Percentage Body Fat by Dual-energy X-ray Absorptiometry is Associated with Menstrual Recovery in Adolescents with Anorexia Nervosa

Abstract

To evaluate correlates of menstrual recovery in adolescents with anorexia nervosa. 37 adolescents with anorexia nervosa and amenorrhea randomized to the placebo arm of a double-blind treatment trial, of whom 29 completed the 18-month follow-up visit, were included in the analysis. Anthropometrics, body composition by dual-energy X-ray absorptiometry (DXA), hormonal studies, and responses to the Beck Depression Inventory-I and the 26-item Eating Attitudes Test were compared between those subjects with menstrual recovery and those without. Logistic regressions fit via generalized estimating equations to account for repeated measurement over time were used to test the association of each factor and return of menses over the 18-month study. Subjects were aged 18 ± 2.8 years (mean ± SD), and self-identified primarily as white (86%). Sixty-five percent (n = 24) had recovery of menses during the study. Length of illness (19 ± 26 months) was similar between those subjects with menstrual recovery and those without, as was the duration of amenorrhea (20 ± 12 months) at baseline. Subjects exercised 7 ± 3 hours/week. Percentage body fat by DXA was associated with menstrual recovery [OR 1.19 (1.06, 1.33), p < 0.01], as were BMI [OR 1.48 (1.13, 1.95), p < 0.01] and percent median body weight [OR 1.09 (1.03, 1.16), p = 0.004]. Estradiol = 30ng/mL, alone, was not associated (p = 0.08), but when coupled with percent mean body weight it was an important predictor of menstrual recovery [OR 2.49 (1.09, 5.65), p = 0.03]. Changes in leptin levels were not associated with return of menses, but the sample size was small (n = 11). Serum cortisol levels and scores on both mental health screens were, similarly, not associated with return of menses. While weight gain is an important goal of treatment in adolescents with anorexia nervosa, percentage body fat may be a useful clinical measure to follow to inform menstrual recovery and can be obtained at the same time as bone density measures.