Relationship Between Serum Testosterone and Measures of Benign Prostatic Hyperplasia in Aging Men

Prostate-specific antigen, androgen, progesterone and oestrogen receptors in Benign prostatic hyperplasia: human tissues and animal model study

BACKGROUND

Direct evidence for the relationship between a large prostate (≥80 ml) and androgen receptor/PSA signal remains lacking in benign prostatic hyperplasia (BPH). Our aim is to identify whether the cause of a large prostate is related to progesterone receptor (PGR) androgen receptor (AR), oestrogen receptor α, β (ERα,β) and prostate-specific antigen (PSA).

MATERIALS AND METHODS

Surgical specimens of BPH in plasmakinetic resection of the prostate (PKRP) with three groups of different prostate-sizes with mean volumes of 25.97 ml, 63.80 ml, and 122.37 ml were collected for immunohistochemical analysis of the tissue microarray with PGR, AR, PSA and ERs. Rats were castrated and treated with testosterone replacement to explore androgen and PGR, AR and ERs expression levels in the prostate. Quantitative real-time reverse transcription polymerase chain reaction (Rt-PCR) for mRNA detection of above genes was conducted.

RESULTS

Immunoblotting, Rt-PCR and immunohistochemistry assays showed that PGR, PSA, AR, ERα expression levels were positively correlated with prostate size and that ERβ expression levels were negatively correlated with prostate volume. Animal experiments have shown that prostate volume is decreased in castrated rats with decreased PGR, AR, ERα and increased ERβ expression levels.

CONCLUSION

PGR, AR, ERs signals can be regarded as important factors for large-sized prostates in BPH patients (≥100 ml).

The Etiology and Pathogenesis of Benign Prostatic Hyperplasia: The Roles of Sex Hormones and Anatomy

Benign prostatic hyperplasia (BPH) mainly causes lower urinary tract symptoms in ageing men, but its exact etiology and pathogenesis have not been established. The objective of this review was to design an update on the advances of human BPH research. We undertook a literature search for identifying studies of the roles of sex hormones (androgens and estrogens) in the onset and development of human BPH using the Pubmed database. In literature, many studies have indicated that ageing and obesity are the factors for preceding the onset of BPH. No evidence for the role of testosterone (T) or dihydrotestosterone (DHT) is found in BPH initiation. Since BPH exclusively occurs in the transitional zone (TZ) surrounding the urethra, it is postulated that years of exposure to uncharacterized urinary toxins could disrupt the homeostasis of the stroma and/or epithelium of this prostatic zone that are typically occurring in ageing men. After cellular damage and subsequent inflammation generated, the intraprostatic DHT produced mainly from T by 5α-reductase promotes BPH development. Further, estrogens could take part in the nodular proliferation of stromal cells in some BPH patients. The confounding of BPH may attenuate the development of prostate tumor in the TZ. In conclusion, evidence in literature suggests that androgens are not etiological factors for BPH, and intraprostatic DHT along with chronic inflammation are mainly responsible for nodular proliferation of stromal and/or epithelial cells in prostatic TZ. The urinary factors for the etiology of BPH and BPH as a prediction of PCa progression still need further investigation.

Asiatic acid mitigates testosterone-induced benign prostatic hyperplasia in rats via activation of PPAR-γ

Prostate enlargement due to benign prostate hyperplasia (BPH) is a common, progressive disorder in elderly males with increasing prevalence. It causes devastating lower urinary tract symptoms with no satisfactory medication. Asiatic acid (AA), a natural pentacyclic triterpenoid, is known to have antiproliferative, antioxidant, and anti-inflammatory activities. The aim of this study was to evaluate the possible preventive activities of AA against BPH induced by testosterone in rats. Finasteride (0.5 mg/kg) was used as a reference drug. AA (10 or 20 mg/kg) administration inhibited the rise in prostatic weight and index induced by testosterone. Histopathological staining proved that AA mitigated the pathological features of BPH induced by testosterone, which was reflected as lower glandular epithelial in AA-treated groups. Also, the administration of AA along with testosterone restored the redox valance by inhibiting lipid peroxidation, and MDA production, and restoring the activities of superoxide dismutase (SOD) and catalase (CAT) activities. Also, AA reduced prostate interleukin-6 (IL-6), cyclooxygenase-2 (COX-2), tumor necrosis factor-alpha (TNF-α), and nuclear factor-kappa B (NF-κB) protein expression. In addition, AA modulated mRNA expression of Bax and Bcl-2 in favor of apoptosis. The effects of AA (20 mg/kg) were comparable to those of finasteride. Further, AA ameliorated the rise in insulin-like growth factor 1 receptor (IGF-1R) mRNA expression. This was associated with the enhancement of the prostatic content of PPAR-γ. It can be concluded that AA mitigated the features of BPH induced by testosterone in rats. This involves antioxidant, anti-inflammatory and pro-apototic activities of AA as well as its ability to down-regulate IGF-1R expression and enhance PPAR-γ concentration in prostatic tissues.

Early investigational agents for the treatment of benign prostatic hyperplasia'

INTRODUCTION

Benign prostatic hyperplasia (BPH), as a clinical entity that affects many people, has always been in the forefront of interest among researchers, pharmaceutical companies, and physicians. Patients with BPH exhibit a diverse range of symptoms, while current treatment options can occasionally cause adverse events. All the aforementioned have led to an increased demand for more effective treatment options.

AREAS COVERED

This review summarizes the outcomes of new medications used in a pre-clinical and clinical setting for the management of male lower urinary tract symptoms (LUTS)/BPH and provides information about ongoing trials and future directions in the management of this condition. More specifically, sheds light upon drug categories, such as reductase‑adrenoceptor antagonists, drugs interfering with the nitric oxide (NO)/cyclic guanosine monophosphate (GMP) signaling pathway, onabotulinumtoxinA, vitamin D3 (calcitriol) analogues, selective cannabinoid (CB) receptor agonists, talaporfin sodium, inhibitor of transforming growth factor beta 1 (TGF-β1), drugs targeting the hormonal control of the prostate, phytotherapy, and many more.

EXPERT OPINION

Clinical trials are being conducted on a number of new medications that may emerge as effective therapeutic alternatives in the coming years.

Age, weight and circulating concentrations of total testosterone are associated with the relative prostatic size in adult intact male dogs

Prostatic hyperplasia (PH) is an androgen-dependent condition associated with increased prostatic size that is common in intact dogs, and similar to the condition in men. In dogs, the increase in prostatic size is most prominent the first years, and after approximately four years (in beagles), a plateau is reached, and further growth is slower. Why the prostate continues to grow more in some individuals is not clear. Most testosterone in the circulation is bound to albumin or sex hormone binding globulin (SHBG) and only a minor part is unbound and biologically active. The binding to SHBG has higher affinity than that to albumin. In addition, SHBG has own biological functions, modifying testosterone action. The aim of the present study was to investigate if there is an association between relative prostatic size and the variables total testosterone concentration, SHBG concentration, an estimation of bioavailable testosterone: the ratio between testosterone and SHBG (free androgen index, FAI), estradiol concentration, the estradiol/testosterone ratio, dog age and dog weight. Hormone concentrations were measured in serum from 79 intact male dogs aged ≥ four years, weighing ≥ five kg. The size of the prostate was estimated using ultrasonography, and relative prostate size, S_rel, was calculated as the estimated size related to the normal size for a 4-year-old dog of the same weight. There as a negative correlation between testosterone concentration and age (ρ = -0.27, P = 0.018) and a positive correlation between age and S_rel (ρ = 0.27, P = 0.016) and between SHBG and weight (ρ = 0.38, P = 0.001). The FAI was negatively correlated with dog weight (ρ = -0.32, P = 0.004). There were no significant correlations between S_rel and SHBG or FAI or between estradiol or estradiol/testosterone and S_rel, age or weight. A multiple regression analysis showed significant associations between log S_rel and log testosterone concentration, log age and log weight of the dog, with an adjusted R² of 9.5%. Although the variables total testosterone concentration, age and weight of the dog were all significantly associated with S_rel, the coefficient of determination was low, indicating that they only explained a minor part of the prostatic size. The results support the analysis of total testosterone in studies of prostatic growth in the dog.

The European Academy of Andrology (EAA) ultrasound study on healthy, fertile men: Prostate-vesicular transrectal ultrasound reference ranges and associations with clinical, seminal and biochemical characteristics

Background

Transrectal ultrasound (TRUS) parameters are not standardized, especially in men of reproductive age. Hence, the European Academy of Andrology (EAA) promoted a multicenter study to assess the TRUS characteristics of healthy‐fertile men (HFM) to establish normative parameters.

Objectives

To report and discuss the prostate and seminal vesicles (SV) reference ranges and characteristics in HFM and their associations with clinical, seminal, biochemical parameters.

Methods

188 men (35.6 ± 6.0 years) from a cohort of 248 HFM were studied, evaluating, on the same day, clinical, biochemical, seminal, TRUS parameters following Standard Operating Procedures.

Results

TRUS reference ranges and characteristics of the prostate and SV of HFM are reported herein. The mean PV was ∼25 ml. PV lower and upper limits were 15 and 35 ml, defining prostate hypotrophy and enlargement, respectively. PV was positively associated with age, waistline, current smoking (but not with T levels), seminal volume (and negatively with seminal pH), prostate inhomogeneity, macrocalcifications, calcification size and prostate arterial parameters, SV volume before and after ejaculation, deferential and epididymal size. Prostate calcifications and inhomogeneity were frequent, while midline prostatic cysts were rare and small. Ejaculatory duct abnormalities were absent. Periprostatic venous plexus size was positively associated with prostate calcifications, SV volume and arterial peak systolic velocity. Lower and upper limits of SV anterior‐posterior diameter after ejaculation were 6 and 16 mm, defining SV hypotrophy or dilation, respectively. SV total volume before ejaculation and delta SV total volume (DSTV) positively correlated with ejaculate volume, and DSTV correlated positively with sperm progressive motility. SV total volume after ejaculation was associated negatively with SV ejection fraction and positively with distal ampullas size. SV US abnormalities were rare. No association between TRUS and time to pregnancy, number of children or history of miscarriage was observed.

Conclusions

The present findings will help in better understanding male infertility pathophysiology and the meaning of specific TRUS findings.

Relationship between serum total testosterone and prostate volume in aging men

Total testosterone levels decline with age, while prostate volume and the prevalence of benign prostatic hyperplasia increase with age. We sought to investigate the correlation of serum testosterone levels with prostate volume in aging men. We analyzed clinical data obtained from 416 ostensibly healthy men who underwent routine health check-ups and recruited and collected data from these subjects 4 years later. We analyzed the correlation between prostate volume and relevant factors, as well as the correlation between changes in prostate volume and low testosterone over a 4-year period. Men with low testosterone had significantly larger prostate volume than those in the normal testosterone group (26.86 ± 8.75 vs. 24.06 ± 6.77 P = 0.02), and subjects with low testosterone had significantly higher levels of obesity-related factors, including waist circumference, body mass index, and insulin (all P < 0.001). After adjustment for age, testosterone level was negatively correlated with prostate volume (P = 0.004), and prostate volume and 4-year changes in prostate volume were associated with low testosterone. With increased testosterone level, prostate volume showed a significant linear decreasing trend. These findings provide evidence of the relationship between testosterone and prostate volume. Additional large studies are needed to confirm these preliminary results.

Prospective evaluation of the association between varicocele and benign prostatic hyperplasia in men over 40 years of age

We investigated the association between varicocele and benign prostatic hyperplasia in men over the age of 40 years. A total of 296 outpatients were evaluated. Prostate volume was measured with transrectal ultrasound. Varicocele was diagnosed by physical examination and ultrasound. Prostatic hyperplasia was defined as prostate volume greater than or equal to 40 ml. Two groups were compared: patients with prostate volume less than 40 ml and patients with prostate volume greater than or equal to 40 ml. There was a statistically significant difference between the groups in terms of mean age, post-void residual, International Prostate Symptom Score and PSA. The percentage of patients with clinical varicocele in the group with a volume less than 40 ml and the group with a volume equal to or greater than 40 ml was 38.2% and 47.7% respectively (p = .12). There were no differences between the two groups in the percentage of patients with clinical or subclinical varicocele (43.2% vs. 52.2%, respectively, p = .12). No differences were found in the percentage of patients with varicocele when comparing men with prostates smaller than 40 ml and greater than or equal to 40 ml.

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.

Treatment of experimentally induced benign prostatic hyperplasia with Tadalafil and castration in dogs

New methods are being developed for the treatment of benign prostatic hyperplasia (BPH) in dogs. The aim of the present study was to evaluate the effects of Tadalafil on the treatment of experimentally induced BPH in dogs. Twenty-five adult intact male dogs were randomly divided into five groups (n = 5): normal group; dogs induced with BPH and treated with Tadalafil (5 mg/day p.o.); dogs which received Tadalafil (5 mg/day p.o.); dogs induced with BPH and treated with castration; and dogs induced with BPH. For 4 sequential weeks, the hematologic and prostate-specific factors (dihydrotestosterone (DHT), serum prostate-specific antigen (PSA), serum prostatic acid phosphatase (PAP), and canine prostatic specific esterase (CPSE)) were measured. Significant differences were observed in the level of PSA, CPSE, and PAP concentration between the normal vs. BPH-Tadalafil, BPH-castrated, and BPH groups. Treating BPH-induced dogs with Tadalafil or castration significantly declined the serum PSA, CPSE, and PAP levels compared to those of the untreated BPH-induced group. The treatment of normal dogs with Tadalafil did not affect prostate-specific biomarkers in comparison with normal dogs. In conclusion, and according to the prostatic indices, it could be stated that Tadalafil, compared with castration, could be used for the treatment of BPH in dogs.

The relation between androgenetic thin hair diagnosed by trichoscope and benign prostatic hyperplasia

BACKGROUND

Androgenetic alopecia carries a major cosmetic disfigurement and benign prostatic hyperplasia is associated with many urinary tract symptoms and both diseases are mediated by dihydrotestosterone.

OBJECTIVES

The study aimed to determine the relationship between hair diameter in androgenetic alopecia diagnosed, by trichoscope, to benign prostatic hyperplasia symptoms and signs.

METHODS

Fifty androgenetic alopecia males and 50 normal males as control were included. We used trichoscope for hair examination, transrectal ultrasound for prostate volume, and urodynamic inspectoscope for urinary symptoms, serum total testosterone, dihydrotestosterone, and total prostatic specific antigen were measured in blood samples. All participants answered the International prostate symptom score questionnaire and the International Index of Erectile Function score questionnaire.

RESULTS

A significant difference between patient and control groups was detected as regards hair thickness (P = 0.001), prostatic volume (P = 0.013), urinary symptoms, prostatic specific antigen level (P = 0.015). A significant difference was detected between thin (<0.03 mm, n = 26) and medium to thick hair (>0.03, n = 24) subgroups of patients as regards age (P = 0.001), dihydrotestosterone level (P = 0.001), testosterone level (P = 0.001), and urinary symptoms (P = 0.001).

CONCLUSION

Androgenetic alopecia patients with thin hair diagnosed by trichoscopy are more prone to prostatic enlargement and its related symptoms. Androgenetic alopecia severity can be diagnosed by trichoscopy in addition to Hamilton-Norwood scale.

Systemic Comorbidity Burden Using the ACTIONS Phenotype Predicts Urologic Medication Discontinuation Following Transurethral Resection of the Prostate

OBJECTIVE

To assess the impact of systemic comorbidities on a validated health phenotype score (ACTIONS: Anxiety, Cardiovascular, Testosterone, Insulin/diabetes, Obesity, Neurologic, Sleep apnea) on outcomes of transurethral resection of prostate (TURP) for benign prostatic hyperplasia (BPH) for symptoms and medication discontinuation.

MATERIALS AND METHODS

Comorbidities of men undergoing TURP for BPH from 2004 to 2015 were assessed with the validated ACTIONS phenotype totaling a score from 0 to 2 for each domain (Anxiety, Cardiovascular, Testosterone, Insulin/diabetes, Obesity, Neurologic, Sleep apnea). BPH medication discontinuation, change in International Prostate Symptom Score, postvoid residual, and patient satisfaction were assessed. Descriptive and comparative statistics were calculated with significance set at P <.05.

RESULTS

The 319 men had a median age of 74.0 (interquartile range 67-78). Mean ACTIONS score was significantly lower in men who discontinued alpha-blockers or 5-alpha reductase inhibitors compared to those who did not (3.37 ± 2.14vs 4.79 ± 2.75, P <.0001). ACTIONS score <4 was significantly associated with medication discontinuation (P = .0014). Lower scores in Testosterone (P = .04), Neurologic (P = .003), and Sleep apnea (P = .04) domains were significantly associated with medication discontinuation. Total ACTIONS score was not independently associated with changes in International Prostate Symptom Score or postvoid residual.

CONCLUSION

Lower ACTIONS score was associated with BPH medication discontinuation after TURP, suggesting men with lower comorbidity burdens do better after the procedure. The ACTIONS phenotype score is easily calculated and may aid the preoperative counseling of men undergoing TURP for BPH.

Testosterone and Benign Prostatic Hyperplasia

INTRODUCTION

Benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS) are frequent in aging. Nonetheless, their pathogenesis is largely unknown. The androgen dependence of the first phases of prostate development have inspired the historical view that higher testosterone (T) may be involved in BPH occurrence; however, recent evidence suggests a different scenario.

AIM

To review the available knowledge on the pathogenesis of BPH particularly concerning the role of T and the possible connections with metabolic impairments.

METHODS

Relevant records were retrieved by an extensive search in Medline, including the following keywords ("testosterone"[MeSH Terms] OR "testosterone"[All Fields]) AND ("prostatic hyperplasia"[MeSH Terms] OR ("prostatic"[All Fields] AND "hyperplasia"[All Fields]) OR "prostatic hyperplasia"[All Fields] OR ("benign"[All Fields] AND "prostatic"[All Fields] AND "hyperplasia"[All Fields]) OR "benign prostatic hyperplasia"[All Fields]). There were no limitations in terms of publication date or study design.

MAIN OUTCOME MEASURES

Preclinical and clinical studies have been reported, with special emphasis on our contribution and interpretation.

RESULTS

Inflammation is a key aspect of BPH development. Along with infectious agents, prostate inflammation can be triggered by metabolic stimuli, such as dyslipidemia, an important component of metabolic syndrome (MetS). Low T and hyperestrogenism frequently occur in MetS. Mounting evidence shows that low, rather than high, T and hyperestrogenism may favor prostate inflammation. Considering these data as a whole, we postulate that BPH is the result of the action of multiple factors, which reinforce their mutual detrimental effects.

CONCLUSION

T is not detrimental for the prostate, and treating hypogonadism could even produce relief from LUTS and limit prostatic inflammation, which generates and maintains the process leading to BPH. Rastrelli G, Vignozzi L, Corona G, et al. Testosterone and Benign Prostatic Hyperplasia. Sex Med Rev 2019;7:259-271.

Diet-Induced Hyperinsulinemia as a Key Factor in the Etiology of Both Benign Prostatic Hyperplasia and Essential Hypertension?

Benign prostatic hyperplasia and hypertension are common age-related comorbidities. Although the etiology of benign prostatic hyperplasia (BPH) is still largely unresolved and poorly understood, a significant age-independent association was found between BPH and hypertension, indicating a common pathophysiological factor for both diseases. It has previously been suggested that the development of essential hypertension may be related to diet-induced hyperinsulinemia. This study follows the question, whether BPH may develop due to the same mechanism, thereby explaining the well-known comorbidity of these 2 disorders. The scientific evidence presented shows that BPH and hypertension share the same pathophysiological changes, with hyperinsulinemia as the driving force. It further shows that significant dietary changes during human history cause disruption of a finely tuned metabolic balance that has evolved over millions of years of evolution: high-insulinemic food, typical of current “Western” diets, has the potential to cause hyperinsulinemia and insulin resistance, as well as an abnormally increased activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system, alterations that play a pivotal role in the pathogenesis of BPH and hypertension.

Uvaria rufa Blume attenuates benign prostatic hyperplasia via inhibiting 5α-reductase and enhancing antioxidant status

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional medicine has used Uvaria rufa Blume as an ethnomedicinal plant for treating fever, skin allergies, intestinal ulcers and prostate disorders including BPH. However, no scientific evidence supports the traditional use.

AIM OF THE STUDY

This study aimed to evaluate the therapeutic potential of U. rufa on BPH using in vitro and in vivo models.

MATERIALS AND METHODS

In vitro studies screened the efficacy of a 5α-reductase (5αR) inhibition and antioxidant activity of petroleum ether, ethyl acetate, ethanol and aqueous extracts from the stem of U. rufa. Phytochemical screening was performed to determine the active compound using high-performance liquid chromatography (HPLC). Ethyl acetate extract (UR-EtOAc) of U. rufa was used to evaluate the therapeutic efficacy in vivo models. BPH was induced by subcutaneous injection of testosterone propionate (3mg/kg) to male rats for 30 days. After 30 days of oral administration of UR-EtOAc at doses of 10 and 20mg/kg and finasteride at a dose of 1mg/kg, the prostate weight, prostate index (PI), testosterone and androgen receptor (AR) levels, and histopathological alteration of prostate gland were determined. Also, oxidative status and toxicity indices were assessed.

RESULTS

UR-EtOAc exhibited the highest potency of inhibition of 5αR and possessed potent antioxidants rich in phenolics and flavonoids contents. The active compound analyzed by HPLC was β-sitosterol. In vivo results show a significant reduction in prostate weight, PI, and AR in all treated groups when compared to the BPH model group (P<0.001). Also, the UR-EtOAc and finasteride treated groups had increased prostatic and serum testosterone levels when compared to the BPH model group. A histopathological investigation of the prostate glands supported the above results. UR-EtOAc elevated the antioxidant enzymes and reduced the malondialdehyde level in BPH-induced rats. Moreover, treatment of UR-EtOAc at all doses had no toxic effects on the vital organs and serum biochemical indices.

CONCLUSIONS

UR-EtOAc from the stem of Uvaria rufa Blume appears to have the potential as a phytotherapeutic agent in the management of BPH, which provides the scientific evidence for traditional use.

Cross-sectional analysis between prostate volumes and serum sex hormones in Japanese men attending a urological clinic

AIM

To evaluate epidemiologically the association between measured prostate volume and sex hormones.

METHODS

Between December 2012 and September 2014, 226 patients attending the urological clinic were assessed for the relationship between prostate volume (PV) and, serum sex hormones, physical size, personal habits, etc. Prostate volume was measured by using transabdominal ultrasonography. Statistically, the Pearson correlation coefficients test was used.

RESULTS

Total cases, the cases of PV ≤ 25 ml, and the cases of PV > 25 ml were evaluated respectively. Total cases and the cases of PV > 25 ml showed a positive significant correlation with testosterone (T), but the cases of PV ≤ 25 ml showed no such correlation. The cases of PV > 25 ml had a positive significant correlation with estradiol (E2), but total cases and cases of PV ≤ 25 ml did not. Dehydroepiandrosterone sulfate (DHEAS) showed no correlation with any case of PV, however it decreased significantly with age and had a correlation with alopecia. The E2/T ratio had no correlation with any case of PV, but on the other hand, the T/DHEAS and E2/DHEAS ratios had significant positive correlation with PV > 25 ml.

CONCLUSIONS

Serum T and E2 had significant positive correlation with measured PV especially in larger prostates. This result seems to correspond with the conventional theory that T and E2 have an etiological effect on benign prostatic hyperplasia. DHEAS did not show direct correlation with PV, however it appeared to suppress the role of T and E2 on benign prostatic hyperplasia growth. DHEAS might be a key to understanding the etiology of benign prostatic hyperplasia with aging.

Relationship of age, prostate-specific antigen, and prostate volume in Indonesian men with benign prostatic hyperplasia

BACKGROUND

To investigate the relationship between age, prostate specific antigen (PSA), and prostate volume (PV) in Indonesian men with histologically proven benign prostatic hyperplasia.

METHODS

Data were generated from our BPH database from June 1994 until December 2013. Subjects were men with a minimum age of 40 years with chief complaint of LUTS or urinary retention, diagnosed with BPH. All patients underwent TRUS-guided prostate biopsy. Patients with PSA level >10 ng/mL were excluded from the study to exclude the possibility of occult prostate cancer. PV was measured with TRUS. Appropriate statistical tests were employed for data analysis.

RESULTS

In all, 1638 patients were enrolled in our study. There was a statistically significant difference in PSA (P = 0.03) and PV (P < 0.0001) between age groups. Overall correlation between age, PSA, and PV were: i). Age and PV (r = 0.12, P < 0.0001); ii). Age and PSA (r = 0.07, P = 0.008); iii). PSA and PV (r = 0.26, P < 0.0001). Subgroup analysis in terms of indwelling catheter use versus without: i). Age 66.09 ± 8 years versus 65.38 ± 7.66 years (P = 0.158); ii). PSA 4.93 ± 2.62 ng/mL versus 4.68 ± 2.82 ng/mL (P = 0.038); iii). PV 47.58 ± 21.33 mL versus 41.43 ± 20.55 mL (P < 0.0001). Correlation between age, PSA, and PV in patients were similar in patients with and without indwelling catheter.

CONCLUSION

In Indonesian men with biopsy-proven BPH, both PV and PSA increased with ageing. Prostate volume was significantly correlated with PSA. Even though the results were weaker, these results are consistent with results in other sets of population. The results vary between different countries and thus, ethnicities. Indonesia is a populous a sociocultural and ethnically diverse country. Therefore, aside from PSA, age, and PV, when investigating men with BPH, ethnicity may also need to be taken into account.

Testosterone and benign prostatic hyperplasia

The use of testosterone to treat the symptoms of late-onset hypogonadal men has increased recently due to patient and physician awareness. However, concerns regarding the effect of testosterone on the prostate, in particular any possible effect on the risk of prostate cancer have prompted further research in this regard. Surprisingly, numerous retrospective or small, randomized trials have pointed to a possible improvement in male lower urinary tract symptoms (LUTS) in patients treated with testosterone. The exact mechanism of this improvement is still debated but may have a close relationship to metabolic syndrome. For the clinician, the results of these studies are promising but do not constitute high levels of evidence. A thorough clinical examination (including history, examination and laboratory testing of testosterone) should be undertaken before considering the diagnosis of late-onset hypogonadism or instigating treatment for it. Warnings still remain on the testosterone supplement product labels regarding the risk of urinary retention and worsening LUTS, and these should be explained to patients.

Do baseline estrogen and testosterone affect lower urinary tract symptoms (LUTS) prior to or after pharmacologic treatment with tadalafil?

Little is known about how total testosterone and estradiol-17β influence lower urinary tract symptoms (LUTS) in men with benign prostatic hypertrophy (BPH). We analyzed data from a subset of men aged ≥18 years randomized to tadalafil 5 mg once-daily or placebo who had ≥6 month history of LUTS and an International Prostate Symptom Score (IPSS)≥13 enrolled in one of three randomized, placebo-controlled tadalafil clinical trials (N = 958). Three specific aims were addressed, as follows: (i) To characterize enrolled men by treatment randomization and testosterone level; (ii) to assess cross-sectional associations of estradiol-17β, testosterone, and LUTS prior to treatment with tadalafil; and, (iii) to assess longitudinal associations between baseline estradiol-17β and testosterone and improvements or worsening of LUTS during a 12-week period of tadalafil or placebo administration. LUTS were assessed by total IPSS, IPSS voiding sub-score (IPSS-V) and IPSS storage sub-score (IPSS-S) for cross-sectional analyses, and change in total IPSS (ΔIPSS), ΔIPSS-V, and ΔIPSS-S between baseline and 12-week visit for longitudinal analyses. Correlation analyses and linear regression examined associations. Baseline testosterone was not significantly associated with IPSS. In contrast, estradiol-17β was inversely correlated with IPSS (r = -0.08; p < 0.05) and IPSS-S (r = -0.14; p < 0.05). Tadalafil treatment resulted in greater IPSS improvements in men with lower baseline estradiol-17β versus those with higher baseline estradiol-17β. Lower baseline estradiol-17β was significantly associated with modestly improved ΔIPSS-V (p = 0.04) and Δtotal IPSS (p = 0.05) but not with ΔIPSS-S, following treatment which may substantiate the role of bladder dysfunction because of nerve and smooth muscle changes in the bladder in addition to benign prostatic enlargement in LUTS. Circulating baseline testosterone did not predict ΔIPSS. Men with lower baseline estradiol-17β levels showed greater responsiveness to tadalafil 5 mg treatment than those with higher baseline estradiol-17β levels when responsiveness was measured using total IPSS and IPSS-V.

The interaction of serum testosterone levels and androgen receptor CAG repeat polymorphism on the risk of erectile dysfunction in aging Taiwanese men

Testosterone has been found to play important roles in men's sexual function. However, the effects of testosterone can be modulated by androgen receptor (AR) CAG repeat polymorphism. It could also contribute to the risk of erectile dysfunction (ED). The aim of this study is to evaluate the interaction of serum testosterone levels and AR CAG repeat polymorphism on the risk of ED in aging Taiwanese men. This cross-sectional data of Taiwanese men older than 40 years were collected from a free health screening held between August 2010 and August 2011 in Kaohsiung city, Taiwan. All participants completed a health questionnaires included five-item version of the International Index of Erectile Function (IIEF-5) and the International Prostate Symptoms Score, received a detailed physical examination and provided 20 cm3 whole blood samples for biochemical and genetic evaluation. The IIEF-5 was used to evaluate ED. Serum albumin, total testosterone (TT), and sex hormone-binding globulin levels were measured. Free testosterone level was calculated. AR gene CAG repeat polymorphism was determined by direct sequencing. Finally, 478 men with the mean age of 55.7 ± 4.8 years were included. When TT levels were above 330 ng/dL, the effect of testosterone level on erectile function seemed to reach a plateau and a significantly negative correlation between AR CAG repeat length and the score of IIEF-5 was found (r = -0.119, p = 0.034). After adjusting for other covariates, the longer AR CAG repeat length was still an independent risk factor for ED in subjects with TT above 330 ng/dL (p = 0.006), but not in TT of 330 ng/dL or below. In conclusion, both serum testosterone levels and AR CAG repeat polymorphism can influence erectile function concomitantly. In subjects with normal TT concentration, those with longer AR CAG repeat lengths have a higher risk of developing ED.

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.

Relationship between benign prostatic hyperplasia/lower urinary tract symptoms and total serum testosterone level in healthy middle-aged eugonadal men

INTRODUCTION

Scant data are available concerning the relationship between lower urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH) and total serum testosterone level (TT) in eugonadal state.

AIM

We performed this study to evaluate the relationship between LUTS/BPH and TT in eugonadal men.

METHODS

A cross-sectional study was conducted that included a total of 2,308 eugonadal (TT ≥ 3.0 ng/mL) male police officers aged 40-59 years who had participated in a health examination. LUTS/BPH were assessed by prostate-specific antigen level, international prostate symptom score (IPSS), total prostate volume (TPV), maximal flow rate (Qmax), postvoid residual urine volume (PVR), and a full metabolic workup. We then investigated their relationship using the Spearman correlation test, multiple linear regression, and logistic regression analyses.

MAIN OUTCOME MEASURES

Associations of TT with IPSS, Qmax, and PVR.

RESULTS

The median age and TT level were 49.0 years and 5.37 ng/mL, respectively. The TT level showed significant positive correlations with Qmax (r = 0.043, P = 0.048) and a significant negative correlation with PVR (r = -0.050, P = 0.022). No significant correlation was found between TT and TPV or IPSS. However, Qmax and PVR as well as TPV and IPSS did not significantly correlate with TT after adjusting for age and/or metabolic syndrome. On logistic regression, no significant difference was found in surrogate measures of LUTS/BPH (TPV > 30 mL, IPSS > 7, Qmax < 15 mL/second, and PVR > 50 mL) between the highest quartile TT group (median: 7.07 ng/mL) and the lowest quartile group (median: 3.92 ng/mL).

CONCLUSION

In our study, TT was not clearly correlated with LUTS/BPH in middle-aged eugonadal men.

Benign prostatic hyperplasia: a new metabolic disease of the aging male and its correlation with sexual dysfunctions

Metabolic syndrome (MetS) is a well-recognized cluster of cardiovascular (CV) risk factors including obesity, hypertension, dyslipidemia, and hyperglycaemia, closely associated with an increased risk of forthcoming cardiovascular disease and type 2 diabetes mellitus. Emerging evidence indicates that benign prostate hyperplasia (BPH) and its related lower urinary tract symptoms (LUTS) represent other clinical conditions frequently observed in subjects with MetS. Several modifiable factors involved in MetS determinism, such as inadequate diet, lack of physical exercise, and smoking and drinking behaviours are emerging as main contributors to the development of BPH. The pathogenetic mechanisms underlying the connection between MetS and BPH have not been completely clarified. MetS and its components, hypogonadism, and prostate inflammation probably play an important role in inducing BPH/LUTS. Although historically considered as a "normal" consequence of the aging process, BPH/LUTS should now be faced proactively, as a preventable disorder of the elderly. Type of diet and level of physical activity are now considered important factors affecting prostate health in the aging male. However, whether physical exercise, weight loss, and modifications of dietary habit can really alter the natural history of BPH/LUTS remains to be determined. Further research is advisable to better clarify these points.

Antiinflammatory effect of androgen receptor activation in human benign prostatic hyperplasia cells

Progression of benign prostatic hyperplasia (BPH) involves chronic inflammation and immune dysregulation. Preclinical studies have demonstrated that prostate inflammation and tissue remodeling are exacerbated by hypogonadism and prevented by testosterone supplementation. We now investigated whether, in humans, hypogonadism was associated with more severe BPH inflammation and the in vitro effect of the selective androgen receptor agonist dihydrotestosterone (DHT) on cultures of stromal cells derived from BPH patients (hBPH). Histological analysis of inflammatory infiltrates in prostatectomy specimens from a cohort of BPH patients and correlation with serum testosterone level was performed. Even after adjusting for confounding factors, hypogonadism was associated with a fivefold increased risk of intraprostatic inflammation, which was also more severe than that observed in eugonadal BPH patients. Triggering hBPH cells by inflammatory stimuli (tumor necrosis factor α, lipopolysaccharide, or CD4(+)T cells) induced abundant secretion of inflammatory/growth factors (interleukin 6 (IL6), IL8, and basic fibroblast growth factor (bFGF)). Co-culture of CD4(+)T cells with hBPH cells induced secretion of Th1 inducer (IL12), Th1-recruiting chemokine (interferon γ inducible protein 10, IP10), and Th2 (IL9)- and Th17 (IL17)-specific cytokines. Pretreatment with DHT inhibited NF-κB activation and suppressed secretion of several inflammatory/growth factors, with the most pronounced effects on IL8, IL6, and bFGF. Reduced inflammatory cytokine production by T-cells, an increase in IL10, and a significant reduction of T cells proliferation suggested that DHT exerted a broad anti inflammatory effect on testosterone cells [corrected]. In conclusion, our data demonstrate that DHT exerts an immune regulatory role on human prostatic stromal cells, inhibiting their potential to actively induce and/or sustain autoimmune and inflammatory responses.

Relationship of sex hormones and nocturia in lower urinary tract symptoms induced by benign prostatic hyperplasia

OBJECTIVE

The study sought to clarify the relationship between sex hormone levels and lower urinary tract symptoms (LUTS) in patients with benign prostate hyperplasia.

METHODS

Between 2007 and 2010, serum total testosterone (TT), free testosterone, and estradiol were prospectively measured in patients who were transferred to our university hospital. The 924 subjects were divided into two groups. Group I (n = 646) were treated with an alpha blocker only and group II (n = 278) were treated with an alpha blocker + a 5-alpha reductase inhibitor over 3 months before their visit. Clinical conditions were assessed by digital rectal examination, prostate-specific antigen, International Prostate Symptom Score (IPSS), transrectal ultrasonography and maximum urinary flow rate and postvoid residual urine.

RESULTS

The mean age was 69.65 ± 6.56 years. The total IPSS and subscore (storage symptom) was significantly associated with age (p < 0.001/p < 0.05) and the TT level (p < 0.05/p < 0.05). TT level was significantly decreased in patients with ≥ 4 episodes of nocturia. The TT level was significantly related to the presence of severe LUTS (p < 0.05).

CONCLUSIONS

Endogenous testosterone may have a beneficial effect on lower urinary tract function and that a high frequency of nocturia may induce testosterone deficiency.

The impact of androgen receptor CAG repeat polymorphism on andropausal symptoms in different serum testosterone levels

INTRODUCTION

In addition to a depletion of androgen, attenuated action of androgen receptor (AR) might also contribute to andropausal symptoms.

AIM

To evaluate the interaction of AR cytosine adenine guanine (CAG) repeat polymorphism and serum testosterone levels and their effect on andropausal symptoms in aging Taiwanese men.

METHODS

From August 2007 to April 2008, a free health screening for men older than 40 years was conducted by a medical center in Kaohsiung City, Taiwan. All participants received physical examination, answered questionnaires to collect their demographic information and medical histories, completed the Androgen Deficiency in the Aging Male (ADAM) questionnaire, and provided 20-cm(3) whole blood samples for biochemical and genetic evaluation.

MAIN OUTCOME MEASURES

The ADAM questionnaire was used to evaluate andropausal symptoms. Serum albumin, total testosterone (TT), and sex hormone-binding globulin levels were measured. Free testosterone level was calculated. AR gene CAG repeat polymorphism was determined by direct sequencing.

RESULTS

Seven hundred two men with the mean age of 57.2 ± 6.5 years were included. There was no significant association between TT levels and the distribution of AR CAG repeat polymorphism. When TT levels were above 340 ng/dL, subjects with AR CAG repeat lengths ~25 showed significantly higher risk of developing andropausal symptoms, as compared with those with AR CAG repeat lengths ~22 (P = 0.006), but this was not observed when TT levels were 340 ng/dL or below. Age and number of comorbidities were also independent risk factors for andropausal symptoms.

CONCLUSION

In subjects with normal TT concentration, those with longer AR CAG repeat lengths have a higher risk of developing andropausal symptoms. Age and number of comorbidities can also influence the appearance of andropausal symptoms. In clinical practice, a multifactorial approach to evaluate andropausal symptoms and the interactions between those risk factors is suggested.

Waist circumference is an independent risk factor for prostatic hyperplasia in Taiwanese males

PURPOSE

Benign prostatic hyperplasia is a common disease affecting older males. As obesity becomes an increasing problem worldwide, its role in prostatic hypertrophy has been discussed recently. The purpose of this study is to evaluate the relationship between waist circumferences and prostatic hyperplasia in Taiwan.

METHODS

There were 539 men enrolled in the study who had health examinations at the Healthcare Center of Chang Gung Memorial Hospital; 53 were excluded because of history of conditions affecting prostatic volume. Their anthropometry was measured and serum prostate-specific antigen (PSA) levels as well as lipid profiles were analyzed. Prostate volume was measured by transrectal ultrasonography performed by experienced urologists.

RESULTS

The mean prostate volume was 26.43 mL, whereas mean body mass index (BMI) was 25.27 kg/m(2) and mean waist circumference (WC) was 90.81 cm. By age-adjusted logistic regression, PSA > 4 ng/mL, WC ≥ 90 cm, and BMI > 24 kg/m(2) are associated with increased risk of developing prostatic hyperplasia; only WC ≥ 90 cm can be validated by multiple logistic regression. Further analysis of obesity patterns showed that abdominal overweight/obesity places patients at increased risk independently rather than high WC or high BMI alone.

CONCLUSIONS

Study results showed that waist circumference ≥ 90 cm is an independent risk factor of prostatic hyperplasia in Taiwan. Men with abdominal overweight/obesity (WC ≥ 90 cm and BMI > 24 kg/m(2)) have a twofold risk of developing prostatic hyperplasia.

Significant association between serum dihydrotestosterone level and prostate volume among Taiwanese men aged 40-79 years

INTRODUCTION

We evaluated the association between serum sex hormone levels and prostate volume in Taiwanese men.

METHODS

A cross-sectional study was conducted in 505 men (aged 40-79 years, mean age 58 years). Serum total testosterone (TT), free testosterone (FT), dihydrotestosterone (DHT) and estradiol (E2) levels were measured. Total prostate volume (TPV) and transition zone volume (TZV) were measured by transrectal ultrasonography. Body mass index (BMI), DHT/TT and E2/TT were calculated. Correlations were determined using univariate and multivariate regression analyses.

RESULTS

Apart from DHT, an age-dependent change of sex hormone levels were observed. On univariate analyses, age, BMI, serum DHT level and DHT/TT ratio, as well as serum E2 level and E2/TT ratio, but not serum TT and FT levels showed a significant association with prostate volume. On multivariate analysis, however, only serum DHT level and DHT/TT ratio remained significant. Logistic regression analysis showed that the odds ratios (95% confidence interval) of the second, third, and fourth quartiles of serum DHT levels for benign prostatic hyperplasia (defined as TPV ≥ 20 ml) risk were 2.06 (1.21-3.51), 2.66(1.56-4.53) and 7.15(4.0-12.6), respectively (p < 0.001).

CONCLUSIONS

Higher serum DHT level and DHT/TT ratio were associated with larger prostate volume and higher prevalence of BPH in Taiwanese men.

Diagnosis and treatment of sexual dysfunctions in late-onset hypogonadism

Testosterone is the principal androgen in the human male. The decline of testosterone with aging was recognized to be associated with a number of symptoms and signs that reduce the quality of life and that may even have severe, debilitating consequences. Clinically, late-onset hypogonadism (LOH) is diagnosed by use of biochemical and clinical measures. Despite published guidelines and recommendations, however, uncertainty surrounds the profile of clinical symptoms as well as the biochemical threshold of diagnosis. Clinicians should be aware of these shortcomings while adhering to the guidelines. Current treatment methods are centered on restoring testosterone to mid to lower levels of young men with natural testosterone replacements. Although recent studies have highlighted possible additional benefits involving improvement of systemic disorders, the goal of treatment is to improve sexual function, while observing for adverse effects in the prostate. Overall, the problem of LOH in debilitating the quality of life and well-being is real, and by following proper guidelines with attentiveness to the results of treatment trials, testosterone replacement therapy presents a safe and effective treatment option.

Serum testosterone levels significantly correlate with nocturia in men aged 40-79 years

OBJECTIVE

To investigate the association between serum sex hormone levels and lower urinary tract symptoms in men aged 40-79 years.

METHODS

A cross-sectional study was conducted in 509 men (mean age 58 years). The serum total testosterone (TT), dihydrotestosterone, and estradiol levels were measured. The total prostate volume measured by transrectal ultrasonography and International Prostate Symptom Score (IPSS) questionnaire were obtained. Correlations were determined using univariate and multivariate regression analysis.

RESULTS

The subjects with moderate to severe lower urinary tract symptoms (total IPSS≥8) were older, with a greater incidence of hypertension and diabetes, a larger prostate, and had lower serum TT levels. On the univariate analysis, the serum TT levels were negatively associated with the total IPSS, IPSS storage subscore, weak stream, and nocturia. After adjusting for age, hypertension, diabetes, and total prostate volume, only the serum TT level was significantly associated with nocturia (>2 times/night; P=.042), and men with serum TT levels in the greatest quartile had a 44% reduced risk of nocturia than in the lowest quartile (P=.037).

CONCLUSION

In our relative healthy male cohort, most IPSS items showed no significant association with serum sex hormone levels, except for nocturia, which showed a negative correlation with the serum testosterone level.

Associations between longitudinal changes in serum estrogen, testosterone, and bioavailable testosterone and changes in benign urologic outcomes

Some men have rapid increases in benign prostatic enlargement and lower urinary tract symptoms (LUTS), and it is not clear how sex steroid hormones contribute to the rates of change in these urologic outcomes. Therefore, the authors conducted a population-based cohort study of 648 men residing in Olmsted County, Minnesota, from 1990 to 2007, to examine associations between baseline sex steroid hormones, the rate of change in these hormones, and the rates of change in LUTS, maximum urinary flow rate, and prostate volume. Annual changes in hormone levels and urologic outcomes were calculated using mixed-effects regression models. Associations between hormone variables and rates of change in urologic outcomes were assessed with linear regression models. Higher baseline estradiol levels and rapid declines in estradiol over time were associated with rapid increases in LUTS and rapid decreases in maximum flow rate. Lower baseline bioavailable testosterone levels and more rapid declines in bioavailable testosterone were associated with more rapid increases in prostate volume. These results suggest that both absolute sex steroid hormone levels and the rates at which the levels change may be important in the development of urologic conditions in aging men.

Role of insulin and testosterone in prostatic growth: who is doing what?

Previous studies have demonstrated increased incidence of benign prostatic hyperplasia in insulin-resistant individuals. In addition to androgens, prostatic growth is sensitive to the peptide growth factors including insulin. Experimental studies employing intervention of selective β-cell toxin streptozotocin and castration suggest that depletion of either insulin or testosterone results in the severe prostatic atrophy (>80%). Exogenous testosterone and diet-induced experimental hyperinsulinemia induces prostatic enlargement in rats. Further, hyperinsulinemia sensitizes prostate towards the growth promoting effect of testosterone, and testosterone augments prostatic growth even in the hypoinsulinemic rats. However, in castrated rats diet-induced hyperinsulinemia fails to promote prostatic growth. Based on these evidences it is hypothesized that in the presence of testosterone insulin plays an important role in the prostatic growth. The epidemiological reports witnessing increased incidences of prostatic enlargement in men with metabolic syndrome, which are known to have increased level of insulin, provides a validating clue to the hypothesis. Further, the hypothesis suggests that targeting insulin signaling pathway could be a new objective for the treatment of prostatic enlargement.

Serum steroid and sex hormone-binding globulin concentrations and the risk of incident benign prostatic hyperplasia: results from the prostate cancer prevention trial

The authors conducted a nested case-control study of serum steroid concentrations and risk of benign prostatic hyperplasia (BPH), using data from the placebo arm of the Prostate Cancer Prevention Trial (1993-2003). Incident BPH over 7 years (n = 708) was defined as receipt of treatment, a report of 2 International Prostate Symptom Score (IPSS) values greater than 14, or 2 increases of 5 or more from baseline IPSS values with at least 1 value greater than or equal to 12. Controls (n = 709) were selected from men who reported no BPH treatment or any IPSS greater than 7. Baseline serum was analyzed for testosterone, estradiol, estrone, 5alpha-androstane-3alpha, 17beta-diol-glucuronide, and sex hormone-binding globulin. Covariate-adjusted odds ratios contrasting the highest quartiles with the lowest quartiles of testosterone, estradiol, and testosterone:17beta-diol-glucuronide ratio were 0.64 (95% confidence interval (CI): 0.43, 0.95; P(trend) = 0.04), 0.72 (95% CI: 0.53, 0.98; P(trend) = 0.09), and 0.64 (95% CI: 0.46, 0.89; P(trend) = 0.004), respectively. Findings did not differ by age, body mass index, time to BPH endpoint, or type of BPH endpoint. High testosterone levels, estradiol levels, and testosterone:17beta-diol-glucuronide ratio are associated with reduced BPH risk, which may reflect decreased activity of 5-alpha-reductase. Genetic or environmental factors that affect the activity of 5-alpha-reductase may be important in the development of symptomatic BPH.