Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder characterized by insulin resistance and hyperglycemia. Emerging evidence suggests that variations in white blood cell (WBC) counts among individuals with T2DM may provide insights into the inflammatory and immune responses associated with the disease. This study aims to investigate WBC count variations in T2DM and their relationship with glycemic control and other clinical parameters.

A cross-sectional study was conducted at Colombo Medi Lab, Bambalapitiya, Sri Lanka, involving 321 participants categorized into pre-diabetic (FBS:100–125 mg/dl, Postprandial Blood Glucose: 140-199mg/dl; HbA1c: 5.7-6.4%) and diabetes (FBS>126 mg/dl; Postprandial Blood Glucose: >200mg/dl; HbA1c: ≥6.5%) groups. WBC counts and demographic data were collected, and statistical analyses were performed using Microsoft Excel and SPSS 20.0, with a significance threshold of p < 0.05.

Among the 321 participants, 171 were T2DM patients (30 pre-DM, 113 females, 58 males), while 150 were healthy individuals (95 females, 55 males). Significant differences (p < 0.05) were observed between the DM, pre-DM, and control groups in WBC count, neutrophil count, lymphocyte count, N/L ratio, MID count, and FBS.

WBC, lymphocyte, and MID counts showed a significant (p < 0.001) positive correlation with age, whereas neutrophil count, N/L ratio, and FBS showed a negative correlation. The N/L ratio and MID count positively correlated with gender, while WBC, lymphocyte count, and FBS were negatively correlated. WBC count, neutrophil count, N/L ratio, and FBS correlated positively with BMI, whereas lymphocyte and MID counts were negatively correlated.

This study highlights WBC count variations as potential biomarkers for monitoring T2DM progression. Future research should focus on longitudinal and interventional studies to explore causal relationships and clinical applications in diabetes management.