Body mass index and comorbidity are associated with postoperative renal function after nephrectomy

Abstract

Purpose:To explore the association of body mass index (BMI) and comorbidity with renal function after nephrectomy.Materials and Methods:We retrospectively analyzed 263 patients submitted to partial or radical nephrectomy from 2000-2013. Variables assessed included BMI, Charlson Comorbidity Index (CCI), race, tobacco use, tumor histology, surgical approach, Fuhrman nuclear grade, and tumor (T) classification. Glomerular filtration rate (GFR) was estimated using the Cockroft-Gault equation, adjusted for gender. Logistic regression was performed and included all interaction terms.Results:Median follow-up was 19.6 months (IQR 5.2, 53.7). Median preoperative GFR was 86.2mL/min/1.73m2 and median postoperative GFR was 68.4mL/min/1.73m2. BMI (OR 1.07, 95%CI 1.02-1.11), CCI (OR 1.19, 95%CI 1.04-1.37), and radical nephrectomy (OR 3.09, 95%CI 1.51-6.33) were significantly associated with a decline in renal function of ≥25%.Conclusion:BMI and CCI are associated with postoperative decline in renal function after nephrectomy. Additionally, radical nephrectomy is significantly associated with decreasing renal function compared to partial nephrectomy. These findings highlight the importance of assessing patient comorbidity in the decision making process for patients presenting with a renal mass.

Incident Chronic Kidney Disease After Radical Nephrectomy for Renal Cell Carcinoma

“…We have reported previously that age ≥65 years, lower preoperative eGFR, and male sex were associated with incident CKD in patients with T1a RCC managed with radical nephrectomy, 12 which is consistent with the findings of this study (Table 2), and the existing literature. 21,22 The finding that BMI >30 kg/m 2 was associated with CKD has also been reported previously, 23 and is likely because increased body weight can adversely affect the health of the kidneys through many downstream mediators, typically leading to increased oxidative stress, inflammation, ectopic lipid accumulation, and glomerular hypertension. 24 We found that diabetes mellitus was not a mediator of the association between obesity and postoperative CKD.…”

Hypertension and diabetes mellitus are not associated with worse renal functional outcome after partial nephrectomy in patients with normal baseline kidney function

“…Initially, HTN/DM was associated with a slightly more detrimental effect on the eGFR, but was also associated with faster recovery, ultimately leading to a predicted eGFR that was the same (83 mL/min/1.73 m 2 ) for both groups 24 months after PN. eGFR outcome was similar despite the higher age, tumor size, BMI, CCI and lower baseline eGFR in the HTN/DM group, all of which are associated with worse functional outcome . Because all patients had normal baseline kidney function (i.e.…”

“…eGFR outcome was similar despite the higher age, tumor size, BMI, CCI and lower baseline eGFR in the HTN/DM group, all of which are associated with worse functional outcome. 13,14 Because all patients had normal baseline kidney function (i.e. eGFR ≥60), it is likely that sufficient nephron reserve negated the detrimental effect of DM and HTN on functional outcome in 2 years.…”

Prediction of significant estimated glomerular filtration rate decline after renal unit removal to aid in the clinical choice between radical and partial nephrectomy in patients with a renal mass and normal renal function

“…Our findings dovetail with a recent report by Isharwal et al [25] demonstrating that comorbidity status fails to predict renal functional decline after renal surgery. The literature in this space is contradictory [23,26,27], but the greatest predictor of eGFR decline to ≤45 mL/min/1.73 m 2 remains RN [28,29]. Woldu et al [30] recently compared renal functional outcomes after NSS and RN among patients with CKD I and II.…”