The correlation between metabolic syndrome and prostatic growth in patients with benign prostatic hyperplasia

Low 25-OH vitamin D is associated with benign prostatic hyperplasia

PURPOSE

We tested the hypothesis that low vitamin D is associated with benign prostatic hyperplasia. We also studied whether body composition, sex hormones, serum sex hormone-binding globulin, albumin corrected serum calcium, adiponectin and lipid status are associated with benign prostatic hyperplasia.

MATERIALS AND METHODS

We investigated 184 representative, randomly selected men 72 to 76 years old enrolled in the Gothenburg arm of the Osteoporotic Fractures in Men Study (MrOS). Men with a history of prostate cancer, prostate operation or medication for benign prostatic hyperplasia were excluded from study, leaving 155 available for analysis. A cross-sectional study was performed in which benign prostatic hyperplasia measured by total prostate volume was related to clinical, anthropometric, endocrine and metabolic factors on univariate and multivariate analyses with regression models.

RESULTS

Median prostate volume was 40 ml. In multivariate models only 25-OH vitamin D, albumin corrected serum calcium, serum sex hormone-binding globulin and high density lipoprotein cholesterol were significantly and inversely associated with large prostate glands.

CONCLUSIONS

The current report adds 4 independent factors associated with benign prostatic hyperplasia, including low 25-OH vitamin D, serum calcium, sex hormone-binding globulin and high density lipoprotein cholesterol.

Metabolic syndrome associated with reduced lower urinary tract symptoms in middle-aged men receiving health checkup

OBJECTIVE

To investigate the impact of metabolic syndrome on lower urinary tract symptoms in a sample of middle-aged men receiving a health checkup.

METHODS

Subjects aged 45 years or older who voluntarily underwent a medical checkup were enrolled. Participant demographics and health history were collected by a self-administered questionnaire. All participants were stratified into 2 groups by the presence of metabolic syndrome, as defined according to the updated National Cholesterol Education Program's Adult Treatment Panel III. Prostate volume and prostate-specific antigen levels were used for subgroup analysis.

RESULTS

During January through December of 2010, 708 subjects with a mean age of 55.6 ± 9.72 years were enrolled into the study. Compared to the nonmetabolic syndrome group, the metabolic syndrome group had lower total international prostatic symptoms score (7.89 ± 6.63 vs 6.85 ± 6.52, P = .05) and lower severity of weak urinary stream (1.24 ± 1.60 vs 0.95 ± 1.50, P = .021). In the higher prostate volume group (prostate volume ≥ 30 mL), total international prostatic symptoms score, storage score, and urinary frequency, urgency and incomplete emptying were lower in men vs those without metabolic syndrome (all P < .05). The negative association between voiding score, severity of lower urinary tract symptoms, and metabolic syndrome became particularly pronounced as the number of metabolic syndrome factors increased (P for trend < .01).

CONCLUSION

We confirmed that metabolic syndrome had favorable effects on lower urinary tract symptoms, including voiding and storage symptoms in healthy middle-aged men. This beneficial effect was most significant in men with enlarged prostate and/or high prostate specific antigen levels.

Influence of body mass index on Benign Prostatic Hyperplasia-related complications in patients undergoing prostatectomy

Objectives

To examine the link between increased body mass index and benign prostatic hyperplasia (BPH) related complications, namely: acute urinary retention (AUR), Bladder stones and Bladder diverticula.

Material and methods

Patients: We reviewed the medical records of BPH patients who underwent prostatectomy over three years period from 2010–2012. Prostatectomy was either done in the gold standard transurethral resection of the prostate (TURP) or using green light laser selective photo-vaporization (PVP). Age, PSA, Prostate Volume (PV) as measured by ultrasonography, patients’ weight & height, BPH related complications mainly AUR, bladder stones, and bladder diverticula were all taken in account. The BMI was calculated as weight in kg divided by square height in meters. The BMI was divided in 4 categories according to WHO classification: underweight if BMI ≤18.50 kg/m2; normal weight if BMI = 18.50-24.9 kg/m2; overweight: BMI ≥25 kg/m2; and obese BMI if ≥30 kg/m2. Statistical analysis: done using the SPSS package version 16. Chi-square test was used for comparison between groups where p-value was considered significant if <0.05 and ANOVA test was used for comparison between multiple variables.

Results

197 patients were included in this study, of those 95(48%) underwent TURP and 102(52%) underwent PVP. The two groups were found to be similar in mean age and PSA, and significantly different in prostate volume and operating room (O.R.) time.

Conclusions

Although the mean weight for patients undergoing prostatectomy in this study was in the overweight range, yet only 59/197(30%) patients with increased BMI presented with AUR. In this particular cohort of patients undergoing prostatectomy there was no significant differences in the development of AUR, bladder stone and diverticulum formation between patients with increased BMI (overweight and obese) and those with normal BMI. Further studies are recommended to explore the influence of increased BMI on BPH-related complications.

The effect of metabolic syndrome upon the success of varicocelectomy

We aimed to investigate the impact of metabolic syndrome (MetS) on the varicocele treatment. 101 patients underwent spermatic vein ligation between 2007 and 2010 were retrospectively analyzed. Those patients were divided into two groups as without (n: 56, Group 1) or with MetS (n: 48, Group 2). All the patients underwent left microsurgical subinguinal spermatic vein ligation. Groups were compared by the improvement on sperm parameters and spontaneous pregnancy rates at a mean of 19 (±4) months followup. When sperm parameters were compared postoperatively, the significant improvement in total sperm count, motile sperm count percentage, and normal sperm percentage was reported. The groups were compared to each other and the improvement seemed significantly better in Group 1. There was no statistically significant improvement difference in the normal sperm percentage between groups. Spontaneous pregnancy rate after two years was 45% in Group 1 and 34% in Group 2 (P < 0.05). Patients with MetS and varicocele improved after surgery, but not as well as the similar group without MetS. This may help to show that MetS can be a factor for male infertility.

Metabolic syndrome and lower urinary tract symptoms: the role of inflammation

BACKGROUND

Epidemiological data indicate that lower urinary tract symptoms (LUTS)/BPH can be associated with metabolic syndrome (MetS). Chronic inflammation has been proposed as a candidate mechanism at the crossroad between these two clinical entities.Aim of study is to examine the correlation among pre-operatory LUTS/BPH severity, MetS features and inflammatory infiltrates in prostatectomy specimens.

METHODS

A total of 271 consecutive men treated with simple prostatectomy were retrospectively selected for this study in two tertiary referral centers for LUTS/BPH. Prostate diameters and volume were measured by transrectal ultrasound, LUTS scored by International Prostate Symptom Score (IPSS) and obstruction by uroflowmetry. The International Diabetes Federation and American Heart Association and the National Heart, Lung and Blood Institute was used to define MetS. The inflammatory infiltrate was investigated combining anatomic location, grade and extent of flogosis into the overall inflammatory score (IS); the glandular disruption (GD) was used as a further marker.

RESULTS

Eighty-six (31.7%) men were affected by MetS. Prostatic volume and anterior-posterior (AP) diameter were positively associated to the number of MetS components. Among MetS determinants, only dyslipidaemia (increased serum triglycerides and reduced serum high-density lipoprotein) was associated with an increased risk of having a prostatic volume >60 cm(3) (hazard ratio (HR) = 3.268, P < 0.001). A significant positive correlation between the presence of MetS and the IS was observed. MetS patients presented lower uroflowmetric parameters as compared with those without MetS (Maximum flow rate (Q(max)): 8.6 vs 10.1, P = 0.008 and average flow rate (Q(ave)): 4.6 vs 5.3, P = 0.033, respectively), and higher obstructive urinary symptoms score (P = 0.064). A positive correlation among both IS-GD and IPSS Score was also observed (adjusted r = 0.172, P = 0.008 and adjusted r = 0.128, P = 0.050).

CONCLUSIONS

MetS is associated with prostate volume, prostatic AP diameter and intraprostatic IS. The significantly positive association between MetS and prostatic AP diameter could support the observation that MetS patients presented lower uroflowmetric parameters. In conclusion, MetS can be regarded as a new determinant of prostate inflammation and BPH progression.

Relationships between Prostate-Specific Antigen, Prostate Volume, and Components of Metabolic Syndrome in Healthy Korean Men

Purpose

Metabolic syndrome (MS) plays a potential role in the etiology of benign prostatic hyperplasia (BPH). Recent studies have reported on an association between MS and BPH. However, there has been no consensus on recent results. This study was conducted to evaluate the associations among prostate-specific antigen (PSA), prostate volume (PV), and metabolic components in men who visited our health promotion center.

Materials and Methods

During the period from January 2005 to December 2010, 521 consecutive men (age range, 40 to 70 years) who underwent transrectal ultrasonography were enrolled in this retrospective study. The health screening program includes blood pressure, body measurements (height, weight, waist circumference, body mass index), biochemical analysis (serum glucose, total cholesterol, triglycerides, high-density and low-density lipoprotein cholesterol, fasting plasma glucose, tumor markers), stool and urine analysis, and a detailed clinical examination.

Results

The serum PSA level and PV were significantly higher in patients with MS than in patients without MS, retrospectively (p<0.001, p<0.001). Patients with more than one metabolic component were significantly more likely to have a larger PV and higher serum PSA level. The serum PSA level and PV were increased in a similar manner with the increasing sum of MS components (p<0.0001, p<0.0001).

Conclusions

The MS components were associated with larger PV and higher serum PSA level. Therefore, each MS component could be an important factor in BPH development and management.

Aromatase up-regulation, insulin and raised intracellular oestrogens in men, induce adiposity, metabolic syndrome and prostate disease, via aberrant ER-α and GPER signalling

For some years now, reduced testosterone levels have been related to obesity, insulin resistance, type 2 diabetes, heart disease, benign prostatic hypertrophy and even prostate cancer--often considered guilty more by association, than actual cause--with little attention paid to the important role of increased intracellular oestrogen, in the pathogenesis of these chronic diseases. In the final stage of the steroidogenic cascade, testosterone is metabolised to oestradiol by P450 aromatase, in the cytoplasm of adipocytes, breast cells, endothelial cells and prostate cells, to increase intracellular oestradiol concentration at the expense of testosterone. It follows therefore, that any compound that up-regulates aromatase, or any molecule that mimics oestrogen, will not only increase the activation of the mainly proliferative, classic ER-α, oestrogen receptors to induce adipogenesis and growth disorders in oestrogen-sensitive tissues, but also activate the recently identified transmembrane G protein-coupled oestrogen receptors (GPER), and deleteriously alter important intracellular signalling sequences, that promote mitogenic growth and endothelial damage. This paper simplifies how stress, xeno-oestrogens, poor dietary choices and reactive toxins up-regulate aromatase to increase intracellular oestradiol production; how oestradiol in combination with leptin and insulin cause insulin resistance and leptin resistance through aberrant serine phosphorylation; how the increased oestradiol, insulin and leptin stimulate rapid, non-genomic G protein-coupled phosphorylation cascades, to increase fat deposition and create the vasoconstrictive, dyslipidemic features of metabolic syndrome; how aberrant GPER signalling induces benign prostatic hypertrophy; and how increased intracellular oestradiol stimulates mitogenic change and tumour-cell activators, to cause prostate cancer. In essence, the up-regulation of aromatase produces increased intracellular oestradiol, increases ER-α activation and increases GPER activation, in combination with insulin, to cause aberrant downstream transduction signaling, and thus induce metabolic syndrome and mitogenic prostate growth. To understand this fact, that raised intracellular oestradiol levels in men, induce and promote obesity, gynecomastia, metabolic syndrome, type two diabetes, benign prostatic hypertrophy and prostate cancer, rather than low testosterone, represents a shift in medical thinking, a new awareness, that will reduce the rising incidence of obesity, metabolic syndrome and prostate disease, and significantly improve the health of men worldwide.

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.

Benign prostatic hyperplasia: from bench to clinic

Benign prostatic hyperplasia (BPH) is a prevalent disease, especially in old men, and often results in lower urinary tract symptoms (LUTS). This chronic disease has important care implications and financial risks to the health care system. LUTS are caused not only by mechanical prostatic obstruction but also by the dynamic component of obstruction. The exact etiology of BPH and its consequences, benign prostatic enlargement and benign prostatic obstruction, are not identified. Various theories concerning the causes of benign prostate enlargement and LUTS, such as metabolic syndrome, inflammation, growth factors, androgen receptor, epithelial-stromal interaction, and lifestyle, are discussed. Incomplete overlap of prostatic enlargement with symptoms and obstruction encourages focus on symptoms rather than prostate enlargement and the shifting from surgery to medicine as the treatment of BPH. Several alpha antagonists, including alfuzosin, doxazosin, tamsulosin, and terazosin, have shown excellent efficacy without severe adverse effects. In addition, new alpha antagonists, silodosin and naftopidil, and phosphodiesterase 5 inhibitors are emerging as BPH treatments. In surgical treatment, laser surgery such as photoselective vaporization of the prostate and holmium laser prostatectomy have been introduced to reduce complications and are used as alternatives to transurethral resection of the prostate (TURP) and open prostatectomy. The status of TURP as the gold standard treatment of BPH is still evolving. We review several preclinical and clinical studies about the etiology of BPH and treatment options.

Association of metabolic syndrome and benign prostate enlargement in young korean males

Purpose

This study was designed to evaluate the association of metabolic syndrome and benign prostate enlargement in young Korean males. We analyzed the clinical data associated with metabolic syndrome and prostate volume in the study population.

Materials and Methods

We retrospectively analyzed the clinical data obtained from 1,506 young men under the age of 60 who visited the health promotion center in our institution for routine checkups. The patients were interviewed with a questionnaire including the International Prostate Symptom Score (IPSS) and were evaluated by medical history, blood chemistry, digital rectal examination, and prostate volume via transrectal ultrasonography. The presence of metabolic syndrome was determined according to the modified National Cholesterol Education Program Expert Panel on Detection, Evalution, And Treatment of High Blood Cholesterol in Adults criteria. We divided the subjects into two groups: those with metabolic syndrome and those without. Logistic regression analysis was carried out to determine which metabolic components were associated with an increased risk of benign prostate enlargement.

Results

Significant differences in prostate volume were noted between the groups. The prostate volumes were significantly larger in the metabolic syndrome group than in the non-metabolic syndrome group in all subgroups divided by age (in decades). However, no significant differences in IPSS or voiding or storage subscore were noted. In the multivariate regression analysis, only diabetes and obesity were identified as risk factors for benign prostate enlargement among the metabolic components.

Conclusions

Metabolic syndrome and prostate volume were significantly related, even in young males. Diabetes and obesity were identified as significant risk factors for benign prostate enlargement in young males under the age of 60.

The correlation between metabolic syndrome and prostatic diseases

CONTEXT

Metabolic syndrome (MetS), a cluster of several metabolic abnormalities with a high socioeconomic cost, is considered a worldwide epidemic. Recent epidemiologic and clinical data suggest that MetS is involved in the pathogenesis and progression of prostatic diseases such as benign prostatic hyperplasia (BPH) and prostate cancer (PCa).

OBJECTIVE

This review evaluates the available evidence of the role of MetS in BPH and PCa development and progression and discusses possible clinical implications for the management, prevention, and treatment of these diseases.

EVIDENCE ACQUISITION

A National Center for Biotechnology Information (NCBI) PubMed search for relevant articles published between 1995 and September 2011 was performed by combining the following Patient population, Intervention, Comparison, Outcome (PICO) terms: male, metabolic syndrome, prostate, benign prostatic hyperplasia, prostate cancer, prevention, diagnosis, treatment, and prognosis. Additional references were obtained from the reference list of full-text manuscripts.

EVIDENCE SYNTHESIS

MetS is a complex, highly prevalent disorder and a worldwide epidemic. Central obesity, insulin resistance, dyslipidemia, and hypertension are the main components of MetS. Notwithstanding all the attempts made to correctly define MetS, a major problem related to most definitions remains the applicability to different populations and ethnic groups. Although there is growing evidence of the association of MetS with the initiation and clinical progression of BPH and PCa, molecular mechanisms and effects on treatment efficacy remain unclear. Further research is required to better understand the role of MetS in BPH and PCa.

CONCLUSIONS

Data from the peer-reviewed literature suggest an association of MetS with BPH and PCa, although the evidence for a causal relationship remains missing. MetS should be considered a new domain in basic and clinical research in patients with prostatic disorders.

Metabolic syndrome and benign prostatic hyperplasia: evidence of a potential relationship, hypothesized etiology, and prevention

Benign prostatic hyperplasia (BPH) is highly prevalent in older men and causes substantial adverse effects on health. The pathogenesis of this disease is not totally clear. Recent reports have suggested a possible relationship between metabolic syndrome (MetS) and BPH. Single components of MetS (obesity, dyslipidemia, hypertension, and insulin resistance) as well as the syndrome itself may predispose patients to a higher risk of BPH and lower urinary tract symptoms (LUTS). This may stem from changes in insulin resistance, increased autonomic activity, impaired nitrergic innervation, increased Rho kinase activity, pro-inflammatory status, and changes in sex hormones that occur in association with MetS. However, the exact underlying mechanisms that regulate the potential relationship between MetS and BPH/LUTS still need to be clarified. Increased physical activity and dietary strategies may help in decreasing the incidence of MetS and its impact on BPH/LUTS. However, differences in the definitions used to address the examined predictors and endpoints preclude the possibility of arriving at definitive conclusions.

Urological aspects of the metabolic syndrome

The metabolic syndrome is common in countries with Western lifestyles. It comprises a number of disorders-including insulin resistance, hypertension and obesity-that all act as risk factors for cardiovascular diseases. Urological diseases have also been linked to the metabolic syndrome. Most established aspects of the metabolic syndrome are linked to benign prostatic hyperplasia (BPH) and prostate cancer. Fasting plasma insulin, in particular, has been linked to BPH and incident, aggressive and lethal prostate cancer. The metabolic syndrome has also been shown to be associated with nonprostatic urological conditions such as male hypogonadism, nephrolithiasis, overactive bladder and erectile dysfunction, although data on these conditions are still sparse. Overall, the results of studies on urological aspects of the metabolic syndrome seem to indicate that BPH and prostate cancer could be regarded as two new aspects of the metabolic syndrome, and that an increased insulin level is a common underlying aberration that promotes both BPH and clinical prostate cancer. Urologists need to be aware of the effect that the metabolic syndrome has on urological disorders and should transfer this knowledge to their patients.

Influence of obesity on tumour volume in patients with prostate cancer

OBJECTIVE

• To investigate the association between body mass index and tumour volume at radical prostatectomy in a large European population.

PATIENTS AND METHODS

• Recent data support the hypothesis that the hormonal environment in overweight and obese men may alter androgen-dependent prostate growth. Body mass index (BMI) has been implicated in prostate cancer pathophysiology. • We analysed 1275 patients with prostate cancer who underwent radical prostatectomy at a single tertiary care institution. Mean tumour volume (TV) was evaluated according to BMI WHO categories (normal <25 kg/m(2) vs overweight 25-30 kg/m(2) vs obese 30-35 kg/m(2) vs severely obese >35 kg/m(2)). • Univariable linear regression analyses targeted the association between BMI and TV at radical prostatectomy. Multivariable analyses were adjusted for age, prostate-specific antigen value, biopsy Gleason sum, clinical stage and prostate volume.

RESULTS

• Mean BMI was 26.3 kg/m(2) (median 26; range 16.7-42.0). Mean TV was 5.6 mL (median 3.3; range 0.1-61.2). The mean prostate-specific antigen value was 10.3 ng/dL (median 6.6; range 0.3-327). • The mean TV was 5.0, 5.8, 6.3 and 9.2 mL in normal, overweight, obese and severely obese patients, respectively (P= 0.03). TVs in men with a normal BMI were 84% smaller than in severely obese men (5.0 vs 9.2 mL). • On univariable analysis, BMI was correlated with TV at radical prostatectomy (P < 0.001). On multivariable analysis, BMI reached the independent predictor status after adjustment for age, prostate-specific antigen value, biopsy Gleason score, clinical stage and prostate volume (P= 0.03).

CONCLUSION

• We showed that BMI is independently associated with prostate cancer volume at radical prostatectomy. The present results confirm that obesity may play a key role in prostate cancer pathophysiology.

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.

Effect of obesity on prostate-specific antigen, prostate volume, and international prostate symptom score in patients with benign prostatic hyperplasia

PURPOSE

We examined the correlation between body mass index (BMI) as a marker of obesity and prostate-specific antigen (PSA), prostate volume (PV), and International Prostate Symptom Score (IPSS) in patients with benign prostatic hyperplasia (BPH).

MATERIALS AND METHODS

From January 2008 to December 2008, we examined 258 patients diagnosed with BPH. Patients taking 5α-reductase inhibitors or those diagnosed with prostate cancer were excluded from this study. BPH was defined as PV≥25 ml and IPSS≥8. BMI (kg/m(2)) was categorized into 4 groups as follows: BMI<18.5 (underweight), BMI 18.5-23.0 (normal), BMI 23.0-27.5 (overweight), and BMI>27.5 (obese). The relationships between PSA, PV, IPSS, and BMI were analyzed by correlation analysis and one-way ANOVA.

RESULTS

The mean age of the patients was 65.19±9.13 years and their mean BMI was 23.7±4.4 kg/m(2). The mean PSA values of each BMI group were as follows: 3.42±1.53, 3.07±1.88, 2.74±1.75, and 2.60±1.44 ng/ml. The PSA value was lowest in the obese group. The correlation analysis showed a negative correlation between BMI and PSA (Pearson's correlation coefficient=-0.142, p=0.023) and positive correlations between BMI and PV (Pearson's correlation coefficient=0.32, p=0.001) and IPSS (Pearson's correlation coefficient=0.470, p=0.02). These correlations were also confirmed by one-way ANOVA.

CONCLUSIONS

Patients with an elevated BMI tended to have lower PSA values, larger PVs, and a higher IPSS. We suggest that weight loss could be helpful for BPH symptom relief as well as for detection of coexisting prostate cancer in BPH patients.

Diabetes, growth hormone-insulin-like growth factor pathways and association to benign prostatic hyperplasia

Diabetes significantly increases the risk of benign prostatic hyperplasia (BPH) and low urinary tract symptoms (LUTS). The major endocrine aberration in connection with the metabolic syndrome is hyperinsulinemia. Insulin is an independent risk factor and a promoter of BPH. Insulin resistance may change the risk of BPH through several biological pathways. Hyperinsulinemia stimulates the liver to produce more insulin-like growth factor (IGF), another mitogen and an anti-apoptotic agent which binds insulin receptor/IGF receptor and stimulates prostate growth. The levels of IGFs and IGF binding proteins (IGFBPs) in prostate tissue and in blood are associated with BPH risk, with the regulation of circulating androgen and growth hormone. Stromal-epithelial interactions play a critical role in the development and growth of the prostate gland and BPH. Previously, we have shown that the expression of c-Jun in the fibroblastic stroma can promote secretion of IGF-I, which stimulates prostate epithelial cell proliferation through activating specific target genes. Here, we will review the epidemiologic, clinical, and molecular findings which have evaluated the relation between diabetes and development of BPH.

The illusion of prostate-specific antigen decline in patients with metabolic syndrome and insulin resistance

What's known on the subject? and What does the study add? Studies have shown that PSA is negatively associated with obesity as a result of hemodilution or metabolic effect. Hemodilution could be the main reason for low PSA levels in obese men. However, the intrinsic metabolic effects such as insulin resistance (IR) or metabolic syndrome (MS) on PSA level have not been clearly evaluated although obesity is closely tied to MS and IR. We regarded MS and IR as the pathophysiological cornerstone of metabolic disorder in obesity and analyzed the relationships among MS, IR, and PSA levels, and plasma volume by using the concept of PSA mass, the total circulating PSA protein. PSA mass did not change depending on the severity of the obesity, MS or IR. Even the group with both MS and IR, which could be the most metabolically disturbed in this study, did not have different PSA mass, comparing with the group without any MS or IR. Thus, the decline in PSA level in men with MS or IR can be also explained by increased plasma volume other than any intrinsic metabolic effects.

OBJECTIVE

• To investigate the detailed mechanism of prostate-specific antigen (PSA) decline in metabolic syndrome (MS) and insulin resistance (IR), which lowers the predictive value of the PSA test, we examined the effect of haemodilution and the possibility of an intrinsic metabolic effect.

PATIENTS AND METHODS

• We analysed 28,315 men who underwent routine check-ups. We compared the age-adjusted mean PSA levels in subjects with and without MS before and after adjusting or stratifying the plasma volume. We analysed changes in PSA level, plasma volume and PSA mass according to obesity grade, number of MS components, IR severity and diagnosis of MS, IR or both using an analysis of covariance.

RESULTS

• The PSA levels were lower in the group with MS than in the group without MS (P= 0.001), but this difference disappeared after adjusting or stratifying the plasma volume (P > 0.05 for all). The PSA levels decreased, plasma volume increased, and PSA mass did not change as the number of MS components increased (P= 0.002, P < 0.001, P= 0.55, respectively) or the IR severity increased (P= 0.001, P < 0.001, P= 0.34, respectively). • Similarly, PSA levels were lower, plasma volumes were higher and PSA masses were the same in subjects with MS (P= 0.002, P < 0.001, P= 0.10, respectively), IR (P= 0.018, P < 0.001, P= 0.94, respectively), or both (P= 0.003, P < 0.001, P= 0.86, respectively) than in subjects without those conditions.

CONCLUSION

• The PSA decline in MS and IR may result simply from a haemodilution effect and be unrelated to intrinsic metabolic disturbances. For this reason, PSA levels could be underestimated in patients with MS or IR because of haemodilution.

Pioglitazone attenuates prostatic enlargement in diet-induced insulin-resistant rats by altering lipid distribution and hyperinsulinaemia

BACKGROUND AND PURPOSE

Increased incidence of benign prostatic hyperplasia among insulin-resistant individuals suggests a role for hyperinsulinaemia in prostatic enlargement. We have already reported increased cell proliferation and enlargement of prostate gland in insulin-resistant rats. The present study aimed to elucidate the molecular mechanisms underlying the reversal of prostatic enlargement in insulin-resistant rats by the peroxisome proliferator-activated receptor γ agonist pioglitazone.

EXPERIMENTAL APPROACH

Sprague-Dawley rats were fed a normal pellet or a high-fat diet for 12 weeks with or without pioglitazone (20 mg·kg(-1)). Subgroups of animals fed different diets were castrated. Effects of dietary manipulation and pioglitazone were measured on insulin sensitivity, lipid distribution, cell proliferation and apoptosis.

KEY RESULTS

A high-fat diet led to the accumulation of fat in non-adipose tissues, insulin resistance, compensatory hyperinsulinaemia and prostatic enlargement in rats. Pioglitazone treatment altered fat distribution, improved insulin sensitivity and normalized lipid and insulin level in rats on the high-fat diet. The improved metabolic parameters led to decreased cellular proliferation and increased apoptosis in the prostate gland. High-fat diet feeding and pioglitazone treatment did not change plasma testosterone levels. However, significant prostatic atrophy was observed in castrated rats irrespective of dietary intervention.

CONCLUSIONS AND IMPLICATIONS

Our results show a previously unexplored therapeutic potential of pioglitazone for prostatic enlargement under insulin-resistant condition and further suggest that targeting distribution of lipid from non-adipose tissue to adipose tissue and insulin signalling could be new strategies for the treatment of benign prostatic hyperplasia.

Relative influence of testosterone and insulin in the regulation of prostatic cell proliferation and growth

Prostatic hyperplasia is a common problem of the aged men population. Recent experimental and clinical studies provide sufficient evidence that apart from androgens, insulin also plays an important role in the pathogenesis of prostatic hyperplasia. The present study was aimed to investigate the relative influence of testosterone and insulin on the cellular proliferation and prostatic growth. Effect of testosterone on the prostate of hypoinsulinemic, and glandular injection of insulin-receptor antagonist S961 on the prostate of castrated Sprague-Dawley rat (220±10 g) was examined. Significant decrease in the weight of the ventral prostate was observed in the streptozotocin-induced hypoinsulinemic rats (~6 fold), which is restored by the intervention of testosterone. Although, glandular injection of S961 did not led to any change in the frequency of proliferating cell nuclear antigen (PCNA) positive cells in normal rats, significant decrease was observed in the castrated rats. Castration led to increase in the frequency of the caspase-3 and the TUNEL positive cells in the ventral prostate. Further, long-term (6 weeks) administration of S961 induced significant decrease in the weight of the ventral prostate. Results of the present study provide that both testosterone and insulin promote prostatic cell proliferation and change in the level of either of the hormone results in the destabilization of cellular equilibrium, and modulation of the insulin-receptor signaling in the prostate may provide an alternative strategy for the treatment of prostatic enlargement. Further, studies are required to better understand the interplay between these hormones in the regulation of prostatic growth.

Impact of metabolic syndrome on erectile dysfunction and lower urinary tract symptoms in benign prostatic hyperplasia patients

INTRODUCTION

The aim of this study was to investigate the relationship among metabolic syndrome (MetS), erectile dysfunction (ED) and lower urinary tract symptoms (LUTS) in patients with benign prostatic hyperplasia (BPH).

METHODS

Our study included 106 patients with BPH, 33 (31.1%) of whom had MetS. Blood pressures, waist circumferences, serum levels of fasting blood glucose, high density lipoprotein and triglyceride of patients were recorded. Erectile functions of the patients were evaluated by International Index of Erectile Function (IIEF). Patients were divided into two groups according to IIEF scores, namely 'mild/no ED' and 'moderate/severe ED'. IIEF scores of ED groups were between 17 and 30 and 6-16 in turn. LUTS severities were assessed by International Prostate Symptom Score (IPSS) and classified as mild (IPSS 0-7), moderate (IPSS 8-19) and severe (IPSS 20-35).

RESULTS

There was a significant difference between ED groups concerning MetS presence (p=0.032). MetS presence was not found to be associated with the severity of LUTS (p=0.144). There was no correlation between ED groups regarding LUTS severity (p=0.303).

CONCLUSION

Results of the present study showed a correlation between MetS presence and ED. In the light of our results, MetS seems to play an important role in the etiopathogenesis of ED in patients with BPH.

A higher prediagnostic insulin level is a prospective risk factor for incident prostate cancer

A higher insulin level has been linked to the risk of prostate cancer promotion. However, several reports claim that there is no association between a higher insulin level and the risk of incident prostate cancer. In the present report, the insulin hypothesis was tested once more prospectively in men with a benign prostatic disorder. Three hundred and eighty-nine consecutive patients referred with lower urinary tract symptoms without clinical prostate cancer were included during 1994-2002. Follow-up was performed in 2006. Data were obtained from the Swedish National Cancer Register and the Regional Cancer Register, Oncological Centre, Göteborg, Sweden. At this follow-up, 44 of the patients included had developed prostate cancer. Men with prostate cancer diagnosis had a higher systolic (P<0.001) and diastolic blood pressure (P<0.000), were more obese as measured by BMI (P=0.010), waist (P=0.007) and hip measurements (P=0.041) than men who did not have prostate cancer diagnosis at follow-up. These men also had a higher uric acid level (P=0.040), and a higher fasting serum insulin level (P=0.023) than men who did not have prostate cancer diagnosis at follow-up. Following exclusion of T1a/b prostate cancer cases, the difference of the fasting serum insulin level between the groups was still significant (P=0.038). Our data support the hypothesis that a higher insulin level is a promoter of prostate cancer. Moreover, our data suggest that the insulin level could be used as a marker of the risk of developing prostate cancer. The present findings also seem to confirm that prostate cancer is a component of the metabolic syndrome. Finally, our data generate the hypothesis that the metabolic syndrome conceals early prostate cancer.

Effects of obesity on prostate volume and lower urinary tract symptoms in korean men

Purpose

We investigated the effects of obesity on prostate volume (PV) and lower urinary tract symptoms (LUTS) in Korean men.

Materials and Methods

From December 2007 to 2009, a total of 10,383 ostensibly healthy Korean men aged ≥50 years visited our health promotion center for a routine check-up. Among them, 872 men who wanted a prostate evaluation were enrolled in this study. All men underwent detailed clinical evaluations with the International Prostate Symptom Score (IPSS) questionnaire. Anthropometric measurements, including height, weight, and waist and hip circumferences, were determined. A blood sample was obtained for serum prostate-specific antigen (PSA) measurement. Thereafter, a digital rectal examination and transrectal ultrasound were performed.

Results

In total, 465 men with moderate to severe LUTS (IPSS≥8 points) were included in this prospective study. The participants' mean age was 57.2 years. Multivariate analysis demonstrated that only waist circumference was a significant factor in predicting PV besides age and serum PSA. The univariate analysis showed no statistically significant relations between any of the obesity-related parameters and LUTS. The PV was also not correlated with LUTS.

Conclusions

Central obesity is the more important predictor of PV than overall obesity. There are no significant relations between obesity-related parameters and LUTS.

Serum prostate-specific antigen is better correlated to body surface area than body mass index in a population of healthy Korean men

It has been suggested that the larger vascular volume among obese men causes a dilution effect, decreasing the concentration of serum prostate-specific antigen (PSA). However, plasma volume is proportional to body surface area (BSA) rather than to body mass index (BMI). We determined whether serum PSA level is better correlated to BSA than BMI in a population of ostensibly healthy Korean men. Data from 2604 men who visited our health promotion center were evaluated. All men underwent anthropometric measurements, digital rectal examination, serum PSA determination, and transrectal ultrasound examination. The correlation between serum PSA and other parameters was statistically analyzed. The mean age was 49.9 years and the mean serum PSA level was 1.14 ng/mL. The multivariate analysis revealed that the serum PSA was positively correlated with age, prostate volume, and negatively correlated with BSA only and not with BMI. In addition, BSA, rather than BMI, was the significant factor in predicting the prostate volume. Our results suggest that men with larger BSA (rather than BMI), have larger prostate volumes, and lower serum PSA.

Etiology, epidemiology, and natural history of benign prostatic hyperplasia

Historically, benign prostatic hyperplasia (BPH) has been a major focus of urologic practice and surgery. But a simplistic causal relationship among prostatic enlargement, progressive obstruction, lower urinary tract symptoms, retention, and complications of retention has been challenged by recognition of the incomplete overlap of prostatic enlargement with symptoms and obstruction. The result has been a greater focus on symptoms than prostatic enlargement and a shift from surgery to medical treatment. Therefore, the question can be asked whether BPH per se, the glandular enlargement as it contributes to bladder dysfunction, or hyperplastic enlargement as a biomarker for generalized lower urinary tract dysfunction are concerns. This article addresses these issues.

Benign prostatic hyperplasia: does lifestyle play a role?

Benign prostatic hyperplasia (BPH) is a very common condition in older men, affecting up to 80% of men aged >or= 80 years in the United States. It typically leads to lower urinary tract symptoms, which often require medical management. The exact cause of BPH is unknown, and the only 2 established factors associated with BPH are age and the presence of androgens. Although the presence of testosterone is required for the development of BPH, testosterone is not thought to be the underlying factor causing BPH because testosterone levels decrease in older men. Recent studies have reported that BPH is associated with elevations in plasma estradiol/testosterone ratio, insulin, and insulin-like growth factor-I. Daily aerobic exercise can reduce all of these plasma factors, particularly when combined with a low-fat, high-fiber diet consisting of whole grains, fruits, and vegetables. In cell culture studies, this type of lifestyle regimen has recently been shown to reduce the growth of serum-stimulated prostate epithelial cells and the growth of androgen-dependent prostate cancer cell lines.

Review of exercise and the risk of benign prostatic hyperplasia

It has been long appreciated that a healthy lifestyle plays a critical role in cardiovascular health. It is now apparent that the same is true in the development of benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). Since 1995, 14 studies have been identified that investigate the clinical relationship between exercise and BPH/LUTS. No randomized controlled trials have been performed, but useful prospective cohort data originating from recent publications on the medical treatment of BPH and prevention of prostate cancer are available. Most of the literature supports a clinically significant, independent, and strong inverse relationship between exercise and the development of BPH/LUTS. Several mechanisms for this relationship have been proposed, including decreased sympathetic tone, avoidance of metabolic syndrome, and reduced oxidative damage to the prostate.

The impact of diabetes type 2 in the pathogenesis of benign prostatic hyperplasia: a review

Introduction. Clinical observation of larger prostate glands in men with diabetes mellitus type 2 led some investigators to hypothesize that an association between these two conditions exists. In fact, both diseases are very common in men as they age and seem to be sharing similar epidemiologic features. Several studies examining the above hypothesis were yielded. Aim. The purpose of this paper is to summarize the existing literature focusing on the coexistence of BPH and diabetes mellitus type 2 and to elucidate whether or not an association among these conditions exists. Methods. We identified studies published from 1990 onwards by searching the MEDLINE database of the National Library of Medicine. Initial search terms were benign prostatic hyperplasia, epidemiology, and risk factor, combined with diet hyperinsulinemia, and diabetes mellitus type 2. Results. Diabetes mellitus type 2 and hyperinsulinemia are quite common conditions and often coexist with BPH. There are several studies (observational, epidemiological, and experimental) examining the association between them in literature. Conclusion. Evidence suggests that an association between BPH and diabetes through a common pathogenic mechanism is possible. The specific pathway interfering in the development of both conditions is still poorly investigated; thus, the exact relationship of BPH to diabetes remains unclear.

Lower urinary tract symptoms, benign prostatic hyperplasia, and obesity

Obesity has emerged as a global public health challenge. During the past 20 years, there has been a dramatic increase in obesity in the United States. In 2007, only one state had a prevalence of obesity less than 20%. In this growing epidemic of national concern is an emerging relationship between lower urinary tract symptoms (LUTS), benign prostatic hyperplasia (BPH), and obesity. BPH is the most common neoplastic condition afflicting men and constitutes a major factor impacting the health of the American male. Associations among obesity, physical inactivity, and BPH/LUTS resulting from epidemiological studies have not been explored via clinical trial methodology. A review of the available data appears to support a strong independent relationship between obesity and BPH/LUTS. This review also indicates that gene expression within the prostate varies with prostate size and can be affected by lifestyle modifications. Future studies may lead to office detection of a patient's particular polymorphisms, which may help guide individual treatment and lifestyle modifications that are more likely to succeed.