Chronic kidney disease and urological disorders: systematic use of uroflowmetry in nephropathic patients

Abstract

Background: Chronic kidney disease (CKD) is a highly prevalent condition. Urologic disorders are known causes of CKD, but often remain undiagnosed and underestimated also for their insidious onset and slow progression. We aimed to evaluate the prevalence of urological unrecognized diseases in CKD patients by uroflowmetry.

Methods: We enrolled consecutive stable CKD outpatients. The patients carried out two questionnaires, the International Prostate Symptom Score and Incontinence Questionnaire-Short Form, and they also underwent uroflowmetry, evaluating max flow rate (Q _max), voiding time and voided volume values.

Results: A total of 83 patients (43 males, mean age of 59.8 ± 13.3 years) were enrolled. Our study showed 28 males and 10 females with a significant reduction of Q _max (P < 0.001) while 21 females reported a significant increase of Q _max (P < 0.001) with a prevalence of 49.5% of functional urological disease. Moreover, we showed a significant association between Q _max and creatinine (P = 0.013), estimated glomerular filtration rate (P = 0.029) and voiding volume (P = 0.05). We have not shown significant associations with age (P = 0.215), body mass index (P = 0.793), systolic blood pressure (P = 0.642) or diastolic blood pressure (P = 0.305). Moreover, Pearson's chi-squared test showed a significant association between Q _max altered with CKD (χ² = 1.885, P = 0.170) and recurrent infection (χ² = 8.886, P = 0.012), while we have not shown an association with proteinuria (χ² = 0.484, P = 0.785), diabetes (χ² = 0.334, P = 0.563) or hypertension (χ² = 1.885, P = 0.170).

Conclusions: We showed an elevated prevalence of urological diseases in nephropathic patients; therefore, we suggest to include uroflowmetry in CKD patient assessment, considering the non-invasiveness, repeatability and low cost of examination. Uroflowmetry could be used to identify previously unrecognized urological diseases, which may prevent the onset of CKD or progression to end-stage renal disease and reduce the costs of management.

Keywords: chronic kidney disease; end-stage renal disease; max flow rate; uroflowmetry; urological disorders.

FIGURE 1

Boxes represent the frequencies. The number of CKD+ patients with pathological max flow rate was more than expected. Pearson chi-squared test shows that there is a statistically significant association between CKD+ and pathological max flow rate (χ² = 8.495, P = 0.004). Normal, patients with max flow rate within the normal range; pathological, patients with max flow rate outside the normal range; CKD+, patients with chronic kidney disease; CKD−, patients without chronic kidney disease.