Do biochemical measures change in living kidney donors? A systematic review

Living kidney donation provides a unique opportunity to assess possible biochemical changes attributable to small decrements in glomerular filtration rate. We reviewed studies which followed 5 or more healthy donors, where changes in biochemical measures or anemia were assessed at least 4 months after nephrectomy.

We searched MEDLINE, EMBASE, and Science Citation databases, and reviewed reference lists from 1966 through June 2006. We abstracted data on study and donor characteristics and biochemical outcomes of interest.

Eight studies examined at least one outcome of interest. The average time after donation ranged from 0.4 to 11 years, the postdonation creatinine clearance ranged from 73 to 99 ml/min, and the decrement after donation ranged from 11 to 38 ml/min. Nephrectomy did not change hemoglobin, erythropoietin, serum phosphate, calcium or C-reactive protein levels. The studies were inconsistent as to whether parathyroid hormone levels increased and 1,25-dihydroxyvitamin D levels decreased after nephrectomy. Uric acid levels increased variably post-donation. Plasma homocysteine increased in the single study included in this review.

The mechanistic changes described above and their prognostic significance need clarification. Based on existing evidence, it is not necessary to routinely monitor living kidney donors for changes in these biochemical measures.