Association between CBC-derived inflammatory biomarkers and mortality in osteoarthritis patients: Results from NHANES

The predictive value of inflammatory markers derived from complete blood cell count remains unexplored fully in osteoarthritis (OA) outcomes. This investigation examined the relationship between complete blood cell count-derived inflammatory indices and all-cause and cardio-cerebrovascular disease (CCD) mortality, in a representative adult population with OA. The study encompassed 4763 OA patients from the National Health and Nutrition Examination Survey database (1999-2018), with mortality tracking through the National Death Index until December 31, 2019. We employed multiple analytical approaches, including Kaplan-Meier analyses and Cox proportional hazards modeling, to evaluate mortality associations with various inflammatory markers: neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio, systemic immune-inflammation index (SII), systemic inflammation response index, and aggregate index of systemic inflammation. In order to make the data more in line with a normal distribution, we performed natural logarithmic transformation. The investigation incorporated restricted cubic spline analysis for dose-response assessment, while random survival forest methodology and receiver operating characteristic curves evaluated biomarker predictive capability. Over a median follow-up period of 84 months, a total of 1284 deaths were recorded, of which 431 were attributable to CCD. When log-transformed inflammatory markers were incorporated into the model as continuous variables, their increases were significantly associated with higher all-cause and CCD mortality (all P-values <.05). Random survival forest modeling and receiver operating characteristic analysis identified MLR as the most robust predictor of mortality outcomes. Sensitivity analyses confirmed the robustness of these findings. Some inflammatory markers, including NLR, MLR, SII, systemic inflammation response index, and aggregate index of systemic inflammation, exhibited strong associations with increased all-cause and CCD mortality risk among OA patients. Certain biomarkers, such as NLR, MLR, platelet-to-lymphocyte ratio, and SII, demonstrated nonlinear relationships with all-cause mortality. MLR showed the greatest predictive capacity for mortality.