Neutrophil-to-Lymphocyte Ratio (NLR): A Predictor of Microvascular Complications in Type 2 Diabetes Mellitus

Introduction Diabetes is a major public health challenge in India, and simple, low-cost tools are needed to detect early microvascular complications. We explored whether the neutrophil-to-lymphocyte ratio (NLR) can help predict such complications in people with type 2 diabetes. Methods We conducted a cross-sectional study in 2022-23, enrolling 150 patients aged 40-80 years with type 2 diabetes. Each participant underwent a detailed clinical evaluation, including blood sugar, HbA1c, NLR, and screening for diabetic neuropathy, nephropathy, and retinopathy. Results The mean age of participants was 58.9 ± 9.3 years. Comorbidities were present in 84% of participants (n=126), mainly dyslipidaemia (n=102, 68%) and hypertension (n=86, 57.3%). Almost half of the patients (n=73, 48.6%) had neuropathy, 42.6% (n=64) had nephropathy, and about one-quarter (n=39, 26%) had retinopathy. The mean NLR was higher in patients with microvascular complications than in those without (p < 0.001). The NLR correlated strongly with neuropathy (r = 0.72, p < 0.001) and moderately with nephropathy (r = 0.39, p < 0.001) and retinopathy (p < 0.001). A higher NLR was also associated with poor glycaemic control (HbA1c) (r = 0.41, p < 0.001) and central obesity (waist-to-hip ratio) (r = 0.31, p < 0.001). NLR showed high prediction for neuropathy (cut-off = 1.75, AUC = 0.926, sensitivity 93.2%, specificity 74%) and retinopathy (cut-off = 2.15, AUC = 0.942, sensitivity 94.9%, specificity 78.4%), but not for nephropathy. Conclusion Although the NLR correlated significantly with all microvascular complications in T2DM, it showed strong predictive ability only for neuropathy and retinopathy. Thus, it may serve as a cost-effective marker for predicting microvascular complications.