Body composition changes in female adolescents with anorexia nervosa.
BACKGROUND
Body weight provides limited information about nutritional status of patients with anorexia nervosa (AN).


OBJECTIVE
Our objectives were to determine body composition (BC) changes, to find clinical predictors and endocrine correlates of total body protein (TBPr) depletion, and to compare results on fat mass (FM) obtained with anthropometry (skinfold measurements) and dual-energy X-ray absorptiometry (DXA) in patients with AN.


METHODS
Body weight, body mass index (BMI; in kg/m(2)), BC (with DXA and skinfold measurements), and TBPr [with in vivo neutron activation analysis (IVNAA)] was assessed in 50 AN patients (15.2 y) and 40 healthy sex- and age-matched controls. In 47 AN patients and 22 controls, hormone concentrations were measured.


RESULTS
In AN patients, body weight (44.4 +/- 5.5 kg), BMI (16.7 +/- 1.6), and FM(DXA) (7.0 +/- 3.4 kg) were lower than in controls. Lean tissue mass by DXA (LTM(DXA)) was similar in AN patients and controls (35.7 +/- 4.3 compared with 35.8 +/- 4.5 kg), but TBPr was 87% of that of controls (8.1 +/- 1.0 compared with 9.2 +/- 1.2 kg; P < 0.001). Cortisol was high, testosterone was unchanged, and estradiol and insulin-like growth factor I were low. Severe protein depletion measured by IVNAA seen in 17 AN patients could not be identified with simpler methods. All except 1 of 26 AN patients with a BMI > 16.5 had normal TBPr. The difference in individual percentage of body fat measured with DXA and skinfold measurements came up to 9%.


CONCLUSIONS
The severe protein depletion in 34% of AN patients was not accurately identified by LTM(DXA) or simpler methods, but a BMI > 16.5 indicated normal TBPr. Future studies need to compare DXA and skinfold measurements with a reference technique to assess FM in AN patients.
Haas
Verena K
VK
Department of Gastroenterology, Charité University Hospital, Berlin, Germany. verena.haas@charite.de
Kohn
Michael R
MR
Clarke
Simon D
SD
Allen
Jane R
JR
Madden
Sloane
S
Müller
Manfred J
MJ
Gaskin
Kevin J
KJ
D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000378:metabolism*; D000293:Adolescent; D000856:Anorexia Nervosa / Q000097:blood / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D001823:Body Composition / Q000502:physiology*; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology*; D016022:Case-Control Studies; D002648:Child; D004958:Estradiol / Q000097:blood; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D012044:Regression Analysis; D012885:Skinfold Thickness; D013739:Testosterone / Q000097:blood; D055815:Young Adult
D011506:Proteins; D013739:Testosterone; D004958:Estradiol; D007334:Insulin-Like Growth Factor I; D006854:Hydrocortisone