Association between nutritional scores and multilevel vertebral involvement in tubercular spine: a retrospective cohort study.

Objective: The objective of this study is to evaluate the prognostic value of nutritional scores comprising the Controlling Nutritional Status (CONUT) score and the Prognostic Nutritional Index (PNI), in prediction of multilevel vertebral involvement (> 2 vertebra) in Spinal Tuberculosis (STB).

Methods: Retrospective analysis of 39 STB patients was conducted to assess nutritional indices (CONUT and PNI) and the numbers of vertebral affection. Spearman's correlation was used to examine the association between these variables. Receiver Operating Characteristic (ROC) curves were utilized to determine optimal cutoff values, with Area Under the Curve (AUROC) evaluation. Additionally, multiple logistic regression was performed as a predictive model.

Results: There were 24 males and 15 females, with a mean BMI of 18.88 kg/m² (± 1.37). Spearman's correlation analysis revealed negative correlations between BMI, PNI (rho - 0.68, p < 0.001) and multilevel vertebra involvement, while ESR (rho 0.83, p < 0.001), CRP (rho 0.81, p < 0.001), and CONUT score (rho 0.83, p < 0.001) positively correlated with multilevel vertebral affection (> 2 vertebra). Age and comorbidities showed no correlation with the level of vertebral affection. ROC analysis revealed a CONUT Score ≥ 3 cutoff (sensitivity-95.7%, specificity-87.5%) and PNI ≤ 38.605 (sensitivity-78.3%, specificity-93.8%) for predicting multilevel STB (> 2). PNI exhibited superior specificity and positive predictive value where as CONUT score was a better parameter for sensitivity, negative predictive value and diagnostic accuracy. Both CONUT score and PNI were significant predictors of vertebral involvement in univariate analysis, with multivariate analysis identifying CONUT score as the sole predictor of multilevel vertebral affection.

Conclusion: Nutritional scores, including CONUT score and PNI, emerged as significant predictors of multilevel STB. CONUT score displayed superior sensitivity, negative predictive value, and overall diagnostic accuracy, while PNI served as a nutritional marker with high specificity and positive predictive value in predicting multilevel involvement in spinal tuberculosis.