Kidney transplantation improves baroreceptor sensitivity

Kidney transplant recipients as well as patients on hemodialysis frequently share an increased risk of cardiovascular diseases. Besides other factors, modulations in central neural blood pressure regulation have to be considered as a pathogenetic factor. In this study, baroreceptor function as a possible modulator of blood pressure and the activity of the generating components of the sympathetic nervous system were estimated in 20 kidney transplant recipients, 20 normotensive patients on hemodialysis and 20 age-matched volunteers using the sequence analysis technique and Fast Fourier Transformation (FFT). No blood pressure differences could be measured (83.7 ± 2.5 vs. 82.5 ± 3.8 vs. 79.2 ± 2.4 mm Hg). Pulse interval-blood pressure sequences and the slope of Δ pulse interval/Δ mean arterial blood pressure of these sequences, representing baroreceptor sensitivity, did not differ between kidney transplant recipients and controls (11.2 ± 1.4 vs. 13.4 ± 1.3 ms/mmHg), whereas in hemodialysis patients a reduced baroreceptor sensitivity (5.2 ± 1.2 ms/mmHg) was detected. The 66–129 mHz component (Mayer waves) of heart rate and blood pressure spectrum in normals (650 ± 57 and 630 ± 70 modulus) significantly (p< 0.05) exceeded its equivalent in kidney transplant recipients (430 ± 32 and 452 ± 27 modulus) and patients on hemodialysis (375 + 38 and 394 ± 40 modulus). In conclusion, our study provided evidence that both in kidney transplant and dialysis patients a decreased activity of the generating compounds of the sympathetic nervous system can be detected as compared to healthy volunteers. In contrast to hemodialysis patients, the baroreceptor sensitivity is unaffected in kidney transplant recipients and may, therefore, not contribute to the development of cardiovascular diseases.