Correlation of Serum Alanine Aminotransferase Levels with Hepatic Fibrosis and Steatosis Score Assessed by FibroScan and Controlled Attenuation Parameter (CAP) in Patients with Nonalcoholic Fatty Liver Disease

Abstract

Background: Nonalcoholic fatty liver disease (NAFLD) is an increasingly prevalent cause of chronic liver disease worldwide, affecting approximately one-third of adults in Bangladesh. Serum alanine aminotransferase (ALT) is routinely used as a biochemical marker of hepatocellular injury; however, its ability to accurately reflect the severity of hepatic steatosis and fibrosis remains uncertain. FibroScan-derived liver stiffness measurement (LSM) and controlled attenuation parameter (CAP) offer noninvasive approaches for assessing hepatic fibrosis and steatosis, respectively, and may provide more direct measures of disease severity.

Objective: This study aimed to determine the correlation between serum ALT levels and hepatic fibrosis and steatosis severity measured by FibroScan and CAP in patients with NAFLD.

Methods: This observational study included 97 patients with ultrasonographic evidence of fatty liver disease who attended the Hepatology outpatient department of MH Samorita Hospital and Medical College, Dhaka, Bangladesh between April 2026 to June 2026. The mean age was 40.6 ± 11.3 years, and 52.6% were female. Liver FibroScan with CAP was performed after at least four hours of fasting. Fibrosis was staged according to METAVIR criteria, while steatosis was assessed using CAP. Serum ALT was categorized as normal (≤40 U/L) or elevated (>40 U/L). Spearman rank correlation and Mann-Whitney U tests were used for statistical analysis.

Results: Using an upper normal limit of 40 U/L for ALT, 39 patients (40.2%) had normal ALT levels, while 58 (59.8%) had elevated levels. Common comorbidities included diabetes mellitus (54.7%), hypertriglyceridemia (60.4%), and hypertension (38.0%). The mean liver stiffness measurement was 6.48 ± 3.16 kPa, with the majority of patients (86.6%) classified as having F0-F1 fibrosis. Fibrosis stages F2, F3, and F4 were observed in 2.1%, 5.2%, and 6.2% of patients, respectively. The mean controlled attenuation parameter (CAP) was 302.2 ± 39.5 dB/m. Severe steatosis (S3) was present in 49.5% of patients, while significant steatosis (S2-S3) was identified in 83.5%. The correlation between ALT levels and liver stiffness was weak and did not reach statistical significance (Spearman’s r = 0.191, p = 0.061).

Conclusion: In this cohort of patients with NAFLD, serum ALT levels showed only a weak correlation with the severity of hepatic fibrosis, suggesting that ALT alone may not accurately reflect the extent of fibrotic changes. In contrast, FibroScan and CAP may provide more objective and reliable noninvasive methods for evaluating hepatic fibrosis and steatosis in patients with NAFLD.