Renal Transplantation Significantly Improves Autonomic Function with Normalization of Baroreflex Sensitivity as Early as Three-Month Post-transplantation.

The most common cause of mortality in chronic kidney disease patients is cardiovascular events. Cardiovascular autonomic dysfunction is likely to contribute high incidence of cardiovascular mortality, and in addition to adrenergic overdrive in these patients, there is the presence of impaired reflex control of both sympathetic and parasympathetic outflow to the heart and vasculature. Very few studies are available which show that renal transplantation (RT) improves the baroreflex function along with improvement in cardiovascular variability parameters. This prospective study was designed for the assessment of the autonomic function, i.e., heart rate variability (HRV), blood pressure variability (BPV), and baroreflex sensitivity (BRS) in end-stage renal disease (ESRD) patients before RT and three and six months after RT and to study the effects of RT on cardiac and vascular autonomic tone and on BRS. We studied 81 ESRD patients prospectively slated for RT but only 64 patients (mean age: 33 years) completed both three and six months visits after RT for autonomic function study. Patients were evaluated in detail clinically as well as routine biochemical parameters were done on every three visits. Baroreflex function was quantified by the sequence method. Assessment of short-term HRV and BPV were done using power spectrum analysis of RR intervals and systolic BP by frequency domain analysis. The parameters of HRV after RT showed significant changes in high-frequency domain measures six months post-RT but not in low frequency. HRV in total power was also statistically significant as early as three months postrenal transplant and remained at six months. The favorable effect of RT on decreasing BPV and improving BRS is seen by as early as three months.