Elevated plasma B<sub>12</sub> and betaine levels in women with anorexia nervosa: possible role in illness pathophysiology and epigenetic regulation
Bibliographic record
Abstract
Background: Phenomenology in anorexia nervosa (AN) appears to be subject to epigenetic regulation via DNA methylation. The micronutrients B12 and betaine contribute directly to DNA methylation and have been shown to be abnormally elevated in blood samples from people with AN. Methods: We measured plasma B12 and betaine levels, as well as leukocyte DNA methylation levels, among women with active AN (AN-active group), those in 1-year remission from AN (AN-remitted group), and those who had never experienced an eating disorder (NED group). We compared the groups on micronutrient levels and on the strength of association between micronutrients and methylation. Results: We included 64 women in the AN-active group, 49 in the AN-remitted group, and 49 in the NED group. Relative to those with NED (B12: mean 339.6 [standard deviation (SD) 224.3] μmol/L; betaine: mean 33.74 [SD 17.10] μmol/L), participants with active AN showed high B12 and betaine (B12: mean 571.0 [SD 505.2] μmol/L; betaine: mean 43.73 [SD 22.50] μmol/L); AN-remitted participants had elevated B12 alone (B12: mean 588.2 [SD 379.9] μmol/L; betaine: mean 33.50 [SD 19.20] μmol/L). There were also group-based differences in the strength of association between B12 and site-specific DNA methylation at genes regulating insulin function, glucose metabolism, cell regulation, and neurotransmitter function. These associations between B12 and methylation levels were generally stronger among those without an ED than among those with either active or remitted AN. Limitations: The extent to which plasma nutrient levels provide a meaningful proxy to cellular processes affecting DNA methylation is uncertain and the sample size limits the stability of results. We included only biological females in this investigation. Conclusion: Elevated B12 levels in AN resemble elevations reported among people with autoimmune, neoplastic, or other disorders. Such elevations imply that plasma B12 levels may misrepresent nutritional status among people with AN. Observed associations between levels of B12 and methylation at certain gene regions have ambiguous importance, but may indicate an influence of nutritional status on epigenetic mechanisms or may be the coincidence of separate processes that independently affect levels of micronutrients and DNA methylation.
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 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) | 0.001 | 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".