Increased bone marrow fat in anorexia nervosa.
BACKGROUND
Although women with anorexia nervosa (AN) have severe depletion of body fat, a paradoxical increase in bone marrow fat has been described. Recent data suggest that marrow fat measured by 1H-magnetic resonance spectroscopy (MRS) in combination with bone mineral density (BMD) may be more valuable than either parameter alone in detecting bone weakness.


OBJECTIVE
The objective of the study was to investigate the effect of AN on accumulation of marrow fat in spine and femur using 1H-MRS and the relationship between marrow fat, BMD, and body composition in subjects with AN and normal-weight controls.


METHODS
This was a cross-sectional study.


METHODS
The study was conducted at a referral center.


METHODS
Patients included 10 women with AN (29.8 +/- 7.6 yr) and 10 normal-weight age-matched women (29.2 +/- 5.2 yr).


METHODS
There were no interventions.


METHODS
Marrow fat content of the fourth lumbar vertebra and femur measured by 1H-MRS. BMD of spine and hip measured by dual-energy x-ray absorptiometry.


RESULTS
Subjects with AN had higher marrow fat at the fourth lumbar vertebra and femur compared with controls (P = 0.004-0.01). There was an inverse correlation between marrow fat of L4 and femur and BMD of the spine and hip (r = -0.56 to -0.71, P = 0.01-0.0002) and body mass index and sc adipose tissue of the thigh (r = -0.49 to -0.71, P = 0.03-0.0007). There was an inverse correlation between femur marrow fat and sc and total abdominal adipose tissue (r = -0.53 to -0.67, P = 0.003-0.03).


CONCLUSIONS
Women with AN have greater lumbar and femoral marrow fat than controls, and marrow fat correlates inversely with BMD. This paradoxical increase in marrow fat at a time when sc and visceral fat are markedly reduced raises important questions about functional consequences of this process.
Bredella
Miriam A
MA
Department of Radiology, Massachusetts General Hospital, Yawkey 6E, 55 Fruit Street, Boston, Massachusetts 02114, USA. mbredella@partners.org
Fazeli
Pouneh K
PK
Miller
Karen K
KK
Misra
Madhusmita
M
Torriani
Martin
M
Thomas
Bijoy J
BJ
Ghomi
Reza Hosseini
RH
Rosen
Clifford J
CJ
Klibanski
Anne
A