Clinical utility of liver function tests for resolution of metabolic dysfunction-associated steatotic liver disease after weight loss in the Diabetes Remission Clinical Trial

Aims: Ectopic fat is reduced by effective weight management, but difficult to assess clinically.

Methods: We evaluated paired data on 42 participants in the intervention group of the Diabetes Remission Clinical Trial (DiRECT) at baseline, 12 and 24 months after weight loss as indicators of liver fat content measured by 3-point Dixon MRI.

Results: Baseline liver fat was elevated at 13.0 [7.8-23.3]% with fasting plasma glucose 7.9 [7.1-10.1] mmol/L. Prevalence of baseline MASLD was 86.4%. After weight loss of 11.9 ± 1.2 kg (0-37 kg) at 12 months, remission of MASLD occurred in 74% and liver fat normalised for many (1.8 [1.2-5.2]%; p < 0.0001) as did fasting glucose (5.9 [5.5-7.2] mmol/L; p < 0.0001). Alanine aminotransferase (ALT) and gamma glutamyl transferase (GGT) decreased at 12 months by 38 [19-60]% (p < 0·0001) and 38 [16-53]% (p < 0.0001) respectively. The positive predictive value for decrease in liver fat, with baseline values of >40 IU/L, was 100% for ALT and 87.5% for GGT. As expected, change in liver fat correlated with change in ALT (r = 0.64; p < 0.0001), GGT (r = 0.38; p = 0.013), AST (r = 0.36; p = 0.018), fatty liver index (r = 0.50; p < 0.0001) and hepatic steatosis index (r = 0.44; p < 0.0001).

Conclusion: Metabolic dysfunction-associated steatotic liver disease, an important marker of ill-health is improved by intentional weight loss. If enzyme levels are raised at baseline, following weight loss, changes in ALT and GGT usefully reflect change in liver fat content, with high positive predictive value. Monitoring liver enzymes can provide a simple way to assess change in liver fat following weight loss in day-to-day clinical practice.