Herzog D, Bishop N, Glorieux F, Seidman E G
Department of Pediatrics, Sainte-Justine Hospital, University of Montreal, Quebec, Canada.
Inflamm Bowel Dis. 1998 Nov;4(4):261-7. doi: 10.1002/ibd.3780040402.
Patients with Crohn's disease (CD) often have low bone mineral density (BMD) for their chronological age (CA). However, pediatric cases frequently have growth failure and delayed bone age (BA) and height age (HA). Do they really have the amount of osteoporosis as measured by BMD and calculated for their CA? The aim was to compare z-scores for BMD in relation to CA and z-scores corrected for BA or height age in pediatric patients. A group of 43 pediatric patients (mean age, 12 years; 14 girls, 29 boys) with CD in remission, prospectively had BMD (measured by dual energy x-ray absorptiometry) and BA. Abnormally low z-score for BMD (below 2 standard deviation [SD] for CA was found in 19 patients (44%). Among these, 9 patients (21% overall) had a BA of more than 2 SD lower than their CA and 12 had height age at least 2 years below CA. When the BMD z-score in these patients was corrected for their BA and height age, 6 of 9 and 8 of 12 patients had a normal BMD. In conclusion, when corrected for BA or CA delay, BMD was abnormal in 26 to 30% rather than 44% of cases. Correct assessment of BMD in Crohn's disease patients with bone age delay requires interpretation in terms of BA or HA, rather than CA.
克罗恩病（CD）患者按实际年龄（CA）计算，其骨矿物质密度（BMD）往往较低。然而，儿科病例常出现生长发育迟缓、骨龄（BA）和身高年龄（HA）延迟。按其实际年龄计算，他们的骨质疏松程度真的如BMD测量的那样吗？目的是比较儿科CD患者中BMD相对于实际年龄的z评分以及根据骨龄或身高年龄校正后的z评分。一组43例处于缓解期的儿科CD患者（平均年龄12岁；14名女孩，29名男孩）前瞻性地接受了BMD（采用双能X线吸收法测量）和骨龄检测。19例患者（44%）的BMD z评分异常低（低于实际年龄的2个标准差[SD]）。其中，9例患者（占总体的21%）的骨龄比实际年龄低超过2个标准差，12例患者的身高年龄至少比实际年龄低2岁。当根据这些患者的骨龄和身高年龄校正BMD z评分时，9例中的6例以及12例中的8例患者的BMD恢复正常。总之，校正骨龄或实际年龄延迟后，BMD异常的病例为26%至30%，而非44%。对于骨龄延迟的克罗恩病患者，正确评估BMD需要根据骨龄或身高年龄而非实际年龄进行解读。
