Loss of body cell mass in Cushing's syndrome: effect of treatment.
Cushing's syndrome (CS) is associated with low fat-free mass, but it is unclear whether hypercortisolism causes a loss of whole body protein. Body composition was studied prospectively in 15 patients with untreated CS (n = 14 pituitary adenoma; n = 1 adrenal adenoma), in 15 nonobese healthy controls, and in 15 weight-matched obese controls by 3 different methods: total body potassium counting (TBP), bioelectrical impedance analysis (BIA), and anthropometry. In 6 patients, body composition was studied before and within 6 months after pituitary surgery. In CS patients and weight-matched controls, body weight and total body fat were significantly higher than in nonobese controls. In CS patients, TBP was 18.4% lower than predicted, whereas in weight-matched controls TBP was 7.1% higher than predicted. As compared with nonobese and weight-matched controls, in CS patients TBP indicated a significant loss of body cell mass (BCM) of -20.2 and -21.1%, respectively. A significantly reduced arm muscle area of -21.3% compared with weight-matched controls also indicated a loss of whole body protein. In CS, however, BIA overestimated BCM when compared with TBP by +18% and agreement between BIA and TBP in the individual patient was poor (limits of agreement plus minus 27.6%), indicating the invalidity of standard BIA equations in this population. Measurements performed before and 6 months after successful pituitary surgery demonstrated a significant loss of body weight (-11%) and body fat (-33%), but BCM and muscle mass remained on a constant low level. In conclusion, this study shows that, in patients with CS, a significantly reduced BCM indicates a true protein loss. The second interesting finding is that in the early recovery after successful treatment of hypercortisolism patients lose body fat without gaining BCM or muscle mass.
Pirlich
Matthias
M
Medizinische Klinik und Poliklinik, Abteilung Gastroenterologie, Universitätsklinikum Charité, Humboldt-Universität zu Berlin D-10098, Germany. matthias.pirlich@charite.de
Biering
Henrik
H
Gerl
Helga
H
Ventz
Manfred
M
Schmidt
Bernd
B
Ertl
Siegfried
S
Lochs
Herbert
H
D000328:Adult; D000368:Aged; D000886:Anthropometry; D001823:Body Composition; D003480:Cushing Syndrome / Q000378:metabolism / Q000473:pathology* / Q000601:surgery*; D017097:Electric Impedance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010902:Pituitary Gland / Q000601:surgery*; D011188:Potassium / Q000378:metabolism; D012016:Reference Values; D016896:Treatment Outcome
D011188:Potassium