Predicting the Return of Menses among Adolescent AN Patients

Patients with premenarcheal onset of AN were at risk for prolonged amenorrhea.

Although amenorrhea is no longer a criterion for making a diagnosis of AN, restoring menstrual function among teens with anorexia nervosa (AN) remains a major treatment goal. Weight rehabilitation is a necessity for reestablishing healthy endocrine function, including normalization of gonadal hormones and leptin levels. According to team of researchers in Germany, patients with premenarcheal onset of AN and those with higher premorbid body mass indexes (BMI, kg/m²) are at particular risk for having protracted amenorrhea in spite of weight rehabilitation (BMC Psychiatry 2013; 13:308).

To investigate clinical variables that might predict the recovery of menstrual function during weight gain among patients  with AN, Dr. Astrid Dempfle and colleagues followed 172 female adolescent patients with first-onset AN (defined by DSM-IV criteria) for 12 months. The women were participants in a multicenter clinical trial comparing inpatient and day-patient treatment for adolescents with AN. The weight threshold for inclusion in the study was a BMI below the 10th percentile. Two groups emerged in the final sample of 152 patients. One was a “menstruating group,” who had menstruated at any time before follow-up and who were not taking oral contraceptives or who reported spontaneous resumption of menses before using oral contraceptives. A second group, the “amenorrheic group,” included patients who were still amenorrheic at the 12-month follow-up point.

At admission, all patients had amenorrhea; most reported secondary amenorrhea, while 36 were classified as pre-menarcheal (31 patients) or as having primary amenorrhea (5 patients). For 47% of the adolescent patients, menses spontaneously returned within the first 12 months after admission. Patients who resumed menses had an average BMI of nearly 19, whereas those who had not resumed menstruation had a significantly lower mean BMI, 17.5.

Amenorrhea at admission predicted persistent disease

The absence of menarche at hospital admission strongly predicted persistent amenorrhea at the 12-month follow-up point. Just as other studies have shown that earlier onset of childhood AN is associated with a worse long-term outcome, in the authors’ study, one-fifth of the patients were premenarcheal when they were first admitted for treatment. The authors concluded that patients with premenarcheal onset of AN and those with a high premorbid BMI are at particular risk of protracted amenorrhea in spite of successful weight rehabilitation.

According to Dr. Dempfle, the outcome of treatment may be improved by waiting to discharge patients until they have reached their individual target weights and then supporting them to maintain this weight gain. Reaching and maintaining a target weight in a range between the 15th and 20th BMI percentiles seemed to be the most favorable for resumption of menses. Should patients with higher premorbid BMIs be given higher target weights? The authors feel this question needs further investigation.