Renal function and its association with blood pressure in Middle Eastern immigrants and native Swedes.

Abstract

Iraqi-born immigrants residing in Sweden are at high risk for type 2 diabetes, obesity and hyperlipidemia compared with native Swedes. Paradoxically, hypertension is less prevalent in this immigrant population. The aim of this study was to investigate differences in renal function and further if differences in blood pressure (BP) levels were associated with differences across ethnicities in renal function as a possible explanation to the paradox. A population-based, cross-sectional study of men and women, born in Iraq or Sweden, aged 30-75 years was conducted in Malmö, Sweden, from 2010 to 2012. Blood samples were drawn, physical examinations performed and self-administrated questionnaires were assessed. Estimated glomerular filtration rate (eGFR) was calculated from the Caucasian Asian Pediatric Adult cohort formula based on cystatin C. Participants without history of cardiovascular disease born in Iraq (n = 1214), irrespective of age and sex, presented with higher eGFR than participants born in Sweden (n = 659), (96.5 ml/min per 1.73 m vs. 93.6, P = 0.009). Furthermore, eGFR showed weaker association with BP in Iraqis than in Swedes, especially for SBP. The relationship was confirmed by a significant interaction between eGFR and country of birth (Pinteraction country of birth × eGFRcystatinC = 0.004). The current study shows differences across ethnicities in renal function and its associations with BP. More studies are needed to understand mechanisms contributing to BP regulation and renal function in populations of different ethnic backgrounds.