Dominance of traditional cardiovascular risk factors over renal function in predicting arterial stiffness in subjects with chronic kidney disease

BACKGROUND: The predictors of arterial stiffness across the spectrum of renal function are unclear. These predictors were investigated across a wide range of estimated glomerular filtration rates (eGFR). METHODS: Carotid-femoral pulse wave velocity (PWV; an index of arterial stiffness) was measured in 264 subjects with chronic kidney disease (CKD) stages 3-5 from three nephrology clinics ('lower GFR group'). PWV was also measured in 149 subjects without previously recognized CKD ('higher GFR group') including n = 26 with eGFR between 30 and 60 ml/min/1.73 m(2) and n = 123 with eGFR between 60 and 100 ml/min/1.73 m(2). The association between PWV and eGFR was investigated using linear regression. RESULTS: The 413 subjects had a mean age of 61.9 years, were 51% male, 28% diabetic and 79% hypertensive. In age-adjusted analyses within the 'lower GFR group', 'higher GFR group' and combined group, PWV correlated with higher systolic blood pressure (SBP), pulse pressure (PP), diabetes mellitus, body mass index (BMI) and resting heart rate (all P < 0.0008). In addition, PWV correlated inversely with eGFR in the 'higher GFR group' (P = 0.03) and combined group (P < 0.0001). In multivariable regression analyses of the combined group (n = 413), PWV was independently predicted by eGFR (P < 0.05). However, eGFR explained at most 4% of the variability in PWV in age-adjusted analyses (compared with 13-15% explained by SBP, PP or diabetes) and <1% of PWV variability in models adjusting for age, SBP, diabetes, heart rate and BMI (P < 0.0001). CONCLUSION: Although eGFR may independently predict PWV, the contribution of GFR per se does not appear to be clinically meaningful when compared with traditional cardiovascular risk factors.