Association between Asia–Pacific body mass index classification and serum liver enzymes: alanine aminotransferase, aspartate aminotransferase and gamma-glutamyl transferase in healthy individuals

Abstract

Abstract Background Elevated levels of serum liver transaminases are good indicators of liver cell damage, and elevated serum gamma-glutamyl transferase (GGT) level is a good indicator of both bile duct and hepatocellular damage. At early stages, elevated serum levels of these liver enzymes can be mostly prevailed as an asymptomatic condition and therefore in an undiagnosed state. This may be resulted in a number of complications and may lead to chronic hepatic damage that will be more severe and difficult to care. Serum liver enzyme levels are affected by age, gender, body mass index (BMI), ethnicity, drugs and viruses. Obesity has been an epidemic in nearly every country in the world. BMI is the best parameter to assess the magnitude of obesity. Having this background, the present study was designed to investigate the correlation between the levels of serum liver enzymes alanine aminotransferase (ALT), aspartate aminotransferase (AST) and GGT and Asia–Pacific cut-off points of BMI in healthy individuals. Methods A descriptive cross-sectional study was conducted using 120 Sinhala, Buddhist subjects which belonged to 18–32 years. BMI was calculated according to the standard protocol. The serum ALT and AST concentrations were measured by UV assay according to the IFCC method without pyridoxal phosphate activation, and the serum GGT concentration was measured by UV assay according to Szasz method, using the Mindray BS-240 Full Automatic Biochemistry Analyser. Results Serum levels of liver enzymes were significantly higher in males than females. In females, serum levels of ALT (r = 0.312, p < 0.001), AST (r = 0.138, p = 0.071) and GGT (r = 0.212, p = 0.047) positively correlated with BMI. In males too, serum levels of ALT (r = 0.431, p < 0.001), AST (r = 0.324, p = 0.013) and GGT (r = 0.314, p = 0.031) were positively correlated with BMI. The minimum values of serum ALT, AST and GGT levels were observed in underweight group, while the maximum values were observed in obese group in both genders. Conclusions ALT had the strongest correlation with BMI in both females and males. Therefore, ALT can be suggested as the best liver enzyme that can be used in screening purposes by concerning BMI.