Non‐obese patients with nonalcoholic fatty liver disease may use a lower liver stiffness cut‐off to assess fibrosis stages

Abstract

Aims The diagnostic performance of liver stiffness measurement (LSM) is important to evaluate fibrosis stages in non‐alcoholic fatty liver disease (NAFLD) patients. However, whether LSM differs between non‐obese vs. obese NAFLD is unknown. Methods Patients diagnosed as NAFLD by liver biopsy according to NASH CRN scoring system were consequentially enrolled in this study. Non‐obese was defined as BMI less than 25 kg/m². LSM measurement was performed by experienced physicians within 2 weeks of liver biopsy. Results A total of 158 patients were included. The average BMI of non‐obese (n = 68) and obese (n = 90) patients was 23.2 ± 1.6 kg/m² and 27.9 ± 2.5 kg/m², respectively. After adjusting age, fibrosis stage, steatosis grade and diabetes, non‐obese patients had generally 3.5 kPa lower LSM than obese patients (P = 0.003). LSM values of non‐obese patients were evidently lower stratified by fibrosis stage, especially in cirrhosis patients (F4, P = 0.021). Applying separated cut‐off for non‐obese vs obese 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), diagnostic odds ratios (DORs) were improved than using overall cut‐off values. In non‐obese NAFLD, using separated cut‐off could avoid 9% cirrhosis patients being underestimated. Conclusions Non‐obese NAFLD patients had lower LSM values than obese patients. Different cut‐offs should be used in non‐obese and obese NAFLD patients.