Abstract:
Although the tight connection of the cardiovascular system and the kidneys is well
known, using of cystatin C (Cys-C) opens new horizons in studying early renal failure
stages. The study aimed to compare the functional status of the kidneys in patients with
hypertension and extrasystole to the level of Cys-C. 156 patients with stage II
hypertension (EH II) were examined. 124 of them had frequent symptomatic extrasystoles
(74 - of supraventricular origin and 50 - ventricular), 32 patients had no arrhythmias,
and were referred to the comparison group. The control group consisted of 30 healthy
people with normal blood pressure (BP). All patients underwent a complete clinical
examination, blood pressure measurement, daily blood pressure monitoring, daily
electrocardiogram monitoring, echocardiography, and determination of renal function
(creatinine, blood electrolytes, serum cystatin C) followed by calculation of glomerular
filtration rate (GFR). The level of Cys-C in patients with hypertension was significantly
higher (p<0.001) compared with healthy individuals. Among patients with arrhythmias,
the highest level of Cys-C was noted in patients with ventricular arrhythmias. The
correlation analysis showed that the level of Cys-C was higher in the presence of
frequent extrasystoles (namely of ventricular origin), smoking, high blood pressure,
increased systolic and pulse blood pressure, the presence of concentric left ventricular
hypertrophy, dyslipidemia, increased creatinine level and decreased GFR. All three EH
II patient groups had significantly lower GFR (calculated by creatinine level) (p<0.001).
The lowest creatinine-based GFR was revealed in patients with ventricular extrasystole.
All patients with EH II had significantly lower Cys-C based GFR than the control group
(p<0.001). Mean Cys-C-based GFR values in patients with extrasystole were significantly
lower than in patients without extrasystole (p<0.03). The analysis of GFR levels depending
on the extrasystole origin was provided. The lowest level of GFR was recorded in
patients with ventricular extrasystole. It was significantly different from the patients with
supraventricular extrasystole (p=0.02). Our findings confirm the opinion of other
researchers that Cys-C is an early marker of renal dysfunction in patients with
hypertension, which is more sensitive than creatinine. Another finding is that ventricular
extrasystole is more hemodynamically and metabolically unfavorable compared to
supraventricular based on clinical and prognostic evaluation
