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- Almqvist, Catarina, et al.
(författare)
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The impact of birth mode of delivery on childhood asthma and allergic diseases : a sibling study
- 2012
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Ingår i: Clinical and experimental allergy. - Stockholm : Karolinska Institutet, Dept of Medical Epidemiology and Biostatistics. - 1365-2222 .- 0954-7894.
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Tidskriftsartikel (refereegranskat)abstract
- Background: Caesarean section (CS) has been reported to increase the risk of asthma in offspring. This may be due to that infants delivered by CS are unexposed to vaginal flora, according to the ‘hygiene hypothesis’. Objective: Our aim was to investigate if CS increases risk of childhood asthma, and if the risk increase remains after adjustment for familial confounding using sibling design. Methods: A register-based cohort study with 87 500 Swedish sibling pairs was undertaken. Asthma outcome variables were collected from national health registers as diagnosis or asthma medication (ICD-10 J45-J46; ATC code R03) during the 10th or 13th year of life (year of follow-up). Mode of delivery and confounders were retrieved from the Medical Birth Register. The data were analysed both as a cohort and with sibling control analysis which adjusts for unmeasured familial confounding. Results: In the cohort analyses, there was an increased risk of asthma medication and asthma diagnosis during year of follow-up in children born with CS (adjusted ORs, 95% CI 1.13, 1.04–1.24 and 1.10, 1.03–1.18 respectively). When separating between emergency and elective CS the effect on asthma medication remained for emergency CS, but not for elective CS, while both groups had significant effects on asthma diagnosis compared with vaginal delivery. In sibling control analyses, the effect of elective CS on asthma disappeared, while similar but non-significant ORs of medication were obtained for emergency CS. Conclusions and Clinical Relevance: An increased risk of asthma medication in the group born by emergency CS, but not elective, suggests that there is no causal effect due to vaginal microflora. A more probable explanation should be sought in the indications for emergency CS.
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| 2. |
- Tedner, Sandra G, et al.
(författare)
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Fetal growth and risk of childhood asthma and allergic disease
- 2012
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Ingår i: Clinical & Experimental Allergy. - Stockholm : Karolinska Institutet, Dept of Medical Epidemiology and Biostatistics. - 1365-2222 .- 0954-7894.
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Early genetic and environmental factors have been discussed as potential causes for the high prevalence of asthma and allergic disease in the western world, and knowledge on fetal growth and its consequence on future health and disease development is emerging. Objective: This review article is an attempt to summarize research on fetal growth and risk of asthma and allergic disease. Current knowledge and novel findings will be reviewed and open research questions identified, to give basic scientists, immunologists and clinicians an overview of an emerging research field. Methods: PubMed-search on pre-defined terms and cross-references. Results: Several studies have shown a correlation between low birth weight and/or gesta- tional age and asthma and high birth weight and/or gestational age and atopy. The exact mechanism is not yet clear but both environmental and genetic factors seem to contribute to fetal growth. Some of these factors are confounders that can be adjusted for, and twin studies have been very helpful in this context. Suggested mechanisms behind fetal growth are often linked to the feto-maternal circulation, including the development of placenta and umbilical cord. However, the causal link between fetal growth restriction and subse- quent asthma and allergic disease remains unexplained. New research regarding the catch-up growth following growth restriction has posited an alternative theory that dis- eases later on in life result from rapid catch-up growth rather than intrauterine growth restriction per se. Several studies have found a correlation between a rapid weight gain after birth and development of asthma or wheezing in childhood. Conclusion and clinical relevance: Asthma and allergic disease are multifactorial. Several mechanisms seem to influence their development. Additional studies are needed before we fully understand the causal links between fetal growth and development of asthma and allergic diseases.
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| 3. |
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| 4. |
- Flanigan, Catherine, et al.
(författare)
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Prenatal maternal psychosocial stress and offspring’s asthma and allergic disease : a systematic review and meta-analysis
- 2018
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Ingår i: Clinical & Experimental Allergy. - Stockholm : Karolinska Institutet, Dept of Medical Epidemiology and Biostatistics. - 1365-2222 .- 0954-7894.
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Prenatal maternal stress may influence offspring's atopic risk through sustained cortisol secretion resulting from activation of the hypothalamic-pituitary-axis (HPA), leading to Th2-biased cell differentiation in the fetus. We undertook a systematic review and meta-analysis investigating the relationship between prenatal maternal psychosocial stress and risk of asthma and allergy in the offspring. METHODS: We searched 11 electronic databases from 1960 to 2016, search the grey literature, and contacted experts in the field. Type of stress indicator included mood disorders, anxiety, exposure to violence, bereavement and socio-economic problems occurring during pregnancy, both objectively or subjectively measured. We included all possible asthma and IgE-mediated allergy outcomes. We conducted random-effects meta-analyses to synthesize the data. RESULTS: We identified 9,779 papers of which 30 studies (enrolling >6 million participants) satisfied inclusion criteria. The quality of 25 studies was moderate, four were strong, and one was weak. Maternal exposure to any type of stressors was associated with an increased risk of offspring atopic eczema/dermatitis (OR 1.34, 95%CI 1.22-1.47), allergic rhinitis (OR 1.30, 95%CI 1.04-1.62), wheeze (OR 1.34, 95%CI 1.16-1.54) and asthma (OR 1.15, 95%CI 1.04-1.27). Exposure to anxiety and depression had strongest effect compared to other stressors. Exposure during the third trimester had the greatest impact compared to first and second trimesters. The increased risk was stronger for early-onset and persistent than for late-onset wheeze. Bereavement of a child (HR 1.28, 95%CI 1.10-1.48) or a spouse (HR 1.40, 95%CI 1.03-1.90) increased the risk of offspring asthma. CONCLUSIONS: Exposure to prenatal maternal psychosocial stress was associated with increased risk, albeit modestly, of asthma and allergy in the offspring. The pronounced risk during the third trimester may represent cumulative stress exposure throughout pregnancy rather than trimester-specific effect. Our findings may represent a causal effect or a result of inherent biases in studies, particularly residual confounding.
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| 5. |
- Tedner, Sandra G, et al.
(författare)
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Depression or anxiety in adult twins is associated with asthma diagnosis but not with offspring asthma
- 2017
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Ingår i: Clinical & Experimental Allergy. - Stockholm : Karolinska Institutet, Dept of Medical Epidemiology and Biostatistics. - 1365-2222 .- 0954-7894.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: Asthma is common in both children and adults in the Western world, just like anxiety and depression. While some research has revealed that these diseases might share important environmental and pathophysiological aspects, the exact mechanisms still remain unclear. Objective: To study the correlation firstly between depression or anxiety and asthma diagnosis in adult twins, and secondly the association between parental depression or anxiety and offspring asthma in children of twins. Methods: In total, 24,685 adult twins aged 20-47 years were interviewed or completed a web-based questionnaire and their children were identified through the Multi-Generation Register. Asthma diagnosis was obtained from the Patient Register and the Prescribed Drug Register. Assessment of depression and anxiety was obtained from questionnaires using Center for Epidemiologic Studies Depression Scale (CES-D), Major Depression and Generalized Anxiety Disorder (GAD) from DSM-IV. The association between depression or anxiety and asthma was analyzed with logistic regression adjusting for confounders in twins and offspring. To address genetic and familial environmental confounding we performed a co-twin analysis using disease-discordant twin pairs. Results: We found an association between asthma and CES-D, major depression and GAD, e.g. adjusted OR for major depression and register-based asthma 1.56(1.36-1.79). Most of the point estimates remained in the co-twin control analysis, indicating that the association was likely not due to genetic or familial environmental factors. There was no association between parental depression and/or anxiety and asthma diagnosis in the offspring which implies lack of genetic confounding. Conclusions: We found an association between own asthma diagnosis and anxiety or depression, but not with offspring asthma. Our results indicate that the associations were not due to confounding from genes or environment shared by the twins.
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