Objective: We aimed to estimate the optimal cut-off values of liver stiffness measurement (LSM) for diagnosing and staging fibrosis in non-obese and obese patients with nonalcoholic fatty liver disease (NAFLD).
Methods: NAFLD patients diagnosed by liver biopsy according to the Nonalcoholic Steatohepatitis Clinical Research Network scoring system were enrolled in this study. Non-obesity was defined as a body mass index (BMI) less than 25 kg/m2 . LSM was performed by experienced physicians within 2 weeks before or after liver biopsy.
Results: A total of 158 patients were included. Average BMI of the non-obese (n = 68) and obese (n = 90) groups was 23.2 ± 1.6 and 27.9 ± 2.5 kg/m2 , respectively. After adjusted for age, fibrosis stage, steatosis grade and type 2 diabetes mellitus, the obese group had a LSM of 3.522 kPa higher than the non-obese patients (P = 0.003). LSM values of the non-obese patients had a lower trend when stratified by fibrosis stage, especially in cirrhosis (F4; P = 0.021). Applying separate cut-off values for patients with NAFLD in individual fibrosis stage, 5.8 vs 7.5 kPa (≥ F1), 7.6 vs 8.5 kPa (≥ F2), 9.1 vs 11.2 kPa (≥ F3), and 12.5 vs 14.3 kPa (F4), improved their diagnostic odds ratios compared with overall cut-off values. In the non-obese NAFLD group, using a separate cut-off avoided underestimating 9.1% of patients with cirrhosis.
Conclusions: Non-obese NAFLD group had lower LSM than the obese group. Different cut-off values should be used to measure liver fibrosis stage in non-obese and obese NAFLD patients.
Keywords: diagnostic performance; liver fibrosis; liver stiffness measurement; non-alcoholic fatty liver disease; obesity.
© 2020 Chinese Medical Association Shanghai Branch, Chinese Society of Gastroenterology, Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine and John Wiley & Sons Australia, Ltd.