Nocturnal polyuria in men performing uroflowmetry for lower urinary tract symptoms

Purpose: To assess the prevalence of nocturnal polyuria (NP) in males performing uroflowmetry (UF) for lower urinary tract symptoms (LUTS), the impact of NP on UF outcomes, and bladder emptying, the association between NP and LUTS. Materials and methods: Men scheduled for UF were recruited in two Centres. Data collected were medical history, IPSS, UF, post-void residual urine volume (PVR), 3-day frequency-volume charts (FVC). The NP index was used to assess NP with a threshold of ≥ 33%. The relationship between NP and patient’s aging was assessed. Results: 162 patients were included in the analysis. Mean age was 70.95 ± 8.04 years. The prevalence of NP was 54.9% (89/162). 110 (68%) patients reported nocturia, and among these, NP was documented in 76 (69%). Nocturia was found in 85% (76/89) of the population with NP. Total IPSS score, IPSS items #1, #2 and #7 showed a significant difference in men with NP compared with those without. Maximum flow rate and PVR did not significantly change comparing men with or without NP. Mean voiding volume (VV) of the night-time micturitions was significantly higher in men with NP compared to those without NP (532.1 ± 275.6 ml vs 175 ± 168.7 ml respectively, p < 0001), while mean VV day-time micturitions and mean VV at UF did not change between groups.Conclusions: NP had a high prevalence in men with LUTS performing UF. Aged males were more commonly affected by NP. Data demonstrated a strong relationship between NP and nocturia and increased urinary frequency while voiding symptoms were poorly related to NP.

On the issue of the excretion of chlorides and urine in cardiac patients

During clinical observations of cardiac patients, it was long ago noted that the excretion of urine in them sharply differs from that in healthy people. Quinque's investigations allowed him to come to the conclusion that in these patients, at a certain period of the disease, nocturnal polyuria was observed, as he also noted for some renal patients, argeriosclerotic and cachectic patients.

Dietary Salt With Nitric Oxide Deficiency Induces Nocturnal Polyuria via Hyperactivation of Intrarenal Angiotensin Ⅱ-SPAK-NCC Pathway

Nocturnal polyuria is the most frequent cause of nocturia, a common disease associated with a compromised quality of life and increased mortality. Its pathogenesis is complex, and the detailed underlying mechanism remains unknown. Herein, we report that concomitant intake of a high-salt diet and reduced nitric oxide (NO) production achieved through Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME) administration in mice resulted in nocturnal polyuria recapitulating the clinical features in humans. High salt intake under reduced NO production overactivated the angiotensin II-SPAK (STE20/SPS1-related proline–alanine-rich protein kinase)-NCC (sodium chloride co-transporter) pathway in the kidney, resulting in the insufficient excretion of sodium during the day and its excessive excretion at night. Excessive Na excretion at night in turn leads to nocturnal polyuria due to osmotic diuresis. Our study identified a central role for the intrarenal angiotensin II-SPAK-NCC pathway in the pathophysiology of nocturnal polyuria, highlighting its potential as a promising therapeutic target.