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AlzRisk Cohort Detail

Cohort: Swedish Twin Registry
Risk Factors:

Introduction to the Cohort
The Swedish Twin Registry (STR) was established in the late 1950s by the Karolinska Institute in Sweden to study the impact of smoking and alcohol consumption on cancer and cardiovascular disease while controlling for genetic factors. The STR is the largest twin registry in the world with over 86,000 pairs of twins. It consists of several birth cohorts. The first cohort consists of like-sexed twins born between 1886 and 1925 in Sweden. In the 1970s the registry was expanded to include twins born between 1926 and 1967, and in 1993, twins born between 1959 and 1990 were recruited via record linkage to the medical birth registry.

Investigators sent out questionnaires to the older cohorts in 1961, 1963, 1967, 1970 and 1973 to obtain information about health-related behaviors such as smoking, diet, physical activity, personality and exposure to environmental stressors. The STR is regularly matched to an address registry, as well as the cancer registry and the cause of death registry in Sweden.

Several aging studies have been conducted within the STR, including the Swedish Adoption and Twin Study of Aging (SATSA), Origins of Variance in the Oldest-Old (OCTO-TWIN; a subcohort of twin pairs who were at least 80 years old in 1991) and Study of Dementia in Swedish Twins (HARMONY; a subcohort of participants who were at least 65 years old in 1998). Other complex diseases are investigated in separate STR projects such as the Screening Across the Lifespan Twin Study (SALT).

Ethnicity Breakdown
All participants were residents of Sweden.

Diagnosis & Evaluation Methods
For detailed descriptions of the structure of the Swedish Twin Registry, see Lichtenstein, et al. 2002 and Lichtenstein et al. 2006.

Lichtenstein P, de Faire U, Floderus B et al. The Swedish Twin Registry: a unique resource for clinical, epidemiological and genetic studies. J Intern Med 2002; 252: 184-205.

Lichtenstein P, Sullivan PF, Cnattingius S, Gatz M, Johansson S, Carlström E, Björk C, Svartengren M, Wolk A, Klareskog L, de Faire U, Schalling M, Palmgren J, Pedersen NL. The Swedish Twin Registry in the third millennium: an update. Twin Res Hum Genet. 2006 Dec;9(6):875-82.