Effect of weight-regulating practices on potassium level in patients with anorexia or bulimia nervosa

Objective: The authors evaluated retrospectively data from 397 patients with anorexia (AN) and bulimia nervosa(BN). Method: Patients were divided into six pre-defined and symptom-related subgroups and their hypokalemia frequencies compared. The correlation between potassium level and disease-related patterns was assessed. Results: The two purging type AN groups were at greatest risk of hypokalemia. Vomiting frequency, body mass index (BMI) and laxative dosage had an effect on potassium levels within the overall group but only accounted for 19% of the variance of potassium level. Effects could not be proved for fasting, sport and disease duration. Discussion: Patients with anorexia or bulimia nervosa are very heterogeneous due to the considerable range of potential weight-regulating measures. Taking this heterogeneity into consideration by dividing patients into diagnostic subgroups and considering their symptomatology thus considerably aids the estimation of hypokalemia risk when treating eating disorders. Copyright (C) 2004 John Wiley & Sons, Ltd and Eating Disorders Association.