Notice bibliographique
Résumé
Osteoarthritis (OA) is a multifactorial disease of the joints, common among older adults, which can lead to pain, impaired function and reduced quality of life. This thesis aims to investigate the associations and predictive value of various hormonal, inflammatory and imaging biomarkers with OA outcomes in population-based studies of people with and without prevalent OA. Two population samples were used in this thesis. The first group was a population-based sample of older adults aged 50-80 years (mean age: 62 years; 51% female). Followup measurements were conducted 2.7 (2.6-3.3) years later and again for questionnaire data 5.0 (5.3-6.8) years later. Magnetic resonance imaging (MRI) on the right knees was undertaken at baseline and first followup: knee cartilage volume, tibial bone area, cartilage defects and bone marrow lesions (BMLs) were measured or scored; cartilage mean T1 signal intensity and thickness were measured by semi-automated software. Baseline knee and hip x-rays were scored for joint space narrowing (JSN) and osteophytes. Serum leptin and cytokine levels were measured by immunoassay at baseline and first followup. Body morphometry was measured at baseline. Fat and lean mass measures were measured at baseline using dual-energy x-ray absorptiometry (DXA). Knee pain was assessed by questionnaires (WOMAC, Western Ontario and McMasters Osteoarthritis Index) at all timepoints. The second group was a population-based sample of younger adults aged 26-51 (mean age 41; 64% female). Anthropometric, x-ray and MRI-derived scores and measures were obtained as in the first group. Urinary C-terminal crosslinking telopeptide of type II collagen (U-CTX-II) was measured by measured by immunoassay. This thesis consists of 6 studies. In the first study, in older adults, circulating levels of both leptin and interleukin-6 (IL-6) were associated with hip JSN in both sexes and females respectively, independently of BMI. Adiposity was associated with hip JSN, but not after adjustment for leptin. In the second study, baseline levels of both IL-6 and tumor necrosis factor alpha (TNF-˜í¬±) were associated with medial tibiofemoral knee JSN. Baseline IL-6, change in IL-6 and change in TNF-˜í¬± were associated with cartilage volume loss. In the third study, in older adults, baseline or change over 2.9 years in circulating levels of high sensitivity C-reactive protein (hs-CRP), IL-6 and TNF-˜í¬± were associated with change over 5 years in sub-scale or total WOMAC knee pain. In the fourth study, higher leptin in older adults was significantly associated with lower femoral, tibial and patellar cartilage thickness. Fat measures were negatively associated with cartilage thickness, largely mediated by leptin. Baseline and change in leptin were associated with medial tibial cartilage thickness loss. In the fifth study, knee cartilage defects in older adults were found to be common, not likely to regress, and to predict cartilage volume loss and risk of knee replacement. In the final study, mean T1 MRI signal intensity of cartilage was negatively associated with BMI and same-region cartilage defects in younger and older adults; with U-CTX-II in younger adults; and with JSN and osteophytes in older adults at various sites. It predicted cartilage thickness loss over 2.7 years in older adults. In conclusion, inflammatory and metabolic factors may play important roles in aetiology of cartilage loss and/or symptoms in OA. Cartilage defects predict cartilage loss and risk of knee replacement, and mean T1 MRI signal intensity of cartilage predicts loss of cartilage thickness. All these are potential biomarkers for OA at risk of development or progression, and thus possible targets for intervention.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,004 | 0,008 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,002 | 0,001 |
| Bibliométrie | 0,003 | 0,004 |
| Études des sciences et des technologies | 0,001 | 0,002 |
| Communication savante | 0,005 | 0,002 |
| Science ouverte | 0,001 | 0,002 |
| Intégrité de la recherche | 0,002 | 0,002 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,009 | 0,004 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».