Ethnicity and migration as determinants of human prostate size

Effects of green tea on prostate carcinogenesis in rat models and a human prostate cancer xenograft model

BACKGROUND

There is evidence to suggest that green tea soy may have protective effects against prostate cancer, but there are several epidemiologic and clinical studies that did not identify such an effect. We tested the notion of protective effects in a rat model of prostate carcinogenesis that has been predictive of the effects of selenium and vitamin E in randomized clinical trials and a human prostate cancer xenograft model in nude mice and rat prostate tumor cells transplanted in immune-competent syngeneic animals.

METHODS

Prostate cancer was induced in rats with methylnitrosourea and testosterone and tumor incidence was determined. Subcutaneous tumor growth was measured resulting from injected cells isolated from rat prostate cancers grafted in syngeneic animals and from the prostate-specific antigen (PSA)-producing human prostate cancer PC346 xenografted in nude mice. Brewed decaffeinated green tea infusion or caffeinated green tea extract and the same 300 mg/ml concentration of caffeine were provided in drinking water of the rats and nude mice.

RESULTS

Caffeinated green tea extract and caffeine provided in drinking water did not modify the induction of prostate cancer in the rat model compared with control rats. The same drinking water treatments also did not affect the growth and PSA production of PC346 human prostate cancer xenografts in nude mice and the growth of two transplantable rat prostate cancer tumor lines in Wistar Firth rats. Brewed green tea infusion as drinking water did also not affect tumor growth in these xeno- and allograft models.

CONCLUSION

These animal studies with drinking water exposure to green tea and caffeine do not support the idea that green tea is protective against prostate cancer.

Age, height, BMI and FBG predict prostate volume in ageing benign prostatic hyperplasia: Evidence from 5285 patients

AIMS

Several studies have reported a potential association between prostate volume (PV) and prostate disease. Here, we classified the risk factors for PV among benign prostatic hyperplasia (BPH) patients.

METHODS

In all, 4293 BPH patients with available clinical information were enrolled. Body mass index (BMI) was obtained as weight divided by height squared. PV was calculated as length × width × height (cm) × π/6. Mann-Whitney U tests were used to determine the differences between PV subgroups. Univariate and multiple linear regression tests were performed to uncover the connection between clinical features and PV. The differences in the age, BMI, height and fasting blood glucose (FBG) of the subgroups were evaluated by Kruskal-Wallis tests and adjusted with Bonferroni post hoc correction. A nomogram was created to directly illustrate the mutual interaction of amalgamator parameters.

RESULTS

PV did not influence the incidence of kidney stones (P = .815), whereas prostate calculi were positively associated with an enlarged prostate (>30 mL) (P < .001). Age (adjusted R = 0.363, P < .001), height (adjusted R = 0.088, P < .001), BMI (adjusted R = 0.039, P = .013) and FBG (adjusted R = -0.034, P = .027) were the independent risk/protective factors related to enlarged PV among BPH patients. The nomogram illustrated the predictive risk of an enlarged prostate (>30 mL) in men. The area under the ROC curve value was 0.659 in the training cohort and 0.677 in an internal validation cohort.

CONCLUSIONS

Age, height and BMI were positive independent risk factors of enlarged PV in BPH patients, and FBG had a protective role.

Factors affecting the efficacy and safety of phosphodiesterase 5 inhibitor and placebo in treatment for lower urinary tract symptoms: meta-analysis and meta-regression

PURPOSE

We aimed to investigate the real benefit and safety of phosphodiesterase 5 inhibitor (PDE 5I) for benign prostatic hyperplasia/lower urinary tract symptoms (BPH/LUTS) by determining the affecting factors and to overcome the previous meta-analysis studies.

METHODS

We conducted a systematic review of improvements in LUTS using International Prostate Symptom Score (IPSS), voiding subscore of IPSS (voiding IPSS), storage subscore of IPSS (storage IPSS), quality of life (QoL), maximal urinary flow rate (Qmax), and post-voided residual volume (PVR), and also investigated adverse events and relevant withdrawal rate.

RESULTS

Final included studies were 28 studies with 19,820 subjects (9800 treatment group and 10,020 control group). The overall weighted mean differences of total IPSS, voiding IPSS, storage IPSS, and QoL showed significant improvement. Single placebo group showed significant improvement in all outcomes except PVR. The weighted prevalence of overall withdrawal rate and adverse event-specific withdrawal rate was 10 and 3%, respectively. Meta-regression showed that baseline IPSS, dosage of PDE 5I, and country affect clinical improvement compared with placebo.

CONCLUSIONS

This study clarifies the efficacy of PDE 5I on treatment of BPH/LUTS as an initial treatment strategy. However, baseline IPSS, dosage of PDE 5I and country affected the clinical improvement. Moreover, adverse event-specific withdrawal rate was not as high as suspected based on the overall withdrawal rate.

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.

Challenging the Inevitability of Prostate Enlargement: Low Levels of Benign Prostatic Hyperplasia Among Tsimane Forager-Horticulturalists

BACKGROUND

Often considered an inevitable part of male aging, benign prostatic hyperplasia (BPH) is the most common non-life threatening disease to affect men in Western populations. We examine age-related change in prostate size and BPH risk and related serum biomarkers among the Tsimane Amerindians of the Bolivian Amazon who live a traditional lifestyle of hunting and small-scale horticulture. The Tsimane are a critical case study for understanding the etiology of BPH as they have low levels of obesity and metabolic syndrome, as well as lower levels of testosterone than age matched U.S. males, factors associated with BPH in previous research.

METHODS

Ultrasounds were conducted on 348 men aged 28-89 years (median age 56 years). Testosterone, prostate specific antigen, sex hormone binding globulin, and glycosylated hemoglobin were examined in relationship to prostate size and BPH.

RESULTS

Tsimane have less than half of the BPH prevalence experienced by U.S. men, and prostate volumes 62.6% smaller. While Tsimane have low levels of testosterone and subclinical levels of metabolic syndrome compared to U.S. men, Tsimane with high testosterone were more likely to experience BPH, as were those with higher glycosylated hemoglobin, suggesting targets for clinical interventions to reduce BPH.

CONCLUSIONS

These results have clinical significance for the growing number of men taking testosterone supplementation; even at low levels the additional testosterone exposure could be placing these men at higher risk of BPH. Overall, these data suggest that BPH may not have been an inevitable part of male aging throughout human evolutionary history.

Epidemiology and etiology of benign prostatic hyperplasia and bladder outlet obstruction

Benign prostatic hyperplasia (BPH) is a histological diagnosis associated with unregulated proliferation of connective tissue, smooth muscle and glandular epithelium. BPH may compress the urethra and result in anatomic bladder outlet obstruction (BOO); BOO may present as lower urinary tract symptoms (LUTS), infections, retention and other adverse events. BPH and BOO have a significant impact on the health of older men and health-care costs. As the world population ages, the incidence and prevalence of BPH and LUTS have increased rapidly. Although non-modifiable risk factors – including age, genetics and geography – play significant roles in the etiology of BPH and BOO, recent data have revealed modifiable risk factors that present new opportunities for treatment and prevention, including sex steroid hormones, the metabolic syndrome and cardiovascular disease, obesity, diabetes, diet, physical activity and inflammation. We review the natural history, definitions and key risk factors of BPH and BOO in epidemiological studies.

The effect of statins on testosterone in men and women, a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Statins are extensively used for cardiovascular disease prevention. Statins reduce mortality rates more than other lipid-modulating drugs, although evidence from randomized controlled trials also suggests that statins unexpectedly increase the risk of diabetes and improve immune function. Physiologically, statins would be expected to lower androgens because statins inhibit production of the substrate for the local synthesis of androgens and statins' pleiotropic effects are somewhat similar to the physiological effects of lowering testosterone, so we hypothesized that statins lower testosterone.

METHODS

A meta-analysis of placebo-controlled randomized trials of statins to test the a priori hypothesis that statins lower testosterone. We searched the PubMed, Medline and ISI Web of Science databases until the end of 2011, using '(Testosterone OR androgen) AND (CS-514 OR statin OR simvastatin OR atorvastatin OR fluvastatin OR lovastatin OR rosuvastatin OR pravastatin)' restricted to randomized controlled trials in English, supplemented by a bibliographic search. We included studies with durations of 2+ weeks reporting changes in testosterone. Two reviewers independently searched, selected and assessed study quality. Two statisticians independently abstracted and analyzed data, using random or fixed effects models, as appropriate, with inverse variance weighting.

RESULTS

Of the 29 studies identified 11 were eligible. In 5 homogenous trials of 501 men, mainly middle aged with hypercholesterolemia, statins lowered testosterone by -0.66 nmol/l (95% confidence interval (CI) -0.14 to -1.18). In 6 heterogeneous trials of 368 young women with polycystic ovary syndrome, statins lowered testosterone by -0.40 nmol/l (95% CI -0.05 to -0.75). Overall statins lowered testosterone by -0.44 nmol/l (95% CI -0.75 to -0.13).

CONCLUSIONS

Statins may partially operate by lowering testosterone. Whether this is a detrimental side effect or mode of action warrants investigation given the potential implications for drug development and prevention of non-communicable chronic diseases. See commentary article here http://www.biomedcentral.com/1741-7015/11/58.

Lower urinary tract symptoms in relation to region of birth in 95,393 men living in Australia: the 45 and Up Study

PURPOSE

Lower urinary tract symptoms (LUTS) are very common among older men globally, but evidence regarding the relationship between LUTS and country of origin is limited. This study aimed to investigate the relationship between the prevalence of LUTS and region of birth in a large, ethnically diverse population of older men resident in New South Wales, Australia.

METHODS

Data on LUTS, demographic and behavioural factors were collected by postal questionnaire from 2006 to 2009 and analysed for 95,393 men aged 45 and over from the 45 and Up Study, who had not had previous prostate surgery. Logistic regression was used to investigate the association between region of birth and moderate/severe LUTS, ascertained using a modified International Prostate Symptom Score, adjusting for age, income, education, alcohol consumption and smoking.

RESULTS

Overall, 18,530 (19.4 %) men had moderate or severe LUTS. Compared to Australian-born men, prevalence of moderate/severe LUTS was significantly higher in men born in the Middle East & North Africa, Southeast Asia and North America regions (adjusted odds ratios (OR) = 1.43; 95 % CI = 1.23-1.66, OR = 1.25; 1.10-1.42, OR = 1.26; 1.05-1.52, respectively), whereas men from the UK & Ireland had significantly lower prevalence (OR = 0.85; 0.80-0.90). Patterns of association were generally similar for storage- and voiding-related types of LUTS. However, participants born in Sub-Saharan Africa showed a significantly elevated prevalence of moderate/severe voiding symptoms (1.22; 1.03-1.45) but not storage symptoms, compared to Australian-born respondents.

CONCLUSION

The prevalence of LUTS and of specific subtypes of LUTS varies according to region of birth.

Relationship between serum sex hormones levels and degree of benign prostate hyperplasia in Chinese aging men

Benign prostatic hyperplasia (BPH) is one of the most common medical conditions in middle aged and older men. This study investigated the relationship between serum levels of sex hormones and measures of BPH in the aging male population of China. Prostate symptoms were assessed as part of a free health screening program for men ≥ 40 years of age. The examination included digital rectal examination, determination of serum prostate-specific antigen levels, International Prostate Symptom Score (IPSS) and transrectal ultrasonography. Serum levels of total testosterone (TT), sex hormone binding globulin (SHBG), free testosterone (FT), luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin (PRL) and estradiol (E(2)) were evaluated. The men also completed a health and demographics questionnaire and received a detailed physical examination. The final study population consisted of 949 men with a mean age of 58.9 years. Pearson correlation analysis indicated that there were significant correlations between age and levels of all sex hormones except TT, and between age and prostate volume (PV; r=0.243; P<0.01) or IPSS (r=0.263; P<0.01). Additional significant correlations were found between IPSS and serum levels of LH (r=0.112; P<0.01) and FSH (r=0.074; P<0.05), but there were no significant correlations between sex hormone levels and PV. Multivariate linear regression analysis showed significant correlations between age and body mass index (BMI) with PV (P<0.0001). In addition, there was a significant correlation between age and PV with IPSS (P<0.0001). Serum sex hormone levels did not correlate with PV or IPSS. The effects of endocrine changes on measures of BPH in aging men require further investigation in longitudinal and multicenter studies that include patients with all severities of BPH.

Clinical Implications of Residual Urine in Korean Benign Prostatic Hyperplasia (BPH) Patients: A Prognostic Factor for BPH-Related Clinical Events

Purpose

Although post-void residual urine (PVR) is frequently utilized clinically in patients with benign prostatic hyperplasia (BPH), mainly because of its procedural simplicity, its role as a clinical prognostic factor, predictive of treatment goals, is still under much dispute. We investigated the predictive value of PVR for BPH-related clinical events including surgery, acute urinary retention (AUR), and admission following urinary tract infection (UTI).

Methods

From January to June of 2006, patients over 50 years of age who were diagnosed with BPH for the first time at the outpatient clinic and were then treated for at least 3 years with medications were enrolled in this study. The variables of patients who underwent surgical intervention for BPH, had occurrences of AUR, or required admission due to UTI (Group 1, n=43) were compared with those of patients who were maintained with medications only (Group 2, n=266).

Results

Group 1 had a significantly higher PVR, more severe symptoms, and a larger prostate at the time of the initial diagnosis in both the univariate and the multivariate analysis. In the 39 patients who underwent BPH-related surgery, although there was a significant change in Qmax at the time of surgery (mean, 13.1 months), PVR and the symptom score remained unchanged compared with the initial evaluation. In the receiver-operating characteristic curve analysis, the area under the curve of Group 1 was in the order of prostate volume (0.834), PVR (0.712), and symptom score (0.621). When redivided by arbitrarily selected PVR cutoffs of 50 mL, 100 mL, and 150 mL, the relative risk of clinical BPH progression was measured as 3.93, 2.61, and 2.11.

Conclusions

These data indicate that, in the symptomatic Korean population, increased PVR at baseline is a significant indicator of BPH-related clinical events along with increased symptom score or prostate volume.

Influence of prostate weight, obesity and height on surgical outcomes of robot-assisted laparoscopic radical prostatectomy in Korean men

The purpose of this study was to determine if different body habitus, including prostate weight, body mass index (BMI) and height, are associated with surgical outcomes in patients undergoing robot-assisted laparoscopic radical prostatectomy (RLRP). Between July 2005 and June 2007, 135 patients underwent RLRP by a single surgeon. Information was collected retrospectively on prostate weight, BMI and height. Surgical outcome was assessed by total operative time, estimated blood loss (EBL) and surgical margin as parameters of technical difficulty. When statistically analyzed, prostate size was significantly related to total operative time (P = 0.001) and EBL (P = 0.033). But prostate size was not significantly related to the surgical margin. Patient BMI and height did not appear to affect surgical outcomes. Despite a shift in body frames towards the western standard, most Asians still have shorter stature, lower BMI and smaller prostates. We have found from our experience that different body habitus is not significantly related to surgical outcomes of RLRP, and therefore, it seems promising to operate successfully on Asian patients. However, it is important to obtain long-term outcomes on a larger cohort of patients in order to confirm our findings.

Metabolic factors associated with benign prostatic hyperplasia

CONTEXT

Benign prostatic hyperplasia poses a significant public health problem, but its etiology remains unclear. Obesity and associated abnormalities in glucose homeostasis may play a role in benign prostatic hyperplasia development by influencing prostate growth.

OBJECTIVE

The objective of this study was to determine whether obesity, fasting plasma glucose concentration, and diabetes are associated with radiologically determined prostate enlargement, an objective measure of benign prostatic hyperplasia.

DESIGN

This study was a cross-sectional analysis with robust variance estimates to account for multiple measures over time in the same individuals.

SETTING

This prospective cohort study was composed of community volunteers.

PATIENTS

Patients studied were 422 adult men enrolled in The Baltimore Longitudinal Study of Aging.

MAIN OUTCOME MEASUREMENTS

Total prostate volume as determined by pelvic magnetic resonance imaging was measured.

RESULTS

Among 422 participants, 91 (21.6%) had prostate enlargement (defined as total prostate volume >/= 40 cc) at first visit. Compared with men of normal weight [body mass index (BMI) < 25 kg/m(2)], the age-adjusted odds ratio (OR) for prostate enlargement for overweight men (BMI, 25-29.9 kg/m(2)) was 1.41 (95% CI, 0.84-2.37), for obese men (BMI, 30-34 kg/m(2)) was 1.27 (95% CI, 0.68-2.39), and for severely obese men (BMI >/= 35 kg/m(2)) was 3.52 (95% CI, 1.45-8.56) (P = 0.01). Men with elevated fasting glucose (>110 mg/dl) were more likely to have an enlarged prostate than men with normal fasting glucose (

CONCLUSIONS

Obesity, elevated fasting plasma glucose, and diabetes are risk factors for benign prostatic hyperplasia.

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Key Words Collapse

MESH Headings

• Adult
• Aged
• Aged, 80 and over
• Black People
• Blood Glucose/analysis
• Body Mass Index
• Cohort Studies
• Cross-Sectional Studies
• Diabetes Complications
• Ethnicity
• Humans
• Longitudinal Studies
• Male
• Middle Aged
• Obesity/complications
• Odds Ratio
• Prospective Studies
• Prostate/pathology
• Prostatic Hyperplasia/etiology
• Prostatic Hyperplasia/metabolism
• Prostatic Hyperplasia/pathology
• Testosterone/blood
• Urologic Diseases/etiology
• Waist-Hip Ratio
• White People

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Grants

• Z01 AG000015-49 Intramural NIH HHS

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Affiliation(s)

J Kellogg Parsons Division of Urology, University of California San Diego, 200 West Arbor Drive, San Diego, California 21287, USA.
H Ballentine Carter
Alan W Partin
B Gwen Windham
E Jeffrey Metter
Luigi Ferrucci
Patricia Landis
Elizabeth A Platz

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