Lower urinary tract symptoms are associated with low levels of serum serotonin, high levels of adiponectin and fasting glucose, and benign prostatic enlargement

Antidiabetic drugs, glycemic control and risk of benign prostatic hyperplasia

BACKGROUND

Diabetes has been associated with an increased risk of benign prostatic hyperplasia (BPH). However, the role of antidiabetic drugs as a BPH risk factor is unclear. The objective of our study was to examine the risk of BPH by antidiabetic drug use and glycemic control in a large population-based cohort of Finnish men.

METHODS

A total of 74,754 men in the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC) free of BPH at baseline in 1996-1999 were linked to the national medication reimbursement database for information on physician-prescribed antidiabetic drug purchases. Information on recorded BPH procedures and diagnoses was obtained from the National Care Register for Health Care, and for a subgroup of 17,739 men, information on blood glucose levels (BGLs) from the Fimlab Laboratories database. Cox regression with antidiabetic drug use and BGL as time-dependent variables was used to analyze the risks for starting BPH medication, recorded BPH diagnosis, and undergoing BPH surgery. The analysis was adjusted for age, use of statins, antihypertensive medication, and nonsteroidal anti-inflammatory drugs.

RESULTS

Of the subjects, 14,012 men (18.7%) used antidiabetic medication. Of the subgroup with fasting blood glucose data available, 7487 (42.2%) had diabetic level. The risks for BPH diagnosis (HR: 1.08, 95% CI: 1.03-1.13) and surgery (HR: 1.16, 95% CI: 1.09-1.24) were slightly elevated among antidiabetic drug users compared to nonusers. The association was strongest for insulin use. Similarly, risk of BPH surgery was increased in men with diabetic blood glucose compared to normoglycemic men. The risk association was attenuated by use of antidiabetic drugs.

CONCLUSIONS

Diabetic BGL and antidiabetic medication use, especially insulin, are associated with an elevated risk of BPH surgery compared to nondiabetic men. These findings support the roles of insulin use and untreated hyperglycemia as possible BPH risk factors.

Androgens, aging, and prostate health

Due to late onset hypogonadism (LOH), there is an increased usage of testosterone replacement therapy (TRT) in the aging male population. Since prostate is a target organ for androgens and anti-androgenic strategies are used to treat and palliate benign prostate hyperplasia (BPH) and prostate cancer (PC), the prevalence of both increases with age, the possible influence of TRT on prostate health becomes highly relevant. The present review summarizes existing data on the associations between endogenous hormone concentrations and prostate growth and concludes that circulating concentrations of androgens do not appear to be associated with the risks of development of BPH or initiation or progression of PC. The explanation for these findings relates to an apparent insensitivity of prostatic tissue to changes of testosterone concentrations within the physiological range.

Potential Targets for Overactive Bladder in Older Men Based on Urinary Analysis of Metabolomics

OBJECTIVE

We investigated the association between overactive bladder (OAB) and urinary metabolites in men.

METHODS

This prospective observational study included 42 men aged 65-80 years. The 3-day frequency volume chart (FVC), International Prostate Symptom Score (IPSS), and quality of life score were adapted to assess the micturition behavior. Participants with IPSS urgency score ≥2 were included in the OAB group, and those with IPSS urgency score <2 were included in the control group. We performed a comprehensive metabolomic analysis using urine samples. Metabolites were compared between the groups using an unpaired t test and Fisher's exact test in a nonadjusted analysis. Multivariable logistic regression analysis was performed to investigate the association between OAB and the metabolites.

RESULTS

Overall, 23 men were included in the OAB group and 19 in the control group. There were no differences in the background factors except age between the groups. FVC analysis demonstrated that nocturnal urine volume, 24-h micturition frequency, and nocturnal micturition frequency were significantly higher, and the maximum voided volume was significantly lower in the OAB group than in the controls. Metabolomic analysis revealed 14 metabolites that were differentially expressed between the groups. Multivariate analysis indicated that an increase in the levels of 5-iso prostaglandin F2α-VI (5-iPF2a-VI) and 5-methoxyindoleacetic acid was associated with OAB.

CONCLUSION

Abnormal urinary metabolites, including metabolites in the tryptophan (5-methoxyindoleacetic acid, 3-indoleacetonitrile, and 3-hydroxyanthranilic acid) and arachidonic acid (5-iPF2a-VI) pathways, play a role in the pathogenesis of OAB in older men.

Metabolic syndrome is associated with prostate enlargement: a systematic review, meta-analysis, and meta-regression on patients with lower urinary tract symptom factors

BACKGROUND

Metabolic syndrome (MetS) is defined by at least three of the following five criteria: blood pressure ⩾130/85 mmHg, fasting blood glucose ⩾5.6 mmol/l, triglycerides concentration ⩾1.7 mmol/l, waist circumference ⩾102 cm (for men), and high-density lipoprotein cholesterol concentration <1.03 mmol/l (for men). MetS has been associated with worse lower urinary tract symptoms (LUTS) and higher International Prostate Symptom questionnaire scores.

MATERIALS AND METHODS

MEDLINE, Cochrane, ClinicalTrials.gov, and SCOPUS were critically appraised for all peer-reviewed manuscripts that suitably fulfilled our protocol's inclusion criteria established a priori. Meta-analytical and meta-regression calculations were performed in R using the Sidik-Jonkman and Hartung-Knapp random effects model and predefined covariates.

RESULTS

A total of 70 studies (n = 90,206) were included in qualitative synthesis. From these, 60 studies focused on MetS and LUTS: 44 reported positive correlations, 5 reported negative correlations, 11 reported no association, and 10 studies focused on MetS and total prostate volume (TPV). MetS positively correlated with moderate LUTS [odds ratio (OR)  = 1.56, 95% confidence interval (CI) = 1.35-1.80], severe LUTS (OR = 2.35, 95% CI = 1.82-3.03), overactive bladder (OAB; OR = 3.2, 95% CI = 1.6-5.8), and nocturia severity (OR = 2.509, 95% CI = 1.571-4.007) at multivariate analysis. A total of 30 studies (n = 22,206) were included in meta-analysis; MetS was significantly associated with higher TPV (mean differences = 4.4450 ml, 95% CI = 2.0177-6.8723), but no significant predictive factors for effect sizes were discovered.

CONCLUSION

Our meta-analysis demonstrates a significant association between the aggravating effects of MetS, which commonly coexists with obesity and benign prostate enlargement.

Effects of testosterone replacement on serotonin levels in the prostate and plasma in a murine model of hypogonadism

Benign prostate hyperplasia is a dysfunctional disease with an elevated prevalence. Despite the accepted impact of aging and testosterone (TES) in its pathophysiology, its aetiology remains unknown. Recent studies described that serotonin (5-HT) inhibits benign prostate growth through the modulation of the androgen receptor, in the presence of TES. Accordingly, this work aimed to determine the impact of castration and TES replacement in plasmatic and prostatic 5-HT regulation. C57BL/6 mice were submitted to surgical castration and divided into three groups, continually exposed to either vehicle or different TES doses for 14 days. Plasmatic 5-HT concentration was measured before and after castration, and after TES reintroduction. Finally, total prostatic weight and intra-prostatic 5-HT were determined in the different groups. Our results demonstrate that mice prostate exhibits high 5-HT tissue levels and that intra-prostatic total 5-HT was independent of castration or TES reintroduction, in all studied groups. Also, 5-HT plasmatic concentration significantly increased after castration and then normalized after TES administration. Our findings revealed that mice prostate has a high 5-HT content and that total prostatic 5-HT levels do not depend on androgens' action. On the other hand, castration induced a significant increase in plasmatic 5-HT concentration, raising the hypothesis that androgens might be regulating the production of extra-prostatic 5-HT.

The association between serum serotonin levels and overactive bladder: results from a community-based cross-sectional study in Japan

PURPOSE

To investigate the association between serum serotonin (5-HT) levels and overactive bladder (OAB) in a community-dwelling population.

METHODS

This cross-sectional study analyzed 1024 subjects who participated in the Iwaki Health Promotion Project in 2015 in Hirosaki, Japan. OAB was assessed using the Overactive Bladder Symptom Score (OABSS). OAB was defined as an occurrence of urinary urgency at least once a week and an OABSS of ≥ 3. We assessed serum 5-HT levels, laboratory data, and comorbidities of each participants. Participants' mental health status was evaluated using the Center for Epidemiologic Studies Depression (CES-D) scale. The association of serum 5-HT levels and OAB was analyzed by multivariable logistic regression analysis.

RESULTS

This study included 394 men and 630 women. Of those, 118 (44 male and 74 female) were OAB sufferers. There were significant group differences in age, history of cardiovascular disease, chronic kidney disease, hypertension, diabetes mellitus, and CES-D score. Participants' serum 5-HT levels in the OAB group were significantly lower than those in the non-OAB group (100 vs. 127 ng/mL, P < 0.001). Multivariable analysis showed that age (odds ratio [OR]; 1.06, 95% confidence interval [CI]; 1.04-1.08, P < 0.001) and log serum 5-HT level (OR; 0.25, 95% CI; 0.10-0.68, P = 0.006) were independently associated with OAB.

CONCLUSIONS

Lower serum 5-HT levels could independently be associated with the presence of OAB. Further study is necessary to elucidate a possible causal relationship between serum 5-HT levels and OAB.

Serotonin regulates prostate growth through androgen receptor modulation

Aging and testosterone almost inexorably cause benign prostatic hyperplasia (BPH) in Human males. However, etiology of BPH is largely unknown. Serotonin (5-HT) is produced by neuroendocrine prostatic cells and presents in high concentration in normal prostatic transition zone, but its function in prostate physiology is unknown. Previous evidence demonstrated that neuroendocrine cells and 5-HT are decreased in BPH compared to normal prostate. Here, we show that 5-HT is a strong negative regulator of prostate growth. In vitro, 5-HT inhibits rat prostate branching through down-regulation of androgen receptor (AR). This 5-HT’s inhibitory mechanism is also present in human cells of normal prostate and BPH, namely in cell lines expressing AR when treated with testosterone. In both models, 5-HT’s inhibitory mechanism was replicated by specific agonists of 5-Htr1a and 5-Htr1b. Since peripheral 5-HT production is specifically regulated by tryptophan hydroxylase 1(Tph1), we showed that Tph1 knockout mice present higher prostate mass and up-regulation of AR when compared to wild-type, whereas 5-HT treatment restored the prostate weight and AR levels. As 5-HT is decreased in BPH, we present here evidence that links 5-HT depletion to BPH etiology through modulation of AR. Serotoninergic prostate pathway should be explored as a new therapeutic target for BPH.

The role of sex steroid hormones in benign prostatic hyperplasia

INTRODUCTION

The etiology of benign prostatic hyperplasia (BPH) remains a mystery to scientists; estrogen/androgen imbalance in aged men has been implicated.

METHODS

Thirty (30) apparently healthy men and newly diagnosed BPH patients were recruited from the Ghana Police Hospital. Lower urinary tract syndrome (LUTS) and prostate volume were assessed via the prostate symptom score sheet (IPSS) and abdominopelvic scan, respectively. Laboratory assays for total prostate specific antigen (tPSA) and hormones [androstenedione (AED), testosterone (T), dihydrotestosterone (DHT), androstanedioladiol (3α-adiol), androstanediol (3β-diol), estrone (E1) and estradiol (E2)] were performed via ELISA techniques. Non-parametric analyses were employed. p < 0.05 was considered significant.

RESULTS

AED was significantly higher in controls compared to the BPH patients. AKRIC2 (3α-diol/DHT) was significantly higher in the BPH group (p < 0.001) whiles AKRIC1 (3β-diol/DHT) was significantly lower. Estradiol was significantly higher in BPH (p= 0.029). Age correlated negatively with T, while a negative correlation was observed between TIPSS and 3β-diol and AKRIC1. Also, prostate volume correlated negatively with fT.tPSA correlated positively with E2 and aromatase activity (E2/T) and negatively with fT. On multiple linear regression, DHT and 3β-diol remained independent predictors for TIPSS and fT for tPSA.

CONCLUSION

Estrogens and androstanediols seem to play a role in BPH development.

Overactive bladder in children

Overactive bladder (OAB) is a ubiquitous syndrome that is defined by urinary urgency with, or without urinary incontinence. OAB is observed in all parts of the world, with a prevalence of 5-12% in children (5-10 years of age) and a prevalence of 0.5% in older adolescents (16-18 years of age). Published data indicate that around a third of children with OAB are likely to become adults with similar complaints. Studies in children and in adults with OAB indicate that these individuals are more likely to also have anxiety, depression and attention deficit problems, and that appropriate treatment of these comorbidities can often improve the patient's OAB symptoms. Furthermore, data from twin studies and familial surveys seem to indicate a genetic component of OAB. Pharmacological treatments of OAB in children have improved in the past 5 years, moving beyond anticholinergic agents and including the off-label use of α-blockers, β3-agonists and intravesical botulinum toxin. Use of several different electrical stimulation techniques is also effective, both as first-line treatments, and for patients with treatment-refractory symptoms. Overall the outlook of children with OAB seems to be improving, with a greater understanding of the pathophysiology of this syndrome. Treatment modalities that target the source of the underlying problem, especially in children, are likely to provide the best patient outcomes.

Lower urinary tract symptoms, benign prostatic hyperplasia and metabolic syndrome

Epidemiological studies have shown that age is the principal unmodifiable risk factor of lower urinary tract symptoms (LUTS). Until the past decade, the process of lower urinary tract ageing was, therefore, considered unmodifiable - as ageing per se. However, the traditional dogma that BPH-related LUTS (BPH-LUTS) is an immutable consequence of old age is no longer acceptable. Results from multiple preclinical and clinical studies indicate that several modifiable, age-related metabolic aberrations (metabolic syndrome, obesity, dyslipidaemia, diabetes) are important determinants in both the development and the progression of BPH-LUTS. Metabolic syndrome and its related comorbidities, such as sex steroid alterations and low-grade inflammation, have been related to BPH-LUTS development and progression. With the correct treatment and recommended lifestyle changes, many individuals with metabolic syndrome might be able to prevent or delay the onset of metabolic-syndrome-related complications; however, whether promoting healthier lifestyles can really alter a man's propensity to develop BPH-LUTS remains to be clarified.