43rd Annual Congress of the Italian Urodynamic Society, Rome, Italy, 13th-15th June 2019: Nocturnal polyuria in males with LUTS: Prevalence and association with nocturia, IPSS and uroflowmetry

Introduction and aim of the study: Nocturnal Polyuria (NP) is a common finding in males with nocturia and/or lower urinary tract symptoms (LUTS) [1]. This condition needs a multidisciplinary management and should be assessed to avoid misleading diagnoses and following useless and/or unsatisfactory treatment. Aims of the study were to evaluate in males with LUTS: 1) the prevalence of NP; 2) the relation between NP, nocturia, and both International Prostate Symptom Score (IPSS) and uroflowmetry (UF). Materials and methods: From 9/2016 to 11/2017 we enrolled 461 consecutive pts with LUTS into a prospective double‐centre study. Data collected were: detailed medical history, UF, Post Void Residual urine volume (PVR), a self‐administered IPSS and a 3 days frequency volume charts (FVC), indicating “bedtime” and “waking time”. Frequency, voided volume and Nocturnal Polyuria index (NPi) were assessed by 3 days‐FVC, and compared with IPSS data. NP was defined as a NPi >33%, and severe NP as NPi >50% [2], nocturia as at least 1 mean episode of nocturnal voiding at 3 daysFVC. Analyses were performed considering: total IPSS score; IPSS‐item #2 (frequency score); IPSS‐item #7 (nocturia score); IPSS‐item #8 (bother score); peak flow (Qmax) at the UF; PVR. A subanalysis according to patients age was also performed. For statistics the Kruskal‐Wallis test was used. Results: Both IPSS and 3‐days FVC were completed in 162 pts (mean age 70.95 ± 8.04 years). Prevalence of NP was 54,9% (89/162 pts), while severe NP rate was 9.88% (16/162 pts) with a mean NPi of 34.4% ±11,2. Table 1 shows NP prevalence according to patients ages. TABLE 1 NP prevalence according to patients ages; median IPSS answers, peak flow and PVR, stratified according to NPi. IQR=interquartile range. *the Kruskal‐Wallis test.Frequency volume chart analysis showed nocturia in 110 pts (68%), of these 69% (76/110) referred NP. Nocturia was documented in 85% of the population with NP (76/89). Similar results can be found in literature [3]. In Table 1 are also listed median IPSS scores, Qmax, and PVR stratified according to NPi. Only median IPSS #7 and total IPSS showed significant difference.Interpretation of results: Our data showed a high NP prevalence (>50%) among males complaining LUTS. In only a minor part of the patients NP was severe (<10%). NP was diagnosed also in pts without nocturia. More than 2/3 patients reporting nocturia had nocturnal polyuria. Therefore, misleading this two pathological conditions could involve useless and/or unsatisfactory treatments. These data stress the necessity to a whole evaluation of males with nocturia and not a simple focus on nocturia per se. NP influenced outcomes of median IPSS domain 7 and total IPSS score but not findings of IPSS domain related to quality of life and frequency. UF data (Qmax and PVR) did not change according to NPi. Therefore, NP did not impact the micturition and the bladder emptying. Conclusions: NP was a common condition in males with LUTS and nocturia, however it was severe only in a minority. Nocturnal production of urine did not influence the voiding pattern, nor the bladder emptying. IPSS was a valid tool to diagnose nocturia, while only FVC could identify NP. Our data suggest that physicians should look for NP among males with LUTS and nocturia to manage these patients with the most appropriate treatments using both FVC and IPSS.