Evaluation of Neutrophil-to-Lymphocyte Ratio as a Predictive Marker of Glycemic Control in Patients with Type 2 Diabetes Mellitus

Introduction: Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease marked by sustained hyperglycaemia and a persistent, low-grade inflammatory state. The neutrophil-to-lymphocyte ratio (NLR), which can be readily derived from a routine complete blood count, has gained attention as a pragmatic marker of systemic inflammation and metabolic disturbance. This study evaluates the relationship between NLR and glycaemic control in individuals with T2DM.

Materials and Methods: This cross-sectional observational study was conducted in the Departments of General Medicine and Endocrinology at Satguru Partap Singh Hospital, Ludhiana, between May 2023 and July 2024. We enrolled 100 adults (≥18 years) with T2DM diagnosed per ADA criteria. For each participant, clinical and anthropometric data were obtained, and laboratory measurements included fasting and post-prandial plasma glucose, glycated haemoglobin (HbA1c), and a complete blood count. Participants were stratified as having good glycaemic control (HbA1c ≤7%) or poor control (HbA1c >7%). The neutrophil-to-lymphocyte ratio (NLR) was computed as absolute neutrophils divided by absolute lymphocytes. Statistical analyses included the independent t-test, Pearson correlation, and receiver operating characteristic (ROC) analysis.

Results: The cohort had a mean age of 52.1 ± 8.8 years, and 56% were female. Average HbA1c was 9.09 ± 2.55%, and the mean NLR was 2.19 ± 0.94. Overall, 81% of participants had poor glycaemic control. NLR was significantly higher in the poor-control group than in the good-control group (p < 0.05). NLR correlated positively with HbA1c (r = 0.34, p < 0.01). Receiver-operating characteristic analysis indicated moderate discriminative ability of NLR for poor control (AUC = 0.71).

Conclusion: An increased neutrophil-to-lymphocyte ratio is independently linked with higher HbA1c, indicating poorer glycaemic control in T2DM. As a simple, inexpensive, and non-invasive marker of systemic inflammation, NLR can complement HbA1c in routine diabetes monitoring, especially in resource-constrained settings.