Obesity and Loss of Kidney Function: Two Complications to Face for Older Living Kidney Donors

Abstract

Objectives: Although living kidney donors have a minimal lifetime risk of developing end-stage renal disease, long-term complications and physiologic and psychologic sequelae resulting from donation remain unclear because of lack of optimum follow-up after transplant. Here, we evaluated renal function, complications, and physical and mental performance of living kidney donors.

Materials and Methods: We evaluated 147 patients who donated living kidneys between 1981 and 2012 at Baskent University Hospital. We collected data on donor age, sex, body mass index, smoking status, hypertension before and after nephrectomy, proteinuria, estimated glomerular filtration rate according to the Modification of Diet in Renal Disease formula, and duration after donation. All donors answered the Medical Outcomes Study short-form general health survey; results were evaluated according to answers to 11 questions totaling 22 points.

Results: Body mass index of donors showed that 31 (21.1%) were in normal range, 66 (44.9%) had mild obesity (body mass index of 26-30 kg/m(2)), and 30 (34%) had moderate to high obesity (body mass index > 30 kg/m(2)). Results from the general health survey showed that 117 donors (80%) had no loss, 13 (9%) had mild loss, 12 (8%) had moderate loss, and 5 (3%) had high loss of ability. When we compared estimated glomerular filtration rates according to donor age, donors who were 18 to 34 years had a mean estimated glomerular filtration rate of 113.5 +/- 40, donors 35 to 49 years had a mean rate of 95.01 +/- 23.4, donors 50 to 64 years had a mean rate of 87.43 +/- 25.4, and donors older than 65 years had a mean rate of 63.76 +/- 11.35 mL/min/1.73 m(2), revealing a statistically significant loss of kidney function with aging (P = .001).

Conclusions: Careful evaluation of kidney donors before and after donation is essential for the most common risk factors, such as obesity, and for loss of kidney function, especially in older donors.