A nested case-control study of serum 25-hydroxyvitamin D levels and risk of adult-onset asthma – The HUNT study
Bibliographic record
Abstract
Background: The impact of low vitamin D status on the development of asthma is not clear. We conducted a nested case-control study to investigate the relation of baseline serum 25-hydroxyvitamin D [25(OH)D] levels and adult-onset asthma. Methods: A total of 25,616 adults aged 19-55 years who participated in the second Norwegian Nord-Trøndelag Health Study (HUNT), were followed-up for 11 years. A nested case-control study consisted of all the new onset asthma cases during the follow-up (n=600) and a random sample of non-asthma controls (n=2013). Baseline blood samples were available in 584 asthma cases and 1958 non-asthma controls. Baseline serum 25(OH)D levels were measured by automated antibody-based chemiluminescence assay. Results: The mean level of baseline serum 25(OH)D was slightly lower in asthma cases compared with controls in both men (geometric mean: 51 vs. 54 nmol/L, p=0.04) and women (geometric mean: 52 vs. 55 nmol/L, p=0.02). Men with a serum 25(OH)D levels <50 nmol/l at baseline had a significantly higher risk of asthma (crude OR 1.75, 95%CI 1.14-2.68) compared with those with a serum 25(OH)D level of 75 nmol/l or higher. After adjustment for age, smoking, family history of asthma, education, physical activity, social benefit, and economic difficulties, the OR was 1.60 (95% CI 1.02-2.50). Further adjustment for body mass index (BMI) yielded an OR of 1.47 (95%CI 0.93-2.32). In women, baseline serum 25(OH)D level was not associated with the risk of asthma in either unadjusted or adjusted models. Conclusions: After adjustment for BMI and other covariates, baseline levels of serum 25(OH)D were not independently associated with adult-onset asthma.
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 | 0.002 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 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".