East-west differences and migration in Finland: Association with cardiometabolic risk markers and IMT. The Cardiovascular Risk in Young Finns Study

BACKGROUND: Coronary heart disease mortality has been internationally high in eastern Finland. The excessive mortality risk in Eastern compared with western Finns is explained by differences in cardiometabolic risk profile. Current risk profile differences and association with migration have not been reported. We examined the association of place of residence (east-west) and specifically migration with cardiometabolic risk markers and carotid intima-media thickness (IMT).

METHODS: The study population included 2204 participants with data available from childhood/youth in 1980 and follow-up examination in 2007.

RESULTS: Participants residing in eastern Finland in adulthood had 0.022±0.004mm higher IMT than Western participants. Those who migrated east-to-west had lower IMT than those staying in the east (0.027±0.006mm, p<0.0001) while no difference to those continuously living in the west was found. Those who moved east-to-west had a lower body mass index (25.3±4.3 kg/m² vs. 26.2±4.5kg/m², p=0.01), waist circumference (85.7±12.8cm vs. 88.6±12.8cm, p=0.001), prevalence of metabolic syndrome (13% vs. 21%, p=0.01), and higher socioeconomic status (16.6±3.3 vs. 15.0±3.3 school years, p<0.0001) than those who stayed in the east.

CONCLUSIONS: Higher IMT was found in eastern Finns than in western Finns. Participants who migrated east-to-west had a lower IMT and a better cardiometabolic risk profile than those who stayed in the east.