Higher Platelet Count Mostly in the Normal Range Is Associated with the First Episode of Peritonitis Risk in Incident Peritoneal Dialysis Patients

Abstract

Introduction: Platelets play parts in infection and immune processes. However, the association between platelet count and the risk of peritoneal dialysis (PD)-associated peritonitis is unclear. Methods: This was a retrospective, observational, single-center cohort study. A Cox regression analysis was used to evaluate the independent association of platelet count with the occurrence of first PD-associated peritonitis. Models were adjusted for gender, age, body mass index, cardiovascular disease, diabetes mellitus, white blood cell count, neutrophil-lymphocyte ratio, hemoglobin level, albumin level, potassium level, and anti-platelet medication usage. Results: A total of 2,374 patients were enrolled in this study (59% men; mean age 47.40 ± 12.12). The average platelet count was 229.30 ± 82.12 × 109/L. 467 (20%) patients suffered from PD-associated peritonitis at least once. In the multivariable model, the adjusted hazard ratios (HRs) for quartiles 2, 3 and 4 versus quartile 1 were 1.428 (95% CI 1.060–1.924, p = 0.019), 1.663 (95% CI 1.240–2.229, p < 0.001) and 1.843 (95% CI 1.363–2.492, p < 0.001) with baseline data. A nonlinear relationship between platelet count and first PD-associated peritonitis was observed. Further, the association between platelet and first PD-associated peritonitis was significant in the patients with hypokalemia (P for interaction = 0.040). Conclusion: In PD patients, elevated platelet counts were significantly associated with an increased risk of the first onset of PD-associated peritonitis.