AT A GLANCE

A new study published in Frontiers in Immunology concludes that the neutrophil percentage-to-albumin ratio independently predicts the risk of developing osteoporosis in rheumatoid arthritis.¹

“Osteoporosis (OP) frequently coexists with rheumatoid arthritis (RA), but validated predictors of early risk are not extensively studied,” explain study authors Zhang et al. “This study seeks to examine the relationship between the neutrophil percentage-to-albumin ratio (NPAR) and the likelihood of developing RA-related OP (RA-OP).”

As part of a clinical retrospective study enrolling 718 RA patients, the relationship between the NPAR and RA-OP was assessed; the authors then further validated the association using data from the National Health and Nutrition Examination Survey (NHANES) database (2005–2020 cycles). Enrolled patients were categorized into low-NPAR (<1.7598) and high-NPAR (≥1.7598) groups based on the median NPAR. Extracted clinical data of interest included demographic characteristics, comorbidities, serological markers, and other laboratory parameters.

During analysis, preliminary univariate and multivariate logistic regression was used to assess potential associations between NPAR and RA-OP, while multi-model adjusted logistic regression was subsequently applied to evaluate the independent association. In addition, subgroup analyses were conducted to examine consistency across demographic and clinical strata. Receiver operating characteristic (ROC) curve analysis was performed to assess NPAR's diagnostic performance, while restricted cubic splines were employed to visualize potential non-linear relationships. Finally, using the identical statistical framework, the authors validated findings within the NHANES cohort.

According to the authors, the high-NPAR group exhibited a significantly greater OP incidence than the low-NPAR group (39.0% vs. 26.5%). Even after full adjustment, NPAR remained independently associated with an increased RA-OP risk as a categorical variable.

They add that subgroup analyses revealed no significant interaction effects other than disease duration. The ROC curve showed an area under the curve (AUC) value of 0.58 and an NPAR cut-off of 1.886, while the covariate-adjusted RCS indicated a linear dose–response relationship. Finally, NHANES cohort analysis independently validated both the NPAR–RA-OP association and its linear characteristic.

“NPAR, serving as a novel composite biomarker integrating neutrophil-mediated inflammation and nutritional status (via albumin), independently predicts OP risk in RA. Its derivation from routine clinical parameters renders NPAR a readily deployable, cost-effective tool for OP risk stratification in clinical practice,” the authors conclude.

Reference

1.     Zhang Y, He Z, Li K, et al. Neutrophil-to-albumin ratio: a novel predictor of osteoporosis in rheumatoid arthritis (September 17, 2025). Front Immunol.