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.