The concept of non-alcoholic fatty liver disease (NAFLD) is currently changing as it is no longer considered as an uncommon and benign condition.  It was observed that approximately, 70% type 2 diabetes mellitus (T2DM) patients have a fatty liver, which may progress into more aggressive form with necro-inflammation and fibrosis.

The current cross-sectional clinic-based study determined the profile of liver enzymes with impaired glucose tolerance (IGT), new onset treatment naive T2DM and normal glucose tolerance (NGT) in patients with and without NAFLD. The trial included 152 IGT and 158 recently detected T2DM patients, aged between 30 and 69 years. These patients were compared with 160 age and gender matched controls with NGT. All these patients underwent an ultrasonography scan of the upper abdomen to analyze presence of fatty liver. In addition, these patients were assessed for anthropometry, lipid profile and liver enzymes. Unpaired t-test, Chi-square/Fisher Exact, Pearson/Spearmen correlation test were used to determine remarkable difference, association and correlation between two or more groups, respectively.

The outcome showed that although NAFLD was remarkably correlated with higher alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT), it was not associated with ALP levels in IGT and T2DM patients. In addition, ALT, GGT was remarkably associated with waist circumference, body mass index, fasting insulin, homeostatic model assessment- insulin resistance, fasting blood glucose, high density lipoprotein cholesterol, and triglyceride. 57% of NAFLD patients reported with normal ALT between 25 and 40 U/L while 53% of NAFLD patients had normal GGT between 15 and 30 U/L. Moreover, ALT <25 U/L and GGT <15 U/L exhibited highest negative predictivity whereas ALT >40 U/L and GGT > 30 U/L had highest positive predictivity for presence of NAFLD.

The study concluded that even in patients with IGT and recently detected T2DM, mild elevations of liver enzymes in the upper normal range can be related to features of metabolic syndrome and NAFLD. Therefore, new cut-offs for liver enzymes are warranted to avert redundant diagnostic work-ups and for prompt diagnosis of NAFLD to lessen the risk of cirrhosis, hepatocellular carcinoma and cardiovascular disease in T2DM and IGT patients.

Source: Indian J Endocrinol Metab. 2015 Sep-Oct;19(5):597-601.