The cardiovascular risk in young Finns (YFS) study is a stratified random sample of children and adolescents aged 3–18 years from five university cities and surrounding areas with medical schools.21, 22 Subjects were born in years 1962, 1965, 1968, 1971, 1974 and 1977 and followed up every 3–5 years, beginning in 1980. Temperament data used in these analyses were collected in 2001; 2105 persons had valid phenotype data, and of these 1383 were genotyped and passed QC (54% female). The mean age of participants was 32.5 (±5.1) years.
