Clinical and psychological features of normal-weight women with subthreshold anorexia nervosa: a pilot case-control observational study.

Objective: Weight preoccupations have been frequently reported in normal-weight subjects. Subthreshold anorexia nervosa (s-AN, all DSM IV TR criteria except amenorrhea or underweight) is a form of eating disorder not otherwise specified that has received scarce scientific attention. Under a case-control design we compared the general characteristics, body composition, and psychopathological features of normal-weight patients with s-AN with those of BMI- and sex-matched controls.

Design: Participants in this pilot study included 9 normal-weight women who met the DSM IV TR criteria for s-AN and 18 BMI-matched normal-weight controls. The general characteristics of the study participants were collected by questionnaire. Body composition was measured by bioelectrical impedance. Behavioral and psychological measures included the standardized symptom checklist (SCL-90-R) and the eating disorder inventory (EDI-2).

Results: There were no differences in age, education, employment status, marital status, and history of previous slimming treatment in the two study groups. In addition, anthropometric measures and body composition of s-AN patients and BMI-matched normal weight controls were not significantly different. In the s-AN subgroup, we found a significant relationship between waist circumference and the SCL-90-R obsessivity-compulsivity scale (n=9, r=-0.69, p<0.05). After multiple regression analysis, the SCL-90-R obsessivity-compulsivity scale (beta = 0.61, t=2.7, p=0.017) was the only independent predictor of the presence s-AN in our study cohort.

Conclusions: These pilot results suggest that psychopathological criteria (particularly related to the obsessivity-compulsivity dimension) may be more useful than anthropometric measures for screening of s-AN in normal-weight women.