Bone Abstracts

Children and adolescents with inflammatory bowel disease (IBD) have defects in bone mineral density (BMD) and bone structure that do not completely normalize with clinical remission.

The objective of the study was to determine bone turnover marker (BTM) concentrations and factors behind altered bone metabolism in a case-control setting.

We measured the bone formation marker PINP and bone resorption markers CTX and TRACP5b in 42 adolescents and young adults (22 females; mean age 18.8 years, range from 10.7 to 25.0) with ulcerative colitis or Crohn’s disease and in 42 age and sex-matched control subjects. Study protocol was approved by Research Ethics Committee.

Half of the patients had disease duration over 8.5y and 62% of patients were in clinical remission. Patients with IBD were shorter (mean, 167 vs 173 cm, P=0.012) and had lower BMI (20.8 vs 22.4, P=0.025) than controls. BMD Z-scores were lower in IBD patients for lumbar spine (mean (95% CI for mean), −0.7 (−1.0 – −0.4) vs −0.2 (−0.5 – 0.1), P=0.040) and whole body (−0.5 (−0.8 – −0.2) vs 0.1 (−0.3 – 0.4), P=0.011). TRACP5b was higher in patients with IBD (5.6 U/L (4.6–6.7) vs 4.4 (3.9–5.0), P=0.001), but no difference in other BTMs was observed, when adjusting for whole-body bone area. In the patient group, all BTMs were significantly lower in postpubertal subjects when compared to prepubertal and pubertal subjects as expected (P<0.05). Current use of contraceptive pills associated with lower PINP (n=6 vs n=12; 39 ng/ml (33–47) vs 94 (73–121), P<0.001) and CTX (0.47 ng/ml (0.32–0.69) vs 0.80 (0.61–1.06), P=0.014) concentrations in patients with IBD.

In conclusion, bone health of young patients with IBD, though in clinical remission, is compromised. BTMs reflect increased bone resorption in adolescents and young adults with IBD, which could contribute to lower BMD.