Correlation of insulin resistance with dyslipidemia and liver enzymes in lean non-alcoholic fatty liver disease: A case–control study in a tertiary care hospital

Background: Non-alcoholic fatty liver disease (NAFLD) is a widespread hepatic condition with excessive fat accumulation in the liver without alcohol consumption. Conventionally, NAFLD is linked with obesity, although lean individuals can also develop it with significant metabolic changes. Aims and Objectives: The purpose of our study is to investigate the correlation between insulin resistance (IR), dyslipidemia, and liver enzyme levels in lean NAFLD patients compared to age/sex-matched healthy controls. Materials and Methods: The current case–control study was conducted at a tertiary care hospital, comprising lean NAFLD patients (body mass index [BMI] <23 kg/m2) and age and sex-matched healthy controls. Fasting blood sugar (FBS) and homeostatic model assessment of IR (HOMA-IR) were used to assess the IR. Lipid profiles: Total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-c), and low-density lipoprotein cholesterol (LDL-c) were determined as per standard assay protocol. Other parametric analyses done were liver enzymes: Alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and gamma-glutamyl transferase (GGT). Statistical analyses were performed to determine the significance of differences between groups. Results: Lean NAFLD group showed elevated FBS, serum insulin, and HOMA-IR levels compared to obese NAFLD patients and healthy controls with a significant statistical disparity. The lean NAFLD patients had significantly lower waist circumference and systolic blood pressure when compared to obese NAFLD patients, indicating that the visceral adipose tissues of lean NAFLD may be metabolically more active conferring metabolic risk to NAFLD. No statistically significant correlation was documented between HOMA-IR and HDL-C, LDL-C, ALT, AST, and GGT. Conclusion: This study reveals significant metabolic and biochemical disparity among lean NAFLD, obese NAFLD, and control group. Lean NAFLD patients exhibit pronounced IR, despite having lower BMI as compared to obese. Moreover, lean NAFLD patients show substantial liver dysfunction, marked by higher levels of ALT, AST, and GGT.