Study design, materials and methods
An established online database was queried for men who completed a 24-hour bladder diary (24HBD) and Lower Urinary Tract Symptom Score (LUTSS) between 2015 and 2019 using a mobile app* . If a patient had more than one bladder diary and LUTSS, only the first submission was used. Women and patients with incomplete or flawed entries were excluded. Age, gender, uroflow (Qmax), post-void residual urine (PVR), and voided volume were obtained from the patient’s electronic medical records (EMR). Patients were divided into three groups based on the 24HBD: polyuria (>2.5 L/24 H), oliguria (<1L/24 H) and normal (1 to 2.5 L/24 H) . Those with polyuria were the focus of the study. This data was analyzed via the SPSS statistics software utilizing a one-way ANOVA looking at LUTS scores, bladder diary data, and urodynamic data between the three urinary groups. In addition, independent two-tailed sample t-tests were run comparing the polyuria and oliguria groups. The p-value was considered significant when it was ≤.05. Data for all three groups were gathered and analyzed but only the polyuria group is presented in table 1.
The initial cohort had 504 patients (331 men and 173 women, mean age 59 SD 18). After applying exclusion criteria, there were 331 men of whom 86 (26%) had polyuria, 42 (13%) had oliguria and 203 (61%) had normal 24H VV. There was no difference in total or any of the 6 symptom LUTSS sub-scores between the men with polyuria, oliguria, and normal 24H VV. All LUTSS, 24HBD, and Urodynamic data was analyzed but only the most pertinent data for our discussion are presented in Table 1. In the polyuria group, 37 patients had contemporaneous Qmax, Voided Volume, and PVR. It is important to note that voided volume refers to the volume associated with the uroflow (Qmax) data and is distinct from 24H VV. Lastly, there was no statistically significant difference in terms of LUTSS subscores between the three urinary groups. There was also no difference when comparing the polyuria to the oliguria group.
Interpretation of results
The rationale for considering fluid restriction and Bmod as a viable treatment for men with BPH symptoms is empirically based on the following criteria – 24H VV large enough so that fluid restriction does not pose a health threat, sufficient bladder capacity, a large number of voids per 24 H and low likelihood of severe urethral obstruction. In this series, 26% of BPH patients had polyuria. These men had a mean 24H VV of 3480 mL, a sufficient MVV of 473 mL, voided a mean of 13 times per day and had a mean Qmax of 18 mL/S, thus fulfilling all of the criteria cited above. In addition, those with polyuria were, on average, younger (mean age = 55 compared to 65 years) in the oliguria group. This suggests that younger patients may drink out of habit or because of increased health consciousness.
The fact that there was no difference in any of the LUTSS subscores amongst the three groups (polyuria, oliguria and normal) indicates that there is no ready way to make the distinctions alluded to above based on symptoms; a bladder diary is crucial.