Hypertensive Live Kidney Donors Have An Exaggerated Increase in Serum Creatinine in the Post Donation Period Compared with Age and Sex Matched "Normotensive" Controls

Background: The number of live donor kidney transplantation in the United Kingdom is increasing1. There is evidence for better graft and recipient outcomes compared to cadaveric kidney transplantation2. Hypertensive individuals are being accepted in live related programs as part of an effort to increase the number of transplantation. However, little is known of the trajectory of serum creatinine after donation in hypertensive live kidney donors. Method: Medical records and laboratory results of 121 living kidney donors from our database of live donations from 2002 to 2010 were reviewed. Donors with hypertension at first clinic visit [defined as blood pressure > 130/80mmHg] or who was taking anti-hypertensive for known hypertension were identified. Serial creatinine following nephrectomy was analysed. Peak creatinine was identified and proportional change in creatinine was calculated as: (peak creatinine - pre-operative creatinine) ÷ pre-operative creatinine. The proportional change in creatinine was compared with sex and age matched “normotensive” live donors. Results: 24 live donors [age range 27 - 66 years, 13 males and 11 females] were identified. 11 patients were on anti-hypertensive medication(s). The proportional change in creatinine was significantly greater in the hypertensive group compared with age and sex matched controls {0.7 [95% CI 0.63-0.79] vs 0.6 [95% CI 0.53-0.67]; P value 0.0337}. There was no difference in pre-donation creatinine between the groups {mean creatinine 75 μmol/l vs 77 μmol/l; P value 0.50}. Conclusion: To our knowledge, no study has looked at the effect of kidney donation on future creatinine in hypertensive donors. Our results indicate that there is an exaggerated change in creatinine in the immediate post donation period in hypertensive donors compared with “normotensive” age and sex matched donors. This may be due to a difference in the adaptive capability of the single kidney in hypertensive donors. It may be a marker of future renal function, but further studies are necessary with larger numbers of donors and longer period of follow-up to confirm these findings. This also raises the question of how to counsel hypertensive prospective donors prior to nephrectomy.