P4.11 ENDOTHELIAL DYSFUNCTION IN URBANIZED AFRICANS WITH LOW PLASMA RENIN LEVELS: THE SABPA STUDY

Abstract

Background and objectives: It is known that high renin levels could damage the vasculature and may cause retinal detachment, stroke, heart failure and kidney failure. The objective of this part of the SABPA study was to determine if renin levels in low and high renin participants could contribute to endothelial dysfunction. Methods: This part of the SABPA study consisted of 113 black urbanized Africans (men and women) from the same socio-economic status (school teachers) from South Africa. The participants were stratified into low (<6.18 pg/ml) and high (≥6.18 pg/ml) renin levels. Blood pressure and other variables were determined with known methods. Active renin levels were determined with a radio-immunometric assay (Renin III Generation, CIS bio-international, Cedex, France). The Von Willebrand Factor (vWF) was analysed with ELISA assay. (DAKO, SA). A calorimetric method were used for urine creatinine and a turbidimetric method for albumin measurement. Results: In single regression analysis, renin levels associated negatively with the Von Willebrand Factor (r=−0.3756; p=0.016) only in the low renin African men. With partial regression analysis after adjustment for age and BMI, the association remained. Renin levels also associated negatively (r=−0.4846; p=0.002) with systolic blood pressure only in low renin men. No associations could be encountered with markers of inflammation (IL-6; CRP and TNF-α) as well as stiffness. Conclusion: The results revealed that renin causing endothelial dysfunction in low renin African men and may lead to high blood pressure in later life.