Correlation of neutrophil-to-lymphocyte ratio and monocyte-to-high-density lipoprotein cholesterol ratio with carotid atherosclerosis in postmenopausal patients with type 2 diabetes mellitus

Abstract Background The neutrophil-to-lymphocyte ratio (NLR) and monocyte-to-high-density lipoprotein cholesterol ratio (MHR) are emerging inflammatory markers closely associated with chronic inflammatory disorders, including cardiovascular and cerebrovascular diseases and diabetes mellitus (DM). Postmenopausal women with type 2 diabetes mellitus (T2DM) face a synergistically elevated cardiovascular risk due to the combined effects of estrogen deficiency-related vascular dysfunction and chronic hyperglycemia-induced inflammatory activation. However, whether these readily accessible inflammatory indices can effectively identify carotid atherosclerosis (CAS) in this high-risk subpopulation remains unclear. This study aimed to investigate the association between NLR, MHR, and the presence of carotid atherosclerosis (CAS) in postmenopausal patients with T2DM. Methods A single-center retrospective cross-sectional observational study was conducted on 370 postmenopausal patients with T2DM who were hospitalized at Beijing Anzhen Nanchong Hospital of Capital Medical University & Nanchong Central Hospital from May 2024 to September 2025. According to carotid duplex ultrasound findings, patients were divided into a CAS group (n = 205) and a control group with normal carotid arteries (n = 165). General clinical data were collected, fasting venous blood samples were analyzed for complete blood count and biochemical parameters, and NLR and MHR were calculated. Patients were stratified into four subgroups based on NLR quartiles for intergroup comparisons. Logistic regression analysis identified factors associated with the presence of CAS, and receiver operating characteristic (ROC) curve analysis evaluated the discriminative value of various indicators. Results Compared with the control group, the CAS group exhibited significantly higher levels of age, body weight, red cell distribution width-coefficient of variation (RDW-CV), NLR, glycated hemoglobin (HbA1c), MHR, and urinary protein positivity rate, whereas total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels were significantly lower (all P < 0.05). With the increase in NLR quartiles, age, body weight, HbA1c, TC, CRP, and MHR showed statistically significant differences across quartiles (all P < 0.05). Logistic regression analysis demonstrated that age, weight, NLR, HbA1c, and MHR were associated with the presence of CAS in postmenopausal patients with T2DM after adjustment for the available covariates (all P < 0.05). ROC curve analysis indicated that the AUC values of NLR, MHR, the combination of NLR and MHR (derived from logistic regression model-fitted probability estimates), age, body weight, and HbA1c for identifying CAS were 0.775, 0.702, 0.798, 0.616, 0.625, and 0.713, respectively, with corresponding sensitivities of 75.6%, 80.0%, 81.5%, 75.6%, 60.0%, and 84.9%. DeLong’s test showed that the combined model did not significantly outperform NLR alone ( P = 0.078), but significantly outperformed MHR alone ( P = 0.001); NLR significantly outperformed MHR alone ( P = 0.046). Conclusion NLR and MHR were associated with prevalent CAS in postmenopausal patients with T2DM and showed moderate discrimination within the study sample. The combined model had a numerically higher AUC than either marker alone; however, it did not significantly outperform NLR alone (DeLong’s test, P = 0.078), although it significantly outperformed MHR alone ( P = 0.001). These findings support NLR and MHR as exploratory biomarkers rather than established clinical risk-stratification tools; prospective external validation, calibration assessment, and evaluation of clinical net benefit are required.