From the Guidelines

Yes, fatty liver disease can cause elevated ALT levels, as evidenced by the most recent study from 2023 1.

Fatty liver disease, including non-alcoholic fatty liver disease (NAFLD) and alcohol-induced fatty liver disease, is a common cause of mild increases in aminotransferases, including ALT.
The elevation of ALT in fatty liver disease is due to hepatocyte injury and the release of liver enzymes into the bloodstream.
The degree of ALT elevation typically correlates with the severity of liver inflammation, though some patients with significant fatty liver may have normal or only mildly elevated enzymes.
ALT levels in fatty liver disease are usually moderately elevated, typically less than 5 times the upper limit of normal.

Treatment focuses on addressing the underlying cause, such as weight loss, exercise, and dietary changes for NAFLD, or alcohol cessation for alcoholic fatty liver.
Persistent elevation of ALT may indicate ongoing liver damage and should be monitored by a healthcare provider to prevent progression to more severe conditions like cirrhosis.
As noted in a 2021 study 1, interventions that improve metabolic abnormalities in patients with diabetes, such as weight loss and glycemic control, are also beneficial for fatty liver disease.

Patients with type 2 diabetes or prediabetes and elevated liver enzymes (ALT) or fatty liver on ultrasound should be evaluated for the presence of nonalcoholic steatohepatitis and liver fibrosis.
Noninvasive tests, such as elastography or fibrosis biomarkers, may be used to assess the risk of fibrosis, but referral to a liver specialist and liver biopsy may be required for definitive diagnosis.

From the Research

Fatty liver, also known as non-alcoholic fatty liver disease (NAFLD), is a common hepatic manifestation of metabolic syndrome affecting 20-30% of the adult population worldwide 2.
The pathophysiology of NAFLD includes steatosis, inflammation, and fibrosis, which are exacerbated by dyslipidemia and insulin resistance 2.
Elevated alanine transaminase (ALT) levels are often associated with NAFLD, and statin treatment has been shown to reduce ALT values in interventional studies with a mean difference reduction of -27.2 U/L (95% CI -35.25/-19.15) and a percentage mean difference reduction of -35.41% (95% CI -44.78/-26.04) 3.

Statins have been considered potential interventions for NAFLD due to their pleiotropic effects beyond cholesterol-lowering, which affect pathways related to inflammation, fibrogenesis, oxidative stress, and microcirculation 2.
A systematic review and meta-analysis found that statin treatment reduced ALT, AST, and GGT levels in NAFLD patients, suggesting liver safety of statins in NAFLD patients 3.
However, another study found that intensive lowering of low-density lipoprotein-cholesterol (LDL-C) compared to low-intensity lowering was associated with an increased risk of NAFLD progression 4.

The association between statins and the development or progression of NAFLD in patients with diabetes is still unclear, with some studies suggesting no significant association 4.
A retrospective propensity score-matched cohort study found that statin use in patients with diabetes was not associated with decreased or increased risk of NAFLD progression 4.
Further studies are needed to demonstrate the efficacy of statins in liver disease and to establish their role in specifically reversing nonalcoholic steatohepatitis (NASH) 2, 5.