title: Cohort Profile: Swedish Twin Study on Prediction and Prevention of Asthma (STOPPA).
abstract: Asthma is a common childhood disease and several risk factors have been identified; however, the impact of genes and environment is not fully understood. The aim of the Swedish Twin study On Prediction and Prevention of Asthma (STOPPA) is to identify environmental (birth characteristics and early life) and genetic (including epigenetic) factors as determinants for asthmatic disease. Based on the Child and Adolescent Twin Study in Sweden (CATSS) (parental interview at 9 or 12 years, N ~23,900) and an asthma and/or wheezing algorithm, we identified a sample of monozygotic (MZ) and dizygotic (DZ) same-sexed twin pairs. The twin pairs were classified as asthma concordant (ACC), asthma discordant (ADC) and healthy concordant (HCC). A sample of 9- to 14-year-old twins and their parents were invited to participate in a clinical examination. Background characteristics were collected in questionnaires and obtained from the National Health Registers. A clinical examination was performed to test lung function and capacity (spirometry with reversibility test and exhaled nitric oxide) and collect blood (serology and DNA), urine (metabolites), feces (microbiota), and saliva (cortisol). In total, 376 twin pairs (752 individual twins) completed the study, response rate 52%. All participating twins answered the questionnaire and >90% participated in lung function testing, blood-, and saliva sampling. This article describes the design, recruitment, data collection, measures, and background characteristics, as well as ongoing and planned analyses in STOPPA. Potential gains of the study include the identification of biomarkers, the emergence of candidates for drug development, and new leads for prevention of asthma and allergic disease.
authors.affiliation: Department of Medical Epidemiology and Biostatistics,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Catarina
authors.initials: C
authors.lastname: Almqvist
authors.affiliation: Department of Medical Epidemiology and Biostatistics,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Anne K
authors.initials: AK
authors.lastname: Örtqvist
authors.affiliation: Department of Medical Epidemiology and Biostatistics,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Vilhelmina
authors.initials: V
authors.lastname: Ullemar
authors.affiliation: Department of Medical Epidemiology and Biostatistics,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Lundholm
authors.affiliation: Department of Medical Epidemiology and Biostatistics,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Paul
authors.initials: P
authors.lastname: Lichtenstein
authors.affiliation: Department of Medical Epidemiology and Biostatistics,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Patrik K E
authors.initials: PK
authors.lastname: Magnusson
mesh_terms: D000293:Adolescent; D000465:Algorithms; D001249:Asthma / Q000453:epidemiology* / Q000235:genetics / Q000517:prevention & control; D001944:Breath Tests; D002648:Child; D004247:DNA / Q000097:blood; D004200:Diseases in Twins / Q000453:epidemiology* / Q000235:genetics / Q000517:prevention & control; D015777:Eicosanoids / Q000652:urine; D005243:Feces / Q000382:microbiology; D005260:Female; D005500:Follow-Up Studies; D006403:Hematologic Tests; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis; D008019:Life Style; D008297:Male; D064307:Microbiota; D009569:Nitric Oxide / Q000032:analysis; D010290:Parents; D011627:Puberty; D012042:Registries; D012107:Research Design; D012135:Respiratory Sounds; D012307:Risk Factors; D012463:Saliva / Q000737:chemistry; D013147:Spirometry; D013315:Stress, Psychological / Q000453:epidemiology; D011795:Surveys and Questionnaires; D013548:Sweden; D014429:Twins, Dizygotic / Q000523:psychology / Q000706:statistics & numerical data*; D014430:Twins, Monozygotic / Q000523:psychology / Q000706:statistics & numerical data*
chemical_list: D015777:Eicosanoids; D009569:Nitric Oxide; D004247:DNA; D006854:Hydrocortisone
keywords: allergic disease; asthma; concordance; discordance; epidemiology; epigenetic; genetic; lung function; twin