Correlates of urinary symptom scores in men

The influence of intermittent hypoxia, obesity, and diabetes on male genitourinary anatomy and voiding physiology

We used male BTBR mice carrying the Lep^ob mutation, which are subject to severe and progressive obesity and diabetes beginning at 6 wk of age, to examine the influence of one specific manifestation of sleep apnea, intermittent hypoxia (IH), on male urinary voiding physiology and genitourinary anatomy. A custom device was used to deliver continuous normoxia (control) or IH to wild-type and Lep^ob/ob (mutant) mice for 2 wk. IH was delivered during the 12-h inactive (light) period in the form of 90 s of 6% O₂ followed by 90 s of room air. Continuous room air was delivered during the 12-h active (dark) period. We then evaluated genitourinary anatomy and physiology. As expected for the type 2 diabetes phenotype, mutant mice consumed more food and water, weighed more, and voided more frequently and in larger urine volumes. They also had larger bladder volumes but smaller prostates, seminal vesicles, and urethras than wild-type mice. IH decreased food consumption and increased bladder relative weight independent of genotype and increased urine glucose concentration in mutant mice. When evaluated based on genotype (normoxia + IH), the incidence of pathogenic bacteriuria was greater in mutant mice than in wild-type mice, and among mice exposed to IH, bacteriuria incidence was greater in mutant mice than in wild-type mice. We conclude that IH exposure and type 2 diabetes can act independently and together to modify male mouse urinary function. NEW & NOTEWORTHY Metabolic syndrome and obstructive sleep apnea are common in aging men, and both have been linked to urinary voiding dysfunction. Here, we show that metabolic syndrome and intermittent hypoxia (a manifestation of sleep apnea) have individual and combined influences on voiding function and urogenital anatomy in male mice.

Inhibition of the CXCL12/CXCR4 axis prevents periurethral collagen accumulation and lower urinary tract dysfunction in vivo

BACKGROUND

Several studies show that prostatic fibrosis is associated with male lower urinary tract dysfunction (LUTD). Development of fibrosis is typically attributed to signaling through the transforming growth factor β (TGF-β) pathway, but our laboratory has demonstrated that in vitro treatment of human prostatic fibroblasts with the C-X-C motif chemokine ligand 12 (CXCL12) chemokine stimulates myofibroblast phenoconversion and that CXCL12 has the capacity to activate profibrotic pathways in these cells in a TGF-β-independent manner. We have previously reported that feeding mice high-fat diet (HFD) results in obesity, type II diabetes, increased prostatic fibrosis, and urinary voiding dysfunction. The purpose of this study was to test the hypothesis that in vivo blockade of the CXCL12/CXCR4 axis would inhibit the development of fibrosis-mediated LUTD in HFD-fed mice.

METHODS

Two-month-old male senescence-accelerated mouse prone-6 mice were fed either a HFD or low-fat diet (LFD) for 8 months. Half of each dietary group were given constant access to normal water or water that contained the C-X-C chemokine receptor type 4 (CXCR4; CXCL12 receptor) antagonist CXCR4AIII. At the conclusion of the study, mice were weighed, subjected to oral glucose tolerance testing and cystometry, and lower urinary tract tissues collected and assessed for collagen content.

RESULTS

HFD-fed mice became significantly obese, insulin resistant, and hyperglycemic, consistent with acquisition of metabolic syndrome, compared with LFD-fed mice. Anesthetized cystometry demonstrated that HFD-fed mice experienced significantly longer intercontractile intervals and greater functional bladder capacity than LFD-fed mice. Immunohistochemistry demonstrated high levels of CXCR4 and CXCR7 staining in mouse prostate epithelial and stromal cells. Picrosirius red staining indicated significantly greater periurethral collagen deposition in the prostates of HFD than LFD-fed mice. Treatment with the CXCR4 antagonist CXCR4AIII did not affect acquisition of metabolic syndrome but did reduce both urinary voiding dysfunction and periurethral prostate collagen accumulation.

CONCLUSIONS

This is the first study to report that obesity-induced lower urinary tract fibrosis and voiding dysfunction can be repressed by antagonizing the activity of the CXCR4 chemokine receptor in vivo. These data suggest that targeting the CXCL12/CXCR4 signaling pathway may be a clinical option for the prevention or treatment of human male LUTD.

Metabolic syndrome and smoking are associated with an increased risk of nocturia in male patients with benign prostatic enlargement

BACKGROUND

To evaluate the relationship between cigarette smoking, metabolic syndrome (MetS) and nocturia in patients with lower urinary tract symptoms (LUTS) and benign prostatic enlargement (BPE).

METHODS

From 2009 onward, a consecutive series of patients with LUTS/BPE were enrolled. Symptoms were assessed using the International Prostate Symptom Score (IPSS). Age, body mass index (BMI), smoker status, prostate volume (PV), prostate-specific antigen (PSA) levels, fasting glucose levels, triglyceride levels, and high-density lipoprotein levels were recorded. MetS was defined according to Adult Treatment Panel III criteria. Moderate/severe nocturia was defined as nocturnal micturition episodes ≥2.

RESULTS

Overall 492 patients were enrolled with median age and BMI of 68 years (IQR 61/74) and 26.5 kg/m² (IQR: 24/29), respectively. Moderate/severe nocturia was reported in 212 (43.1%) patients. MetS was diagnosed in 147 (29.9%) patients and out of them 89 (60.5%) complained moderate/severe nocturia (p = 0.001). Overall 187 (38%) patients were current smokers and out of them 99 (52%) presented moderate/severe nocturia(p = 0.034). Patients with moderate/severe nocturia were older (p = 0.001) and with larger prostate volume (p = 0.003). On multivariate analysis, age (OR: 1.067 per year, 95% CI: 1.036-1.098; p = 0.001), PV (OR: 1.011 per ml, 95% CI: 1.003-1.019; p = 0.006), MetS (OR: 2.509, 95% CI: 1.571-4.007; p = 0.001) and smoking (OR: 1.690, 95% CI: 1.061-2.693; p = 0.027) were associated with nocturia severity.

CONCLUSIONS

MetS and smoking doubled the risk of moderate/severe nocturia in patients with LUTS and BPE. Assessing smoking and metabolic status in LUTS/ BPE patients is suggested.

Diabetic bladder dysfunction

OBJECTIVE

To review studies on diabetic bladder dysfunction (DBD), a common and bothersome complication of diabetes mellitus.

DATA SOURCES

We performed a search of the English literature through PubMed. The key words used were "diabetes" and "bladder dysfunction" or "cystopathy". Our own data and perspective are included in the discussion.

STUDY SELECTION

Studies containing data relevant to DBD were selected. Because of the limited length of this article, we also referenced reviews that contain comprehensive amalgamations of relevant literature.

RESULTS

The classic symptoms of DBD are decreased bladder sensation, increased bladder capacity, and impaired bladder emptying with resultant elevated post-void residual urine. However, recent clinical and experimental evidence indicate a strong presence of storage problems such as urge incontinence in diabetes. Recent studies of DBD in animal models of type 1 diabetes have revealed temporal effects of diabetes, causing an early phase of compensatory bladder function and a later phase of decompensated bladder function. The pathophysiology of DBD is multifactorial, including disturbances of the detrusor, urothelium, autonomic nerves, and urethra. Polyuria and hyperglycemia play important but distinctive roles in induction of bladder dysfunction in type 1 diabetes. Polyuria causes significant bladder hypertrophy in the early stage of diabetes, whereas oxidative stress in the bladder caused by chronic hyperglycemia may play an important role in the late stage failure of bladder function.

CONCLUSIONS

DBD includes time-dependent and mixed manifestations. The pathological alterations include muscle, nerve, and urothelium. Polyuria and hyperglycemia independently contribute to the pathogenesis of DBD. Treatments for DBD are limited. Future clinical studies on DBD in type 1 and type 2 diabetes should be investigated separately. Animal studies of DBD in type 2 diabetes are needed, from the natural history to mechanisms. Further understanding of the molecular mechanisms of DBD will provide multiple potential targets for therapeutic intervention.

Obesity-induced diabetes and lower urinary tract fibrosis promote urinary voiding dysfunction in a mouse model

BACKGROUND

Progressive aging- and inflammation-associated fibrosis effectively remodels the extracellular matrix (ECM) to increase prostate tissue stiffness and reduce urethral flexibility, resulting in urinary flow obstruction and lower urinary tract symptoms (LUTS). In the current study, we sought to test whether senescence-accelerated mouse prone (SAMP)6 mice, which were reported to develop prostatic fibrosis, would also develop LUTS, and whether these symptoms would be exacerbated by diet-induced obesity and concurrent Type 2 Diabetes Mellitus (T2DM).

METHODS

To accomplish this, SAMP6 and AKR/J background strain mice were fed regular mouse chow, low fat diet chow, or high fat diet chow for 8 months, then subjected to glucose tolerance tests, assessed for plasma insulin levels, evaluated for urinary voiding function, and assessed for lower urinary tract fibrosis.

RESULTS

The results of these studies show that SAMP6 mice and AKR/J background strain mice develop diet-induced obesity and T2DM concurrent with urinary voiding dysfunction. Moreover, urinary voiding dysfunction was more severe in SAMP6 than AKR/J mice and was associated with pronounced prostatic and urethral tissue fibrosis.

CONCLUSIONS

Taken together, these studies suggest that obesity, T2DM, lower urinary tract fibrosis, and urinary voiding dysfunction are inextricably and biologically linked.

Commonly used antihypertensives and lower urinary tract symptoms: results from the Boston Area Community Health (BACH) Survey

Study Type - Prevalence (inception cohort) Level of Evidence 1b What's known on the subject? and What does the study add? Certain antihypertensives, particularly diuretics and calcium channel blockers, are known to be associated with increased risk of LUTS including nocturia, but little is known about gender-specific effects. This is the first epidemiological study, to our knowledge, to compare the prevalence of several urological symptoms (storage, voiding and nocturia) among male and female users of a wide variety of common antihypertensives using a community-based sample.

OBJECTIVE

To examine differences in the prevalence of lower urinary tract symptom (LUTS) among users of five common AHT classes compared with non-users, adjusted for LUTS risk factors in a large, representative sample.

SUBJECTS AND METHODS

Data were from the Boston Area Community Health Survey, a population-based study of community-dwelling male and female (30-79 years) residents of Boston, MA, USA for whom prescription drug information was collected between 2002 and 2005. The urological symptoms of storage, voiding, and nocturia were assessed using interviewer-administered questionnaires and the American Urological Association Symptom Index. This analysis was conducted among 1865 participants with an AHT indication. Associations of angiotensin-converting enzyme inhibitors, beta blockers, calcium channel blockers (CCBs) and loop and thiazide diuretics with the three groups of LUTS were estimated using odds ratios (ORs) and 95% confidence intervals (CIs) from multivariate logistic regression (referent group: untreated hypertension). Overlap in use was accounted for using monotherapy and combination therapy exposure categories.

RESULTS

Among women, monotherapy with CCBs was associated with increased prevalence of nocturia (OR = 2.65, 95% CI: 1.04-6.74) and voiding symptoms (OR = 3.84, 95% CI: 1.24-11.87); these results were confined to women aged <55 years. Among men of all ages, positive associations were observed for thiazides and voiding symptoms (monotherapy OR = 2.90, 95% CI: 1.17-7.19), and loop diuretics and nocturia (combination therapy OR = 2.55, 95% CI: 1.26-5.14).

CONCLUSION

Results are consistent with the hypothesis that certain AHTs may aggravate LUTS. The presence of new or worsening LUTS among AHT users suggests medications should be reviewed and a change in AHT class considered.

Determinants of male reproductive health disorders: the Men in Australia Telephone Survey (MATeS)

BACKGROUND

The relationship between reproductive health disorders and lifestyle factors in middle-aged and older men is not clear. The aim of this study is to describe lifestyle and biomedical associations as possible causes of erectile dysfunction (ED), prostate disease (PD), lower urinary tract symptoms (LUTS) and perceived symptoms of androgen deficiency (pAD) in a representative population of middle-aged and older men, using the Men in Australia Telephone Survey (MATeS).

METHODS

A representative sample (n = 5990) of men aged 40+ years, stratified by age and State, was contacted by random selection of households, with an individual response rate of 78%. All men participated in a 20-minute computer-assisted telephone interview exploring general and reproductive health. Associations between male reproductive health disorders and lifestyle and biomedical factors were analysed using multivariate logistic regression (odds ratio [95% confidence interval]). Variables studied included age, body mass index, waist circumference, smoking, alcohol consumption, physical activity, co-morbid disease and medication use for hypertension, high cholesterol and symptoms of depression.

RESULTS

Controlling for age and a range of lifestyle and co-morbid exposures, sedentary lifestyle and being underweight was associated with an increased likelihood of ED (1.4 [1.1-1.8]; 2.9 [1.5-5.8], respectively) and pAD (1.3 [1.1-1.7]; 2.7 [1.4-5.0], respectively. Diabetes and cardiovascular disease were both associated with ED, with hypertension strongly associated with LUTS and pAD. Current smoking (inverse association) and depressive symptomatology were the only variables independently associated with PD. All reproductive disorders showed consistent associations with depression (measured either by depressive symptomatology or medication use) in both age-adjusted and multivariate analyses.

CONCLUSION

A range of lifestyle factors, more often associated with chronic disease, were significantly associated with male reproductive health disorders. Education strategies directed to improving general health may also confer benefits to male reproductive health.

The effects of lifestyle factors on the incidence of nocturia

PURPOSE

Cross-sectional studies have shown an association between obesity and nocturia but controversial findings on the relationship between smoking, alcohol and coffee consumption, and nocturia. Prospective studies of the role of lifestyle factors in individuals with nocturia are scarce. We investigated the effects of lifestyle factors on the incidence of nocturia.

MATERIALS AND METHODS

The target population consisted of men who were 50, 60 or 70 years old and residing in Tampere in 1994. A questionnaire was mailed to 3,143 randomly selected men in 1994 and the survey was repeated in 1999 with the 2,837 who were still eligible. The followup sample consisted of 1,580 men with information on nocturia at baseline and 5-year followup. Nocturia was assessed by the Danish Prostate Symptoms Score 1 questionnaire and graded as mild--1 or 2, moderate--3 or 4 and severe--5 or more nightly voids.

RESULTS

Higher body mass index at baseline was associated with an increased incidence of nocturia. Obese men were at 1.6 times (95% CI 1.1-2.4) higher risk for mild nocturia and at 2.3 times (95% CI 1.1-4.7) higher risk for moderate or severe nocturia compared with men who had a normal body mass index. Men who consumed less than 150 gm alcohol per week were at lower risk for moderate or severe nocturia than abstainers (adjusted incidence rate ratio 0.4, 95% CI 0.2-0.8). No statistically significant associations were found for smoking and coffee consumption. The frequency of nocturia at baseline did not increase the incidence of obesity at followup.

CONCLUSIONS

Our findings suggest that obesity increases the risk of nocturia. The link between other lifestyle factors and nocturia is weak or absent.

Concordance rates and modifiable risk factors for lower urinary tract symptoms in twins

INTRODUCTION

Lower urinary tract symptoms, which are common in older men, are thought to be determined genetically and by modifiable environmental risk factors. We examined the contribution of these 2 etiologic components in a cohort of U.S. twins.

METHODS

In 1998, a questionnaire that assessed lower urinary tract symptoms, weight, height, alcohol consumption, cigarette smoking, and physical activity was sent out to members of the National Academy of Science-National Research Council Twins Registry. We analyzed 1,723 complete twin pairs with information on lower urinary tract symptoms and zygosity and who did not have a previous diagnosis of prostate cancer. We calculated concordance rates of categories of the International Prostate Symptom Score in monozygotic (MZ) and dizygotic (DZ) twins. Generalized estimating equations were used to calculate the odds ratio of having high-moderate/severe lower urinary tract symptoms.

RESULTS

Concordance rates were higher in MZ than in DZ twins with concordance rate ratios of 2.2 and 6.9 depending on the specificity of definition of symptoms. Genetic factors contributed 72% to the risk of high-moderate/severe lower urinary tract symptoms. Taking into account correlated individuals, we observed high odds of lower urinary tract symptoms in obese men compared with lean men (odds ratio = 1.91; 95% confidence interval = 1.16-3.15 comparing first versus fourth quartile). Cigarette smoking was not associated with lower urinary tract symptoms, but alcohol consumption was positively associated. Men who were more physically active tended to have lower odds of lower urinary tract symptoms compared with less active men (0.62; 0.36-1.08).

CONCLUSION

The findings indicate a strong genetic component of lower urinary tract symptoms, but also support previous studies that modifiable environmental risk factors are associated with this condition.

Risk factors for lower urinary tract symptoms in southern Chinese men

OBJECTIVES

To study, in a large prospective cohort study of 2000 Chinese men 65 to 92 years of age in Hong Kong, the role of lifestyle and medical risk factors for moderate to severe lower urinary tract symptoms (LUTS). Previous epidemiologic studies evaluating the risk factors for LUTS were mainly conducted in non-Chinese populations.

METHODS

After excluding men with prostate or bladder cancer or surgery and those who took alpha-blockers and antiandrogens, 1739 subjects provided responses to a structured interviewer-administered questionnaire and physical examination.

RESULTS

A clustered case-control analysis was performed, comparing subjects with moderate to severe LUTS with those with mild or no LUTS. A total of 38.2% of subjects had moderate to severe LUTS. On multiple logistic regression analysis, a history of heart disease was independently associated with an increased risk of moderate to severe LUTS (odds ratio 1.50, 95% confidence interval 1.13 to 1.98). Physical activity was independently associated with reduced risk of moderate to severe LUTS (odds ratio 0.66, 95% confidence interval 0.48 to 0.90). A mild increase in the body mass index (23 to 24.9 kg/m2) was associated with a reduced risk of LUTS (odds ratio 0.72, 95% confidence interval 0.56 to 0.93).

CONCLUSIONS

These results have shown that LUTS are a significant health problem in Chinese men and that, similar to results from previous studies, LUTS are associated with medical and lifestyle factors in the Chinese.

Nocturia in sleep-disordered breathing

BACKGROUND AND PURPOSE

Nocturia is a common complaint in sleep-disordered breathing (SDB), but there is no study demonstrating the prevalence and frequency of nocturnal urination in a large number of SDB patients. To determine the prevalence and frequency of nocturnal urination among patients with SDB of different severities and to discover the factors related to nocturia.

METHOD

A retrospective chart review was conducted among 1970 SDB patients. Nocturia was assessed using a standard questionnaire. Four groups of SDB patients were compared with regard to frequency of nocturnal urination and additional demographic, clinical, and polysomnographic (PSG) variables, by analysis of variance (ANOVA) with Tukey's honest significant difference (HSD) post-hoc comparisons. Partial correlation analysis was performed to detect the relationships between frequency of nocturnal urination and PSG and demographic variables. Logistic regression analysis was employed to examine the independent predictors of nocturia.

RESULTS

Significant correlations were found between the frequency of nocturnal urination and mean age, body mass index (BMI), respiratory disturbance index (RDI), apnea-hypopnea index (AHI), respiratory effort index (REI) and lowest oxygen saturation. The frequency of nocturnal urination showed significant differences between four groups of individuals with SDB (P<0.001). Nocturnal urination of more than three episodes per night was reported significantly more by severe SDB patients (P<0.001).

CONCLUSION

Age, BMI, hypertension (HT), AHI, and REI were found to be significantly associated with nocturia.

Association of cigarette smoking, alcohol consumption and physical activity with lower urinary tract symptoms in older American men: findings from the third National Health And Nutrition Examination Survey

OBJECTIVES

To examine the association of cigarette smoking, alcohol consumption and physical activity with lower urinary tract symptoms (LUTS) in older men.

SUBJECTS AND METHODS

The study included 2797 men participating in the Third National Health and Nutrition Examination Survey (NHANES III), who were aged > or = 60 years. During an interview, LUTS, smoking history, alcohol consumption and physical activity were assessed. Cases comprised men with at least three of the symptoms of nocturia, hesitancy, weak stream and incomplete emptying. Men who had had prostate surgery unrelated to cancer were not included as cases. Controls were men with no symptoms or surgery. We adjusted for age and race in logistic regression models and used sampling weights to account for selection probability.

RESULTS

Current cigarette smokers had no higher odds of LUTS than 'never' smokers, but former heavy smokers (> or = 50 pack-years) had a higher odds of LUTS than never smokers (odds ratio 2.01; 95% confidence interval 1.04-3.89). Men who drank alcohol daily had a lower chance of LUTS than non-drinkers (0.59; 0.37-0.95; P trend, 0.07). All levels of moderate and vigorous activity were statistically significantly inversely associated with LUTS (P trend, 0.06), whereas men who reported no leisure-time physical activity had a greater odds of LUTS (2.06; 1.26-3.39).

CONCLUSIONS

Moderate alcohol consumption and physical activity may be protective against LUTS. Current cigarette smoking was not consistently associated with the condition. The possible association in former smokers warrants further investigation.

Therapy Insight: sexual and bladder dysfunction associated with diabetes mellitus

Diabetes mellitus affects 3-6% of the population. Patients with diabetes experience chronic vascular complications, which lead to a wide range of medical problems. Genitourinary problems are included among these complications, related to both neuropathy and vasculopathy. The most important clinical features relating to genitourinary involvement in patients with diabetes include erectile dysfunction (ED) and retrograde ejaculation in men, and bladder dysfunction. There is a 36% prevalence of ED in men with diabetes, which is about three times higher than in the general population. With so many other factors contributing to the risk of developing ED, it is important that men with diabetes are advised not only regarding glycemic control, but also in relation to lifestyle factors that might contribute to the development of ED, such as smoking. Diabetes-associated bladder dysfunction, characterized by decreased bladder sensation, increased bladder capacity, and impaired detrusor contractility, is another important condition to consider when treating patients with diabetes. Accurate assessment is important in these patients in order to reduce the damage associated with neurogenic bladder dysfunction. Management goals for these patients include voiding strategies for relief of symptoms, prevention and treatment of infections, continence, and adequate bladder emptying. This review discusses the mechanisms behind urologic conditions that are often encountered when treating patients with diabetes, and summarizes the evaluation and management of these patients.

Behavioral Therapies at the Primary Care Level

Urinary incontinence, the complaint of any involuntary loss of urine, is a troubling symptom experienced by men and women of all ages. Options for treatment include a range of behavioral, pharmacologic, and surgical therapies. Behavioral therapies, such as dietary modification, pelvic floor muscle training, and bladder training, are noninvasive, with little risk of side effects, and experts agree they should represent the first line of treatment whenever possible. These therapies can be initiated and monitored at the primary care level, thereby enhancing the accessibility of care for those affected. The purpose of this article is to methodically review what is and is not known about behavioral therapies, with attention to research needs. Although there is clear evidence for pelvic floor muscle training in women with urinary incontinence and modest evidence in men for a short time after radical prostatectomy, less is known about bladder training, prompted voiding, habit retraining, and timed voiding. Additional research is required to enhance our understanding of the comparative efficacy of behavioral interventions in specific populations. This research must take an increasingly long-term focus, given the potentially chronic nature of urinary incontinence.

A prospective study of nocturia and the quality of life of elderly patients with obstructive sleep apnea or sleep onset insomnia

OBJECTIVE

To prospectively evaluate the relationship between obstructive sleep apnea syndrome (OSAS), nocturia and quality of life in elderly patients free of the urologic and medical conditions that lead to increased nocturia.

METHODS

Prospective study of nocturia in men 65 years and older with isolated OSAS or sleep onset insomnia. After a 7-day nocturia evaluation and nocturnal polysomnography, Epworth Sleepiness Scale (ESS), Beck Depression Inventory (BDI), Quality of Life (SF-36) were administered.

RESULTS

OSAS patients with frequent nocturia had significantly greater body mass index (BMI), greater apnea-hypopnea index (AHI), lower lowest oxygen saturation and lower SF-36 subscale scores. Treatment with nasal continuous positive airway pressure (CPAP) for OSAS and behavioral techniques for insomnia improved ESS and BDI scores for all three groups. SF-36 subscale scores improved more in subjects with multiple nocturia. AHI and BMI explain 38% of the variance for nocturia.

CONCLUSION

Nasal CPAP reduces OSA and nocturia and improves quality of life of elderly patients.

Cholinergic innervation and function in the prostate gland

The mammalian prostate is densely innervated by hypogastric and pelvic nerves that play an important role in regulating the growth and function of the gland. While there has been much interest in the role of the noradrenergic innervation and adrenoceptors in prostate function, the role of cholinergic neurones in prostate physiology and pathophysiology is not well understood. This review focuses on the role of acetylcholine and cholinoceptors in prostate function. Nitric oxide, vasoactive intestinal polypeptide, and/or neuropeptide Y are co-localised with cholinesterase and/or acetylcholine transporter in some of the nerve fibres supplying the prostate. Their roles are also briefly discussed in this review. A dense network of cholinesterase-staining fibres supplies both prostate epithelium and stroma, suggesting a role of acetylcholine and/or co-localised neuropeptides in the modulation of prostatic secretions, as well as smooth muscle tone. A predominantly epithelial location for prostate muscarinic receptors indicated a major secretomotor role for acetylcholine. The muscarinic receptor subtype mediating muscarinic agonist-induced smooth muscle contraction or enhancement of contractions evoked by nerve stimulation differs in different species. In the human, there is evidence for M(1) receptors on the epithelium, M(2) receptors on the stroma, and both M(1) and M(3) receptors in some prostate cancer cell lines. Several recent investigations indicate that muscarinic receptors may also mediate or modulate normal, benign, and malignant prostate growth. The role of muscarinic agonists and their receptors and the influences of age, testicular, and other steroids in regulating the effects are reviewed.

Protein kinase C and the sub-sensitivity and sub-reactivity of the diabetic rat prostate gland to noradrenaline

Concentration-response curves to noradrenaline (1 nM-100 microM) were obtained in prostates from 6-week streptozotocin diabetic, insulin-treated diabetic or control rats. Compared to the curve obtained in controls, those obtained in prostates from diabetic and insulin-treated diabetic rats were shifted rightward. The alpha1-adrenoceptor antagonist, prazosin (100 nM), caused a rightward shift of the curves in prostates from all groups. In contrast, the uptake 1 inhibitor, nisoxetine (300 nM), only produced a leftward shift of the curves in prostates from control and insulin-treated diabetic rats. However, frequency-response curves obtained in prostates from both control and diabetic rats were shifted leftward by nisoxetine (300 nM). The concentration-response curve to the alpha1-adrenoceptor agonist, methoxamine (10 nM-100 microM), obtained in prostates from diabetic rats was shifted rightward compared with controls. Calphostin C (500 nM), a protein kinase C inhibitor, caused a leftward shift of the curve in prostates from diabetic, but not control, rats. The protein kinase C inhibitor, bisindolylmaleimide I (500 nM), beta-adrenoceptor antagonist, propranolol (500 nM) and muscarinic cholinoceptor antagonist, atropine (300 nM), had no effect on the noradrenaline concentration-response curves of prostates from control or diabetic rats. Our results suggest that diabetes reduces the sensitivity and reactivity of the prostate to noradrenaline-induced stimulation, and this reduction may be due to changes in protein kinase C activity.

Natural history of benign prostatic hyperplasia

Studies in varied settings have provided estimates of the prevalence of surrogate markers of benign prostatic hyperplasia (BPH). In population-based studies, the prevalence of moderate-to-severe lower urinary tract symptoms and depressed peak urinary flow rates increases across successively older age groups. Prostatic volume follows a similar pattern. Unlike clinic-based studies in which correlations are almost nonexistent, the population-based studies demonstrate a modest correlation among lower urinary tract symptoms, peak urinary flow rates, and prostatic volume. These cross-sectional observations extend to serum prostate-specific antigen levels and postvoid residual urine volumes. Data collected during the longitudinal follow-up study of men participating in the Olmsted County Study of Urinary Symptoms and Health Status Among Men provide a more detailed description of the natural history of changes in these surrogate markers of BPH. They also provide insights into their relation with each other and with long-term outcomes of BPH, such as acute urinary retention and treatment of BPH. These data demonstrate the progressive nature of BPH and are useful for the design and interpretation of clinical trials. Furthermore, they suggest that observational studies of etiology and prognosis should take advantage of the spectrum of disease reflected by the full range of values of these quantitative traits, rather than an arbitrary dichotomized outcome.