Kidney function and thickness of carotid intima-media complex in patients with treated arterial hypertension.

The aim of the study was to evaluate of the association between renal function and the intima-media thickness of common carotid artery (CCA-IMT) in treated hypertensive patients. Eighty-seven hypertensives (51.7% diabetic), aged >45 years, were examined. Renal function was evaluated by plasma concentration of creatinine, cystatin C (in 64 patients) and creatinine clearance, calculated according to the Cockcroft-Gault formula. HbA1c measurement and blood pressure monitoring were performed. CCA-IMT was measured at near and far wall of the CCA and of the bulb on both sides and averaged. In 63 hypertensives (72.4%) IMT was over 0.9 mm. These subjects were older (71.17+/-9.72 vs 57.75+/-7.76 years; p<0.0001), had higher pulse pressure (57.45+/-11.73 vs 49.35+/-8.35, p = 0.004), cystatin C concentration (1.25+/-0.34 vs 0.99+/-0.17 mg/l; p = 0.002), higher HbA1c (7.24+/-1.59 vs 6.25+/-1.28, p = 0.01), and lower creatinine clearance (71.28+/-28.32 vs 93.86+/-25.04; p<0.0001) in comparison to patients with IMT <0.9 mm. Groups did not differ with respect to creatinine concentration. The logistic regression analysis showed that CCA-IMT was independently influenced only by age, and the effect of age was stronger in older patients. After exclusion of age, 0.1 mg/l higher concentrations of cystatin C or 10 ml/min lower estimated creatinine clearance were significantly associated with 56% and 34%, respectively, higher probability of CCA-IMT of more than 0.9 mm. Cystatin C concentration seems to be a useful indicator of renal function impairment associated with carotid intima-media thickening. Similar information is obtained when estimated creatinine clearance is used.