Reduced muscle mass and bone size in pediatric patients with inflammatory bowel disease.
BACKGROUND
Decreased bone mineral density has been reported in children with inflammatory bowel disease (IBD). We used peripheral quantitative computed tomography (pQCT) to assess bone mineralization, geometry, and muscle cross-sectional area (CSA) in pediatric IBD.


METHODS
In a cross-sectional study, pQCT of the forearm was applied in 143 IBD patients (mean age 13.9 +/- 3.5 years); 29% were newly diagnosed, 98 had Crohn's disease, and 45 had ulcerative colitis. Auxological data, cumulative glucocorticoid dose, disease activity indices, laboratory markers for inflammation, and bone metabolism were related to the results of pQCT.


RESULTS
Patients were compromised in height (-0.82 +/- 1.1 SD), weight (-0.77 +/- 1.0 SD), muscle mass (-1.12 +/- 1.0 SD), and total bone cross-sectional area (-0.79 +/- 1.0 SD) compared to age- and sex-matched healthy controls (z-scores). In newly diagnosed patients, the ratio of bone mineral mass per muscle CSA was higher than in those with longer disease duration (1.00 versus 0.30, P = 0.007). Serum albumin level and disease activity correlated with muscle mass, accounting for 41.0% of variability in muscle mass (P < 0.01). The trabecular bone mineral density z-score was on average at the lower normal level (-0.40 +/- 1.3 SD, P < 0.05).


CONCLUSIONS
Reduced bone geometry was explained only in part by reduced height. Bone disease in children with IBD seems to be secondary to muscle wasting, which is already present at diagnosis. With longer disease duration, bone adapts to the lower muscle CSA. Serum albumin concentration is a good marker for muscle wasting and abnormal bone development.
Bechtold
Susanne
S
Division of Pediatric Endocrinology, Dr. v. Haunersches Kinderspital, University, Munich, Germany.
Alberer
Martin
M
Arenz
Tina
T
Putzker
Stefanie
S
Filipiak-Pittroff
Birgit
B
Schwarz
Hans Peter
HP
Koletzko
Sibylle
S
D000293:Adolescent; D001827:Body Height; D015519:Bone Density; D001842:Bone and Bones / Q000473:pathology*; D002648:Child; D003093:Colitis, Ulcerative / Q000188:drug therapy / Q000473:pathology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D015212:Inflammatory Bowel Diseases / Q000188:drug therapy / Q000473:pathology*; D008297:Male; D009132:Muscles / Q000473:pathology*; D009929:Organ Size; D012720:Severity of Illness Index; D013997:Time Factors; D015898:Tomography Scanners, X-Ray Computed; D055815:Young Adult
D007166:Immunosuppressive Agents