Long-term effects of kidney donation on renal function and blood pressure in African Americans

African Americans (AAs) have four times higher prevalence of ESRD than Caucasians. Therefore, long-term effects of kidney donation are of considerable importance in this patient population.

GFR was measured by (125)I-iothalamate clearance, 24-hour urine albumin excretion, and 24-hour BP monitoring in 33 AAs and 11 CAs who donated kidneys for transplantation 5 to 23 years previously.

Mean GFRs were 76 ± 13 and 78 ± 11 ml/min per 1.73 m(2) for AA and CA donors, respectively. Nine percent of the AA donors and none of the CA donors had GFRs below 60 ml/min per 1.73 m(2). AA donors had a tendency for lower prevalence of microalbuminuria compared with CA donors (18.1% versus 36.3%) and a tendency for higher prevalence of macroalbuminuria compared with CAs (12.1% versus 0.0%). Twenty-four percent of the AAs, and 45% of the CAs were hypertensive with mean daytime BP ≥135/85 mmHg. Only 6% of AAs had a decrease in mean nocturnal systolic BP of 10% or more as compared with daytime readings. Older age at time of donation was associated (P = 0.046) with lower GFR values compared with younger ages.

Carefully selected AA kidney donors have well preserved renal function and a low prevalence of hypertension many years after kidney donation. Abnormal albumin excretion and loss of physiologic decrease in nocturnal BP is more prevalent in AA donors than the general AA population. Older age at donation may predict lower GFR after donation.