Children with IBD have increased bone matrix mineralization

Last Updated: 2017-07-27

By Will Boggs MD

NEW YORK (Reuters Health) - Bone matrix mineralization is increased in treatment-na ve children with inflammatory bowel disease (IBD), according to results of quantitative backscatter electron imaging of 20 children's biopsies.

"It was surprising to see that IBD, inflammation, and malabsorption already had an impact on bone matrix mineralization in children as early as after five months of Crohn's disease (CD) or ulcerative colitis (UC) symptoms," Dr. Barbara M. Misof from Ludwig Boltzmann-Institute of Osteology, Hanusch-Hospital, Vienna, Austria told Reuters Health by email.

Bone mineral density (BMD) is consistently low in pediatric IBD patients, and fractures due to osteoporosis have been reported.

Previous studies of treatment-na ve youth with IBD have reported lower than normal bone mass and biochemical markers of bone turnover, and biopsies have revealed static parameters of bone formation and reductions in cortical width.

Dr. Misof and colleagues investigated the pattern of bone mineralization by using quantitative backscatter electronic imaging to measure bone mineral density distribution (BMDD), a measure of the degree and heterogeneity of bone mineralization, in trans-iliac bone biopsies from 20 treatment-na ve children with IBD (17 with Crohn's disease; three with ulcerative colitis).

BMDD of the cancellous bone showed significant shifts towards higher calcium concentrations (i.e., increased mineralization) in children with IBD, compared with reference values, according to the July 10th online report in Bone.

In cortical bone, mineralization heterogeneity and calcium concentration were increased in IBD patients.

Higher bone calcium concentrations were associated with lower levels of serum alkaline phosphatase, bone-specific alkaline phosphatase, and urinary crosslinked N-telopeptide, markers of bone turnover.

"Noteworthy, we compared also the BMDD from children with CD (the majority of our cohort) alone to reference and found similar results as observed for the entire cohort," the researchers note. "This indicates that the shift of the BMDD to higher calcium concentrations is a robust finding in this cohort and shows that the BMDD changes might be typical of the two/both inflammatory gastrointestinal diseases of autoimmune origin and might be mediated by the malabsorption and the inflammation."

"Increased bone matrix mineralization may lead to increased brittleness of the bone material," they conclude.

"Our work provides first information on bone matrix mineralization in treatment-naive children with IBD, showing that the degree of mineralization is increased compared to reference data," Dr. Misof said. "In particular, this might be important when these young patients are treated with glucocorticoids as it is unclear whether treatment might exacerbate matrix mineralization and further contribute to bone fragility."

SOURCE: http://bit.ly/2v0X65w

Bone 2017.