Persistence of musculoskeletal abnormalities in children and adolescents with inflammatory bowel disease: a prospective longitudinal study

McCarrison S; A Mason; Wong SC; S Shepherd; McGrogan P; R Russell; Ahmed SF

doi:10.1530/boneabs.4.P141

Objectives: To evaluate musculoskeletal development using pQCT and DXA in childhood onset inflammatory bowel disease (IBD).

Methods: Prospective longitudinal study with 12 months follow-up in 43 children (23 males) with IBD: 30 crohn’s disease(CD), 13 ulcerative colitis (UC) and inflammatory bowel disease unclassified (IBDU). pQCT at 4% and 66% radius, DXA for total body (TB), lumbar spine (LS) bone mineral content were assessed at baseline and 12 months. pQCT parameters for area and circumference were adjusted for height. DXA BMC was adjusted for bone area. Results reported as median (range).

Results: In CD, 3/30 (10%) and 4/30 (13.3%) were on oral Prednisolone at baseline and 12 months. In CD, 2/30 (6.7%) and 8/30 (26.7%) were on anti-TNF therapy at baseline and 12 months. In UC/IBDU, 2/13 (15.4%) and 3/13 (23.1%) were on oral Prednisolone at baseline and 12 months. In UC/IBDU, 0/13 and 1/13 (7.7%) were on anti-TNF therapy at baseline and 12 months. No child had surgical resection during follow-up.

There were no gender differences in changes in DXA, pQCT parameters in both IBD sub-groups. Baseline IGF1:IGFBP3 z-score was associated with change in volumetric BMD (r=0.42, P=0.02).

Table 1
	CD baseline (n, 30)	CD 12 months (n, 30)	P value	UC/IBDU baseline (n, 13)	UC/IBDU 12 months (n, 13)	P value
Age (years)	13.8 (10.4, 16.5)	14.8 (11.5, 17.6)	–	13.2 (9.8, 15.8)	14.2 (10.8, 16.7)	–
Ht for bone age Z score	−0.1 (−2.1, 2.7)	−0.1 (−2.4, 2.2)	0.51	0.0 (−1.7, 2.6)	−0.2 (−2.2, 1.1)	0.65
Pre-pubertal	6/30 (20%)	1/30 (3%)	–	3/13 (23%)	2/13 (15%)	–
Early/mid puberty	11/30 (37%)	14/30 (47%)	–	8/13 (62%)	7/13 (54%)	–
Late puberty	13/30 (44%)	15/30 (50%)	–	2/13 (15%)	4/13 (31%)	–
ESR (mm/h)	13 (1, 102)	12 (1, 70)	0.80	17 (7, 42)	14 (6, 47)	0.87
Remission/mild disease	30/30 (100%)	28/30 (93%)	–	12/13 (92%)	12/13 (92%)	–
DXA
TB BMC (bone area) Z score	−0.3 (−0.7, 0.8)	−0.3 (−0.7, 0.6)	0.21	−0.1 (−0.7, 0.8)	−0.2 (−1.0, 0.9)	0.45
LS BMC (bone area) Z score	0.3 (−1.3, 1.4)	−0.5 (−1.6, 1.2)	0.10	0.5 (−1.3, 1.2)	−0.2 (−1.0, 0.9)	0.91
PQCT
Volumetric BMD Z score	−1.0 (−2.8, 1.2)	−1.3 (−2.9, 2.8)	0.19	−1.0 (−2.6, 2.0)	−1.0 (−2.7, 1.3)	0.20
Trabecular BMD Z score	−0.9 (−3.9, 1.4)	−0.8 (−3.5, 2.7)	0.60	−0.7 (−2.9, 2.5)	0.3 (−2.5, 2.7)	0.20
Cortical BMD Z score	−1.2 (−5.2, 2.0)	−0.2 (−3.6, 2.0)	0.05*	−0.9 (−3.7, 1.7)	−0.7 (−3.9, 1.9)	0.35
Periosteal circumference Z score	−1.1 (−2.8, 1.9)	−0.6 (−5.2, 2.1)	0.72	−0.4 (−2.6, 1.6)	−0.7 (−2.4, 0.5)	0.01*
Endosteal circumference Z score	2.8 (0.9, 5.0)	2.6 (−1.2, 5.1)	0.72	3.5 (−0.7, 0.8)	3.4 (1.5, 6.2)	0.17
Muscle area Z score	−1.7 (−4.3, 0.1)	−2.3 (−7.9, −0.1)	0.40	−2.0 (−3.2,1.5)	−2.4 (−3.0, 0.8)	0.19

Conclusion: Despite relatively mild disease and pubertal progression, children with IBD have persistent abnormal bone geometry suggestive of reduction in cortical thickness. With follow-up, trabecular BMD appears to be more affected in those with CD, whereas cortical BMD was more affected in UC/IBDU. Long term follow-up studies of bone development in childhood onset IBD and the relationship with the GH-IGF axis are needed.

Disclosure: The authors declared no competing interests.

Bone Abstracts

P141