title: Are twins and singletons comparable? A study of disease-related and lifestyle characteristics in adult women.
abstract: The classic twin study is sometimes described as "the perfect natural experiment" for the investigation of the aetiology of complex disease, but assumptions of the twin design need to be empirically tested if their results are to be considered unbiased and representative of singleton populations. In this study comparisons of disease and prevalence of lifestyle characteristics have been made between twin participants in the St Thomas' Hospital UK adult twin registry, the largest twin volunteer register in the UK for the study of diseases of ageing, and a parallel population-based study of singleton women. The only differences found were for weight, where monozygotic (MZ) twins were lighter and had a smaller variance than dizygotic (DZ) twins and singletons. For the other variables studied, volunteer twins were not found to differ from age-matched singleton women in distribution or prevalence of: bone mineral density, osteoarthritis, blood pressure, hypertensive drug use, height, history of hysterectomy and ovariectomy, menopausal status and current alcohol and overall tobacco consumption. We conclude that the results of twin studies can be generalised to singleton populations for these measures and disease outcomes.
authors.affiliation: Twin Research and Genetic Epidemiology Unit, St Thomas' Hospital, London, UK. toby.andrew@kcl.ac.uk
authors.forename: T
authors.initials: T
authors.lastname: Andrew
authors.forename: D J
authors.initials: DJ
authors.lastname: Hart
authors.forename: H
authors.initials: H
authors.lastname: Snieder
authors.forename: M
authors.initials: M
authors.lastname: de Lange
authors.forename: T D
authors.initials: TD
authors.lastname: Spector
authors.forename: A J
authors.initials: AJ
authors.lastname: MacGregor
mesh_terms: D000428:Alcohol Drinking / Q000453:epidemiology; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001794:Blood Pressure; D001827:Body Height; D015519:Bone Density; D005260:Female; D006801:Humans; D008019:Life Style; D008593:Menopause; D008875:Middle Aged; D009017:Morbidity; D010003:Osteoarthritis / Q000453:epidemiology; D012907:Smoking / Q000453:epidemiology; D012923:Social Class; D014427:Twins
chemical_list: D000959:Antihypertensive Agents