Cardiovascular Effects of Unilateral Nephrectomy in Living Kidney Donors at 5 Years

Abstract

Kidney donation reduces renal function by ≈30% allowing study of the cardiovascular effects of a reduced estimated glomerular filtration rate without comorbidities. We report 5-year results of a longitudinal, parallel-group, blinded end-point study of living kidney donors (n=50) and healthy controls (n=45). The primary end point, left ventricular mass, was measured using cardiac magnetic resonance. Secondary end points, 24-hour ambulatory blood pressure, and pulse wave velocity were measured using validated blood pressure monitors and the SphygmoCor device. Effect sizes were calculated as differences between change from baseline in the donor and control groups. In donors, estimated glomerular filtration rate was 95±15 mL/min per 1.73 m2 at baseline (predonation) and 67±14 mL/min per 1.73 m2 at 5 years. In controls, there was a −1±2 mL/min per 1.73 m2 decline per annum. Change in left ventricular mass at 5 years was not significantly different between donors and controls (mean difference, +0.40 g [95% CI, −4.68 to 5.49] P =0.876), despite an initial increase in mass in donors compared with controls at 12 months. Pulse wave velocity, which increased in donors at 12 months, returned to levels not different from controls at 5 years (mean difference, −0.24 m/s [95% CI, −0.69 to 0.21]). Change in ambulatory systolic blood pressure was not different in donors compared with controls (mean difference, +1.91 mm Hg [95% CI, −2.72 to 6.54]). We found no evidence that the reduction in estimated glomerular filtration rate after kidney donation was associated with a change in left ventricular mass detectable by magnetic resonance imaging at 5 years.