RESUMO
OBJECTIVES: JIA is the most common paediatric rheumatic disease, thought to be influenced by both genetics and the environment. Identifying environmental factors associated with disease risk will improve knowledge of disease mechanism and ultimately benefit patients. This review aimed to collate and synthesize the current evidence of environmental factors associated with JIA. METHODS: Four databases (MEDLINE, Embase, Web of Science and Cumulative Index to Nursing and Allied Health Literature) were searched from inception to January 2020. Study quality was rated using the Newcastle-Ottawa Scale. Pooled estimates for each environmental factor were generated using a random-effects, inverse-variance method, where possible. The remaining environmental factors were synthesized in narrative form. RESULTS: This review includes 66 environmental factors from 39 studies (11 cohort and 28 case-control studies) over 45 years. Study sample sizes ranged from 41 to 1.9 million participants. Eight environmental factors from ten studies were meta-analysed. Caesarean section delivery was associated with increased JIA risk [pooled odds ratio (OR) 1.11, 95% CI: 1.01, 1.22]. Conversely, presence (vs absence) of siblings (pooled OR 0.60, 95% CI: 0.44, 0.81) and maternal prenatal smoking (pooled OR 0.70, 95% CI: 0.58, 0.84) were associated with decreased JIA risk. CONCLUSION: This review identifies several environmental factors associated with JIA and demonstrates the huge breadth of environmental research undertaken over five decades. We also highlight the challenges of combining data collected over this period due to limited between study comparability, evolution in healthcare and social practices, and changing environment, which warrant consideration when planning future studies.
Assuntos
Artrite Juvenil/etiologia , Exposição Ambiental , Humanos , Fatores de RiscoRESUMO
BACKGROUND: Juvenile idiopathic arthritis associated uveitis (JIA-U) is the most common extra-articular manifestation of juvenile idiopathic arthritis (JIA) and carries considerable risk to vision. The aim of this systematic review was to synthesise evidence of environmental risk factors for JIA-U and identify risk factors which may be modifiable or used to stratify JIA patients. METHODS: This systematic review was carried out in accordance with PRISMA guidelines. Four online databases - Cumulative Index of Nursing and Allied Health Literature, Web of Science, MEDLINE and Embase - were searched from database inception to 12th August 2020. Identified studies were screened by two independent reviewers against pre-defined inclusion and exclusion criteria. Data was extracted from all primary studies meeting inclusion criteria and independently checked. RESULTS: We identified three studies from 895 unique records which met the inclusion criteria, each examining a different environmental risk factor. This systematic review includes 973, predominantly female, participants with JIA across these three studies. The use of allergy medication or documentation of "allergy"/"allergic" in the medical records was associated with an increased risk of JIA-U in all models presented. Vitamin D sufficiency was associated with reduced risk of JIA-U. There was insufficient evidence to support an association between seasonality and JIA-U. CONCLUSIONS: This review identifies a potential role for allergy and vitamin D in JIA-U. It also illustrates the paucity of data regarding environmental risk factors for JIA-U and highlights the need for further research to both identify additional risk factors and replicate existing findings.