Association of Neutrophil-Lymphocyte Ratio with Glucose Intolerance: An Indicator of Systemic Inflammation in Patients with Type 2 Diabetes

Background: The neutrophil-lymphocyte ratio (NLR) has been demonstrated to be a better risk factor than total white blood cell count in the prediction of adverse outcomes in various medical conditions. This study analyzed the association of NLR with different grades of glucose tolerance and insulin resistance in Asian Indians. Subjects and Methods: Study subjects were recruited from Phase 3 of the Chennai Urban Rural Epidemiology Study (CURES). For this cross-sectional analysis, subjects with normal glucose tolerance (NGT) (n = 237), impaired glucose tolerance (IGT) (n = 63), and type 2 diabetes mellitus (DM) (n = 286) were selected. The hemogram was done in all subjects using a five-part hematology analyzer (model SF-3000; Sysmex, Kobe, Japan). The NLR was calculated as the ratio between counts for neutrophils and total lymphocytes. Fasting insulin was measured by enzyme-linked immunosorbent assay, and insulin resistance was calculated using the homeostasis model assessment (HOMA-IR). Results: Subjects with DM showed a significantly higher NLR (2.2 +/- 1.12) compared with IGT subjects (1.82 +/- 0.63), who in turn had a higher ratio than NGT subjects (1.5 +/- 0.41) (P < 0.01). Pearson correlation analysis showed a significant positive correlation of NLR with glycated hemoglobin (r = 0.411), fasting plasma glucose (r = 0.378), and HOMA-IR (r = 0.233) (P < 0.001). Regression analysis showed a linear increase in NLR with increasing severity of glucose intolerance even after adjusting for age, waist circumference, blood pressure, triglycerides, and smoking. Conclusions: This is the first report on the correlation of NLR with different grades of glucose intolerance and insulin resistance. NLR can be used as an adjuvant prognostic marker for macro- and microvascular complications in patients with glucose intolerance.