A study of renal outcomes in obese living kidney donors.
BACKGROUND
Little is known about the long-term outcomes of obese living kidney donors (OLKDs). We undertook this study to describe renal outcomes of OLKDs several years after donation.


METHODS
We invited 101 OLKDs for follow-up health evaluation.


RESULTS
Thirty-six subjects (35.6%) completed evaluation at 6.8±1.5 years postdonation. The mean estimated glomerular filtration rate (eGFR) using the abbreviated modification of diet in renal disease (MDRD) equation (MDRD-eGFR) at follow-up was 72.1±16.3 (range: 42-106) mL/min per 1.73 m, and 47.2% of subjects had an MDRD-eGFR of 30 to 59. The absolute decrease in MDRD-eGFR from the time of donation to follow-up was 27.2 ± 13.1 mL/min per 1.73 m (P<0.001 on paired t test), which represents a 29.2% drop in the serial MDRD-eGFRs. Seven subjects (19.4%) had microalbuminuria (30-300 μg/mg creatinine). Subjects with microabuminuria were more likely to have MDRD-eGFR of less than 60 mL/min per 1.73 m (P=0.021). Subjects whose body mass index was greater than or equal to 35 kg/m (n=14) were found to have an absolute decrement in MDRD-eGFR similar to those with body mass index less than 35 kg/m (31.5 ± 15.6 and 24.7 ± 11.0 mL/min/1.73 m, respectively; P=not significant). Fifteen (41.6%) were hypertensive at follow-up.


CONCLUSIONS
On medium-term follow-up, a large proportion of OLKDs will have a MDRD-eGFR of less than 60 mL/min per 1.73 m, and the likelihood increases markedly among those who develop microalbuninuria. This raises concern for hyperfiltration injury. Furthermore, OLKDs experience a substantial incidence of hypertension. Caution is advised in selecting OLKDs pending further data on long-term outcomes.
Nogueira
Joseph M
JM
Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA. jnogueir@medicine.umaryland.edu
Weir
Matthew R
MR
Jacobs
Stephen
S
Breault
Denyse
D
Klassen
David
D
Evans
Debora A
DA
Bartlett
Stephen T
ST
Cooper
Matthew
M
D000328:Adult; D015992:Body Mass Index; D003404:Creatinine / Q000097:blood; D051799:Delayed Graft Function; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006801:Humans; D016030:Kidney Transplantation; D019520:Living Donors / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy; D009765:Obesity / Q000453:epidemiology*; D013997:Time Factors; D016896:Treatment Outcome
D003404:Creatinine