Metabolic Profile of Lean/Non Obese NAFLD (Non Alcoholic Fatty Liver Disease) Subjects

Introduction: Non Alcoholic Fatty Liver Disease (NAFLD) in the absence of overweight and obesity has been defined as ‘lean NAFLD’. Metabolic syndrome associated diseases in low and middle income countries have variable phenotypes and clinical outcomes. Hypothetically, ‘Lean NAFLD’ can be a part of the spectrum of classical obesity related NAFLD or separate entity with different pathophysiology. Aim: 1) To characterise the NAFLD in lean/non obese subjects; 2) To explore how it differs from classical ‘obese phenotype’ of the NAFLD; 3) To explore how these lean/non obese subjects with NAFLD are different from healthy lean/non obese subjects in terms of metabolic profile. Materials and Methods: The present study was a cross- sectional observational study conducted over a period of six months. Forty subjects were categorised into four groups (1. Lean NAFLD without Diabetes; 2. Lean NAFLD with Diabetes; 3. Obese NAFLD with Diabetes; 4. Lean healthy subjects). Clinical history, examination, anthropometry, biochemical data including insulin resistance by Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) were analysed. Results: Mean Body Mass Index (BMI), Fasting Blood Glucose (FBG) and HbA1c (Glycated haemoglobin) of group 2 and group 3 were significantly higher than that of group 1 and group 4 subjects (p<0.001). Mean HOMA-IR of the patients of group 2 and group 3 were significantly higher than that of group 1 and group 4 (p<0.001). No significant difference was seen in HOMA- IR between patients of group 1 and group 4 (p>0.05) and also of group 2 and group 3 subjects (p>0.05). Conclusion: Lean NAFLD subjects have a different metabolic profile than overweight-obese patients with NAFLD, particularly in relation to diabetes. On the basis of all metabolic parameters and insulin resistance, authors propose a spectrum of insulin resistance ‘Non obese Control - Non obese NAFLD without Diabetes Mellitus (DM) - Non obese NAFLD with DM - Obese NAFLD with DM’.