Exploring the hemoglobin-to-red blood cell distribution width ratio (HRR) to clinical complications of KD nexus:a retrospective cohort study

Background Kawasaki disease (KD) is a childhood systemic vasculitis whose etiology remains unknown. The Hemoglobin-to-Red cell distribution width Ratio (HRR) is an emerging inflammatory marker, but its relationship with KD complications is not well established. Purpose This study categorized patients according to the presence or absence of Coronary Artery Lesions (CALs), liver function impairment, pulmonary complications, aseptic meningitis, and other complications to investigate the relationship between HRR and the incidence of complications in Kawasaki disease. Methods A retrospective cohort study was conducted on KD patients from 2005 to 2023. Patients were grouped by the presence of complications (CALs, hepatic damage, etc.). The relationship between HRR and CALs was analyzed using logistic regression and Restricted Cubic Splines, adjusting for covariates. Results This study demonstrated that elevated HRR levels correlated with a reduced incidence of CALs. In our fully adjusted model, the odds ratios for coronary artery damage in the second, third, and fourth quartiles of HRR, compared to the first quartile, were 0.819, 0.464, and 0.476. For every unit increase in HRR, the probability of CALs diminished by 52.4%. The linear regression model indicated that the threshold effect established when HRR was 7.07×10 ^− 1 . To the right of this breakpoint, a negative connection existed between HRR and CALs (OR = 0.654, 95% CI: (0.545, 0.784), P  < 0.001). Furthermore, during investigations into HRR and other complications associated with KD, we identified significant differences in the univariate analysis between individuals with and without liver damage, pulmonary complications, digestive system problems, and concomitant aseptic meningitis ( P < 0.05 ). Nonetheless, in the Multivariate Logistic Regression, we were unable to identify HRR as a predictor for these complications. Conclusion HRR demonstrates a t inverse relationship with CALs, suggesting a protective role and potential as an auxiliary indicator. However, it is not robust enough to serve as an independent predictor for CALs or other KD complications in clinical practice.