Subprojects from old cohort
GenomEUtwin (PI Leena Peltonen) is a European Union-funded project running from 2002 to 2007 that combines twin cohorts/registers from seven European countries (Denmark, Finland, Italy, the Netherlands, Norway, Sweden and United Kingdom) and Australia. The GenomEUtwin sample consists of almost 700.000 twin pairs. We have participated in studies of height, BMI, migraine, cardiovascular risk factors, coronary heart disease and stroke, and longevity as part of the project. In the project standard operating procedures and standardized data reporting procedures have been developed. To permit multicentre analyses without jeopardizing data security, a federated database has been created. A 2003 special issue of Twin Research was devoted to the project, to which the reader is referred (Peltonen, 2003).
The Finnish Twin Study on Aging (FITSA) lead by Professor Taina Rantanen is a study of genetic and environmental effects on the disablement process in older female twins. Four hundred and fourteen female pairs aged 63 to 76 years old and alive in 2000 were initially contacted. Further description of the participation in FITSA was reported earlier (Pajala et al., 2004; Tiainen et al., 2004; Tiainen et al., 2005). The final study sample at baseline included 103 MZ and 114 DZ complete pairs, who participated in a 1-day laboratory assessment of functional abilities (such as muscle strength, walking speed, balance), and health status (such as hearing ability and risk of falls during a 1-year follow-up) at the University of Jyväskylä. Three years later an invitation to participate in the follow-up examinations was sent to all baseline participants. As 106 individuals consented to participate solely in an interview, the follow-up sample consisted of 145 MZ and 168 DZ individuals after excluding deceased subjects and refusals. These 313 twins participated in the laboratory measurements in addition to the interview.
Study on older twins
In collaboration with the University of Turku and the Turku PET Centre, elderly (born before 1938) MZ and DZ twins were being screened to identify twin pairs discordant with respect to Alzheimer's disease. Screening was completed in 2006. Out of a large number of twin pairs, we first identified a small sample of MZ pairs discordant for dementia. These pairs were then invited for clinical assessment and underwent extensive neuroimaging using MRI and PET imaging (Järvenpää et al., 2004; Järvenpää et al., 2003a; Järvenpää et al., 2003b). We have shown that binge-drinking in middle age predicts dementia 25 years later (Järvenpää et al., 2005)