Role of estrogens in human benign prostatic hyperplasia

Comparison of prostate size and anthropometric parameters between diabetic and non-diabetic Congolese patients who underwent transurethral prostate resection in the Democratic Republic of Congo

Background

Benign prostate hyperplasia (BPH) and type 2 diabetes mellitus are prevalent in older men, and both represent a challenge to public health. Prior studies reported a correlation between BPH and (hyper)glycaemia, a component of the metabolic syndrome, which is on the increase in sub-Saharan Africa (SSA) due to rapid modernization. This study was designed to evaluate the association of prostate volume and anthropometric parameters among diabetic and non-diabetic patients who had transurethral resection of the prostate (TURP) for BPH.

Results

We analyzed data of 159 selected patients who had TURP over a three-year period (February 2014–January 2017) for histologically confirmed BPH. Mean age in the entire cohort was 68 ± 8.5 years. Out of the 159 patients, 94 (59.1%) were non-diabetics and 65 (40.9%) were diabetics. International Prostate Symptom Score (IPSS) and fasting blood glucose were significantly higher in diabetic than in non-diabetic group (28.6 ± 4.3 vs 25.6 ± 6.4, and p 0.005; 121.7 ± 45.7 vs 85.4 ± 11.7 mg/dl, and p < 0.001, respectively). BMI and waist circumference were statistically greater in non-diabetics than in diabetics (25.1 ± 3.3 kg/m2 vs 23.6 ± 3.5 kg/m2, and p 0.008; 94.6 cm ± 10.3 vs 90.6 ± 10.4 cm, and p 0.018). Diabetic patients had larger prostate volume than non-diabetic in the working age subgroup only (< 65 years of age); beyond 65 years, this difference was not consistent (62.6 ± 23.1 cc vs 50.1 ± 20.7 cc, and p 0.027; 56.2 ± 23.7 cc vs 49 ± 20.2 cc, and p 0.15, respectively). Prostate size was significantly associated with fasting blood glucose (p = 0.002) and PSA (p = 0.027). However, prostate size was not related to age, presence of diabetes, BMI, waist circumference, IPSS, quality of life score, and duration of symptoms.

Conclusion

Prostate volume is not correlated with anthropometric parameters in diabetic and non-diabetic Congolese patients who had TURP in South Kivu. Diabetics were not obese and yet had larger prostate volume than non-diabetics < 65 years of age. It is hoped that these results would form groundwork for further studies on this topic in SSA region.

Phytoestrogenic Activity of Blackcurrant Anthocyanins Is Partially Mediated through Estrogen Receptor Beta

Phytoestrogens are plant compounds with estrogenic effects found in many foods. We have previously reported phytoestrogen activity of blackcurrant anthocyanins (cyanidin-3-glucoside, cyanidin-3-rutinoside, delphinidin-3-glucoside, and delphinidin-3-rutinoside) via the estrogen receptor (ER)α. In this study, we investigated the participation of ERβ in the phytoestrogen activity of these anthocyanins. Blackcurrant anthocyanin induced ERβ-mediated transcriptional activity, and the IC₅₀ of ERβ was lower than that of ERα, indicating that blackcurrant anthocyanins have a higher binding affinity to ERβ. In silico docking analysis of cyanidin and delphinidin, the core portions of the compound that fits within the ligand-binding pocket of ERβ, showed that similarly to 17β-estradiol, hydrogen bonds formed with the ERβ residues Glu305, Arg346, and His475. No fitting placement of glucoside or rutinoside sugar chains within the ligand-binding pocket of ERβ-estradiol complex was detected. However, as the conformation of helices 3 and 12 in ERβ varies depending on the ligand, we suggest that the surrounding structure, including these helices, adopts a conformation capable of accommodating glucoside or rutinoside. Comparison of ERα and ERβ docking structures revealed that the selectivity for ERβ is higher than that for ERα, similar to genistein. These results show that blackcurrant anthocyanins exert phytoestrogen activity via ERβ.

Metabolic syndrome and benign prostatic hyperplasia: An update

Metabolic syndrome (MetS) is a cluster of metabolic abnormalities related to central adiposity and insulin resistance. Its importance is increasingly recognized as it associates with increased risks of metabolic and cardiovascular diseases. These metabolic aberrations of MetS may lead to development of benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS) in men. A 26.5%-55.6% prevalence of MetS in men with LUTS was reported in worldwide studies. Although the exact biological pathway is not clear yet, insulin resistance, increased visceral adiposity, sex hormone alterations and cellular inflammatory reactions played significant roles in the related pathophysiological processes. Clinician should recognize the cardiovascular and metabolic impacts of MetS in men with LUTS, early risk factors optimization and use of appropriate medical therapy may possibly alter or slower the progression of LUTS/BPH, and potentially avoid unnecessary morbidities and mortalities from cardiovascular and metabolic diseases for those men.

Opposing roles of ERα and ERβ in the genesis and progression of adenocarcinoma in the rat ventral prostate

BACKGROUND

Prostate cancer is a common malignancy in men and although hormone ablation therapy is effective, men develop hormone resistance. There is need for therapies applicable earlier, such as treatment of prostatic intraepithelial neoplasia (PIN). Estrogens besides androgens play a role in prostate cancer pathogenesis via two receptors ERα and ERβ and both receptors are thought to play different, opposing, roles with ERα having proliferative properties and ERβ having anti-proliferative properties. To differentiate between the roles both receptors play in prostate cancer an ERα and an ERβ agonist, ERA-45 and ERB-26, have been tested in a rodent model for prostate carcinogenesis.

METHODS

The influence of ERα on prostate cancer progression was studied in intact male rats treated with testosterone in combination with the ERα agonist, ERA-45 for either a long-term (20-week) period or a shorter term (6-week) period. The ERβ agonist was tested in the shorter term model in intact male rats treated with testosterone in combination with the ERα agonist, ERA-45, followed by administration of the ERβ agonist, ERB-26, during the last 2 weeks.

RESULTS

Treatment of rats with testosterone in combination with ERA-45 induced mild PIN lesions at 6 weeks and severe precancerous PIN lesions at 20 weeks. The ERβ agonist prevented the onset of PIN lesions at 6 weeks. Moreover, prostate epithelial cell apoptosis was increased and proliferation was decreased.

CONCLUSION

These findings confirm the opposing roles ERα and ERβ play in prostate carcinogenesis and suggest a therapeutic opportunity of ERβ for treating precancerous PIN lesions.

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.

Effect of storage and processing of Brazilian flaxseed on lipid and lignan contents

Flaxseed has been widely studied around the world; its incorporation into products habitually consumed by human populations has been stimulated due to its unique nutritional value. The objective of this study was to evaluate the chemical composition of Brazilian flaxseed, to analyze the stability of lipids present in whole flaxseed flour (WFF) or partially defatted flaxseed flour (DFF) stored under several temperatures, and to investigate the effect of bread making on a product containing flaxseed. Whole flaxseed flour presented (g.100 g-1) 25.7 of insoluble fiber, 10.7 of soluble fiber, 38.9 of lipids, and 2.65 of lignan. Defatted flaxseed flour presented 65% less lipids, 36% more fiber and 56% more lignan than whole flaxseed flour. The fatty acid profile was maintained in the defatted flaxseed flour, and it presented a stable composition during storage under ambient temperature, refrigeration, and freezing. The fatty acid profile was similar in the bread containing defatted flaxseed flour after dough development, baking, and storage at room temperature or refrigerated. After baking, 89% of the lignan content was kept in bread. Results show that Brazilian flaxseed has an interesting chemical composition, and that defatted flaxseed, by-product of lipid extraction, presents a good stability to grind and storage under several temperatures. Thus, defatted flaxseed flour can be incorporated in bread, increasing its nutritional and functional value.

Increased infiltrated macrophages in benign prostatic hyperplasia (BPH): role of stromal androgen receptor in macrophage-induced prostate stromal cell proliferation

Infiltrated macrophages may play important roles in the development and progression of benign prostatic hyperplasia (BPH), but the underlying mechanisms remain largely unknown. We found increased macrophages infiltration in human and mouse BPH tissues. By establishing a co-culture transwell system, we found increased migration of macrophages and proliferation of prostate stromal cells during co-culture. Importantly, stromal androgen receptor (AR) could enhance the migration of macrophages and macrophage-mediated stromal cell proliferation. We identified CCL3 as an AR downstream player, and found CCL3 levels were notably increased in human and mouse BPH prostates. Ablation of prostate stromal AR in a mouse BPH model significantly reduced CCL3 expression levels in prostates. Consistently, targeting AR via an AR degradation enhancer, ASC-J9®, or neutralization of CCL3 with an antibody, resulted in suppression of macrophage migration and prostate stromal cell growth. Our study provides mechanistic insights on the regulation of prostate stromal cells by macrophages via stromal AR/CCL3 signaling pathways, which could potentially allow the development of therapeutic approaches for battling BPH with persistent inflammation.

The functional role of reactive stroma in benign prostatic hyperplasia

The human prostate gland is one of the only internal organs that continue to enlarge throughout adulthood. The specific mechanisms that regulate this growth, as well as the pathological changes leading to the phenotype observed in the disease benign prostatic hyperplasia (BPH), are essentially unknown. Recent studies and their associated findings have made clear that many complex alterations occur, involving persistent and chronic inflammation, circulating hormonal level deregulation, and aberrant wound repair processes. BPH has been etiologically characterized as a progressive, albeit discontinuous, hyperplasia of both the glandular epithelial and the stromal cell compartments coordinately yielding an expansion of the prostate gland and clinical symptoms. Interestingly, the inflammatory and repair responses observed in BPH are also key components of general wound repair in post-natal tissues. These responses include altered expression of chemokines, cytokines, matrix remodeling factors, chronic inflammatory processes, altered immune surveillance and recognition, as well as the formation of a prototypical 'reactive' stroma, which is similar to that observed across various fibroplasias and malignancies of a variety of tissue sites. Stromal tissue, both embryonic mesenchyme and adult reactive stroma myofibroblasts, has been shown to exert potent and functional regulatory control over epithelial proliferation and differentiation as well as immunoresponsive modulation. Thus, the functional biology of a reactive stroma, within the context of an adult disease typified by epithelial and stromal aberrant hyperplasia, is critical to understand within the context of prostate disease and beyond. The mechanisms that regulate reactive stroma biology in BPH represent targets of opportunity for new therapeutic approaches that may extend to other tissue contexts. Accordingly, this review seeks to address the dissection of important factors, signaling pathways, genes, and other regulatory components that mediate the interplay between epithelium and stromal responses in BPH.

Dietary fatty acid quality affects AR and PPARgamma levels and prostate growth

BACKGROUND

Fatty acids are among the most important nutritional factors associated with the ethiopathogenesis of prostate cancer, therefore the main objective of this work was to evaluate the effect of quality of fatty acid on the rat ventral prostate growth, tissue organization, and expression of androgen receptor (AR) and peroxisome proliferation activator receptor gamma (PPARgamma).

METHODS

Wistar rats were distributed into five groups, which were fed isocaloric normolipidic diets containing soybean oil (7% Control), linseed (7% or 3.5% linseed plus 3.5% soybean oil) and rendered pork fat (7% or 3.5% lard plus 3.5% soybean oil) for 10 weeks after weaning.

RESULTS

At the end of treatment, the experiments demonstrated that lard and linseed oil caused opposite effects on prostatic growth. While the lard promoted an increase in prostatic weight associated to epithelial hyperplasia (confirmed by stereology); the linseed resulted in a significantly lighter organ. Immunohistochemistry and Western blotting demonstrated increased expression of AR and PPARgamma in groups fed with lard diet, while linseed oil promoted a decrease.

CONCLUSIONS

Prostatic growth is influenced by dietary fatty acids with concurrent variation in the expression of AR and PPARgamma. PPARgamma might represent the link between diet and prostate growth and AR expression and function. Since the levels of testosterone were altered it is also possible that prostatic changes are secondary to systemic effects of the diet.

Serum sex steroid hormones and lower urinary tract symptoms in Third National Health and Nutrition Examination Survey (NHANES III)

OBJECTIVES

To evaluate the association of circulating sex steroid hormones and sex hormone binding globulin (SHBG) with lower urinary tract symptoms (LUTS).

METHODS

We included 260 men, 60 years old or older, who participated in Phase 1 (1988 to 1991) of the Third National Health and Nutrition Examination Survey and for whom surplus serum was available. We measured the serum concentrations of testosterone, androstanediol glucuronide (AAG), estradiol, and SHBG. Free testosterone was calculated from the circulating testosterone, SHBG, and albumin. The cases (n = 128) were men with two to four symptoms (nocturia, hesitancy, incomplete emptying, and weak stream), but who had never undergone noncancer prostate surgery. The controls (n = 132) were men who neither had symptoms nor had undergone noncancer prostate surgery. We adjusted for age, race/ethnicity, waist circumference, cigarette smoking, alcohol consumption, and physical activity in logistic regression models and used sampling weights.

RESULTS

The cases had statistically significantly greater AAG and estradiol concentrations than did the controls. After multivariate adjustment, the men in the top tertile of AAG (odds ratio 2.62, 95% confidence interval 1.12 to 6.14) had a greater risk of LUTS compared with men in the bottom two tertiles. Also, men with a greater estradiol concentration (odds ratio 1.78, 95% confidence interval 0.91 to 3.49) and a greater estradiol/SHBG molar ratio (odds ratio 2.41, 95% confidence interval 1.39 to 4.17) had a greater risk of LUTS than did men with lower concentrations. No consistent associations were seen for circulating testosterone, free testosterone, or SHBG.

CONCLUSIONS

In this cross-sectional study representative of older U.S. men, circulating AAG, a metabolite of dihydrotestosterone, and estradiol were associated with an increased risk of having LUTS.

An investigation of the relationship between sex-steroid levels and urological symptoms: results from the Boston Area Community Health survey

OBJECTIVES

To investigate whether circulating levels of sex hormones are associated with urological symptoms, using data from the Boston Area Community Health (BACH) Survey.

SUBJECTS AND METHODS

BACH used a multistage stratified-cluster approach to randomly sample 5506 adults aged 30-79 years in Boston, MA, USA. Anthropometric measures, lifestyle and psychosocial factors, comorbidities and urological symptoms were obtained using a questionnaire administered by an interviewer. Serum testosterone, sex hormone-binding globulin (SHBG), dehydroepiandrosterone sulphate (DHEAS), dihydrotestosterone (DHT) and oestradiol (E2) levels were measured, and bioavailable testosterone (BT) was calculated in 1899 men (538 Black, 651 Hispanic and 710 White). Regression analysis was used to investigate the relationships between androgen levels and American Urological Association symptom index (AUA-SI), lower urinary tract symptoms (LUTS) (> or = 8 on the AUA-SI), urinary incontinence (UI), dribble and hesitancy.

RESULTS

Of all subjects, 19% reported LUTS, 6% UI, 9% dribble and 4% hesitancy. Testosterone, BT and DHEAS levels were inversely related to the AUA-SI (P = 0.009, <0.001 and <0.001, respectively); SHBG values and the AUA-SI were positively correlated (P < 0.001). Adjusting for age, BT and DHEAS levels had negative relationships with the AUA-SI; BT and DHEAS levels were negatively related to LUTS and SHBG was positively related to LUTS (both P < 0.001); after age adjustment, only LUTS and DHEAS remained related, and only the relationship between dribble and E2 remained significant; no hormone levels were related to hesitancy.

CONCLUSIONS

Circulating levels of sex hormones are generally not significant predictors of urological symptoms in men after adjusting for age. The pathophysiology of LUTS is complex and probably includes factors other than circulating sex steroid levels.

Angiotensin II-mediated calcium signals and mitogenesis in human prostate stromal cell line hPCPs

Western blots and immunocytochemistry were used to detect angiotensin 1 (AT(1)) and angiotensin 2 (AT(2)) receptors in human primary cultures of the prostate stromal compartment (hPCPs). Immunohistochemistry was performed on human prostate tissue-embedded paraffin. In addition, pharmacological tools were applied in combination with photometry experiments to characterize the physiological activity of AT(1) and AT(2) receptors in hPCPs cell culture. A proliferation assay was used to describe the mitogenic activity of angiotensin II (Ang II) on hPCPs cells. Only the AT(1) receptor was detected in Western blot analysis. Immunocytochemistry of hPCPs cells showed that the AT(1) receptor is present in both the smooth muscle type and the fibroblastic type. In the stromal compartment of human prostate tissue, immunoreaction with antibodies against the AT(1) receptor was detectable.Fura-2-loaded hPCPs cells showed an instantaneous and linear rise in free intracellular calcium ion concentration ([Ca(2+)](i)) after local perfusion with Ang II in concentrations of 10 nM. Removing of external calcium or emptying intracellular calcium stores before Ang II application diminished or abolished this [Ca(2+)](i) response. The response to Ang II was also diminished when hPCPs cells were perfused with the AT(1) receptor inhibitor losartan prior to Ang II application. No inhibition of the [Ca(2+)](i) increase was detectable after perfusion with PD 123319, a specific inhibitor of the AT(2) receptor.hPCPs cells were stimulated with Ang II in various concentrations over a period of 2 days. The subsequently performed proliferation assay revealed a mitogenic effect of Ang II on hPCPs in concentrations starting at 10 nM. This effect could be inhibited by losartan.

Pilot study to explore effects of low-fat, flaxseed-supplemented diet on proliferation of benign prostatic epithelium and prostate-specific antigen

OBJECTIVES

Dietary factors may influence the prostate and have an impact on prostatic growth and disease. A small number of studies have suggested that flaxseed-supplemented, fat-restricted diets may thwart prostate cancer growth in both animals and humans. Unknown, however, is the potential effect of such a diet on benign prostatic epithelium.

METHODS

We undertook a pilot study to explore whether a flaxseed-supplemented, fat-restricted diet affects the proliferation rates in benign epithelium. We also explored the effects on circulating levels of prostate-specific antigen (PSA), total testosterone, and cholesterol. Fifteen men who were scheduled to undergo repeat prostate biopsy were instructed to follow a low-fat (less than 20% kcal), flaxseed-supplemented (30 g/day) diet and were provided with a supply of flaxseed to last throughout the 6-month intervention period. The PSA, total testosterone, and cholesterol levels were determined at baseline and at 6 months of follow-up. Reports from the original and repeat biopsies were compared, and proliferation (MIB-1) rates were quantified in the benign prostatic epithelium.

RESULTS

Statistically significant decreases in PSA (8.47 +/- 3.82 to 5.72 +/- 3.16 ng/mL; P = 0.0002) and cholesterol (241.1 +/- 30.8 to 213.3 +/- 51.2 mg/dL; P = 0.012) were observed. No statistically significant change was seen in total testosterone (434.5 +/- 143.6 to 428.3 +/- 92.5 ng/dL). Although 6-month repeat biopsies were not performed in 2 cases because of PSA normalization, of the 13 men who underwent repeat biopsy, the proliferation rates in the benign epithelium decreased significantly from 0.022 +/- 0.027 at baseline to 0.007 +/- 0.014 at 6 months of follow-up (P = 0.0168).

CONCLUSIONS

These pilot data suggest that a flaxseed-supplemented, fat-restricted diet may affect the biology of the prostate and associated biomarkers. A randomized controlled trial is needed to determine whether flaxseed supplementation, a low-fat diet, or a combination of the two regimens may be of use in controlling overall prostatic growth.

Preventing diseases of the prostate in the elderly using hormones and nutriceuticals

The prostate has only one function, namely to secrete fluid containing substances that are needed for reproduction. This requires an extremely high concentration of androgens in the tissues. Benign prostatic hypertrophy (BPH) seems to be related to the long-term exposure of the prostate to the strong androgen 5alpha-dihydrotestosterone (DHT) and, possibly, to estrogens. The relation between prostate cancer and androgens is suggested to be U-shaped, with both extremes of androgen concentrations being associated with increased risk of invasive cancer. In the treatment of patients with BPH, the lipidic liposterolic extracts of Serenoa repens were as effective as the pharmaceutical inhibitors of the 5alpha-reductase enzyme or alpha1-adrenergic blockers in relieving urinary symptoms. In addition to moderately inhibiting the 5alpha-reductase activity, Serenoa seems to exert anti-inflammatory and complementary cellular actions with beneficial effects on the prostate. Unlike the pharmaceutical 5alpha-reductase inhibitors, finasteride and dutasteride, Serenoa does not suppress serum PSA, facilitating the follow-up and the early detection of prostate cancer. We suggest a strategy to prevent prostate cancer that aims at providing men with partial androgen deficiency correct testosterone substitution with a sustained release buccal bio-adhesive tablet. In addition, food supplementation with extracts of Serenoa repens and a combination of the antioxidants selenium, (cis)-lycopene and natural vitamin E, together with fish oil rich in long-chain polyunsaturated essential fatty acids of the omega-3 group seems warranted. Clearly, a holistic approach including careful clinical and biological monitoring of the aging man and his prostate remains mandatory.

Id proteins in epithelial cells

Id helix-loop-helix (Id HLH) proteins are negative regulators of basic HLH transcription factors. They are expressed during embryonic development and are important for the regulation of cell phenotypes in adults. They participate in the molecular networks controlling cell growth, differentiation, and carcinogenesis, through specific basic HLH and non-basic HLH protein interactions. Recent in vitro and in vivo data implicate Id HLH as important orchestrating proteins of homeostasis in glandular and protective epithelia. In particular, Id proteins have been reported to be involved in cell behavior in epidermis, respiratory system, digestive tract, pancreas, liver, thyroid, urinary system, prostate, testis, endometrium, cervix, ovary, and mammary gland. The purpose of this review is to summarize the evidence implicating Id proteins in the regulation of mammalian epithelial cell phenotypes.

Enhancement of alpha-adrenoceptor-mediated responses in prostate of testosterone-treated rat

The present study was undertaken to investigate the effect of testosterone on the alpha-adrenoceptor-mediated contractile responses in ventral lobe of rat prostate. Contractile responses to various alpha-adrenoceptor agonists (phenylephrine, A61603 (N-[5-(4,5-dihydro-1H-imidazol-2-yl)-2-hydroxy-5,6,7,8-tetrahydronaphthalen-1-yl] methanesulphonamide), clonidine, guanfacine, ST587 ((2,3-dihydro-benzo[1,4]dioxin-2-ylmethyl)-[2-(2,6-dimethoxy-phenoxy)-ethyl]-amine) and xylazine) were tested in prostate strips obtained from control and testosterone (3 mg/kg, s.c. 5 days a week for 15 days-10 doses total)-treated rats. Dose-response curves for alpha-adrenoceptor agonists in testosterone-treated animals showed a leftward shift, indicating increased sensitivity of tissue to alpha-adrenoceptor agonists. To find the mechanism of increased sensitivity, K(A) value and receptor reserve of phenylephrine were estimated. Neither the K(A) value nor the receptor reserve of phenylephrine was altered in testosterone-treated rats. The concentration-occupancy curve for A61603 was shifted leftward and the K(A) value for A61603 decreased about four-fold. The K(B) value of 2-(2,6-dimethoxyphenoxyethyl) aminomethyl-1,4-benzodioxane (WB4101) was not altered, however, the K(B) value for prazosin was decreased approximately 5.5-fold. These findings indicate that the testosterone-mediated increase in sensitivity of prostate to alpha-adrenoceptor agonists is due to alterations in the alpha(1)-adrenoceptor pool.

Body size and serum levels of insulin and leptin in relation to the risk of benign prostatic hyperplasia

PURPOSE

Obesity has been implicated in the etiology of benign and malignant prostatic growth due to its influence on metabolic and endocrine changes. Because obesity is an important determinant of serum levels of insulin and leptin (the product of the obesity gene Ob), we investigated the role of obesity and serum levels of insulin and leptin in benign prostatic hyperplasia (BPH) etiology.

MATERIALS AND METHODS

Fasting serum levels of insulin and leptin as well as the body mass index, a measure of overall obesity, and waist-to-hip ratio, an indicator of abdominal obesity, were determined in 200 men newly diagnosed with BPH who were hospitalized for surgery and in 302 randomly selected healthy male subjects from the population in Shanghai, China.

RESULTS

A higher waist-to-hip ratio and higher serum insulin were significantly associated with an increased risk of BPH. Relative to men in the lowest waist-to-hip ratio quartile (less than 0.856) those in the highest quartile (greater than 0.923) were at 2.4-fold risk (odds ratio 2.42, 95% confidence interval [CI] 1.34 to 4.37, test for trend p = 0.01). Similarly relative to men in the lowest quartile of insulin (less than 5.87 microU. per ml.) those in the highest quartile (greater than 9.76 microU. per ml.) were at significantly increased risk (odds ratio 2.47, 95% CI 1.35 to 4.54, test for trend p = 0.009). The effect of insulin on BPH risk was more pronounced in men in low and middle tertiles of the waist-to-hip ratio (odds ratios comparing high to low insulin tertiles 2.8 and 2.7, respectively), while among men in the highest waist-to-hip ratio tertile insulin was not significantly associated with BPH risk. In contrast, we found no significant odds ratio comparing the highest to lowest quartiles of leptin (odds ratio 0.62, 95% CI 0.33 to 1.17) or body mass index (odds ratio 1.64, 95% CI 0.96 to 2.81).

CONCLUSIONS

Our results suggest that abdominal obesity and increasing serum insulin, and possibly overall obesity but not serum leptin are associated with a higher risk of BPH. Further prospective and laboratory studies are needed to confirm these results and elucidate the underlying mechanisms.

Testosterone and oestradiol in relation to tobacco smoking, body mass index, energy consumption and nutrient intake among adult men

There is substantial evidence linking steroid hormones and diet to cancer aetiology. The evidence on lifestyle determinants of steroid hormones, however, is limited. We have conducted a study to identify dietary and other lifestyle predictors of testosterone and oestradiol among adult men. Subjects were 112 healthy Greek men, recruited as controls in a case-control study on the aetiology of liver cancer. Demographic data and detailed histories of smoking habits and alcohol consumption were recorded. Diet was assessed through an interviewer-administered validated food-frequency questionnaire. Serologic measurements of oestradiol, testosterone and sex hormone binding globulin were also conducted. We developed linear regression models to evaluate the associations of smoking and dietary factors with serum testosterone and oestradiol. The results indicate that, among men, both testosterone and oestradiol serum levels decline with age, whereas body mass index may be inversely related with testosterone and positively with oestradiol. The evidence concerning alcohol in relation to these hormones is inconclusive. Emerging evidence concerning smoking suggests positive associations with both hormones in the blood. The principal nutritional findings are a positive association of carbohydrate intake with testosterone levels and a set of inverse associations of vitamins with oestradiol.

Future concepts in the medical therapy of benign prostatic hyperplasia

The standard medical therapy for symptomatic benign prostatic hyperplasia is still alpha-blockers and 5alpha-reductase inhibitors. Ongoing studies demonstrate the long-term safety and efficacy of these two classes of therapeutic approaches. Although there have been no new Food and Drug Administration approved medical therapies for the treatment of benign prostatic hyperplasia over the past year, interest in and the use of phytotherapeutic agents continues to increase. In this review, we will discuss the developments that have occurred over the past year in the medical management of benign prostatic hyperplasia. In addition, we present ongoing efforts at our center to obtain a better understanding of and manipulate the apoptotic pathway as it pertains to the pathophysiology of benign prostatic hyperplasia.