Lean Versus Obese Nonalcoholic Fatty Liver Disease (NAFLD): Comparative Analysis of Lipid Profiles

Abstract

Non-alcoholic fatty liver disease (NAFLD) has become a major global health concern, closely associated with obesity, insulin resistance, and dyslipidemia. However, the occurrence of NAFLD in non-obese individuals, referred to as lean NAFLD, remains poorly understood, particularly regarding lipid metabolism and biochemical alterations. Therefore, this study aimed to compare lipid profiles, liver enzyme levels, and biochemical parameters between lean and obese NAFLD patients to clarify potential metabolic differences contributing to disease pathogenesis and progression. A cross-sectional study was conducted on 95 NAFLD patients diagnosed by ultrasound and paraclinical evaluations in Kurdistan provinces between 2021 and 2024. Participants were categorized as lean (BMI <25 kg/m²) or obese (BMI ≥30 kg/m²). Serum lipid profiles (TC, TG, HDL, LDL) and liver enzymes (AST, ALT) were analyzed using a BT3500 autoanalyzer. Statistical analysis was performed using SPSS version 22, with Mann–Whitney U, Chi-square, and Spearman correlation tests applied where appropriate. No significant difference was observed in gender distribution between groups (P=0.115). LDL levels were significantly higher in obese patients compared to lean counterparts (P=0.046), while triglycerides and HDL showed no statistical differences. BMI demonstrated significant positive correlations with liver fat grade (r=0.205, P=0.025), total cholesterol (r=0.212, P=0.02), and LDL levels (r=0.229, P=0.012). Liver enzyme levels were elevated in both groups without significant intergroup variation. Dyslipidemia was observed in both lean and obese NAFLD patients, with higher LDL levels detected among obese individuals. These findings suggest that metabolic alterations may occur across different NAFLD phenotypes and are not limited to obesity status. Further studies with larger samples and comprehensive analytical adjustments are needed to clarify the clinical implications of these observations.