To Study the Impact of Donor Nephrectomy on Blood Pressure as Measured by Ambulatory Blood Pressure Monitoring and Renal Function

Prospective living kidney donors need meticulous evaluation prior to kidney donation. Ambulatory blood pressure monitoring (ABPM) is considered the reference standard for diagnosing hypertension. With no prior study available in India in this context, we undertook this study to evaluate the utility of ABPM in kidney donors and effect of donor nephrectomy on renal function. This was a prospective observational study involving healthy prospective kidney donors between 18 and 70 years with normal office blood pressure measurements (OBPM). Detailed clinical and biochemical parameters were recorded. OBPM and 24-hour ABPM was done preoperatively and 3 months following donor nephrectomy. There were 51 donors with a mean age of 46.1 +/- 11.3 years, of which 40 (78.4%) were females. Preoperatively, three (5.8%) donors were hypertensive on ABPM but normal on OBPM (P = 0.08). Three months post nephrectomy, hypertension was present in seven (13.7%) donors by ABPM, while only two (3.9%) donors were diagnosed as hypertensive by OBPM (P = 0.02). Median pre-nephrectomy proteinuria was 70 mg (10 mg-180 mg) with a mean estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease (MDRD) formula of 86.86 +/- 19.1 ml/min. Six donors developed > 300 mg/day proteinuria, and 17 (33.3%) had a 24-hour urinary protein excretion greater than 150 mg/day. Mean serum creatinine (0.79 +/- 0.11 vs 1.03 +/- 0.16 mg/dl) significantly increased post donation, more so in donors > 55 years of age (1.14 +/- 0.25 mg/dl). Our study shows that in transplant donors, ABPM is better for diagnosing hypertension, which otherwise remains masked in 10% of the donors on routine OBPM. Significance of post-nephrectomy hypertension and increasing proteinuria needs further evaluation.