Assessment of adolescents with anorexia nervosa and atypical anorexia nervosa monitored as outpatient

Among the restrictive eating and eating disorders, anorexia nervosa (AN) and atypical anorexia nervosa (AAN) are the ones that present the greatest medical complications. Objective: Describe the characteristics of patients with AN and AAN and their differences in demographic and clinical parameters. Patients and Method: The records of patients <19 years of age with AN admitted to Clinica Santa Maria between 2013 and 2019 were reviewed. The evolution time, amenorrhea, z-BMI, percentage and speed of weight loss, and complications were recorded. Results were expressed as mean and standard deviation or median and range. Comparisons were made using the Mann-Whitney test, the t-student test, and the chi-square test; Pearson's coefficient was used for correlations. Results: 76 patients with AN were admitted (64% AAN). The median age was 15.4 years. AN and AAN differed in age at diagnosis (p < 0.03), z-BMI (p < 0.001), bradycardia (p < 0.009), blood pressure (p < 0.003), and cholesterol (p < 0.02), without other differences. The z-BMI correlated with heart rate (r = 0.39 p < 0.002); systolic pressure (r = 0.43 p<0.000), and HDL (r =-0.39 p < 0.005). The percentage of weight loss was correlated with time of amenorrhea (r = 0.27 p < 0.05); alanine aminotransferase (r = 0.0.37 p < 0.031), and HDL (r = 0.47 p < 0.001) and the speed of weight loss with glycemia (r =-0.46 p < 0.001) and urea nitrogen (r =-0.39 p < 0.005). Conclusion: AAN was the most frequent AN condition in this sample and variables such as the percentage and speed of weight loss were as important as BMI in medical complications.