Family origin and mortality: prospective Finnish cohort study

BACKGROUND Death rates are notably higher in eastern Finland than in western Finland, and life expectancy of Finnish speakers shorter than that of Swedish speakers. The mortality differences correspond to recent genetic mappings of the population and are prominent for causes of death that are known to be associated with genetic risk factors. METHODS Using intergenerational data, we studied the impact of parental birth area on all-cause mortality risks of middle-aged men in Finland 1985-2003, assuming that geographic family origin reflects genetic predisposition to complex disorders. Relative death risks at ages 30-49 years were estimated by parental birth region and ethnicity, according to Cox regressions standardised for own education, family type at childhood, and year of birth. RESULTS The death risk of Finnish speakers born in eastern Finland was 1.13 (95% confidence interval 1.01 to 1.26) that of Finnish speakers born in western Finland, whereas that of Swedish speakers was only 0.60 (0.52 to 0.71). In Finnish speakers, the effects of own birth area and area of residence disappeared when parental birth area was accounted for. The death risk of persons with at least one parent born in eastern Finland was 1.23 (1.09 to 1.39) that of people with both parents born in western Finland. CONCLUSIONS Parental birth area is the driving force behind the regional mortality difference in Finland. The findings highlight and give further support for the potentially important role of genetic risk factors in mortality. Close monitoring of persons' geographic and ethnic ancestry may promote public health and avoid many early deaths.