Lean non-alcoholic fatty liver disease and associated metabolic disturbance: A Saudi Arabian cross-sectional study

Non-alcoholic liver disease (NAFLD) is a metabolic liver disease associated with visceral adiposity and insulin resistance. Recently, NAFLD has been described in lean individuals who additionally have impaired metabolic parameters similar to their non-lean counterparts. We aimed to explore this further in Saudi Arabia. From 2016 to 2019, we prospectively studied a group of newly diagnosed NAFLD patients at a tertiary hospital in Saudi Arabia. Patients were classified into three groups: lean (body mass index [BMI] <25), overweight (BMI ≥25 and <30), and obese (BMI ≥30). We made comparisons between these groups on basic clinical, demographic, and laboratory parameters. In total, 1753 patients were recruited and 1262 patients met the inclusion criteria. Altogether, 159 (12.6%), 365 (29%), and 737 (58.4%) patients were in the lean, overweight, and obese categories, respectively. Lean NAFLD patients were, on average, younger than those in the overweight group (mean 49.95 ± 15.3) and had a significantly higher high-density lipoprotein value (HDL) (mean 52.56 ± 16.27). Sex, hyperlipidemia, type 2 diabetes, and hypertension were significantly associated with BMI. Lean NAFLD patients displayed the features of metabolic syndrome including elevated glycosylated hemoglobin and abnormal lipid profile but had higher serum HDL. This is in contrast to the widely held belief that lean individuals have no dysmetabolic changes compared to overweight individuals. Recognition of this problem is essential so that lean NAFLD patients can be screened for metabolic changes and managed appropriately to prevent complications.