Association of the DeRitis ratio with insulin resistance in non-obese adults ‒ a cross-sectional study from South India

Introduction and aim. Beyond overt obesity, insulin resistance (IR) is increasingly recognized in non-obese individuals, particularly South Asians. Liver enzymes, especially aspartate aminotransferase (AST) and alanine aminotransferase (ALT), and their ratio (DeRitis) have emerged as potential surrogate markers of metabolic dysfunction. To the best of our knowledge, this is the first study to evaluate the DeRitis ratio as a surrogate marker of IR specifically in non-obese South Indian adults, addressing an important evidence gap. With this background, the aim was to estimate the IR prevalence in non-obese adults by homeostasis model assessment of IR (HOMA-IR) and to assess the correlation and diagnostic performance of the DeRitis ratio. Material and methods. This cross-sectional study included 100 non-obese adults (body mass index (BMI) <25kg/m²) selected using a convenience sampling technique attending a tertiary care hospital in Pondicherry, India. Data collected by structured proforma and biochemical assays of fasting plasma glucose, fasting insulin, and liver enzymes. HOMA-IR ≥2.5 as confirmed IR. The correlation and diagnostic accuracy of the DeRitis ratio for predicting IR was analyzed using SPSS software (V_25.0); p<0.05 considered statistically significant. Results. IR (HOMA-IR 2.5) was present in 13% of participants. Overweight individuals showed significantly higher fasting insulin levels and HOMA-IR values compared to adults with normal BMI. The DeRitis ratio was positively correlated with HOMA-IR (r=0.516, p<0.001). Using the cut-off AST/ALT >1.0, the ratio demonstrated good discriminatory ability for IR (AUC=0.778), with 82.5% sensitivity and 83.3% specificity. Conclusion. The DeRitis ratio shows moderate discrimination for IR and may aid in screening where insulin assays are limited. Validation in larger, multicenter cohorts is warranted.