Sex-Specific Associations of Monocyte-Based Inflammatory Indices with Renal Dysfunction and Hyperuricemia in the Saudi General Adult Population

Background/Objectives: Chronic kidney disease (CKD) is a major global health burden and is closely linked to persistent low-grade inflammation. Monocyte-based inflammatory indices, including the monocyte-to-high-density lipoprotein cholesterol ratio (MHR), monocyte-to-lymphocyte ratio (MLR), and monocyte-to-neutrophil ratio (MNR), have been associated with various metabolic and inflammatory disorders; however, their relationships with renal dysfunction and hyperuricemia remain insufficiently explored. This study examined the associations of these indices with renal dysfunction and hyperuricemia in the Saudi general population, with particular emphasis on sex-specific differences. Materials and Methods: This retrospective cross-sectional study included 9657 Saudi adults. Estimated glomerular filtration rate (eGFR) was calculated using the 2021 CKD-EPI creatinine equation. Associations of MHR, MLR, and MNR with reduced eGFR and hyperuricemia were examined using sex-stratified comparisons, correlation, risk assessment, receiver operating characteristic analysis, and regression modeling. Results: MHR was the strongest and most consistent marker associated with renal dysfunction. In females, reduced eGFR was associated with higher MHR and MLR, whereas in males it was associated with lower MHR, MLR, and MNR, indicating clear sex-specific divergence. Elevated MHR was associated with higher odds of reduced eGFR in females but lower odds in males. MHR also showed the strongest association with hyperuricemia in both sexes and remained independently inversely associated with eGFR. Conclusions: MHR showed the most consistent overall association with renal dysfunction and hyperuricemia among the evaluated indices. These findings suggest that MHR may provide a simple and accessible marker for sex-informed renal and metabolic risk assessment in the general population.