The role of the bladder diary in phenotyping men with LUTS

The aim of this study was to compare the clinical characteristics of men with lower urinary tract symptoms (LUTS) grouped by 24-h urine output determined from a bladder voiding diary.

An online database was queried to identify men who completed a 24-hour bladder diary (24HBD), and the Lower Urinary Tract Symptom Score (LUTSS) questionnaire from 2015 to 2019 using a mobile app. Data from the bladder diary and questionnaire were contemporaneously matched within a 2-week period. Additional data, including maximum uroflow (Q_max ) and postvoid residual urine (PVR), were obtained from the electronic medical record (EMR). The cohort was divided into three groups: normal, oliguria, and polyuria based on their 24-hour voided volume (24HVV). The LUTSS, 24HVV, maximum voided volume (MVV), maximum flow rate (Q_max ), and PVR were compared between those with oliguria and polyuria.

A total of 327 men (mean age 62, SD: 19) completed the LUTSS questionnaire and contemporaneous 24HBD. Of these, 61% had a normal 24HVV, 13% had oliguria, and 26% had polyuria. A total of 147 patients from the study cohort had contemporaneous Q_max and PVR abstracted from the EMR. There was no difference in symptom severity, bother, or PVR among the three patient groups. However, several objective metrics were significantly correlated with urine output. Men with oliguria, as compared to men with polyuria were older (65 vs. 55 years) and had lower MVV (260 vs. 470 mL), fewer voids/24 h (8 vs. 13), and lower Q_max (8.5 vs. 18.3 mL/s).

These observations suggest that men with oliguria or polyuria and LUTS constitute easily distinguished phenotypes that might require different diagnostic and therapeutic algorithms. Those with oliguria were older, and had lower MVVs and much lower uroflows, suggesting that they are more likely to have underlying disorders such as bladder outlet obstruction and detrusor underactivity or may be patients with overactive bladder who reduced fluid intake to improve symptoms.