Reprinted from Eating Disorders Review
November/December 2008 Volume 19, Number 6
©2008 Gürze Books
Elevated liver enzyme levels are often detected when a young woman with anorexia nervosa (AN) undergoes clinical evaluation. Alanine aminotransferease (ALT) levels, which reflect hypovolemia or cardiac dysfunction, may be more than 132 times normal among hospitalized patients with AN. Less severe elevations of ALT and gamma-glutamyl transpeptidase (GGT) have been reported among ambulatory patients, but the cause of this form of liver inflammation are still unclear.
Catherine M. Gordon, MD, and her colleagues at Harvard Medical School and Children’s Hospital, Boston, measured serum concentrations of liver enzymes and hormones in a cross-sectional study of 53 ambulatory female AN patients to see if they could identify predictors of elevated liver enzyme levels (J Pediatrics. 2008;153:247). Anthropomorphic, dietary, and body composition information was collected for all patients. The homeostasis model assessment of insulin resistance (HOMA) score was calculated from the fasting srum insulin and glucose levels. None of the AN patients had a known history of liver disease or any external signs on clinical examination.
One-fourth had abnormal ALT levels
Among the 53 ambulatory patients, 14 (26%) had elevated ALT levels, 10 (19%) had elevated aspartate aminotransferase (AST) levels, 5 (9%) had elevated GGT levels, and 3 (6%) had elevated alkaline phosphatase (AP) levels. Nineteen, or 41%, had low fasting insulin levels, but none had fasting hyperinsulinemia.
Of the 14 young women with abnormal ALT levels, only 1 (8%) reported drinking alcohol, and that was 1 drink per week. Six of the women (43%) were being treated with antidepressants, including fluoxetine, sertraline, and escitalopram. Nutritional analysis showed that the percentage of calories consumed as protein was significantly correlated with GGT levels, but no other relationships were noted.
The women were divided into two subgroups on the basis of percentage of body fat. Thirty (57%) had a body fat percentage less than 18% and were designated as having low body fat. The mean body mass index (BMI, or kg/m2) was 18.0.
Dr. Gordon and her colleagues reported that one of their most compelling findings was that BMI and percentage of body fat were inversely correlated with ALT and GGT. In contrast, no significant relationship was found between lean body mass and liver enzyme levels. They did identify a relationship between hormonal markers of severity of disease (such as low T3, elevated cortisol, low insulin, and low HOMA and GGT levels. These findings were of concern because they might signify previously unrecognized and clinically relevant liver disease in AN. Age, duration of illness, and duration of amenorrhea were not related to liver enzyme concentrations.