Menstrual cycle irregularity in bulimia nervosa. Associated factors and changes with treatment.

OBJECTIVES: This study determined the clinical and nutritional variables associated with menstrual disturbance in women with bulimia nervosa (BN).
METHODS: Eighty-two women with DSM-IV BN underwent psychiatric, nutritional and menstrual related assessments prior to an outpatient treatment programme and at 12 months follow-up.
RESULTS: Forty-five percent reported a current irregular menstrual cycle. A high frequency of vomiting, low thyroxine concentrations and low dietary fat intake were independently associated with irregular menses at pretreatment. At 12 months follow-up, 30.5% reported irregular menstrual cycles. A greater difference between past maximum and minimum body weight, smoking and depression were associated with menstrual irregularity at 12 months follow-up. Of those with irregular menstrual cycles at pretreatment, 56.8% became regular at 12 months follow-up.
CONCLUSION: Menstrual irregularity in BN is associated with indices of nutritional restriction that are not reflected by low body weight or energy intake. Depression, cigarette smoking and fluctuations in body weight may act as metabolic stresses that contribute to the perpetuation of menstrual disturbances.