Objective: We tested nine hypotheses among eating disorder subgroups a
nd a control group on spinal bone density and investigated the relatio
nship of their spinal bone density with a critical fracture threshold
and five clinical variables - age of onset, years ill, percentage of i
deal body weight (IBW), months of amenorrhea, and hours per week of ex
ercise. Method: Dual photon absorptiometry measured spinal bone densit
y. Results: Anorectic patients had significantly less spinal bone mass
than bulimic patients with no history of anorexia nervosa or control
patients. Eating disordered patients with past or present anorexia ner
vosa had significantly more spinal bone density values below a critica
l fracture threshold. Duration of amenorrhea and exercise significantl
y predicted spinal bone density. Discussion: Anorectic women were unli
kely to reach their peak bone density, thus possibly developing osteop
orosis later in life, and were likely to be at risk for nontraumatic s
pinal fractures. Predicting spinal bone density of anorectic women cou
ld be done by knowing their duration of amenorrhea and exercise. (C) 1
995 by John Wiley & Sons, Inc.