Breath test using 13 C methacetin does not seem to be useful in the assessment of liver function in girls with anorexia nervosa: a case control study.

BACKGROUND: Anorexia nervosa (AN) concerns approximately up to 1.8% of the pediatric female population. One of the complications that can occur in the course of this disease is acute liver failure. This study's objective was to assess the usefulness of the 13 C labeled Methacetin Breath Test (MBT) in the diagnostics of the liver function in girls with eating disorders.

METHODS: For the study 81 girls aged 12 to 17 years were recruited, including 41 patients with confirmed diagnosis of AN (mean age 14.7 ± 1.48 years) and 40 age-matched controls. The diagnosis was based on the present Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria. Weight and height were measured in all study participants and the Body Mass Index (BMI) was calculated. In the study and control group laboratory tests assessing the liver function and the MBT were performed.

RESULTS: In all controls the anthropometric as well as laboratory liver function parameters were normal. In the study group 25 patients (61%) had BMI below the lower limit for age. The total percentage of 13 CO2 recovery in the 120th minute of the test did not exceed the lower limit in patients and controls. A result of the 13 CO2 cumulative recovery above the upper normal range was found in 18 girls with AN (44% of the study group) and 2 controls (5%). Patients with AN were characterized by significantly higher 13 CO2 cumulative dose recovery after ingestion of the substrate in comparison to the control group in all time points of the test.

CONCLUSIONS: The obtained results confirm a significant stimulation of the liver metabolism of 13 C labeled methacetin in female patients with AN. The increased cumulative dose recovery of the substrate in girls with AN impacts the credibility of this measurement and implies a risk of false negative results.