Longitudinal assessment of bone mineral density in children and adolescents with inflammatory bowel disease.
OBJECTIVE
Low bone mineral density (BMD) is recognized as a potential problem in children with inflammatory bowel disease (IBD). We aimed to describe the longitudinal development of BMD in a population of Swedish pediatric patients with IBD.


METHODS
A total of 144 patients with IBD (93 males; 83 with ulcerative colitis [UC], 45 with Crohn disease [CD]) were examined with dual-energy x-ray absorptiometry at baseline. At follow-up 2 years later, 126 of the initial 144 patients were reexamined. BMD values are expressed as z scores.


RESULTS
Children with UC and CD had significantly lower mean BMD z scores for the lumbar spine (LS) at baseline and after 2 years. The reduction in BMD was equally pronounced in patients with UC and CD, and neither group improved their z score during the follow-up period. Furthermore, significantly lower mean BMD z scores for the LS were found at baseline in boys (-1.1 SD, ±2.7 SD, P < 0.001), but not in girls (-0.0 SD, ±3.0 SD). This finding remained unchanged at follow-up. Subanalyses of the different age groups at baseline showed the lowest BMD values in the group of patients ages 17 to 19 years in boys (mean z score for the LS 1.59 SD, ±3.1 SD) and in girls (mean z score for the LS -3.40 SD, ±3.1 SD); however, at follow-up, these patients had improved their BMD significantly (mean change z score for the LS 1.00 SD, 95% CI 0.40-1.60; 1.90 SD, 95% CI 0.60-3.20).


CONCLUSIONS
In this longitudinal study, the entire group of pediatric patients with IBD showed permanent decreases in their BMD z scores for the LS; however, our data indicate that afflicted children have the potential to improve their BMD by the time they reach early adulthood.
Department of Pediatrics, Institute of Clinical, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden. schm-sus@online.no
Susanne
S
Schmidt
Dan
D
Mellström
Ensio
E
Norjavaara
Valter
V
Sundh
Robert
R
Saalman
D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D018488:Bone Demineralization, Pathologic / Q000453:epidemiology / Q000209:etiology* / Q000378:metabolism; D015519:Bone Density; D002648:Child; D003093:Colitis, Ulcerative / Q000150:complications* / Q000378:metabolism; D003424:Crohn Disease / Q000150:complications* / Q000378:metabolism; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008159:Lumbar Vertebrae / Q000378:metabolism*; D008297:Male; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult