Long-Term Development of Bone Geometry and Muscle in Pediatric Inflammatory Bowel Disease
ABSTRACT The muscle-bone unit is crucial for normal bone development. As muscle mass is frequently reduced in pediatric patients with inflammatory bowel disease (pIBD), we investigated the impact of muscles on the bone development over time.
Bone and muscle parameters were measured repeatedly in 102 pIBD patients (67 boys; 82 Crohn's disease; 30 newly diagnosed) by peripheral quantitative computed tomography (pQCT) at the forearm. The first and last measurements were included in the evaluation. Results were expressed as sex- and age-specific and partly height-corrected Z-scores for a healthy reference population.
At baseline, patients showed reduced Z-scores for height (median -0.7; range -3.7 to 1.6), trabecular bone mineral density (TrbBMD; -0.6; 3.0-2.8), and for height-corrected cortical cross-sectional area (CSA(height); -0.4; -3.0 to 2.2), cortical thickness (CrtTh(height); -0.7; -3.0 to 1.2), and MuscleCSA(height) (-1.0; -4.9 to 2.0; all P<0.01). Cortical bone mineral density (CrtBMD) and height-corrected TotalCSA(height) Z-scores were elevated (0.57; -4.55 to 2.8, both P<0.01). Over time, TotalCSA(height) (+0.36; -1.5 to 4.5) further increased, CorticalCSA(height) (+0.21; -2.1 to 3.0) and MuscleCSA(height) (+0.64; -2.0 to 3.9, all P<0.01) improved, whereas CrtBMD decreased toward normalization (-0.36; -5.1 to 3.6, P<0.05). The change in MuscleCSA(height) significantly correlated with the changes in TrbBMD (r=0.42), TotalCSA(height) (r=0.35), CorticalCSA(height) (r=0.38), and CrtTh(height) (r=0.24; all P<0.02). The relations became even stronger after adjustment for several confounders.
Bone metabolism and geometry are altered in pIBD patients expressed by low trabecular mineral density, low cortical thickness, and high cortical mineral density. The increased height-corrected cortical CSA might reflect a compensatory effect. In our cohort, treatment increased height-corrected muscle CSA and its changes were closely associated with bone parameters. Therefore, physical activity to enhance muscle mass and bone health should be promoted in pIBD patients.
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ABSTRACT: IntroductionChronic inflammation combined with glucocorticoid treatment and immobilization puts juvenile idiopathic arthritis (JIA) patients at risk of impaired growth and reduced bone mineral density (BMD). Conventional methods for evaluating bone age and BMD are time consuming, or come with additional costs and radiation exposure. In addition, an automated measurement of bone age and BMD is likely to be more consistent than visual evaluation. This study aimed to evaluate feasibility of an automated method for determination of bone age and (cortical) bone mineral density (cBMD) in severely affected juvenile idiopathic arthritis (JIA) patients. A secondary objective was to describe bone age and cBMD in this specific JIA population, eligible for biologic treatment.Methods In total, 69 patients with standard hand radiographs at start of etanercept treatment and of calendar age within the reliability ranges (2.5 to 17 years for boys and 2 to 15 years for girls) were extracted from the Dutch Arthritis and Biologicals in Children register. Radiographs were analyzed with the BoneXpert method, automatically determining bone age and cBMD expressed as bone health index (BHI). Agreement between measurements of the left and right hand radiographs and a repeated measurement of the left hand was assessed with the intraclass correlation coefficient (ICC). Regression analysis was used to identify variables associated with Z-scores of bone age and BHI.ResultsBoneXpert reliably evaluated radiographs of 67 patients (radiographs of two patients were rejected due to poor image quality). Agreement between left-right hand radiographs (ICC 0.838 to 0.996) and repeated measurements (ICC 0.999 to 1.000) was good. Mean Z-scores of bone age (¿0.36, P¿=¿0.051) and BHI (¿0.85, P¿<¿0.001) were lower compared with the healthy population. Glucocorticoid use was associated with delayed bone age (0.79 standard deviation (SD), P¿=¿0.028) and male gender was associated with a lower Z-score of BHI (0.65 SD, P¿=¿0.021).Conclusions BoneXpert is an easy-to-use method for assessing bone age and cBMD in patients with JIA, provided that radiographs are of reasonable quality and patients¿ bone age lies within the age ranges of the program. The population investigated had delayed bone maturation and lower cBMD than healthy children.Annals of the Rheumatic Diseases 08/2014; 16(5):424. DOI:10.1186/s13075-014-0424-1 · 9.27 Impact Factor
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ABSTRACT: Background and Aims: Exclusive enteral nutrition (EEN) induces remission in patients with Crohn's disease (CD). We investigated the short-term impact of EEN on bone quality and muscle mass in children with CD. Methods: Ten newly diagnosed CD patients (7 male, 10.6-17.7 years of age) were assessed by peripheral quantitative computed tomography (pQCT) at the forearm before starting an 8-weeks treatment with EEN, and after 12 and 52 weeks. No steroids or biologicals were applied. Trabecular and cortical bone mineral density, total bone, and muscle cross-sectional area (CSA) were measured by pQCT and expressed as age- and sex-specific z-scores; size-dependent CSAs were corrected for low height for age. Wilcoxon rank sum test was applied. Results: Remission at week 12 was achieved in 8 patients; 2 still had mild disease. Initially low trabecular density z-scores improved (+0.3; p = 0.006) at week 12; simultaneously, the increased cortical density z-scores normalized (-0.4; p = 0.027). The low z-score for muscle CSA corrected for height (median -2.5, range -3.49 to -0.97) increased within 12 weeks (+1.0; p = 0.002) with no further improvement thereafter. Conclusions: The results indicate disturbed bone remodeling and severely impaired muscle mass in newly diagnosed CD children. Bone metabolism and muscle mass improved within 3 months after starting EEN with no further normalization thereafter.Annals of Nutrition and Metabolism 07/2013; 63(1-2):10-16. DOI:10.1159/000350369 · 2.75 Impact Factor
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ABSTRACT: Context:Glucocorticoids and inflammation inhibit bone formation; however, the impact on skeletal modeling is unknown.Objectives:To examine changes in bone mineral density (BMD) and cortical structure after Crohn Disease (CD) diagnosis, and identify associations with growth, glucocorticoids and disease activity.Design/Participants:Prospective cohort study among 76 CD participants, ages 5-21. Tibia quantitative CT trabecular BMD and cortical dimensions were obtained at diagnosis, 6, 12 and a median of 42 months later; 51 completed the final visit.Outcomes:Sex, race and age-specific Z-scores were generated for outcomes based on >650 reference participants and cortical dimension Z-scores were further adjusted for tibia length. Generalized estimating equations were used to model changes in Z-scores.Results:Disease activity improved over the study interval (p<0.001). Trabecular BMD-Z improved over the first 6 months; increases were associated with improved disease activity (p<0.001), younger age (p=0.005), and increases in vitamin D levels (p=0.02). Greater increases in tibia length were associated with greater increases in cortical area-Z (p<0.001). Greater glucocorticoid doses and disease activity were significantly associated with failure to accrue cortical area, and were more pronounced with greater linear growth (interaction p<0.05). Mean (±SD) trabecular BMD (-1.0±1.21) and cortical area (-0.57±1.10) Z-scores at the final visit were significantly reduced.Conclusions:CD was associated with persistent deficits in trabecular BMD, although younger participants demonstrated greater potential for recovery. In addition, greater linear growth was associated with greater recovery of cortical dimensions, especially among participants with lesser glucocorticoid exposure and inflammation. These data suggest that younger age and concurrent growth provide a window of opportunity for skeletal recovery.The Journal of Clinical Endocrinology and Metabolism 05/2013; DOI:10.1210/jc.2013-1631 · 6.31 Impact Factor