Physiologic regulators of bone turnover in young women with anorexia nervosa.
OBJECTIVE
To clarify the role of physiologic regulators of bone turnover in patients with anorexia nervosa (AN).


METHODS
Adolescent girls with AN (n = 61) had anthropometric, nutrition, and exercise data acquired, and bone mineral density (BMD) and body composition measured by dual energy x-ray absorptiometry. Serum samples were obtained for hormones, proresorptive cytokines, and bone formation markers, and urine for bone resorption markers.


RESULTS
In bivariate correlation analyses, significant (P <.05) predictors of lumbar BMD included height, weight, and exercise. In multiple regression models, these significant relationships held, even after controlling for the duration of amenorrhea and AN. For total body BMD, the same positive predictors were found and percentage of body fat was a negative correlate. For hip BMD, exercise and weight were found to be positive predictors. Dehydroepiandrosterone sulfate (DHEAS) was inversely correlated with N-telopeptides (NTx), and insulin-like growth factor I (IGF-I) was directly correlated with osteocalcin. Proresorptive cytokine levels were low or undetectable.


CONCLUSIONS
Exercise and weight were positive predictors of BMD. These data are the first to suggest a relationship between DHEAS and increased bone resorption in AN. IGF-I was correlated with bone formation indices. Low cytokine levels suggest that these factors do not mediate the increased bone resorption of AN.
Gordon
Catherine M
CM
Division of Adolescent/Young Adult Medicine, Children's Hospital, Boston, Massachusetts 02115, USA.
Goodman
Elizabeth
E
Emans
S Jean
SJ
Grace
Estherann
E
Becker
Kelly A
KA
Rosen
Clifford J
CJ
Gundberg
Caren M
CM
Leboff
Meryl S
MS
D000293:Adolescent; D000856:Anorexia Nervosa / Q000150:complications*; D015415:Biomarkers; D015519:Bone Density / Q000502:physiology*; D001862:Bone Resorption / Q000209:etiology* / Q000503:physiopathology*; D016207:Cytokines / Q000097:blood; D019314:Dehydroepiandrosterone Sulfate / Q000097:blood; D015444:Exercise; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D015999:Multivariate Analysis; D010012:Osteogenesis / Q000502:physiology*; D012044:Regression Analysis
D015415:Biomarkers; D016207:Cytokines; D019314:Dehydroepiandrosterone Sulfate; D007334:Insulin-Like Growth Factor I