BACKGROUND: Research confirms that inflammatory responses play a significant role in the pathogenesis of type 2 diabetes mellitus (T2DM). However, existing studies primarily rely on single or traditional inflammatory markers. The diagnostic value of emerging composite inflammatory markers, such as the platelet-lymphocyte ratio (PLR), lymphocyte-monocyte ratio (LMR), and others, remains unclear in Chinese populations aged ≥40 years. This study aims to investigate the association between these novel inflammatory markers and T2DM in this age group. This study aims to investigate the association between these novel inflammatory markers and T2DM in Chinese adults aged 40 years and older. METHODS: Data were obtained from the Health Examination Center of the First Affiliated Hospital of Wannan Medical College in Wuhu City, China. Nine inflammatory markers were derived from complete blood counts. Multivariate logistic regression models were employed to assess the association between inflammatory markers and T2DM. Subgroup analyses were conducted to validate the robustness of the findings. RESULTS: Among 194,348 participants (31,951 with T2DM, 162,397 controls), individuals with T2DM exhibited significantly elevated levels of MHR, NLR, SII, SIRI, AISI, and TyG (p < 0.001 for all), while PLR and PNR exhibited inverse associations (p < 0.001). In fully adjusted models, the highest tertile versus lowest tertile showed ORs of 7.20 (95% CI: 6.92-7.50) for TyG, 1.71 (1.64-1.79) for AISI, and 0.62 (0.60-0.65) for PNR. LMR showed no linear trend after full adjustment (p for trend = 0.301). Medication data were incomplete, precluding assessment of whether anti-inflammatory drug use (statins, aspirin) influenced these associations. Subgroup analyses revealed effect modification by age, sex, BMI, and hypertension for PLR, PNR, and TyG indices (p for interaction < 0.05). CONCLUSIONS: Elevated inflammatory markers in patients with T2DM are associated with prevalent diabetes in this cross-sectional analysis. The temporal relationship between inflammation and T2DM development cannot be determined from this study design. These readily available inflammatory markers may hold value for diabetes risk assessment.
