The nonlinear association between red blood cell distribution width (RDW) and bortezomib-related peripheral neurotoxicity (PN): A retrospective cohort study

BACKGROUND: Previous evidence on the association of red blood cell distribution width (RDW) with bortezomib-induced peripheral neuropathy (BIPN) is limited. As a result, in this single-center retrospective cohort analysis, the link between RDW and BIPN was investigated. METHODS: This study4 comprised 376 patients with primary multiple myeloma (MM) who attended the Department of Haematology at Guizhou Provincial People's Hospital between 2013 and 2021. RDW and the occurrence of BIPN were the exposure and outcome variables, respectively. Demographic characteristics, pharmacological agents, co-morbidities, and MM-related indicators were all included as covariates. To investigate the relationship between RDW and BIPN, binary logistic regression and two-piecewise linear regression were utilized. RESULTS: The relationship between RDW and BIPN was found to be non-linear. RDW was not significantly associated with the risk of BIPN (odds ratio (OR): 0.99; 95% confidence interval (CI): 0.95 to 1.02; p-value: 0.4810) to the left of the inflection point (RDW = 72.3); to the right of the inflection point, each 1 ft increase in RDW was associated with an 7% increase in the risk of BIPN (OR: 1.07; 95% CI: 1.01 to 1.15; p-value: 0.046). CONCLUSION: The relationship between RDW and the risk of BIPN demonstrated a threshold effect, with RDW exceeding 72.3 fl, indicating a relatively significant risk of BIPN.