Background: Patients with mild or moderate chronic kidney disease (CKD) are know to have a significant increase in cardiovascular morbidity in which alterations in large arterial as well as endothelial function may play a role. In the present study, we investigated the relationship between glomerular filtration rate (GFR), augmentation index and endothelial function.

Methods: Cross sectional study with healthy controls (CONT, n = 16), patients with essential hypertension (EH, n = 14), and those with essential hypertension and peripheral artery disease (EH+PAD, n = 26). The effect of postocclusive reactive hyperemia (PORH; 220 mmHg, 3 min, %) was measured on skin microcirculation with laser Doppler flowmetry (Periflux 5001). Augmentation index (Aix, %) was evaluated with the newly developed TensioClinic Arteriograph instrument which registers the pulse wave curves with the oscillometric method and automatically calculates AIx. GFR was estimated by the Cocroft-Gault formula.

Results: PORH, AIx and GFR were significantly different in healthy controls (−65.08%; 37.56%; 110.14ml/min) compared to the different patient groups: EH (294.43%; −29.87%; 86.18 ml/min) and EH+PAD (196.81%; 7.75%; 56.15ml/min). Subjects were divided into three groups based on their GFR: 1. GFR > 90; 2. 90 > GFR > 60; 3. 60 > GFR > 30. In the different groups of GFR a deterioration of PORH (1.: 328.54%; 2.: 278.67%; 3.: 200.85%) and AIx (−58.38%; −2.73%; 8.80%) was observed (all p < 0.05). Significant (p < 0.01) correlation was found between GFR and PORH (r = 0.50), and between GFR and AIx (r = −0.81).

Conclusions: AIx and PORH is associated with early renal function loss, suggesting that arterial stiffening and endothelial dysfunction may be involved in the vascular complications of CKD.