Comprehensive Evaluation of Non-Standard Inflammatory and Metabolic Indices in Obesity: A Single-Center Retrospective Study.

Background: Obesity is a major public health concern that predisposes individuals to metabolic and cardiovascular complications through chronic inflammation. This study aimed to evaluate the associations between non-standard inflammatory and metabolic indices [Systemic immune-inflammation index (SII), neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), monocyte/lymphocyte ratio (MLR), C-reactive protein/albumin ratio (CRP/Alb), Fibrosis-4 (FIB-4), triglyceride/high-density lipoprotein (TG/HDL), and triglyceride/glucose (TG/Glucose)] and clinical variables in individuals with obesity. Methods: This single-center retrospective study included 298 adults with varying body mass index (BMI) categories followed at Recep Tayyip Erdoğan University Training and Research Hospital between February 2023 and February 2024. Demographic, clinical, and laboratory data were collected. Hematological (leukocyte, neutrophil, lymphocyte, monocyte, and platelet) and biochemical [glucose, triglyceride, HDL, albumin, CRP, aspartate aminotransferase (AST), and alanine aminotransferase (ALT)] parameters were analyzed, and derived indices (CRP/Alb, TG/Glucose, FIB-4, and SII) were calculated. Statistical analyses were performed using SPSS 25.0, and p < 0.05 was considered significant. Results: The mean age was 38.9 ± 11.5 years, and 54% were female. A positive correlation was found between BMI and CRP/Alb (r = 0.145, p = 0.012), whereas age showed a positive correlation with FIB-4 (r = 0.409, p < 0.001) and a negative correlation with SII (r = -0.117, p = 0.044). FIB-4 and SII were negatively correlated (r = -0.294, p < 0.001). TG/HDL and TG/Glucose were higher in men, whereas PLR was higher in women (p < 0.05). CRP/Alb was elevated in diabetes, and FIB-4 was higher in hypertension and hyperlipidemia. Conclusions: Non-invasive inflammatory and metabolic indices were significantly associated with obesity-related parameters. FIB-4, CRP/Alb, and TG/HDL may serve as complementary indicators of metabolic and fibrotic burden, reflecting the inflammatory-metabolic profile of individuals with obesity.