were not only novel but essential factors associated with cardiovascular disease and mortality in patients with chronic kidney disease and hemodialysis. However, little evidence exams the effect in peritoneal dialysis (PD) patients.


METHODS
This pilot study recruited 46 stable PD patients in a single medical center. Serum levels of IS, PCS and biochemistry were measured concurrently. Clinical outcomes including cardiovascular, all-cause mortality and PD failure event were recorded during a 5-year follow-up.


RESULTS
Serum levels of free and total PCS were lower in patients with residual renal function (11.67 ± 6.92, p = 0.014, 0.77 ± 0.48, p = 0.046, respectively). Multivariate Cox regression analysis showed age (HR: 1.07, p = 0.01), serum CO2 (HR: 0.67, p = 0.02) and total PCS (HR: 1.05, p <0.01) were independently associated with cardiovascular events; only free PCS (HR: 1.42, p <0.01) reached significant correlation with all-cause mortality. Total IS (HR: 1.27, p = 0.03) significantly correlated with PD failure event after adjusting other confounding factors. Kaplan-Meier analysis revealed that patients with higher total and free PCS levels had higher cardiovascular events (log rank p <0.01, log rank p = 0.05, respectively) and mortality event (log rank p = 0.02, log rank p = 0.03, respectively) than those with lower levels. In addition, total IS (log rank p = 0.04), total PCS (log rank p = 0.01) and free PCS (log rank p <0.01) could independently predict PD failure event during the study period.


CONCLUSIONS
Our findings suggest PCS and IS may be a valuable surrogate in predicting poor clinical outcomes in PD patients.
Division of Nephrology, Department of Internal Medicine, Mackay Memorial Hospital, Taipei, Taiwan; Mackay Medicine, Nursing and Management College, Taipei, Taiwan; Institute of Biotechnology, National Taipei University of Technology, Taipei, Taiwan.
Cheng-jui
CJ
Lin
Chi-feng
CF
Pan
Chih-kuang
CK
Chuang
Hsuan-liang
HL
Liu
Fang-ju
FJ
Sun
Tuen-jen
TJ
Wang
Han-hsiang
HH
Chen
Chih-jen
CJ
Wu
D000328:Adult; D002318:Cardiovascular Diseases / Q000209:etiology / Q000401:mortality*; D003408:Cresols / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007200:Indican / Q000097:blood*; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis / Q000009:adverse effects*; D010865:Pilot Projects; D011379:Prognosis; D013463:Sulfuric Acid Esters / Q000097:blood*
D003408:Cresols; D013463:Sulfuric Acid Esters; C408690:4-cresol sulfate; D007200:Indican
Indoxyl sulfate; Peritoneal dialysis; Protein-bound uremic toxin; p-Cresyl sulfate