Bone Abstracts

Skeletal integrity during childhood may be compromised by diseases interfering with bone metabolism. Chronic inflammatory bowel diseases (CIBD; Crohn’s disease, ulcerative colitis) in children is a recognized risk of osteoporosis in adulthood. This study was aimed at assessment of bone mass and bone metabolism in children with CIBD at diagnosis and after 1 year during therapy. Patient population comprised 64 children (boys 23 and girls 42) and adolescents aged 14.6±2.7 years (7–20). Dual X-ray densitometry (lumbar spine) and, measurement of 25-OH D and bone markers (osteocalcin, P1CP, CTX, crosslaps urine, osteoprotegerin) by standard methods were performed. No difference between sexes was found. Densitometry Z-scores (−0.67±1.28; range −3.95 to 2.47) indicating decreased bone mass (<−2) were found in five patients. At time of diagnosis hypovitaminosis D (<50 nmol/l) was found in 69% of patients. Increased bone markers (as compared to adult reference ranges) were observed in 75% for osteocalcin, 95% for P1CP, 98% for CTX and 45% for crosslaps urine. Osteoprotegerin was similar to normal adult values in 92% of patients. After 1 year follow-up statistically significant increase was found for osteocalcin (0.002) and P1CP (0.001), and decrease for crosslaps urine (0.0005) and osteoprotegerin (0.03). Hypovitaminosis D was still present in 41% of cases. These results indicate that CIBD in children and adolescents did not considerably impair the skeleton. Increased bone markers probably indicate increased bone turnover characteristic of growth and puberty. The observed changes of bone markers during follow-up probably reflects recovery and continuation of growth processes. Normal osteoprotegerin levels suggest that bone resorption at diagnosis and during monitoring was not predominant. Prevalence of hypovitaminosis D is a serious problem of this disorder, its treatment and prevention should be a measure for preventing osteoporosis risk.