Ethnic differences in blood pressure in young men living in similar environment: a study of international adoptees in Sweden

Objective To analyze differences in blood pressure in young men with different ethnic backgrounds but living in similar environment. Methods We utilized information on virtually the total Swedish male population born between 1951 and 1987 including 5388 international adoptees, 8834 Swedish adoptees and 1 469 196 Swedish nonadoptees. Systolic blood pressure (SBP), height and weight were measured during conscription examination at the average age of 18.2 years. Results SBP was lower in international adoptees than in native-born Swedes regardless of the geographic area of origin of the adoptees. BMI and height partly explained this difference, but additional adjustment for childhood social position only slightly modified the results. The largest difference was observed in adoptees from the Indian subcontinent when compared with native-born Swedes (-5.21 95% confidence intervals -6.16 to -4.27 when adjusted for height, BMI and childhood social position). Slightly lower SBP was also observed in Swedish adoptees when compared with Swedish nonadoptees. The association between BMI and SBP did not differ between international adoptees and native-born Swedes. Conclusion Our results suggest that international adoptees are not at higher risk for elevated blood pressure in young adulthood than native-born Swedes. Non-white genetic heritage or environmental exposures during pregnancy or in early life specific for adopted children may be associated with lower risk of hypertension. J Hypertens 28: 1393-1399 (C) 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins.