Abstract: Objective The purpose of this study was to compare the metabolic characteristics and liver steatosis in non-obese and obese patients with nonalcoholic fatty liver diseases (NAFLD). Methods 274 patients with NAFLD were recruited in our hospital between January 2015 and June 2021, and were divided into non-obese (n=66) and obese (n=208) groups based on basic mass index equal to 25 kg/m². The liver fat content (LFC) and abdominal subcutaneous fat thickness (ASFT) were obtained by MR scan. The controlled attenuation parameter (CAP) was detected by FibroTouch check-up and the carotid intima-media thickness (CIMT) was assessed by ultrasonography. Results In patients with non-obese NAFLD, the BMI was (23.4±1.4)kg/m², serum alanine aminotransferase level was 24.2(19.6,35.8)U/L, aspartate aminotransferase level was 25.0(18.7, 32.3)U/L, triglyceride level was (1.9±0.4)mmol/L, high-density lipoprotein cholesterol level was (1.3±0.4)mmol/L, fasting blood glucose level was (5.0±0.7)mmol/L, fasting insulin level was 7.0(4.8, 9.4)μU/mL, the HOMA-IR was 1.6(1.1, 2.3) and uric acid level was 376.5(294.3, 430.5)μmol/L, significantly different as compared to [(28.6±3.0)kg/m², 88.4(55.4, 160.5)U/L, 71.5(64.4, 141.6)U/L, (2.8±0.6)mmol/L, (1.1±0.3)mmol/L, (5.8±0.8)mmol/L, 10.4(7.7, 14.2)μU/mL, 2.5(1.8, 3.4) and 442.3(346.4, 484.5)μmol/L, respectively, P<0.05] in obese patients; the LFC was 8.2(6.2, 13.4)%, the ASFT was 为(19.2±5.7)mm, the CAP was (233.2±40.5)dB/m and the CIMT was 0.6(0.6, 0.7)mm, significantly different compared to [14.6(10.0, 18.6)%, (24.6±8.2) mm, (284.6±46.0) dB/m and 0.8(0.6, 0.9)mm, respectively, P<0.05] in obese patients; the incidence of liver steatosis grade Ⅰ was 43.9%, significantly higher than 26.0%, while the incidence of liver steatosis grade Ⅲ was 22.7%, significantly lower than 40.4%(P<0.05) in obese patients. Conclusion The metabolic disorders and liver steatosis in non-obese patients with NAFLD are mild, and how to monitor them is really a challenge in clinical practice.

Key words: Nonalcoholic fatty liver disease, Liver steatosis, Liver fat content, Abdominal subcutaneous fat thickness, Controlled attenuation parameter, Carotid intima-media thickness, Non-obese