The effect of hypertension and diabetes on the degree of renal function deterioration after unilateral nephrectomy

Abstract

Study Type – Prognosis (case series) Level of Evidence 4 What’s known on the subject? and What does the study add? Hypertension and diabetes have long been identified as both initiating and progressing factors in chronic kidney disease, as well as predictors of long‐term renal impairment in individuals undergoing nephrectomy. Radical nephrectomy itself is an independent risk factor for chronic kidney disease and its associated increased risk of morbid cardiac events and death. These data have been used to support the argument for greater use of partial nephrectomy when dealing with small renal masses. Whilst in the past it has always been seen as intuitive that patients with hypertension and diabetes would have worse renal function after removal of a kidney for malignancy, the present study is the first to quantify this fact. This information could be used to identify those patients who would benefit from early intervention to delay the progression of chronic kidney disease, as well as those for whom partial nephrectomy might be a more appropriate surgical option. OBJECTIVE To quantify the effect of hypertension and diabetes – which have been identified as both initiating and progressing factors in chronic kidney disease (CKD), as well as predictors of long‐term renal impairment in patients undergoing nephrectomy – on renal function after unilateral nephrectomy for malignancy. PATIENTS AND METHODS A retrospective analysis was carried out of 80 unilateral nephrectomies performed at the Wagga Wagga Base Hospital, Calvary Private Hospital and Austin Hospital from January 2007 to December 2009. Prognostic variables were patient age, sex and the presence of hypertension or diabetes. The percentage reduction in glomerular filtration rate (GFR) after nephrectomy was measured and compared between variables using a two‐sample Student’s t‐test. RESULTS All patients who had diabetes also had hypertension. Of the 80 patients, 22 (27.5%) fulfilled the criteria for CKD with a preoperative GFR < 60 mL/min. Patients with hypertension and diabetes had a significantly greater percentage reduction in postoperative GFR (36 ± 2%) than those who had neither risk factor (23 ± 2%, P < 0.003). A similar finding was observed for patients with hypertension alone (32 ± 1%, P < 0.009). The difference in postoperative GFR reduction between diabetics and those with hypertension alone was not statistically significant (P= 0.205). The differential reduction in GFR in patients with CKD risk factors persisted at 3–12 months follow‐up. CONCLUSIONS An increased percentage reduction in GFR is seen in patients with hypertension and diabetes undergoing unilateral nephrectomy for malignancy. These data could be used to identify those patients who would benefit from early referral and subsequent intervention to delay the progression of CKD, as well as those for whom nephron‐sparing surgery might be a more appropriate surgical option.

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

“…Our study also contributes with a novel finding in using overall comorbidity, as assessed by the CCI, as a determinant of postoperative renal decline. This adds to the previous literature indicating that diabetes and hypertension contribute to diminished renal function after nephrectomy ( 10 , 20 ). Satasivam et al proposed a method of estimating percent GFR reduction after nephrectomy based on the presence or absence of diabetes and hypertension ( 10 ).…”

“…A limitation of the prior study in relation to what is addressed in the current study is the quantification of kidney function. Their study used the Modification of Diet in Renal Disease (MDRD) formula which does not take into account BMI ( 10 ). According to the US National Kidney Foundation Practice Guidelines, using a formula that accounts for gender, age, race, and BMI is superior to other methods ( 27 ).…”

“…Diabetes and hypertension are well established risk factors for chronic kidney disease (CKD), and these disease processes have demonstrated associations with poorer post-operative renal function in patients submitted to nephrectomy ( 10 ). With the increasing incidence of renal cell carcinoma (RCC) ( 11 ) and therefore the inevitable increase in surgical procedures, it is important for the urologist to understand the impact of physiologic factors, in addition to clinical ones, on patient prognosis.…”

Obesity, hypertension and diabetes mellitus affect complication rate of different nephrectomy techniques

“…7---9 Previous studies have provided inconsistent results as to whether hypertension, DM and obesity might increase the postoperative complication rate of nephrectomy. 10,11 The…”

Effect of nephrectomy for retroperitoneal sarcoma on post‐operative renal function

“…Although 38‐70% of patients will develop CKD (GFR <60), progression to end stage renal failure is rare . Reported risk factors associated with renal function decline post unilateral nephrectomy include post‐operative acute kidney injury, older age, hypertension, and diabetes …”