1.1 ARTERIAL STIFFNESS IS RELATED TO RENAL FUNCTION IN THE GENERAL POPULATION

Abstract

Introduction: Aortic stiffness is related to renal function in patients with chronic kidney disease and may contribute to the high cardiovascular mortality in this group. However, the relationship between renal function and arterial haemodynamics in the general population has not previously been reported. Methods: We analysed the relationship between renal function defined by estimated GFR (eGFR) and aortic pulse wave velocity (aPWV), brachial PWV (bPWV) and radial and central wave reflections (rAIx and cAIx) for participants enrolled in the Anglo-Cardiff Collaborative Trial between 2000–2009. Results: Measurement of eGFR was available for 4795 participants with a mean age of 48±23 years, 45.5% male, BP 130±20/77±11, mean eGFR 92.7±38.8mL/min. Estimated GFR was correlated with aPWV (rho=−0.53*), bPWV (rho=−0.28*), rAIx (rho=−0.20*) and cAIx (−0.25*) (all P<0.001). In multivariate analysis, using a stepwise model including age, mean BP, gender, heart rate, glucose, cholesterol, body mass index and smoking, eGFR remained an independent determinant of aPWV (R2=0.68, P<0.001), rAIx (R2=0.72, P<0.001) and cAIx (R2=0.72, P<0.001) but not bPWV. After exclusion of people with previous CHD, CVA or diabetics (n=4247), eGFR remained an independent predictor of rAIx and cAIx but not of aPWV. Conclusion: In the largest analysis of the general population to date, eGFR is independently associated with aortic stiffness and augmentation index but explains little of the variance compared with established determinants. For aortic stiffness, but not wave reflections, this relationship is explained by the coexistence of impaired renal function and vascular disease.