Bone density, body composition, and psychopathology of anorexia nervosa spectrum disorders in DSM-IV vs DSM-5.

OBJECTIVE: DSM-5 revised the diagnostic criteria for anorexia nervosa (AN) by eliminating the amenorrhea requirement, liberalizing weight and psychological criteria, and adding the formal diagnosis of "atypical AN" for individuals with AN psychological symptoms without low weight. We sought to determine whether bone density (BMD) is impaired in women diagnosed with AN using the new, more liberal, DSM-5 criteria.
METHOD: Cross-sectional study of 168 women, 18 - 45y: (1) AN by DSM-IV (DSM-IV AN) (n = 37), (2) AN by DSM-5 but not DSM-IV criteria (DSM-5 AN) (n = 33), (3) atypical AN (ATYPICAL AN) (n = 77), (4) healthy comparison group (HC) (n = 21). Measurements included dual energy X-ray absorptiometry, Eating Disorder Examination-Questionnaire, Eating Disorder Inventory-2, Hamilton Depression and Anxiety Rating Scales.
RESULTS: BMD Z-score <-1.0 was present in 78% of DSM-IV, 82% of DSM-5, and 69% of ATYPICAL. Mean Z-scores were comparably low in DSM-IV and DSM-5, intermediate in ATYPICAL, and highest in HC. Lack of prior low weight or amenorrhea was, but history of overweight/obesity was not, protective against bone loss. Mean lean mass and percent fat mass were significantly lower in all AN groups than HC. DSM-IV, DSM-5, and ATYPICAL had comparable psychopathology. DISCUSSION: Despite liberalizing diagnostic criteria, many women diagnosed with AN and atypical AN using DSM-5 criteria have low BMD. Presence or history of low weight and/or amenorrhea remain important indications for DXA. Loss of lean mass, in addition to fat mass, is present in all AN groups, and may contribute to low BMD. The deleterious effect of eating disorders on BMD extends beyond those with current low weight and amenorrhea.