Bone mineral density in Canadian children with severe haemophilia A or B: a cross-sectional study
Bibliographic record
Abstract
Abstract Background Previous research has shown that bone mineral density (BMD), a measure of bone strength, may be lower among people with haemophilia. However, the majority of this research has been done in adults and in countries where the treatment for haemophilia differs from the standard of care in Canada, and there is a lack of paediatric data. Aims The primary objective of this study was to determine whether Canadian children and youth with severe haemophilia A and B have BMD similar to healthy controls matched for height, age and weight (HAW-score). Secondary objectives included the exploration of any association between BMD and the following variables: factor replacement regimen, Hemophilia Joint Health Score (HJHS), bleeding history, physical activity level, and dietary intake of calcium, vitamin D, vitamin K and protein. Methods A cross-sectional observational study was designed to determine the BMD of children with severe haemophilia A and B in Canada. Ethical approvals were obtained from participating institutions. Thirty-eight participants aged 3–18 with severe haemophilia A and B were recruited from two treatment centres in Canada. Subjects underwent dual-energy X-ray absorptiometry (DXA) scan, and data was collected from regular clinic visit to identify factor replacement regimen, HJHS, and number of joint bleeds over the lifespan. Physical activity level and dietary intake of calcium, vitamin D, vitamin K and protein were identified using self-report questionnaires. Results Participants showed a mean spine BMD Z-score and HAW-score higher than controls, with no participants showing a spine Z-score or HAW-score of <0. Hip BMD score was within normal range, and 2 participants had a Z-score and HAW-score of <−2. Total body BMD score was lower than controls, with 6 participants having a Z-score of <−2.0, and 3 participants having a HAW-score of <−2.0. Factor replacement regimen, HJHS, calcium intake, and physical activity level had no relationship to BMD Z-score or HAW-score. Low intake of vitamin D was associated with a low hip and spine BMD Z-score and HAW-score. Participants with a HJHS joint score greater than 0 had a higher total body HAW-score than those who had a joint score of 0. Conclusion Canadian children with severe haemophilia A and B demonstrate differences in spine and total body BMD from height-, age-, and weight-matched controls, where spine BMD is higher than controls and total body BMD is lower than controls. Studies with a larger sample size are needed to clarify the status of BMD in children with haemophilia treated with primary prophylaxis.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.003 |
| Science and technology studies | 0.003 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".