Abstract
Background/Objectives: The psoas: lumbar vertebral index (PLVI) is a simple and convenient measure to assess central sarcopenia. Recent studies have utilized the psoas area to indirectly assess sarcopenia and frailty, exploring their associations with various health outcomes. This study aims to investigate the relationship between the PLVI and postherpetic neuralgia (PHN) in patients aged 60 years and above following a herpes zoster (HZ) infection. Methods: We conducted a retrospective analysis of data from 351 patients (≥60 years) who developed HZ between January 2019 and December 2023; the patients were divided into two groups based on the presence or absence of PHN after HZ onset. Results: The analyses using receiver operating characteristic curves revealed a value for the area under the curve of 0.813 for PLVI and 0.769 for the modified frailty index (mFI). In a multivariate logistic regression analysis, numerical rating scale scoring, a low PLVI, and a greater number of categorical mFI variables (adjusted odds ratio: 1.30, 3.27, and 2.46, respectively) were found to be significant independent predictors of PHN. Conclusions: Our findings highlight the association between a low PLVI and PHN in an older population. The PLVI may have potential as a predictive tool for PHN in older patients with HZ, but further research is needed to confirm these results.