Change in Cortical Bone Density and Its Distribution Differs between Boys and Girls during Puberty
Bibliographic record
Abstract
CONCEPT: Postmenarchal girls and premenopausal women have 3-4% higher cortical bone density (CoD, milligrams per cubic centimeter), compared with postpubertal boys and men, respectively. Females' denser cortical bone is thought to serve as a calcium reservoir for reproductive needs. However, prospective data are lacking that describe CoD development and bone mineral density distribution during puberty in both sexes. OBJECTIVE: Thus, our objectives were to assess maturity and sex differences in the 20-month change of CoD and radial distribution of bone mineral density (RDBMD, milligrams per cubic centimeter) in early-, peri-, and postpubertal girls and boys. Maturity groups were based on change in menarcheal status (girls, n = 68) and pubic hair stage (Tanner) (boys, n = 59). Peripheral quantitative computed tomography was used to measure CoD and RDBMD at the tibial middiaphysis. RESULTS: The increase in average CoD was 1.9% [22.8 mg/cm(3); 95% confidence interval (CI), 10-36], 2.8% (33.8 mg/cm(3); 95% CI, 21-47), and 1.5% (55.0 mg/cm(3); 95% CI, 17-93) greater in early, peri-, and postpubertal girls, compared with boys, respectively. Analysis of RDBMD revealed that the change in density distribution varied across pubertal groups in girls. Across puberty, all girls showed an increase in the high density midcortical region, whereas only peripubertal girls showed an increase in the lower density subcortical region. A sex-difference in RDBMD change was noted within early and peripubertal groups. CONCLUSIONS: Our findings of sexual dimorphism in CoD development give support to the hypothesis that female bone deposits calcium for reproductive needs by consolidation of cortical bone during puberty.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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".