Increased bone matrix mineralization seen in children with IBD

Compared with healthy children, treatment-naïve children with inflammatory bowel disease demonstrated decreased bone turnover, resulting in a higher bone matrix mineralization density, study data showed.

“The hallmark of the inflammatory bowel diseases (IBD), namely ulcerative colitis and Crohn’s disease, is a chronic immune-mediated inflammation of the mucosal lining in various regions of the gastrointestinal tract which can affect various other organs, including the skeleton,” Barbara Misof, PhD, of the Ludwig Boltzmann Institute of Osteology, Vienna, Austria, and colleagues wrote. “Fractures due to osteoporosis at diagnosis have been reported in pediatric IBD, and [BMD] parameters are consistently low. … When patients with IBD are treated with glucocorticoids, it is usually difficult to distinguish between the effects of the inflammation on skeletal development per se and those of glucocorticoid therapy.”

The researchers reviewed trans-iliac biopsies of 20 treatment-naïve patients with IBD (Crohn’s disease, n = 17; ulcerative colitis, n = 3). Twelve of the patients were male, and mean age was 14.5 years. Misof and colleagues compared biopsy outcomes to reference data on pediatric BMD distribution.

Compared with reference levels, the BMD distribution in cancellous bone of patients with IBD showed higher mean calcium concentrations (+2.8%; P = .004) and greater portions of highly mineralized bone (+52%; P = .009).

Patients also showed increased mineralization heterogeneity (full width at half maximum of the distribution, +17%; P = .001; percentage of highly mineralized bone area +30.4%; P = .006) in cortical bone.

Higher mean calcium concentrations were associated with lower serum alkaline phosphatase, bone-specific alkaline phosphatase and urinary crosslinked N-telopeptide of type 1 collagen (range, P < .001 to P < .05).

“The [BMD distribution] analysis of cancellous and cortical bone compartments on trans-iliac biopsy samples from treatment-naïve children with IBD points to a slightly higher matrix mineralization compared to healthy children, which is likely due to reduced bone turnover,” the researchers wrote. “Increased bone matrix mineralization may lead to increased brittleness of the bone material. An important question in this context is whether treatment of IBD with glucocorticoids will augment these deviations in [BMD distribution] from normal given the bone turnover-suppressive effects of glucocorticoids, or whether quelling the IBD despite glucocorticoid therapy will lead to a more normal mineralization pattern.” – by Andy Polhamus

Disclosures: The authors report no relevant financial disclosures.