OBJECTIVE To investigate whether the postnephrectomy renal adaptation mechanism, focused on functional
hyperfiltration as well as structural hypertrophy, was affected by abdominal obesity.
MATERIALS AND
METHODS
We retrospectively evaluated 358 patients who underwent simple or radical nephrectomy and
nephroureterectomy between 2009 and 2013. Patients were classified according to waist circumference
(WC), with values >102 cm in men and >88 cm in women considered high (obesity).
Functional renal volume (FRV) was measured using computed tomography performed preoperatively
and 6 months postoperatively to evaluate the degree of remnant kidney hypertrophy. The
degree of hyperfiltration was calculated from the difference between the preoperative and postoperative
glomerular filtration rate (GFR)/FRV.
RESULTS The mean preoperative GFR, FRV, and GFR/FRV were 72.1 mL/min/1.73 m2, 282.8 cm3, and
0.25 mL/min/1.73 m2/cm3, respectively. The percent GFR reduction was significantly greater in
the high WC group (high, 25.9% vs normal, 16.0%, P = .036), although the degree of hypertrophic
volume in the remnant kidney showed no difference. The change in GFR/FRV was statistically
lower in the high WC group (high, 25.7% vs normal, 40.2%, P = .009). The factors associated
with postoperative increased GFR/FRV were low preoperative GFR, proteinuria, high predictive
preserved functional parenchymal volume ratio, absence of hypertension, increased levels of highdensity
lipoprotein cholesterol, and normal WC (all P < .05).
CONCLUSION Patients with high WC might have a large reduction in postoperative renal function, owing to a
lower degree of functional hyperfiltration. UROLOGY ■■: ■■–■■, 2017. © 2017 Elsevier Inc.