Evaluation of Complete Blood Count–Derived Inflammatory Markers as Predictors of Poor Glycemic Control in Patients with Type 2 Diabetes Mellitus: A Retrospective Study

Abstract

Background: Type 2 diabetes mellitus (T2DM) is accompanied by metabolic dysregulation and chronic low-grade inflammation. Routine complete blood count (CBC) parameters and derived inflammatory ratios may provide accessible complementary indicators of this inflammatory state. Methods: This retrospective study included 161 patients with T2DM attending the diabetes clinic at Al-Zahra General Hospital. Patients were classified as controlled (HbA1c <7%; n=69) or uncontrolled (HbA1c ≥7%; n=92). CBC and HbA1c obtained during the same visit were analyzed. NLR and MLR were calculated. Mann–Whitney U, two-way ANOVA, correlation, linear regression, logistic regression, and ROC analyses were performed. Results: WBC, neutrophils, lymphocytes, monocytes, NLR, and MLR were significantly higher in the uncontrolled group (all p<0.001). HbA1c correlated strongly with WBC (r=0.776) and neutrophils (r=0.769). Linear regression explained 66.1% of HbA1c variance, with WBC as the strongest independent predictor (β=1.463, p<0.001). Logistic regression identified WBC (OR=24.41; 95% CI 5.53–107.65) and NLR (OR=7.41; 95% CI 2.14–25.62) as independent predictors. AUCs were 0.884 for neutrophils, 0.873 for WBC, and 0.768 for NLR. Conclusion: Poor glycemic control was consistently associated with higher CBC-derived inflammatory markers. WBC, neutrophils, and NLR may provide useful complementary information, although prospective external validation is required.