Correlation of an Emerging Inflammatory Marker Neutrophil Lymphocyte Ratio with Obesity Markers among Medical Students: A Cross-sectional Study

Introduction: Obesity contributes to chronic low-grade systemic inflammation and increases the risk of non-communicable diseases such as cardiovascular disease, diabetes, and hypertension. The Neutrophil-to-Lymphocyte Ratio (NLR) is a simple and accessible marker that reflects the balance between innate and adaptive immunity, thereby serving as an indicator of early systemic inflammation. Although elevated NLR has been associated with metabolic and cardiovascular disorders, limited evidence is available on its significance in healthy young adults, particularly among medical students. This highlights the need to explore its relationship with obesity markers in this population. Aim: To assess the relationship between obesity markers and NLR among first-year medical students. Materials and Methods: The present cross-sectional study was conducted at a rural medical college in southern India and included 202 first-year undergraduate medical students who provided written informed consent. Demographic details and medical history were recorded. Anthropometric measurements, including height, weight, and waist circumference, were taken using standardised methods. Body Mass Index (BMI) was calculated and classified according to World Health Organisation (WHO) Asian criteria. Venous blood samples were collected for complete blood count, and NLR was calculated by dividing the absolute neutrophil count by the lymphocyte count. Associations were analysed using Pearson correlation in GraphPad Prism version 10.60. Results: Mean NLR values increased across BMI categories: 1.98 in normal weight, 2.2 in overweight, and 2.5 in obese participants (p<0.0001). BMI showed a strong positive correlation with NLR (r=0.604, p<0.0001), while waist circumference also demonstrated a significant correlation (r=0.542, p<0.0001). Total leukocyte count did not differ significantly between BMI groups. Conclusion: NLR increases with rising BMI and waist circumference, indicating subclinical inflammatory changes in healthy young adults. Monitoring NLR may serve as a practical and early marker of systemic inflammation, helping to guide timely preventive interventions for at-risk young individuals. Screening for NLR in obese individuals can aid in the early identification of inflammatory risk.