Gamma-Glutamyl Transferase: A Useful Marker of Habitual Drinking in Cases of Alcohol-Associated Osteonecrosis of the Femoral Head.

ABSTRACT

AIMS: Alcohol intake is one of the factors associated with the occurrence of osteonecrosis of the femoral head (ONFH), and its epidemiological information regarding alcohol intake depends on patients' self-reports. Therefore, we analysed the efficacy of laboratory tests as an objective diagnostic tool to indicate habitual drinking in patients with alcohol-associated ONFH. METHODS: This study included 109 consecutive patients diagnosed with ONFH who underwent primary hip surgery in our institution between 2010 and 2018. The patients were classified into group AL (alcohol-associated ONFH; n = 26) and group NO (alcohol-unassociated ONFH; n = 83), based on their self-reported information. Serum levels of gamma-glutamyl transferase (GGT), mean corpuscular volume (MCV), aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol and triglycerides were compared between both groups. The sensitivities and specificities with the optimal cut-off values for detecting alcohol-associated ONFH were compared among these markers. RESULTS: The median serum levels of GGT, AST and ALT were significantly higher in the AL group than in the NO group. The receiver operating characteristic curve analysis demonstrated an area under the curve of 0.795 for GGT, 0.731 for AST and 0.709 for ALT. The optimal cut-off level of GGT as a marker for alcohol-associated ONFH was 36.5 units/L, with a sensitivity of 76% and specificity of 80%, and it was found to be the best marker among the other examined laboratory markers. CONCLUSION: Serum GGT level is a useful laboratory marker with moderate accuracy that indicates habitual drinking in patients with alcohol-associated ONFH.