Inflammation-related indices and low physical performance in older adults with unintentional weight loss: a cross-sectional study

Sarcopenia is characterized by age-related loss of muscle mass and function and is associated with chronic low-grade inflammation (inflammaging). Novel inflammation- based indices – including the Uric acid to HDL-cholesterol ratio (UHR), Monocyte to HDL ratio (MHR), Triglyceride to HDL ratio (THR), C-reactive protein (CRP) to albumin ratio (CAR), CRP to HDL ratio (CHR), and Systemic immune-inflammation index (SII) – have emerged as markers of inflammaging. This study investigated the relationship between these inflammatory parameters and Low Physical Performance (LPP) in older adults. 490 patients aged 65 years and older who applied to the geriatric medicine outpatient clinic of a university hospital with complaints of weight loss were evaluated retrospectively cross-sectionally (2022–2023). LPP was assessed by SARC-F questionnaire, handgrip strength test (HGST), and the 5 times-sit-to-stand-test (STST), and patients were grouped into Low Physical Performance (LPP, n = 259) or Normal Physical Performance (NPP, n = 231) based on these criteria. UHR, MHR, THR, CAR, CHR, and SII were calculated from laboratory values. Group differences in demographics, comorbidities, geriatric assessment scores, and these inflammatory markers were analyzed. The correlations between new inflammatory markers and standard inflammatory indicators (CRP, neutrophil) were evaluated. Receiver operating characteristic (ROC) analysis determined the ability of each parameter to discriminate LPP. The LPP group was older than NPP (median 76 vs 71 years, p<0.001) and had a higher prevalence of atrial fibrillation (p=0.002) and dementia (p<0.001), while other comorbidities were similar between groups. All inflammatory indices were elevated in the LPP group: median UHR 0.11 vs 0.09, MHR (higher in LPP), CAR 1.37 vs 1.02, CHR 0.13 vs 0.07 and SII 623.5 vs 479.5 (all p<0.001), and THR was slightly higher (2.19 vs 2.15, p=0.012). Serum uric acid, monocyte count and CRP levels were higher in LPP than in NPP group, while albumin and HDL levels were lower (all p<0.01). UHR, CAR, MHR and SII correlated with one another and with CRP and neutrophils (p<0.001 for all). In ROC analysis, UHR showed a modest discriminative ability for identifying individuals with low physical performance (AUC 0.638, 95% CI 0.586–0.690), demonstrating a moderate ability to discriminate participants with low physical performance at a cutoff value of 0.1204 (sensitivity 44%, specificity 83%). CAR and SII demonstrated similar modest performance (AUC 0.602 and 0.626, respectively), while THR had a weaker association (AUC 0.566). UHR performed best with 83% specificity, while CAR and SII performed best with 71% sensitivity but AUC values indicate only modest discrimination. In multivariate logistic regression analyses adjusting for confounding factors, the UHR, SII, CAR, and CHR remained independently associated with physical performance status (all p<0.05). Older adults with low physical performance show higher UHR, MHR, THR, CAR, CHR and SII levels, reflecting an increased inflammatory state. Among these indices, UHR, CAR, and SII demonstrated modest discriminative ability, with UHR showing higher specificity and CAR/SII showing higher sensitivity; however, their modest AUC values indicate limited standalone clinical utility, and thus these indices should be considered supportive rather than independent screening tools for identifying older adults at risk for sarcopenia. Prospective studies with long-term outcomes are needed to confirm the predictive validity of these studies and to determine whether interventions targeting modifiable components (such as serum uric acid, HDL, CRP, albumin, and complete blood count parameters) can positively influence sarcopenia progression and functional decline.