Association and discriminative value of serum inflammatory biomarkers for sarcopenic obesity: A retrospective cross‐sectional study

BACKGROUND: Sarcopenic obesity (SO) is a complex geriatric syndrome characterized by excess adiposity and impaired muscle function, in which chronic low-grade inflammation plays a key role. Serum-based inflammatory indices may provide accessible tools for identifying individuals at risk. This study investigated the association between SO and serum-based inflammatory indices and evaluated their discriminative performance. METHODS: This cross-sectional study included 156 older adults (≥65 years) with obesity, based on retrospectively collected medical records. SO was defined according to European Society for Clinical Nutrition and Metabolism/European Association for the Study of Obesity criteria. Body composition was assessed using bioelectrical impedance analysis. Serum-based inflammatory indices, including neutrophil-to-lymphocyte ratio (NLR), systemic immune-inflammation index (SII), pan-immune-inflammation value (PIV), monocyte-to-lymphocyte ratio, platelet-to-lymphocyte ratio, C-reactive protein-to-albumin ratio, and C-reactive protein-albumin-lymphocyte index, were calculated. Multivariable logistic regression analyses were performed, adjusting for age, sex, marital status, polypharmacy, and Clinical Frailty Scale. Receiver operating characteristic (ROC) analyses were conducted. RESULTS: The prevalence of SO was 28.8%. NLR, SII, and PIV were significantly higher in the SO group (all P < 0.05). In multivariable analyses, NLR (OR 2.56, 95% CI 1.14-5.76, P = 0.023), SII (OR 2.38; 95% CI 1.16-4.89, P = 0.018), and PIV (OR 1.96; 95% CI 1.10-3.48, P = 0.022) remained independently associated with SO. ROC analysis demonstrated modest discriminative ability, with AUC values of 0.643 for NLR, 0.628 for SII, and 0.633 for PIV. CONCLUSIONS: NLR, SII, and PIV are independently associated with SO; however, their discriminative performance is limited, suggesting they should be used as supportive rather than diagnostic markers.