Association between monocyte/HDL cholesterol ratio and air pollution in a highly polluted region: A disease-specific analysis

The monocyte/HDL cholesterol ratio (MHR) is increasingly recognized as a potential marker of inflammation, oxidative stress, and endothelial dysfunction, despite the lack of standardized reference values. This study investigates the association between air pollution and MHR and its relationship with chronic diseases. A retrospective cohort study was conducted with 600 patients admitted to Igdir State Hospital. Patients were grouped by Particulate Matter 10 (PM10) exposure levels (≥50 μg/m³ vs <50 μg/m³). Laboratory data and disease diagnoses were recorded and analyzed. MHR was significantly higher in patients with atherosclerotic cardiovascular disease (ASCVD) (p<0.003) and lower in patients with diabetes mellitus (DM) (p<0.003) on days with PM10≥50 μg/m³. Similar trends were observed on low-pollution days (PM10<50 μg/m³), with a significant positive association between MHR and ASCVD (p<0.012) and cerebrovascular accident (CVA) (p<0.027). A significant correlation was also found between MHR and HbA1c levels (p<0.001). MHR is positively associated with cardiovascular risk and may serve as a low-cost, accessible marker of inflammation in clinical practice.