Analysis of the Pattern, Associations and Impact of Renal Function Status in Patients with Benign Prostatic Obstruction

Abstract

Introduction: The burden of Benign Prostatic Hyperplasia (BPH) is high in older age groups. These patients could have normal renal function or present with obstructive uropathy, obstructive nephropathy or intrinsic renal damage. The aim of this study was to evaluate the prevalence, severity and associations of renal function status in different spectrum of patients with Lower Urinary Tract Symptoms due to BPH and assess its impact on the management of these patients. Methods: Information on medical history, laboratory data and imaging tests were extracted from medical records of patients presenting to our Urology Clinic with BPH between January 2016 and January 2019. Glomerular Filtration Rate (GFR) was calculated using Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula and the severity of renal disease was computed. Patients were classified based on the presence of obstruction and renal impairment. Data analysis was done using SPSS version 20.0 with p-value < 0.05 considered significant. Results: Ninety-three patients were analyzed. Obstructive nephropathy and intrinsic renal damage occurred in 4.3% and 12.9% of them respectively. However, the severity of renal impairment was higher in the former (22.8ml/min/1.73m² versus 39.3ml/min/1.73m ² respectively). Those with obstructive uropathy had Stage 2 GFR (72.5 ml/min/1.73m2) on the average. There was a significant relationship between GFR and age of presentation (p = 0.001). Diabetes mellitus was observed in 10.4% of patients with out nephropathy. The GFR was lower in diabetic nephropathy patients (33.7 ml/min/1.73m²) than in others who also had intrinsic renal damage (43.3 ml/min/1.73m²). Initial urinary drainage was used for the stabilization of renal function before definitive surgery in all patients with obstructive nephropathy. Conclusions: The burden of nephropathy in BPH patients is quite considerable with the occurrence of intrinsic renal damage almost thrice that of obstructive nephropathy. A sizeable proportion of those without renal insufficiency harbour diabetes mellitus, thus, a superimposed obstructive uropathy from BPH could rapidly tilt such patients into end- stage renal disease. There is therefore the need to institute early management and other preventive measures in those with uropathy to prevent their progression to renal impairment.