Effect of homocysteine (Hcy) lowering vitamins on S‐adenosylmethionine (SAM) and S‐adenosylhomocysteine (SAH) in older people.
Bibliographic record
Abstract
Background Elevated plasma Hcy is a risk factor for vascular disease but lowering Hcy with B‐vitamins, including folate, has generally not reduced vascular events in clinical trials. Elevated plasma SAH concentration may be a more sensitive indicator of vascular disease than Hcy (AJCN 2007;86:1581). However, SAH was not correlated with folate concentrations in one study indicating that folate supplementation may not lower SAH (Eur J Clin Invest 2003;33:17). The effect of Hcy lowering vitamins on plasma SAH is not clear. Aim To determine in healthy older people with mildly elevated Hcy (Mean = 17.1 µmol/L) whether lowering Hcy with B vitamins effects plasma SAM and SAH concentrations. Methods This was part of a larger trial to determine the effect of B vitamins on cognition in which 276 healthy participants (= 65 y) were randomized to receive a supplement containing folate (1 mg), vitamin B12 (500 µg) and B6 (10 mg), or placebo, for two years. Of these participants, we selected the first 50 from each treatment group and determined SAM and SAH at baseline and two years by HPLC MS/MS. Results Plasma Hcy was 4.4 (95% CI 3.2, 5.6; P<0.001) µmol/L lower at 2 years in the Vitamins group compared with the Placebo group. At 2 years, there were no significant differences in plasma SAM [+4% (95% CI ‐2, 10); P=0.18], SAH [+2 (95% CI ‐10, 10); P=0.61], or the SAM:SAH ratio [+10% (95% CI 0, 20); P=0.10] between the Vitamins and Placebo groups. Conclusion Supplementation lowered plasma Hcy but had no effect on SAM or SAH concentration.
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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 | 0.002 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.002 |
| 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 | 0.002 | 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".