Mechanism of action of phosphodiesterase type 5 inhibition in metabolic syndrome-associated prostate alterations: an experimental study in the rabbit

Unveiling prostatic inflammation to optimize management of lower urinary tract symptoms: a discussion with experts

Benign prostatic obstruction (BPO) and associated lower urinary tract symptoms (LUTS) are common conditions in men, which increase in frequency and severity with age, and have a significant impact on quality of life. Chronic prostatic inflammation is increasingly being recognized as a key component of BPO. This may lead to new targets for the management of BPO/LUTS. This podcast is based on presentations from a symposium titled 'Unveiling prostatic inflammation to optimize LUTS management' held at the European Association of Urology 2023 Congress. The presenters outline evidence of a role for prostatic inflammation in the development and progression of BPO/LUTS, approaches to the identification of biomarkers of inflammation, and the implications of prostatic inflammation for the optimal management of BPO/LUTS.

Extra-virgin olive oil ameliorates high-fat diet-induced seminal and testicular disorders by modulating the cholesterol pathway

BACKGROUND

Rabbits are sensitive to dietary cholesterol and rapidly develop hypercholesterolemia, leading to prominent subfertility. Sterol regulatory element-binding protein isoform 2 drives the intracellular cholesterol pathway in many tissues, including the testicles. Its abnormal regulation could be the mainly responsible for the failure of suppressing cholesterol synthesis in a cholesterol-enriched environment, ultimately leading to testicular and seminal alterations. However, extra-virgin olive oil consumption has beneficial properties that promote lowering of cholesterol levels, including the recovery of seminal parameters altered under a high-fat diet.

OBJECTIVES

Our goal was to investigate the effects of high-fat diet supplementation with extra-virgin olive oil at the molecular level on rabbit testes, by analyzing sterol regulatory element-binding protein isoform 2 protein and its corresponding downstream effectors.

MATERIALS AND METHODS

During 12 months, male rabbits were fed a control diet, high-fat diet, or 6-month high-fat diet followed by 6-month high-fat diet plus extra-virgin olive oil. Serum lipids, testosterone levels, bodyweight, and seminal parameters were tested. The mRNA and protein levels of sterol regulatory element-binding protein isoform 2, 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, and low-density lipoprotein receptor were determined by semi-quantitative polymerase chain reaction and Western blotting techniques. The expression pattern of sterol regulatory element-binding protein isoform 2 protein in the rabbit testicles was studied by indirect immunofluorescence. In addition, testicular cholesterol was detected and quantified by filipin staining and gas chromatography.

RESULTS

The data showed that the addition of extra-virgin olive oil to high-fat diet reduced testicular cholesterol levels and recovered the expression of sterol regulatory element-binding protein isoform 2, 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, and low-density lipoprotein receptor initially altered by the high-fat diet.

DISCUSSION AND CONCLUSIONS

The combination of high-fat diet with extra-virgin olive oil encourages testicular recovery by modifying the expression of the enzymes related to intracellular cholesterol management.

Impact of High Fat Diet and Sex in a Rabbit Model of Carpal Tunnel Syndrome

Carpal tunnel syndrome (CTS) is a common musculoskeletal disorder, characterized by fibrosis of the subsynovial connective tissue (SSCT) mediated by transforming growth factor beta (TGF-β). Risk factors for CTS include metabolic dysfunction and age. Additionally, the incidence of CTS is higher in women. In this study we hypothesized that a high-fat diet (HFD), a common driver of metabolic dysfunction, would promote SSCT fibrosis found in CTS and that this response would be sex dependent. To test this, we examined the effects of HFD and sex on SSCT fibrosis using our established rabbit model of CTS. Forty-eight (24 male, 24 female) adult rabbits were divided into four groups including HFD or standard diet with and without CTS induction. SSCT was collected for histological and gene expression analysis. HFD promoted SSCT thickening and upregulated profibrotic genes, including TGF-β. Fibrotic genes were differentially expressed in males and females. Interestingly while the prevalence of CTS is greater in women than in men, the converse is observed in the presence of metabolic dysfunction. This work recapitulates this clinical observation and begins to elucidate the sex-based differences found in SSCT fibrosis. This knowledge should drive further research and may lead to metabolic and sex specific therapeutic strategies for the treatment of patients with CTS.

The danger of hyperoxia on the rat kidneys: is tadalafil a real shield?

PURPOSE

Continuous oxygen therapy to compensate for decreased oxygen saturation in the blood is a life-saving treatment used in case lung involvement. Excess oxygen delivery was reported to be a common situation, in which about 50% of the patients showed hyperoxemia and 4% in severe hyperoxemia. In this work, we investigated the effects of hyperoxia on the rat kidneys and whether tadalafil has an effect to reduce this damage.

MATERIALS AND METHODS

Three groups of 8 male rats each weighing 300-350 g were formed. The groups were divided into the control group, hyperoxia group, and hyperoxia and tadalafil administered group for 10 days. At the end of the 10th day, blood and kidney samples were taken for biochemical analysis (SOD and NO levels) and histopathological examination.

RESULTS

While our findings showed that SOD levels were significantly different among the control and experimental groups and within the experimental groups, no statistical difference was found in terms of NO levels among the groups (Table 1). While the glomerular and tubular injury was higher in the Hyperoxia group and the Hyperoxia + Tadalafil group than in the control group (p < 0.001), as a result of the rate of severe glomerular and tubular injury in the hyperoxia group, was 62.5% and 43.8% and in the group given tadalafil was 43.8% and 31.3%, respectively (Table 2).

CONCLUSIONS

Exposure to hyperoxia condition causes renal glomerular and tubular damage, and tadalafil does not show a protective effect on this damage according to this study's dose and exposure time.

Prospective comparison of tadalafil 5 mg alone, silodosin 8 mg alone, and the combination of both in treatment of lower urinary tract symptoms related to benign prostatic hyperplasia

Background

Men with lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH), will have deterioration in the quality of life. Likewise, BPH can be complicated by damage to bladder function, bladder stones formation, hematuria, and impaired kidney function. The goal of treatment is to avoid all those effects caused by BPH.

Objective

To evaluate the efficacy of tadalafil alone, silodosin alone, and the combination of both in the treatment of LUTS associated with BPH.

Patients and methods

Patients in our department with BPH who had LUTS were assigned randomly to three groups: A (101 patients) received tadalafil, 5 mg; B (102 patients) received silodosin, 8 mg; and group C (105 patients) received the combination of tadalafil, 5 mg, and silodosin, 8 mg. For all participants, we asses changes in the maximum urinary flow rate (Qmax), International Prostate Symptom Score (IPSS), International Index of Erectile Function (IIEF) score, Post-voiding urine (PVR) and all results were recorded and analyzed with the (SPSS) and Microsoft Excel 2010.

Results

Qmax, IPSS, PVR and IIEF score improved significantly more with the combination of tadalafil and silodosin than with either drug alone (p < 0.001). Three months after treatment, the mean Qmax values were 14.4 ml/sec in group A, 15.2 ml/sec in group B, and 15.8 ml/sec in group C; and the mean IPSSs were 17.6 in group A, 16.7 in group B, and 15.6 in group C (p < 0.001).

Conclusion

Tadalafil and silodosin are effective treatment options in men with BPH who have LUTS, but the combination of both is more effective and feasible in treating LUTS of BPH.

Efficacy Evaluation of Plant Products in the Treatment of Erectile Dysfunction Related to Diabetes

Erectile dysfunction affects more than 50% of diabetic male patients, with a higher prevalence compared with the general population. Age, clinical factors, and lifestyle habits have been suggested to contribute to the pathophysiology and worsening of erectile dysfunction in diabetic patients. First- and second-line standard treatments are represented by phosphodiesterase type 5 (PDE5) inhibitors and alprostadil, respectively. However, natural compounds have been suggested to ameliorate this clinical condition. This study aims to preclinically characterize the potential synergism among plant-derived products for the improvement of erectile dysfunction in the diabetic condition. The effects of a nutritional supplement composed of Panax ginseng, Moringa oleifera and rutin, as single agents or as a mixture, were evaluated in a streptozotocin (STZ)-induced diabetic rat model with erectile dysfunction. The treatment efficacy was evaluated by measuring sexual-related parameters (i.e., mount and intromission latencies, the mount and intromission frequencies and the ejaculation latency). Results showed that only the mixture was able to significantly reduce the diabetes-related delay in mount latency (p < 0.01). Substantial similar effects were observed by measuring the intromission latency and the mean number of mounts was very similar between rats treated with the mixture and controls. Single agent treatments showed very low effects in terms of intromission frequency, whereas the mixture was able to increase this parameter. Additionally, a statistically significant reduced ejaculation latency was observed in rats treated with the mixture compared with the STZ control. These results are in agreement with the available literature and suggest that the study mixture may ameliorate sexual behavior compared with the administration of the study natural compounds as single agents in diabetic rats. Further preclinical and clinical studies are needed to perform a more comprehensive evaluation of the efficacy and safety of the study mixture.

Tadalafil 5 mg Once Daily Improved Each IPSS Subscore, QOL, and Nocturia in Elderly BPH Patients over 70 Years Old in a Real-World Clinical Setting

OBJECTIVE

No reports have evaluated the treatment effects of tadalafil by age group in a positive, noninterventional observational study of Japanese men. The present study aimed to evaluate the treatment effects of tadalafil by age group in a positive, noninterventional observational study of Japanese men. We therefore divided patients into 2 groups about the age of 70 years and investigated the treatment effects of tadalafil regarding voiding and storage functions by age group.

METHODS

Changes from baseline in each parameter (International Prostate Symptom Score [IPSS], quality of life [QOL] score, Overactive Bladder Symptom Score [OABSS], and residual urine volume) at 4, 12, and 24 weeks after initiating tadalafil for benign prostatic hyperplasia (BPH) patients were compared between groups (50-69 years vs. ≥70 years). In addition, side effects of tadalafil were investigated by age group.

RESULTS

In the 50-69 years group, significant improvements from baseline were seen in IPSS total and QOL score for all time points. In addition, significant improvements in IPSS storage subscore from baseline were observed at the 4- and 24-week time points. In the ≥70 years group, significant improvements from baseline were seen in IPSS total, IPSS voiding and storage subscores, and QOL score at each time point.

CONCLUSIONS

Tadalafil 5 mg once daily appeared effective in clinical settings for elderly BPH patients even over 70 years old.

Hepatic Accumulation of Hypoxanthine: A Link Between Hyperuricemia and Nonalcoholic Fatty Liver Disease

BACKGROUND

An elevated level of plasma uric acid has been widely recognized as a risk factor for non-alcoholic fatty liver disease (NAFLD), where oxidative stress and inflammation play an important role in the pathophysiology of the disease. Although the complete molecular mechanisms involved remain unknown, while under physiological conditions uric acid presents antioxidant properties, hyperuricemia has been linked to oxidative stress, chronic low-grade inflammation, and insulin resistance, basic signs of NAFLD.

AIM OF STUDY

Employing in vivo experimentation, we aim to investigate whether a high-fat diet rich in cholesterol (HFD), modifies the metabolism of purines in close relationship to molecular events associated with the development of NAFLD. In vitro experiments employing HepG2 cells are also carried out to study the phenomenon of oxidative stress.

METHODS

Adult male rabbits were fed for 8 weeks an HFD to induce NAFLD. At the beginning of the experiment and every 15 d until the completion of the study, plasma levels of lipids, lipoproteins, and uric acid were measured. Liver tissue was isolated, and histology performed followed by the biochemical determination of hypoxanthine, protein expression of xanthine oxidoreductase (XOR) by western blot analysis, and xanthine oxidase (XO) activity using an enzymatic kinetic assay. Furthermore, we employed in vitro experimentation studying HepG2 cells to measure the effect of hypoxanthine and H₂O₂ upon the production of radical oxygen species (ROS), XO activity, and cell viability.

RESULTS AND CONCLUSION

Hepatic tissue from rabbits fed the HFD diet showed signs of NAFLD associated with an increased ROS concentration and an altered purine metabolism characterized by the increase in hypoxanthine, together with an apparent equilibrium displacement of XOR towards the xanthine dehydrogenase (XDH) isoform of the enzyme. This protein shift visualized by a western blot analysis, associated with an increase in plasma uric acid and hepatocyte hypoxanthine could be understood as a compensatory series of events secondary to the establishment of oxidative stress associated with the chronic establishment of fatty liver disease.

Endocrinology of the Aging Prostate: Current Concepts

Benign prostate hyperplasia (BPH), one of the most common diseases in older men, adversely affects quality-of-life due to the presence of low urinary tract symptoms (LUTS). Numerous data support the presence of an association between BPH-related LUTS (BPH-LUTS) and metabolic syndrome (MetS). Whether hormonal changes occurring in MetS play a role in the pathogenesis of BPH-LUTS is a debated issue. Therefore, this article aimed to systematically review the impact of hormonal changes that occur during aging on the prostate, including the role of sex hormones, insulin-like growth factor 1, thyroid hormones, and insulin. The possible explanatory mechanisms of the association between BPH-LUTS and MetS are also discussed. In particular, the presence of a male polycystic ovarian syndrome (PCOS)-equivalent may represent a possible hypothesis to support this link. Male PCOS-equivalent has been defined as an endocrine syndrome with a metabolic background, which predisposes to the development of type II diabetes mellitus, cardiovascular diseases, prostate cancer, BPH and prostatitis in old age. Its early identification would help prevent the onset of these long-term complications.

Outcomes of combination therapy with daily tadalafil 5 mg plus tamsulosin 0.4 mg to treat lower urinary tract symptoms and erectile dysfunction in men with or without metabolic syndrome

BACKGROUND

The aim of this study was to assess the impact of tadalafil 5 mg/die plus tamsulosin 0.4 mg/die combination therapy on lower urinary tract symptoms (LUTS) and erectile dysfunction (ED), according to presence vs. absence of metabolic syndrome (MetS).

METHODS

Seventy-five consecutive men presenting with ED and LUTS were enrolled. Patients were divided into two groups according to MetS presence. All subjects were treated with combination therapy for 12 weeks. Patients were re-evaluated after treatment with uroflowmetry and post-void residual volume (PVR), International Prostate Symptoms Score (IPSS), IPSS Quality of Life (QoL), overactive bladder questionnaire (OAB-q) and International Index Erectile Function-5 (IIEF-5) Score.

RESULTS

After enrollment, 50 patients were included: 31 (62.0%) with MetS and 19 (38.0%) without MetS. At baseline, patients without MetS showed a significantly better IPSS, IIEF and OAB-q, as compared to those with MetS. After 12 weeks of combination therapy LUTS, ED and flowmetry significantly improved in both groups (P<0.001). The improvement after 12 weeks was similar between groups in all parameters (P>0.05), except for ∆OAB-q that was significantly better for patients with MetS (P=0.028). Nevertheless, total IPSS, all IPSS subscores and OAB-q were significantly better at 12 weeks in men without MetS (P<0.05). Despite IIEF-5 was significantly different at baseline, after 12 weeks of combination therapy, erectile function was similar in men with or without METS: 16.3±3.8 vs. 17.7±4.7 (P=0.238). No serious adverse event (AE) was reported, and complications were comparable between groups (P>0.05).

CONCLUSIONS

Patients with MetS have worse LUTS and ED profiles. However, tadalafil plus tamsulosin combination treatment provided them a similar ED profile and a greater relief of overactive bladder (OAB) symptoms at the end of the trial. Combination therapy had the same safety profile in men besides MetS. Further randomized controlled trials are needed.

Tadalafil Alone or in Combination with Tamsulosin for the Management for LUTS/BPH and ED

Purpose of Review

Aim of our systematic review is to evaluate and summarize the efficacy and safety of tadalafil alone or in combination with tamsulosin for the management of lower urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH) and erectile dysfunction (ED).

Recent Findings

Daily tadalafil, in particular 5 mg, according to retrieved studies, appears to be both safe and effective in treating LUTS/BPH and ED, compared with placebo or tamsulosin. The combination of daily tadalafil 5 mg and tamsulosin 0.4 mg allows a better improvement of LUTS compared with both the monotherapies, even if with an increased, but acceptable and tolerated, adverse events rate. After discontinuation of tamsulosin or tadalafil in patients previously treated with their combination, the improvement of LUTS retains significance compared with baseline.

Summary

Tadalafil 5 mg should be considered a primary treatment option for patients with LUTS/BPH and ED. Evidence highlight an excellent tolerability, safety, and effectiveness profile, both alone or in combination with tamsulosin 0.4 mg. A better efficacy on LUTS relief has been observed for combination therapy, preserving also sexual function. The further switch to monotherapy allows to preserve LUTS relief, but tadalafil only is able to retain ED improvement. Our results support the evidence for a more and more tailored and modular LUTS treatment.

Comparison of cernitin pollen extract vs tadalafil therapy for refractory chronic prostatitis/chronic pelvic pain syndrome: A randomized, prospective study

AIMS

To compare the efficacy of cernitin pollen extract (cernitin) or tadalafil for treating persistent chronic pelvic pain despite α1-blocker monotherapy in men with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) and lower urinary tract symptoms (LUTS).

METHODS

A total of 100 patients with refractory CP/CPPS despite ongoing α1-blocker monotherapy were randomized to receive add-on therapy with either cernitin (4 capsules/day) or tadalafil (5 mg/d) for 12 weeks. At week 12, changes from baseline in the patients' CP/CPPS, LUTS, and voiding function, as assessed using the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI), the International Prostate Symptom Score (IPSS), and uroflowmetry, respectively, were compared between the groups.

RESULTS

The final analysis included 42 and 45 patients in the cernitin and tadalafil groups, respectively. Although the NIH-CPSI total, NIH-CPSI pain sub-score, and NIH-CPSI quality of life sub-score significantly improved in both groups, the cernitin (vs tadalafil) group showed significantly greater improvements in the NIH-CPSI total score (-6.8 vs -4.6; P = .02) and NIH-CPSI pain sub-score (-4.1 vs -1.5; P < .001). Half (50%) of the patients in the cernitin group showed a reduction greater than 50% in their NIH-CPSI pain sub-score; in the tadalafil group, only four patients (8.9%) showed ≥50% improvement (P < .001). In contrast, the improvement in LUTS was significantly superior in the tadalafil group.

CONCLUSION

Both cernitin and tadalafil significantly ameliorated chronic pelvic pain in patients with refractory CP/CPPS. The add-on of cernitin was more effective than tadalafil for pelvic pain and discomfort.

Inflammation is a target of medical treatment for lower urinary tract symptoms associated with benign prostatic hyperplasia

Purpose

To review the role of a persistent prostatic inflammatory status (PIS) in the development and progression of benign prostatic hyperplasia (BPH) associated with lower urinary tract symptoms (LUTS) and which medical therapies approved for LUTS/BPH may reduce persistent PIS.

Methods

Literature search in PubMed up to July 2019.

Results

The cause of histologically defined persistent PIS or chronic prostatic inflammation is multifactorial. It is evident in many men with LUTS/BPH, particularly in older men and in men with a large prostate volume or more severe (storage) LUTS. Additionally, persistent PIS is associated with an increased risk of acute urinary retention and symptom worsening. Of medical therapies approved for LUTS/BPH, the current evidence for a reduction of persistent PIS is greatest for the hexanic extract of Serenoa repens (HESr). This treatment relieves LUTS to the same extent as α₁-adrenoceptor antagonists and short-term 5α-reductase inhibitors. Limited evidence is available on the effect of other mainstream LUTS/BPH treatments on persistent PIS.

Conclusions

Persistent PIS plays a central role in both the development and progression of LUTS/BPH. In men with LUTS/BPH who have a high chance of harbouring persistent PIS, HESr will not only improve LUTS, but also reduce (underlying) inflammation. Well-designed clinical studies, with a good level of evidence, are required to better evaluate the impact of BPH/LUTS medical therapies on persistent PIS.

Electronic supplementary material

The online version of this article (10.1007/s00345-020-03106-1) contains supplementary material, which is available to authorized users.

Higher expression of phosphodiesterase type 5 in the anterior fibromuscular stroma of the human prostate

PURPOSE

To examine phosphodiesterase type 5 (PDE5) expression in the anterior fibromuscular stroma (AFMS) of the prostate. Although PDE5 expression was identified in the human prostate, differences in PDE5 expression in intra-prostatic regions are unknown. The AFMS in the prostate has peculiar innervations that could contribute to voiding function. Here, we examined regional differences in PDE5 expression in the prostate with special reference to the AFMS.

METHODS

A total 18 human prostate and bladder specimens were obtained. Tissue specimens were processed by hematoxylin-eosin (H&E) staining and immunohistochemistry for PDE5. Immunoreactivity with PDE5 was evaluated using computer-assisted image analysis in the following regions: the AFMS, bladder neck, stromal hyperplasia in the transition zone, glandular hyperplasia in the transition zone (TZ gland), and the peripheral zone (PZ). The correlation between PDE5 expression in the AFMS and clinical data was analysed.

RESULTS

Image analysis revealed that the median ratio of the PDE5-immunoreactive area to smooth muscle area by H&E staining was 74.7% in the AFMS. There was significantly higher PDE5 expression in the AFMS than in the TZ gland (p = 0.034) and PZ (p = 0.002). PDE5 expression in the AFMS was not significantly correlated with age, prostate volume, transition zone volume, or transition zone index. However, older men had a tendency to have higher PDE5 expression in the AFMS.

CONCLUSIONS

We found higher PDE5 expression in the AFMS compared with other prostatic regions, which suggested that the AFMS is a target region of PDE5 inhibitors in the prostate.

A phosphodiesterase 5 inhibitor, tadalafil, suppresses stromal predominance and inflammation in a rat model of nonbacterial prostatitis

BACKGROUND

Chronic inflammation is thought to be a major causative factor for the development of benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). Tadalafil, a phosphodiesterase type 5 inhibitor (PDE5-I), which has been used for the treatment of BPH-LUTS in daily practice, is known to act at several urinary organs. In this study, focused on the prostate, we examined the effect of tadalafil on the pathological changes and inflammatory factors in a rat nonbacterial prostatitis (NBP) model.

METHODS

Forty ten-month-old male Wistar rats were divided into nonbacterial prostatitis (NBP), NBP with tadalafil treatment (NBP-tadalafil), control, and control treated with tadalafil (control-tadalafil) groups (n = 10 per group). The NBP and NBP-tadalafil groups were castrated and then received daily subcutaneous 17β-estradiol for 30 days. The control-tadalafil and NBP-tadalafil groups were administered daily oral tadalafil for 30 days. All rats were then sacrificed and pathological changes and inflammatory factors were assessed in the prostatic tissues.

RESULTS

In the NBP group, the stroma-to-epithelium (S/E) ratio in the ventral prostate was significantly higher than in the control group (P < 0.001). In the NBP-tadalafil group, the S/E ratio was significantly lower than in the NBP group (P < 0.001). The macrophage levels and the extent of T-cell infiltration in the NBP-tadalafil group were significantly lower than in the NBP group (P < 0.005; P < 0.001, respectively). Compared with the NBP group, tissue concentrations of inflammatory cytokines, such as tumor necrosis factor-α, interleukin-8, and interleukin-1β, were significantly downregulated in the NBP-tadalafil group (P < 0.01; P < 0.05; P < 0.005, respectively).

CONCLUSIONS

Tadalafil suppressed stromal predominance and showed anti-inflammatory effects in a rat NBP model in association with downregulation of inflammatory cytokines.

Which Drug to Discontinue 3 Months After Combination Therapy of Tadalafil plus Tamsulosin for Men with Lower Urinary Tract Symptom and Erectile Dysfunction? Results of a Prospective Observational Trial

BACKGROUND

Safety and efficacy of tamsulosin and tadalafil for men with benign prostatic enlargement (BPE) and/or erectile dysfunction (ED) are defined. However, there are only a few pilot studies on combination therapy with these drugs for men with lower urinary tract symptom (LUTS)/BPE and ED. Moreover, preliminary reports are limited to 12 wk, without any information about subsequent therapies.

OBJECTIVE

To evaluate the impact of discontinuation of tamsulosin versus tadalafil 12 wk after combination therapy.

DESIGN, SETTING, AND PARTICIPANTS

Fifty consecutive patients with moderate-to-severe LUTS (International Prostate Symptom Score [IPSS] > 7) and mild-to-severe ED (International Index of Erectile Function-5 [IIEF-5] < 22) were treated with combination therapy (tamsulosin 0.4mg/d plus tadalafil 5mg/d) for 12 wk. After 12 wk, 25 patients discontinued tamsulosin (Group TAD), while 25 patients discontinued tadalafil (Group TAM).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Efficacy variables were IPSS (total, voiding, storage) and IIEF-5. Paired samples t test and analysis of variance were used.

RESULTS AND LIMITATIONS

Groups TAD and TAM presented similar features (age, BMI, metabolic profile) including symptoms scores at baseline. Similar and significant improvements in IPSS (total, voiding, and storage) and IIEF-5 were recorded in both groups after 12 wk of combination therapy (all p< 0.001). Total IPSS was similar between the two groups at the end of the trial. However, we found between-group significant differences from baseline to 24 wk and from 12 to 24 wk in storage-IPSS (Group TAD: -3.32 vs Group TAM: -1.24, p= 0.002; Group TAD: +0.24 vs Group TAM: +1.20, p= 0.040, respectively) and in IIEF-5 (Group TAD: +4.64 vs Group TAM: +0.16, p< 0.001; Group TAD: -1.64 vs Group TAM: -4.40, p= 0.003). No significant treatment-related adverse event was recorded in both groups.

CONCLUSIONS

After 12 wk of combination therapy, monotherapy with tadalafil for further 12 wk allows to preserve the improvement of storage IPSS and IIEF-5, in addition to total IPSS.

PATIENT SUMMARY

In this report we evaluated the discontinuation of tamsulosin or tadalafil after 12 wk of combination therapy. We found that tadalafil monotherapy, for a further 12 wk, aids in retaining the improvement of storage symptoms and erectile function.

Benign Prostatic Hyperplasia and Lower Urinary Tract Symptoms: What Is the Role and Significance of Inflammation?

PURPOSE OF REVIEW

The purpose of this review is to summarize the role and significance of inflammation as a putative additional factor contributing to lower urinary tract symptoms and the progression of benign prostatic hyperplasia. We review (1) the histologic definition of prostatic inflammation and its prevalence, (2) the effects inflammation in the prostate including on risk of acute urinary retention, and (3) the effects of systemic inflammation on the prostate and on voiding.

RECENT FINDINGS

Inflammation is a highly prevalent finding in the prostate, both on a histological and biochemical level. Men with inflammation have higher IPSS scores and increased prostate size; however, these differences appear to be imperceptibly small. Men with inflammation do experience a significantly increased risk of developing acute urinary retention, an event that is associated with significant morbidity. Recently, attempts have been made to identify more specific biochemical markers of local inflammation, and to identify regional patterns of inflamed tissue within the prostate which may be associated with higher IPSS scores, accelerated progression, and AUR. The effects of systemic inflammatory states, most notably MetS, and their role in LUTS have also been examined. Inflammation is a common finding in prostates of aging men, but its contribution to lower urinary tract symptoms and benign prostatic hyperplasia progression appears to be small when considered as a clinically relevant entity. Advances in the understanding of different forms of inflammation, and their impact when experienced in different locations within the prostate, may refine this knowledge. Systemic inflammation affects voiding, including in the absence of a prostate, but again significant effects of systemic inflammation on the prostate itself are also difficult to demonstrate. Prostatic inflammation is associated with a significantly increased risk of acute urinary retention.

Tadalafil 5 mg Alone or in Combination with Tamsulosin 0.4 mg for the Management of Men with Lower Urinary Tract Symptoms and Erectile Dysfunction: Results of a Prospective Observational Trial

Tadalafil 5 mg represents the standard for men with Erectile dysfunction (ED) and lower urinary tract symptoms (LUTS)/benign prostatic enlargement (BPE). We carried out an observational trial aiming to assess the efficacy and safety of Tadalafil compared with Tadalafil plus Tamsulosin. Seventy-five patients complaining of ED and LUTS were treated for 12-weeks with Tadalafil plus placebo (TAD+PLA-group) or with combination therapy tadalafil plus tamsulosin (TAD+TAM-group). Efficacy variables were: International Index of Erectile Function (IIEF), International Prostate Symptom Score (IPSS), maximum urinary flow rate (Qmax) and safety assessments. Data were evaluated using paired samples T-test (baseline vs. 12-weeks) and analysis of variance (Δgroup-TAD+PLA vs. Δgroup-TAD+TAM). At baseline, both groups presented similar characteristics and symptoms scores (all: p > 0.05). From baseline to 12-weeks, all the subjects showed a significant improvement of IIEF, total-IPSS, storage-IPSS, Qmax (all: p < 0.001). Conversely, a significant improvement of voiding-IPSS was observed in TAD+TAM-group (−3.5 points, p < 0.001). Indeed, TAD+PLA-group showed a not significant improvement of voiding-IPSS (−2.0 points, p = 0.074). When we compared between-groups differences at 12-weeks, IIEF (p = 0.255), total-IPSS (p = 0.084) and storage-IPSS (p = 0.08) did not show any statistically significant differences, whereas, voiding-IPSS and Qmax were significantly better in TAD+TAM-group (p = 0.006 and p = 0.027, respectively). No severe treatment adverse events (TAEs) were reported in both groups. Tadalafil achieved the same improvements of IIEF, total-IPSS, storage-IPSS when compared to combination therapy. Instead, Qmax and voiding-IPSS were better managed with combination therapy, without change of TAEs.

Diet-Induced Rabbit Models for the Study of Metabolic Syndrome

Obesity and metabolic syndrome (MetS) have become a growing problem for public health and clinical practice, given their increased prevalence due to the rise of sedentary lifestyles and excessive caloric intake from processed food rich in fat and sugar. There are several definitions of MetS, but most of them describe it as a cluster of cardiovascular and metabolic alterations such as abdominal obesity, reduced high-density lipoprotein (HDL) and elevated low-density lipoprotein (LDL) cholesterol, elevated triglycerides, glucose intolerance, and hypertension. Diagnosis requires three out of these five criteria to be present. Despite the increasing prevalence of MetS, the understanding of its pathophysiology and relationship with disease is still limited. Indeed, the pathological consequences of MetS components have been reported individually, but investigations that have studied the effect of the combination of MeS components on organ pathological remodeling are almost nonexistent. On the other hand, animal models are a powerful tool in understanding the mechanisms that underlie pathological processes such as MetS. In the first part of the review, we will briefly overview the advantages, disadvantages and pathological manifestations of MetS in porcine, canine, rodent, and rabbit diet-induced experimental models. Then, we will focus on the different dietary regimes that have been used in rabbits to induce MetS by means of high-fat, cholesterol, sucrose or fructose-enriched diets and their effects on physiological systems and organ remodeling. Finally, we will discuss the use of dietary regimes in different transgenic strains and special rabbit breeds.

Interventions to chronic prostatitis/Chronic pelvic pain syndrome treatment. Where are we standing and what's next?

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a frustrating syndrome. The pathogenesis and state of the art treatment of CP/CPPS are not known. A wide variety of therapies including anti-inflammatories, antibiotics, alpha-blockers, neuropathic pain modulators, and 5α-reductase inhibitors are in practice. These treatment strategies focus on alleviating symptoms in specific domains without treating root-cause and therapeutic outcome is far from satisfactory. We review the literature on current pharmacological treatments for CP/CPPS in detail and suggest future perspectives to modify the treatment strategies. We suggest that introducing novel treatment strategies such as gene editing, and T_regs expressing chimeric receptors may improve the treatment outcomes by inducing immune tolerance and controlling expression of pro-inflammatory cytokines.

Activation of cGMP/PKG/p65 signaling associated with PDE5-Is downregulates CCL5 secretion by CD8 + T cells in benign prostatic hyperplasia

BACKGROUND

Benign prostatic hyperplasia (BPH) is the most common urological disease in elderly men, but the underlying pathophysiological mechanisms are complex and not fully understood. Phosphodiesterase type 5 inhibitors (PDE5-Is) used to treat BPH could upregulate the cyclic guanosine monophosphate (cGMP)-dependent protein kinase G (PKG) signaling, which was shown to blunt inflammation in the prostate. Our previous findings indicate that CD8⁺ T cells promote the proliferation of BPH epithelial cells (BECs) in low androgen conditions through secretion of CCL5; however, the role of the cGMP/PKG pathway in the process is unclear.

METHODS

Paraffin-embedded tissues were used for expression quantity of CD8⁺ T cells, CCL5, cyclin D1, and PDE5 protein by immunohistology in prostate specimens which were/were not treated with finasteride 5 mg daily for at least 6 months before surgery. BPH-1 cells were cocultured with or without CD8 ⁺ T cells or PDE5-Is in low androgen conditions for 4 days. The conditioned media, BPH-1 cells, and CD8 ⁺ T cells were harvested for the subsequent experiments. The quantitative polymerase chain reaction was used for assaying the level of messenger RNA expression of CCL5. CCL5 in the conditioned media was detected by the enzyme-linked immunosorbent assay. The effect of PDE5-Is on cocultured BPH-1/CD8 ⁺ T-cell proliferation was detected by the cell counting kit-8. A high-fat diet (HFD)-induced prostatic hyperplasia rat model was used to investigate the effect of cGMP/PKG activation in CD8 ⁺ T cells in vivo.

RESULTS

CD8⁺ T-cell infiltration into human BPH tissues was positively correlated with the expression of CCL5, cyclin D1, and PDE5, whereas in an HFD-induced prostatic hyperplasia rat model, the activation of the cGMP/PKG signaling by a PDE5-I could suppress the CD8 ⁺ T-cell infiltration and the CCL5 and cyclin D1 expression. Furthermore, the activation of the cGMP/PKG pathway inhibited CCL5 secretion by CD8 ⁺ T cells by downregulating nuclear factor-κB p65 phosphorylation, which reduced the growth of BPH-1 through CCL5/STAT5/CCND1 signaling.

CONCLUSIONS

Our results indicate that the upregulation of the cGMP/PKG/p65 signaling reduces CCL5 secretion in CD8 ⁺ T cells, which in turn decreases the proliferation of BECs in low androgen conditions, suggesting that the combination of 5α reductase inhibitors lowering androgen levels and PDE5-Is may be a novel, more effective treatment for BPH patients.

Efficacy of tadalafil against lower urinary tract symptoms after low-dose-rate brachytherapy in prostate cancer patients

Objectives:

This study was performed to evaluate the effects of addition of tadalafil to tamsulosin in the treatment of brachytherapy patients with lower urinary tract symptoms (LUTS).

Methods:

Localized prostate cancer patients who developed LUTS after low-dose-rate brachytherapy (LDR-BT) were first treated with alpha-1 blockers (tamsulosin, 0.2 mg per day). Those still suffering from LUTS were additionally treated with phosphodiesterase type 5 inhibitor (tadalafil, 5 mg/day). LUTS was evaluated by the International Prostate Symptom Score (IPSS), IPSS Quality of Life (QOL) score, Overactive Bladder Symptom Score (OABSS), and the International Index of Erectile Function 5 (IIEF5) score before brachytherapy, before treatment with tadalafil, and after three months of treatment with tadalafil.

Results:

Twenty-three patients were enrolled in the study. Each subscore of the IPSS (storage symptom, voiding symptom, and postvoiding symptom) and the QOL score improved, but OABSS and IIEF5 did not show significant recovery after addition of tadalafil treatment. When patient characteristics and each question score were surveyed, time from seed implantation until treatment with tadalafil showed the strongest correlation with recovery.

Conclusions:

Addition of tadalafil to tamsulosin treatment was effective against LUTS in localised prostate cancer patients after brachytherapy.

Evidence level:

2b

The anti-inflammatory and anti-fibrotic effects of tadalafil in thioacetamide-induced liver fibrosis in rats

Liver fibrosis is a health concern that leads to organ failure mediated via production of inflammatory cytokines and fibrotic biomarkers. This study aimed to explore the protective effect of tadalafil, a phosphodiesterase-5 inhibitor, against thioacetamide (TAA)-induced liver fibrosis. Fibrosis was induced by administration of TAA (200 mg/kg, i.p.) twice weekly for 6 weeks. Serum transaminases activities, liver inflammatory cytokines, fibrotic biomarkers, and liver histopathology were assessed. TAA induced marked histopathological changes in liver tissues coupled with elevations in serum transaminases activities. Furthermore, hepatic content of nitric oxide and tumor necrosis factor-alpha, interleukin-6, and interleukin-1 beta were elevated, together with a reduction of interleukin-10 in the liver. In addition, TAA increased hepatic contents of transforming growth factor-beta, hydroxyproline, alpha-smooth muscle actin, and gene expression of collagen-1. Pretreatment with tadalafil protected against TAA-induced liver fibrosis, in a dose-dependent manner, as proved by the alleviation of inflammatory and fibrotic biomarkers. The effects of tadalafil were comparable with that of silymarin, a natural antioxidant, and could be assigned to its anti-inflammatory and anti-fibrotic properties.

Effect of tadalafil on chronic pelvic pain and prostatic inflammation in a rat model of experimental autoimmune prostatitis

BACKGROUND

Experimental autoimmune prostatitis (EAP) shares important clinical features with clinical chronic prostatitis/chronic pelvic pain. We investigated the effect of tadalafil on pelvic pain and prostatic inflammation in a rat EAP model.

METHODS

EAP was induced in rats by intradermal injection of rat prostate antigen and complete Freund's adjuvant on days 0 and 28. Rats were treated with tadalafil (2 mg/kg, p.o.; EAP-tadalafil) or vehicle (EAP-vehicle) once daily from day 0, while sham-operated animals were treated with vehicle only (Sham). Tactile allodynia was measured on days 28, 35, and 42 by applying von Frey filaments to the lower abdomen as an index of pelvic pain. On day 42, the plasma immunoglobulin G (IgG) concentration and the testosterone/estradiol ratio were measured and histopathological analysis of the prostate was performed.

RESULTS

Tactile allodynia in the pelvic region was observed on days 28, 35, and 42 after EAP induction. The tactile allodynia observed on day 42 was significantly reduced by repeated treatment with tadalafil. Plasma IgG concentrations increased after EAP induction but the increase was not changed by tadalafil treatment. Prostate tissues were characterized by epithelial necrosis, infiltration of neutrophils and/or lymphocytes to acini and stroma, and fibrosis, in addition to a high stroma-to-epithelium ratio. Tadalafil treatment significantly suppressed the severity of the lesions.

CONCLUSIONS

EAP rats developed pelvic pain, prostatic inflammation and increased plasma IgG concentrations. Tadalafil inhibited the chronic pelvic pain and prostatic inflammation, suggesting that its anti-inflammatory action may contribute to its blocking of pain development in the EAP model.

Prostatic inflammation: a potential treatment target for male LUTS due to benign prostatic obstruction

BACKGROUND

The purpose of this narrative review is to evaluate the role of prostatic inflammation as a treatment target for lower urinary tract symptoms (LUTS) due to benign prostatic obstruction (BPO) and provide an update on the available therapies.

METHODS

An extensive literature search was conducted for studies on established and investigational treatments with anti-inflammatory mechanism of action that has been assessed for the management of male LUTS due to BPO.

RESULTS

Data on phosphodiesterase 5 inhibitors, nonsteroidal anti-inflammatory drugs, vitamin D3 receptor analogs, phytotherapy, statins, and lifestyle changes have been reviewed and analyzed. Preclinical evidence has shown the anti-inflammatory effect of these treatments on prostate. However, there is a wide variation in the degree of mature of each therapy. In addition, there are significant differences between the studies in terms of design, number of patients, and duration of follow-up.

CONCLUSIONS

Several drugs classes have been investigated for their impact on prostatic inflammation and improvement of male LUTS. The reviewed data support the rationale for use of agents that may alter and improve the inflammatory environment in the prostate in men with LUTS, but further high-quality long-term studies are required for the exact positioning of the new drugs in daily practice.

Young Human Cholinergic Neurons Respond to Physiological Regulators and Improve Cognitive Symptoms in an Animal Model of Alzheimer's Disease

The degeneration of cholinergic neurons of the nucleus basalis of Meynert (NBM) in the basal forebrain (BF) is associated to the cognitive decline of Alzheimer's disease (AD) patients. To date no resolutive therapies exist. Cell-based replacement therapy is a strategy currently under consideration, although the mechanisms underlying the generation of stem cell-derived NBM cholinergic neurons able of functional integration remain to be clarified. Since fetal brain is an optimal source of neuronal cells committed towards a specific phenotype, this study is aimed at isolating cholinergic neurons from the human fetal NBM (hfNBMs) in order to study their phenotypic, maturational and functional properties. Extensive characterization confirmed the cholinergic identity of hfNBMs, including positivity for specific markers (such as choline acetyltransferase) and acetylcholine (Ach) release. Electrophysiological measurements provided the functional validation of hfNBM cells, which exhibited the activation of peculiar sodium (I_Na) and potassium (I_K) currents, as well as the presence of functional cholinergic receptors. Accordingly, hfNBMs express both nicotinic and muscarinic receptors, which were activated by Ach. The hfNBMs cholinergic phenotype was regulated by the nerve growth factor (NGF), through the activation of the high-affinity NGF receptor TrkA, as well as by 17-β-estradiol through a peculiar recruitment of its own receptors. When intravenously administered in NBM-lesioned rats, hfNBMs determined a significant improvement in memory functions. Histological examination of brain sections showed that hfNBMs (labeled with PKH26 fluorescent dye prior to administration) reached the damaged brain areas. The study provides a useful model to study the ontogenetic mechanisms regulating the development and maintenance of the human brain cholinergic system and to assess new lines of research, including disease modeling, drug discovery and cell-based therapy for AD.

The influence of asymptomatic inflammatory prostatitis on the onset and progression of lower urinary tract symptoms in men with histologic benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is a condition that greatly affects the quality of life of middle-aged and elderly men. Histopathologically, hyperplastic changes frequently occur in the prostate tissue of elderly men, the incidence of which has been reported to reach approximately 80% in men in their 70s. In clinical practice, approximately 25% of men with histologic BPH are assumed to experience lower urinary tract symptoms (LUTS) and receive some kind of treatment. In other words, there are some men with histologic BPH who do not exhibit LUTS. For that reason, many factors, such as the change in hormonal environment, the immune or autoimmune response, the alteration of gene expression, and so on, are thought to affect the onset and progression of LUTS in men with histologic BPH. One such factor that has long drawn attention is the presence of asymptomatic histological inflammation, which very often accompanies symptomatic BPH. Recent studies have suggested that asymptomatic histological inflammation causes repeated destruction, healing, and regeneration of the prostate tissue, leading to the enlargement of prostatic nodules, while at the same time causing stromal tissue-predominant remodeling of the prostate tissue, which can increase urination resistance and result in the condition changing from asymptomatic BPH to symptomatic BPH. In future, the biomolecular clarification of the significance of asymptomatic histological inflammation in the prostate tissue could help develop new treatment strategies for BPH accompanied by LUTS.

Lower urinary tract symptoms/benign prostatic hypertrophy and vascular function: Role of the nitric oxide-phosphodiesterase type 5-cyclic guanosine 3',5'-monophosphate pathway

It is well known that there is an association of lower urinary tract symptoms/benign prostatic hypertrophy with cardiovascular disease, suggesting that lower urinary tract symptoms/benign prostatic hypertrophy is a risk factor for cardiovascular events. Vascular function, including endothelial function and vascular smooth muscle function, is involved in the pathogenesis, maintenance and development of atherosclerosis, leading to cardiovascular events. Vascular dysfunction per se should also contribute to lower urinary tract symptoms/benign prostatic hypertrophy. Both lower urinary tract symptoms/benign prostatic hypertrophy and vascular dysfunction have cardiovascular risk factors, such as hypertension, dyslipidemia, diabetes mellitus, aging, obesity and smoking. Inactivation of the phosphodiesterase type 5-cyclic guanosine 3',5'-monophosphate-nitric oxide pathway causes lower urinary tract symptoms/benign prostatic hypertrophy through an enhancement of sympathetic nervous activity, endothelial dysfunction, increase in Rho-associated kinase activity and vasoconstriction, and decrease in blood flow of pelvic viscera. Both endogenous nitric oxide and exogenous nitric oxide act as vasodilators on vascular smooth muscle cells through an increase in the content of cyclic guanosine 3',5'-monophosphate, which is inactivated by phosphodiesterase type 5. In a clinical setting, phosphodiesterase type 5 inhibitors are widely used in patients with lower urinary tract symptoms/benign prostatic hypertrophy. Phosphodiesterase type 5 inhibitors might have beneficial effects on vascular function through not only inhibition of cyclic guanosine 3',5'-monophosphate degradation, but also increases in testosterone levels and nitric oxide bioavailability, increase in the number and improvement of the function of endothelial progenitor cells, and decrease in insulin resistance. In the present review, the relationships between lower urinary tract symptoms/benign prostatic hypertrophy, the phosphodiesterase type 5-nitric oxide-cyclic guanosine 3',5'-monophosphate pathway, vascular function and cardiovascular outcomes are examined.

Adiponectin deficiency contributes to the development and progression of benign prostatic hyperplasia in obesity

The incidence of benign prostatic hyperplasia (BPH) is increasing among obese individuals, but few studies have fully explained the underlying mechanisms. We aimed to elucidate the relationship between obesity and BPH. Herein, we show that in prostatic epithelial and stromal cells, adiponectin exerts multifunctional effects including anti-proliferation, blocking of G1/S-phase progression and the promotion of apoptosis via inhibiting the MEK-ERK-p90RSK axis. Furthermore, we found that a high-fat diet (HFD) led to adiponectin deficiency and microscopic BPH in a mouse model of obesity. And an adiponectin supplement protected the obese mice from microscopic BPH. The present study provides evidence that adiponectin is a protective regulator in the development and progression of BPH and that adiponectin deficiency causally links BPH with obesity.

Ejaculatory dysfunction in the treatment of lower urinary tract symptoms

The link between lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH) and sexual dysfunction is well established. Sexual dysfunction can encompass both ejaculatory dysfunction (EjD) and erectile dysfunction (ED). Ejaculatory dysfunction can consist of premature ejaculation, delayed ejaculation, retrograde ejaculation, anejaculation, decreased force of ejaculation and pain upon ejaculation. The impact of different medical and surgical therapies on ejaculatory function will be reviewed. We reviewed the various categories of LUTS treatment including the canonical epidemiology and pathophysiology as well as the surgical and medical treatments for LUTS/BPH. We note that most surgeries and several medical treatments have a certain but ill-defined negative impact on ejaculatory function. Several MISTs and selected medical therapies appear to have little impact on EjD. Both EjD and BPH are very common disorders in men under the care of an urologist. It is well documented that there is a clinical association between these two entities. Unfortunately many of the medical treatments and almost all surgical treatment impact the ejaculatory function of the patient. The surgical treatment of BPH often leads to retrograde ejaculation while medical treatment leads to anejaculation.

Tadalafil reduces visceral adipose tissue accumulation by promoting preadipocytes differentiation towards a metabolically healthy phenotype: Studies in rabbits

Development of metabolically healthy adipocytes within dysfunctional adipose tissue may represent an attractive way to counteract metabolic syndrome (MetS). In an experimental animal model of high fat diet (HFD)-induced MetS, in vivo, long- and short-term tadalafil treatments were able to reduce visceral adipose tissue (VAT) accumulation and hypertriglyceridemia, and to induce the expression in VAT of the brown fat-specific marker, uncoupling protein 1 (UCP1). VAT preadipocytes (PAD), isolated from the tadalafil-treated HFD rabbits, showed: i) a multilocular morphology; ii) an increased expression of brown fat-specific genes (such as UCP1 and CIDEA); iii) improved mitochondrial structure and dynamic and reduced superoxide production; iv) improved insulin sensitivity. Similar effects were obtained after in vitro tadalafil treatment in HFD rPAD. In conclusion, tadalafil counteracted HFD-associated VAT alterations, by restoring insulin-sensitivity and prompting preadipocytes differentiation towards a metabolically healthy phenotype.

Latest Evidence on the Use of Phosphodiesterase Type 5 Inhibitors for the Treatment of Lower Urinary Tract Symptoms Secondary to Benign Prostatic Hyperplasia

CONTEXT

Several preclinical reports, randomized controlled trials, systematic reviews, and posthoc analyses corroborate the role of phosphodiesterase type 5 inhibitors (PDE5-Is) in the treatment of men with lower urinary tract symptoms (LUTS) associated with benign prostatic enlargement (BPE).

OBJECTIVE

Update of the latest evidence on the mechanisms of action, evaluate the current meta-analyses, and emphasize the results of pooled data analyses of PDE5-Is in LUTS/BPE.

EVIDENCE ACQUISITION

Literature analysis of basic researches on PDE5-Is, systematic literature search in PubMed and Scopus until May 2015 on reviews of trials on PDE5-Is, and collection of pooled data available on tadalafil 5mg.

EVIDENCE SYNTHESIS

Latest evidences on the pathophysiology of LUTS/BPE has provided the rationale for use of PDE5-Is: (1) improvement of LUT oxygenation, (2) smooth muscle relaxation, (3) negative regulation of proliferation and transdifferentiation of LUT stroma, (4) reduction of bladder afferent nerve activity, and (5) down-regulation of prostate inflammation are the proven mechanisms of action of PDE5-Is. Data from eight systematic reviews demonstrated that PDE5-Is allow to improve LUTS (International Prostate Symptom Score mean difference vs placebo: 2.35-4.21) and erectile function (International Index of Erectile Function mean difference vs placebo: 2.25-5.66), with negligible change in flow rate (Qmax mean difference vs placebo: 0.01-1.43). Pooled data analyses revealed that tadalafil 5mg once daily allows the clinically-meaningful improvement of LUTS and nocturnal voiding frequency independent of both erectile dysfunction severity and improvement.

CONCLUSIONS

PDE5-Is are safe and effective in improving both LUTS and erectile function in appropriately selected men with LUTS/BPE. Data on the reduction of disease progression, long-term outcomes, and cost-effectiveness analyses are still lacking.

PATIENT SUMMARY

We reviewed recent literature on phosphodiesterase type 5 inhibitors in men with lower urinary tract symptoms associated with prostatic enlargement. We found evidence to confirm that phosphodiesterase type 5 inhibitors are a valid treatment option for men affected by bothersome urinary symptoms with or without erectile dysfunction.

Obesity and late-onset hypogonadism

Obesity and male hypogonadism (HG) are often associated, as demonstrated in all cross-sectional studies. Prospective studies have indicated that i) having HG at baseline increases the risk of visceral obesity (and metabolic syndrome) and that ii) obesity induces incident HG. Hence, there is a bidirectional relationship between the two conditions. This is the main topic of this review, along with some pathogenic considerations. Meta-analysis of intervention studies indicates that treating obesity is a very efficient treatment for obesity-induced HG. The mechanism by which obesity induces HG has not yet been completely understood, but dietary-induced hypothalamic inflammation, along with a decreased GnRH release, is plausible. Among patients seeking medical care for obesity, the proportion of HG is relatively high. The prevalence of obesity among patients referring for sexual dysfunction is also elevated. Hence, in symptomatic, obese, hypogonadal subjects, testosterone supplementation (TS) can be considered. Whereas long-term uncontrolled register studies suggest that TS could decrease weight, analysis of controlled studies only support a parallel increase in lean mass and decrease in fat mass, with a resulting null effect on weight. Considering that T induces an increase in muscle mass, it is conceivable that the amount of activity obese people can undertake after TS will increase, allowing a closer adherence to physical exercise programs. Some studies, here meta-analyzed, support this concept.

Impact of cardiovascular risk factors and related comorbid conditions and medical therapy reported at baseline on the treatment response to tadalafil 5 mg once-daily in men with lower urinary tract symptoms associated with benign prostatic hyperplasia: an integrated analysis of four randomised, double-blind, placebo-controlled, clinical trials

PURPOSE

The influence of cardiovascular risk factors/comorbidities on response to oral once-daily tadalafil 5 mg was explored in men with lower urinary tract symptoms associated with benign prostatic hyperplasia (LUTS/BPH).

METHODS

This post hoc analysis pooled data from four double-blind studies in which 1498 men with > 6-mo history of LUTS/BPH were randomised and received either once-daily placebo (n = 746) or tadalafil 5 mg (n = 752) for 12 weeks. Descriptive statistics were reported for changes in total International Prostate Symptom Score (IPSS), IPSS voiding and storage subscores, and IPSS quality-of-life (QoL) index. Treatment group differences by baseline clinical and cardiovascular factors and medical therapies were examined using analysis of covariance.

RESULTS

Tadalafil was effective in men with LUTS/BPH and cardiovascular risk factors/comorbidities except for patients receiving > 1 antihypertensive medication. Placebo-adjusted least squares (LS) mean improvements in total IPSS were -1.2 (95% CI: -2.5 to -0.0) in men taking > 1 antihypertensive medication vs. -3.3 (95% CI: -4.4 to -2.1) in men taking one medication (interaction p = 0.020). In addition, placebo-adjusted LS mean improvements in total IPSS were -0.2 (95% CI, -2.1 to 1.7) in men who reported use of diuretics vs. -2.8 (95% CI, -3.7 to -1.9) in men who reported taking other antihypertensive medications vs. -2.3 (95% CI, -3.2 to -1.5) in men who reported not using any antihypertensive drug (p-value for interaction = 0.053).

CONCLUSIONS

Once-daily tadalafil 5 mg improved LUTS/BPH, regardless of severity, in men with coexisting cardiovascular risk factors/comorbidities, except for patients with history of > 1 drug for arterial hypertension. Use of diuretics may contribute to patients' perception of a negated efficacy of tadalafil on LUTS/BPH. Comorbidities should be considered when choosing the optimal medicine to treat men with LUTS/BPH.

Clinical correlates of enlarged prostate size in subjects with sexual dysfunction

Digito-rectal examination (DRE) of the prostate provides useful information on the state of prostate growth and on the presence of suspected peripheral nodules. The aim of this study is to describe the clinical and biochemical correlates of finding an enlarged prostate size at DRE in subjects with sexual dysfunction (SD). A consecutive series of 2379 patients was retrospectively studied. The analysis was focused on a subset of subjects (n = 1823; mean age 54.7 ± 11.4) selected for being free from overt prostatic diseases. Several parameters were investigated. After adjusting for confounders, the presence of an enlarged prostate size at DRE was associated with a higher risk of metabolic syndrome (HR = 1.346 (1.129–1.759); P = 0.030), type 2 diabetes mellitus (HR = 1.489 (1.120–1.980); P = 0.006), increased LDL cholesterol (>100 mg dl⁻¹; HR = 1.354 (1.018–1.801); P = 0.037) and increased mean blood pressure (BP) values (HR = 1.017 (1.007–1.027) for each mmHg increment; P = 0.001). Accordingly, enlarged prostate size was also associated with a higher risk of arteriogenic erectile dysfunction (ED), as well as with other andrological conditions, such as varicocele and premature ejaculation (PE). PSA levels were significantly higher in subjects with enlarged prostate size when compared to the rest of the sample (HR = 3.318 (2.304; 4.799) for each log unit increment in PSA levels; P < 0.0001). Arteriogenic ED, according to different criteria, was also associated with increased PSA levels. In conclusion, our data support the need to examine prostate size either by clinical (DRE) or biochemical (PSA) inspection in subjects with SD, in order to have insights into the nature of the SD and the metabolic and cardiovascular (CV) background of the patient.

Is periurethral calcification associated with urinary flow rate and symptom severity in men with lower urinary tract symptoms-benign prostatic hyperplasia? A retrospective review

OBJECTIVE

To evaluate the association of periurethral calcification (PUC) with urine flow rate and symptom severity in men with lower urinary tract symptoms-benign prostatic hyperplasia (LUTS-BPH).

METHODS

The records of 1199 LUTS-BPH patients were obtained from a prospectively maintained database of men on their first visit from April 2010 to April 2013. Patients with incomplete data or comorbidities affecting voiding function were excluded. The degree of PUC was scored by evaluating the ratio of the calcified urethra to the entire prostatic urethra on the midsagittal plane of a transrectal ultrasonogram. The relationships between prostate-related parameters, International Prostate Symptom Score (IPSS), and uroflowmetric parameters were evaluated.

RESULTS

A total of 1030 patients were eligible for final analysis. There were 654 patients (63.5%) with no PUC, 233 (22.6%) with mild PUC, and 143 (13.9%) with moderate to severe PUC. The total IPSS was 16.21 ± 7.29, 17.74 ± 7.77, and 17.75 ± 7.60 in no, mild, and moderate to severe PUC groups, respectively (P = .007), whereas peak urinary flow rate (Qmax) was 15.05 ± 7.59, 13.62 ± 6.68, and 12.20 ± 6.39 mL/s, respectively (P <.001). In an age-adjusted partial correlation test, PUC significantly associated with total IPSS, the storage symptom score, and Qmax (P <.05). Multivariate analysis revealed that PUC independently associated with Qmax (P = .012), total IPSS (P = .042), and the storage symptom score (P = .018) but not with postvoid residue, the voiding symptom score, or the postmicturition symptom score.

CONCLUSION

PUC is independently associated with Qmax and urinary symptoms indirectly advocating for the recent idea that periurethral fibrosis and stiffness could cause LUTS-BPH in men.

Metabolic syndrome-associated sperm alterations in an experimental rabbit model: relation with metabolic profile, testis and epididymis gene expression and effect of tamoxifen treatment

The influence of metabolic syndrome (MetS) on sperm quality and function is debated. Using a well-established high fat diet (HFD) rabbit model resembling human MetS, including development of hypogonadism, we demonstrate that HFD decreased sperm motility, morphology and acrosome reaction in response to progesterone and increased sperm cholesterol content. All the above parameters were associated with most MetS features, its severity and plasma testosterone (T) at univariate analysis. After T adjustment, sperm morphology and motility retained a significant association, respectively, with mean arterial pressure and circulating cholesterol levels. MetS modified the expression of inflammatory and tissue remodelling genes in the testis and of aquaporins in the epididymis. In a multivariate analysis, sperm morphology resulted associated with testis expression of fibronectin and collagen type 1 genes, whereas motility with epididymis aquaporin 1 gene. Administration of tamoxifen, used in the treatment of idiopathic male infertility, to HFD rabbits partially restored motility, but further decreased morphology and increased spontaneous acrosome reaction, without restoring responsiveness to progesterone. Overall our results indicate that development of MetS produces detrimental effects on sperm quality and functionality by inducing metabolic disorders leading to alterations in testis and epididymis functions and evidence a role of hypertension as a new determinant of abnormal sperm morphology, in line with a previous human study from our group.

Management of benign prostatic hyperplasia: role of phosphodiesterase-5 inhibitors

Several studies have highlighted a strong association between benign prostatic hyperplasia/lower urinary tract symptoms (BPH/LUTS) and erectile dysfunction (ED), particularly in elderly men. Many epidemiological trials, such as in vitro and in vivo studies, have reported the emerging role of metabolic syndrome, including abdominal obesity, impaired glucose metabolism, hypertriglyceridemia, low high-density lipoprotein cholesterol, and hypertension, in the development and progression of urinary and sexual symptoms. Moreover, many authors have focused their studies on the identification of all the shared pathogenetic mechanisms of LUTS/BPH and ED, including alteration of cyclic guanosine monophosphate and RhoA-ROCK pathways or vascular and neurogenic dysfunction. All these are potential targets for proposed phosphodiesterase type 5 inhibitors (PDE5-Is). Therefore, several trials have recently been designed to evaluate the role of PDE5-Is alone or in combination with conventional treatment for BPH, such as α-adrenergic blockers, in men affected by LUTS/BPH, with or without ED. Different PDE5-Is are in clinical use worldwide and currently six of them are licensed for the oral treatment of ED. All these compounds differ in pharmacokinetic factors, with influence on drug action, and subsequently in the overall safety and efficacy profile.

Metformin in vitro and in vivo increases adenosine signaling in rabbit corpora cavernosa

INTRODUCTION

In subjects with erectile dysfunction responding poorly to sildenafil, metformin was reported to improve erections.

AIMS

The aim of this study is to investigate metformin's mechanism of action on erectile function, particularly focusing on adenosine (ADO) and nitric oxide (NO) signaling in an animal model of high-fat diet (HFD)-induced metabolic syndrome.

METHODS

In vitro contractility studies of penile strips. Penile expression of genes related to ADO or NO signaling was also evaluated.

MAIN OUTCOME MEASURE

In vitro contractility studies were used to investigate the effect of in vivo and ex vivo metformin administration on ADO- or acetylcholine (Ach)-induced relaxation of penile strips from HFD as compared with animals fed a regular diet (RD).

RESULTS

Expression of ADO receptor type 3 (A3 R), ADO deaminase (ADA), AMP deaminase type 1 (AMPD1), and 2 (AMPD2) was decreased in HFD as compared with RD. Accordingly, in HFD the ADO relaxant effect was potentiated as compared with RD (P < 0.02). In vivo metformin treatment in both RD and HFD significantly increased the ADO relaxing effect (P < 0.0001 and P < 0.01, respectively, vs. relative untreated groups) although to a different extent. In fact, the half-maximal inhibitory concentration (IC50 )/IC50 ratio in RD increased fourfold vs. HFD (RD IC50 ratio = 13.75 ± 2.96; HFD IC50 ratio = 2.85 ± 0.52). In corpora cavernosa (CC) from HFD, in vivo metformin (i) normalized A3 R, ADA, and AMPD1; (ii) further decreased AMPD2; (iii) increased dimethylarginine dimethylamino-hydrolase; and (iv) partially restored impaired Ach-induced relaxation. Ex vivo metformin time and dose dependently increased the relaxant effect of ADO in RD. The potentiating effect of metformin on ADO-induced relaxation was significantly reduced by preincubation with NO synthase inhibitor N(ω) -Nitro-L-arginine methyl ester hydrochloride (L-NAME). Interestingly, in vivo testosterone supplementation in HFD rabbits (i) increased penile expression of endothelial NO synthase and AMPD2 and (ii) restored metformin's potentiating effect on ADO-induced relaxation up to RD level.

CONCLUSION

Metformin in vivo and ex vivo increases ADO signaling in CC, most probably interfering with NO formation and ADO breakdown.

Benign prostatic hyperplasia: a new metabolic disease?

BACKGROUND

Benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS) are conditions extremely prevalent in the aging male. Although androgens are involved in prostate growth during developmental age, their role in the pathogenesis of BPH/LUTS is debated. Recent data indicate that low testosterone and high estradiol favor disease progression. In addition, the role of other determinants, such as metabolic syndrome or prostate inflammation, is emerging.

AIM

We reviewed the evidence regarding the pathogenesis of BPH/LUTS with particular attention to metabolic influence.

MATERIALS AND METHODS

A review of published evidence was performed using Medline.

RESULTS

Available evidence shows that a three-hit hypothesis can be drawn. An overt, or even a subclinical, bacterial or viral infection could induce prostatic inflammation (first hit) that could be autosustained or exacerbated by the presence of an altered metabolism and in particular by hypercholesterolemia (second hit). Hypogonadism and/or hyperestrogenism could act as a third hit, favoring the maintenance of this inflammatory state. The combined action of all three hits, or even two of them, may result in overexpression of Toll-like receptors (TLRs), transformation of prostatic cells into antigen-presenting cells and activation of resident human prostate-associated lymphoid tissue ending in overproduction of growth factors which, in turn, will induce prostate remodeling and further prostate enlargement. The mechanical obstruction, along with the direct action of the unfavorable metabolic and hormonal milieu on the bladder neck, helps in generating LUTS.

CONCLUSION

Inflammation, dyslipidemia and altered sex-steroid milieu mutually concur in determining BPH/LUTS.

Nonalcoholic steatohepatitis as a novel player in metabolic syndrome-induced erectile dysfunction: an experimental study in the rabbit

A pathogenic link between erectile dysfunction (ED) and metabolic syndrome (MetS) is now well established. Nonalcoholic steatohepatitis (NASH), the hepatic hallmark of MetS, is regarded as an active player in the pathogenesis of MetS-associated cardiovascular disease (CVD). This study was aimed at evaluating the relationship between MetS-induced NASH and penile dysfunction. We used a non-genomic, high fat diet (HFD)-induced, rabbit model of MetS, and treated HFD rabbits with testosterone (T), with the selective farnesoid X receptor (FXR) agonist obeticholic acid (OCA), or with the anti-TNFα mAb infliximab. Rabbits fed a regular diet were used as controls. Liver histomorphological and gene expression analysis demonstrated NASH in HFD rabbits. Several genes related to inflammation (including TNFα), activation of stellate cells, fibrosis, and lipid metabolism parameters were negatively associated to maximal acetylcholine (Ach)-induced relaxation in penis. When all these putative liver determinants of penile Ach responsiveness were tested as covariates in a multivariate model, only the association between hepatic TNFα expression and Ach response was confirmed. Accordingly, circulating levels of TNFα were increased 15-fold in HFD rabbits. T and OCA dosing in HFD rabbits both reduced TNFα liver expression and plasma levels, with a parallel increase of penile eNOS expression and responsiveness to Ach. Also neutralization of TNFα with infliximab treatment fully normalized HFD-induced hypo-responsiveness to Ach, as well as responsiveness to vardenafil, a phosphodiesterase type 5 inhibitor. Thus, MetS-induced NASH in HFD rabbits plays an active role in the pathogenesis of ED, likely through TNFα, as indicated by treatments reducing liver and circulating TNFα levels (T or OCA), or neutralizing TNFα action (infliximab), which significantly improve penile responsiveness to Ach in HFD rabbits.