The association between body size, prostate volume and prostate-specific antigen

Metabolic syndrome-related factors as possible targets for lower urinary tract symptoms in Korean males

INTRODUCTION

A positive association between benign prostate hyperplasia (BPH)/lower urinary tract symptoms (LUTS) and metabolic syndrome (MetS) was reported in several studies, but studies from Asia often showed conflicting results.

MATERIALS AND METHODS

Medical records were obtained from a health promotion center database between 2021 and 2022. Men without a history of treatment for LUTS were evaluated using the International Prostate Symptom Score (IPSS), Overactive Bladder Symptom Score (OABSS), transrectal ultrasonography.

RESULTS

Of 1345 individuals, 603 (44.8%) had MetS. Older age, higher IPSS values, higher prevalence rates of BPH and overactive bladder, higher triiodothyronine, and lower testosterone and sex-hormone binding globulin were observed in individuals with MetS than in individuals without MetS. The severity of LUTS significantly increased in the individuals with MetS (p = .002). In individuals with MetS, age, HbA1c, and cerebrovascular disease (CVD) were associated with IPSS. For OABSS, age, HbA1c, thyroid-stimulating hormone (TSH), coronary artery occlusive disease, and CVD were identified as predictors.

CONCLUSIONS

We confirmed the positive correlation between MetS and BPH/LUTS in Korean. Factors including TSH and atherosclerosis affected LUTS in individuals with MetS. These findings suggested a potential role of thyroid hormones and atherosclerosis in the etiology and treatment of BPH/LUTS in patients with MetS.

A combined treatment with selective androgen and estrogen receptor modulators prevents bone loss in orchiectomized rats

PURPOSE

Enobosarm (EN), a selective androgen receptor modulator and raloxifene (RAL), a selective estrogen receptor modulator, have been shown to improve bone tissue in osteoporotic males. The present study evaluated the effects of a combination therapy of EN and RAL on bone properties in orchiectomized rats compared to the respective single treatments.

METHODS

Eight-month-old male Sprague-Dawley rats were either left intact (Non-Orx) or orchiectomized (Orx). The Orx rats were divided into four groups (n = 15 each): 1) Orx, 2) EN treatment (Orx + EN), 3) RAL treatment (Orx + RAL), 4) combined treatment (Orx + EN + RAL). EN and RAL (0.4 mg and 7 mg/kg body weight/day) were applied immediately after Orx with a soy-free pelleted diet for up to 18 weeks. The lumbar spine and femora were examined by micro-CT, biomechanical, histomorphological, ashing, and gene expression analyses.

RESULTS

EN exhibited an anabolic effect on bone, improving some of its parameters in Orx rats, but did not affect biomechanical properties. RAL exhibited antiresorptive activity, maintaining the biomechanical and trabecular parameters of Orx rats at the levels of Non-Orx rats. EN + RAL exerted a stronger effect than the single treatments, improving most of the bone parameters. Liver weight increased after all treatments; the kidney, prostate, and levator ani muscle weights increased after EN and EN + RAL treatments. BW was reduced due to a decreased food intake in the Orx + RAL group and due a reduced visceral fat weight in the Orx + EN + RAL group.

CONCLUSION

The EN + RAL treatment appeared to be promising in preventing male osteoporosis, but given the observed side effects on liver, kidney, and prostate weights, it requires further investigation.

Association between obesity and frequency of high‑grade prostate cancer on biopsy in men: A single‑center retrospective study

The present study aimed to investigate the relationship between BMI and the prostate cancer (PCa) risk at biopsy in Italian men. Retrospective analyses of the clinical data of 2,372 consecutive men undergoing ultrasound-guided multicore (≥10) prostate biopsy transrectally between May 2010 and December 2018 were performed. BMIs were categorized, according to Western countries' classification of obesity, as follows: <18.5 kg/m² (underweight), 18.5-24.99 kg/m² (normal weight), 25-30 kg/m² (overweight) and >30 kg/m² (obese). The distribution of patients undergoing biopsy was compared with a model population from the official survey data. Patient characteristics and the relationships between characteristics were investigated using correlation analysis, ANOVA, Kruskal-Wallis and Dunn's tests. The present study estimated the influence on cancer incidence not only of BMI but also of other patient characteristics using multi-variable logistic modelling and compared, using the models, the expected outcomes for patients who differed only in BMI. From a sample of 2,372 men, the present study enrolled 1,079 men due to a lack of clinical data [such as prostate specific antigen (PSA) and BMI data] in the other patients undergoing prostate biopsy. Their distribution was significantly different from the model distribution with the probability of undergoing biopsy increasing with increasing BMI. The median age was 69.4 years. The median BMI was 26.4 kg/m², while the median PSA level was 7.60 ng/ml. In total, the biopsies detected PCa in 320 men (29.7%) and high-grade PCa (HGPCa) in 218 men (20.2%). Upon applying the aforementioned Western countries' criteria for BMI categories, there were 4 (0.4%) underweight, 318 (29.5%) of normal weight, 546 (50.6%) overweight, and 211 (19.6%) obese patients. ANOVA/Kruskal-Wallis tests revealed that overweight and obese men were younger than the normal-weight men, while there was no statistical difference in their PSA values. Furthermore, 29.3% of normal-weight men, 29.5% of overweight men and 29.9% of obese men were diagnosed with PCa, while 19.5% of normal-weight men, 20.1% of overweight men and 21.8% of obese men were affected by severe cancer. BMI was found to be positively correlated with PCa risk and negatively correlated with both age and PSA level. Age and PSA level were both positively correlated with PCa risk, while digital rectal examination (DRE) outcome was strongly indicative of PCa discovery if the test outcome was positive. Logistics models attributed a positive coefficient to BMI when evaluated against both PCa risk and HGPCa risk. In patients having a negative DRE outcome who differed only in BMI, logistic regression showed a 60% increased risk of PCa diagnosis in obese patients compared with in normal-weight patients. This risk difference increased when other characteristics were less indicative of PCa (younger age/lower PSA), while it decreased when patient characteristics were more indicative (older age/higher PSA, positive DRE). In conclusion, the present study demonstrated that, in men with higher BMIs, the risk of PCa is higher. The relative difference in risk between low and high BMI is most pronounced in younger patients having a lower PSA level and a negative DRE outcome.

High degree of prostate related LUTS in a prospective cross-sectional community study in Ghana (Mamprobi)

Background

Changing voiding patterns, volume and frequency, may sometimes be mistaken for anxiety, stress or increase in fluid consumption. In the aging male population, the commencement of lower urinary tract symptoms (LUTS) may be silent and perceived as “normal” and unrelated to Benign prostatic enlargement (BPE). The purpose of the study was to determine the prevalence of apparently “silent LUTS” (perceived asymptomatic LUTS) in men in a Ghanaian Community as well as its underlying risk factors.

Methods

One hundred and eleven (111) men (40–70 years) were recruited from a community in Ghana. The International Prostate Symptoms Score (IPSS) questionnaire (administered in the local language and English) and ultrasonographic imaging of the prostate volume (PV) were utlized to collect data. IPSS score >7 plus PV > 30 cm³ was definitive of lower urinary tract symptoms. Eighty-one (81) participants were classified “LUTS Negative” (LN) and 30, “LUTS Positive” (LP). Risk factors i.e., cholesterol (CHOL), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), very low-density lipoprotein (VLDL), coronary risk (CR), BMI and Blood Pressure were also determined.

Results

The prevalence of LUTS using only IPSS definition alone was 42.3%. However, IPSS in combination with Prostate Volume gave a prevalence of 27.0%. LN subjects had enlarged prostate (41.98%) and LP, 100%. Quality of life (QoL) was better in the LUTS Negative than LUTS Positive group (p < 0.001). In the univariant analysis coronary risk, triglyceride and VLDL contributed to LUTS (p = 0.023, 0.22, 0.22, respectively). In a multivariant analysis HDL-C (p = 0.027), BMI (p = 0.047) and triglyceride (p = 0.019) significantly contributed to LUTS.

Conclusions

The prevalence of LUTS (42.3%) is high. Components of Metabolic Syndrome- HDL-C, BMI, and coronary risk were associated with LUTS. This emphasizes the need for community education.

Correlation between body mass index and prostate volume in benign prostatic hyperplasia patients undergoing holmium enucleation of the prostate surgery

Background

Benign prostatic obstruction (BPO) due to benign prostatic hyperplasia (BPH) is a leading cause of morbidity in men over the age of 40. This study examined whether there was an association between body mass index (BMI) and pre-operative prostate volume and whether expression of two genes, alpha-2-macroglobulin (A2M) and transforming growth factor beta 3 (TGFB3), was correlated with BMI, pre-operative prostate volume, and age at surgery.

Methods

Medical records of patients who underwent holmium enucleation of the prostate surgery for treatment of BPO were retrospectively reviewed. Surgical specimens were obtained from formalin-fixed paraffin-embedded blocks, and expression of the targeted genes was quantified using a real time PCR approach. Linear regression analysis was performed to assess association between BMI and prostate volume adjusting for demographic characteristics and co-morbidity. Spearman’s correlation was used to examine whether gene expression was correlated with BMI, prostate volume, and age at surgery.

Results

A total of 278 patients were identified, including 62.9% European Americans (n = 175) and 27.7% Hispanic Americans (n = 77). BMI was significantly correlated with prostate volume (Spearman’s rho = 0.123, P = 0.045). In linear regression analysis, BMI was positively associated with prostate volume (β = 0.01, P = 0.004), while hyperlipidemia was negatively associated with prostate volume (β = −0.08, P = 0.02). A trend for a positive association was also observed for diabetes (β = 0.07, P = 0.099). In the race/ethnicity stratified analysis, age at surgery showed a trend for significantly positive association with prostate volume in European Americans (β = 0.005, P = 0.08), but not in Hispanic Americans. Expression of the A2M gene in the stroma was negatively correlated with age at surgery (P = 0.006). A2M expression in the gland was positively correlated with prostate volume among older men (Age ≥ 70, P = 0.01) and overweight men (BMI 25–30, P = 0.04). TGFB3 expression in the gland was positively correlated with BMI (P = 0.007) among older men.

Conclusions

This study demonstrated the positive correlation between BMI and prostate volume. Expression of TGFB3 and A2M was correlated with BMI, prostate volume, and age at surgery.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12894-020-00753-9.

The correlation between obesity and prostate volume in patients with benign prostatic hyperplasia at Charlotte Maxeke Johannesburg Academic Hospital

Background

Benign prostatic hyperplasia (BPH) is on the increase placing a substantial burden on health care systems. Recent studies have shown that men with high body mass index (BMI) and central obesity, as denoted by waist circumference (WC) have bigger prostate volumes (PV) with subsequent increase in lower urinary tract symptoms (LUTS) than men with normal BMI. The purpose of this research was to investigate the correlation between Obesity and PV in patients with BPH.

Methods

The study included 178 men aged between 50 and 75 years with BPH seen at Charlotte Maxeke Johannesburg academic hospital (CMJAH) Urology Outpatient Department between September 2018 and February 2019. Weight and height measurements were obtained to calculate BMI. Furthermore, WC was measured using a measuring tape, while a transrectal ultrasound (TRUS) was used to measure PV. Patient demographics, clinical characteristics such as hypertension, diabetes, smoking and prostate specific antigen (PSA) were also noted.

Results

Patients in the study had a mean age of 64.87 ± 6.526 years and the mean BMI was 27.31 ± 3.933 kg/m2. The mean PV of each BMI group were 52.92 ± 38.49, 61.00 ± 33.10 and 64.86 ± 37.46 cm3 for normal, overweight and obese groups, respectively, and the average PV score was 59.36 ± 36.507 cm3. The mean PSA score was 4.30 ± 3.126 with a range of 1.3–6.4, while the mean WC was 98.67 cm. There was no correlation between BMI and PV (p value = 0.195) as well as between PV and WC, hypertension, diabetes or smoking. The results revealed that the relationship between PV with PSA level as well as age was significant (p value = 0.001, p value = 0.009, respectively).

Conclusion

The results showed no correlation between BMI and PV. Diabetes and hypertension as well had no positive correlation with PV. A follow-up study may be indicated to look at the correlation between obesity, LUTS and urinary flow rates to establish whether aggressive management of obesity would have significant impact on the management of BPH.

The correlation between body mass index and prostatic-related parameters in men 40 years or older in Zhengzhou

PURPOSE

To understand the relationship between body mass index (BMI), age, prostate volume (PV), prostate-specific antigen (PSA), International Prostate Symptom Score (IPSS) and quality of life (QoL) in Zhengzhou.

MATERIALS AND METHODS

In the cross-sectional study, men living in Zhengzhou were invited to participate in this study. Men who were 40 years or older were subjected to the IPSS and related examination. A total of 1360 participants were included. Body mass index < 18.5 kg/m² was determined as underweight, 18.5-24.99 kg/m² normal, 25-29.99 kg/m² overweight, and ≥30 kg/m² obese.

RESULTS

The mean BMI was 24.92 ± 3.37 kg/m². The mean PSA was 1.06 ± 0.85 ng/mL. The mean PV was 20.10 ± 9.96 mL. The mean age was 62.72 ± 11.03 years. The mean IPSS was 5.87 ± 3.48 scores. The mean QoL was 2.33 ± 1.28 scores. PSA showed a significant tendency to decrease with increasing BMI (r = -0.061, p = 0.018, p_trend = 0.037). The same with age (r = -0.109, p < .001; p_trend = .045). But the result suggested that both IPSS and QoL were positively correlated with BMI (r = 0.120, p < .001, p_trend < .001; r = 0.083, p = .001, p_trend = .021, respectively). PV increased with increasing BMI (r = 0.110, p < .001, p_trend = 0.045 ).

CONCLUSIONS

Age, PSA decreased with increasing BMI. But larger PV, IPSS, and QoL were associated with higher BMI.

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.

The Relationship between Eicosanoid Levels and Serum Levels of Metabolic and Hormonal Parameters Depending on the Presence of Metabolic Syndrome in Patients with Benign Prostatic Hyperplasia

Background: The purpose of our investigation was to analyze the relationship between the serum levels of inflammatory mediators (HETE, HODE) and the levels of selected metabolic and hormonal parameters in patients with benign prostatic hyperplasia (BPH) with regard to concomitant metabolic syndrome (MetS). Methods: The study involved 151 men with BPH. Blood samples were taken for laboratory analysis of the serum levels of metabolic and hormonal parameters. Gas chromatography was performed using an Agilent Technologies 7890A GC System. Results: We found that waist circumference was the only parameter related to the levels of fatty acids, namely: 13(S)-HODE, 9(S)-HODE, 15(S)-HETE, 12(S)-HETE, and 5-HETE. In the patients with BPH and MetS, triglycerides correlated with 9(S)-HODE, 15(S)-HETE, 12(S)-HETE, and 5-HETE, which was not observed in the patients without MetS. Similarly, total cholesterol correlated with 9(S)-HODE, and 15(S)-HETE in the patients with BPH and MetS, but not in those without MetS. In the group of BPH patients with MetS, total testosterone positively correlated with 13(S)-HODE, and free testosterone with 9(S)-HODE. Conclusions: Based on this study, it can be concluded that lipid mediators of inflammation can influence the levels of biochemical and hormonal parameters, depending on the presence of MetS in BPH patients.

Molecular features and physiological roles of K+-Cl- cotransporter 4 (KCC4)

A K⁺-Cl^- cotransport system was documented for the first time during the mid-seventies in sheep and goat red blood cells. It was then described as a Na⁺-independent and ouabain-insensitive ion carrier that could be stimulated by cell swelling and N-ethylmaleimide (NEM), a thiol-reacting agent. Twenty years later, this system was found to be dispensed by four different isoforms in animal cells. The first one was identified in the expressed sequence tag (EST) database by Gillen et al. based on the assumption that it would be homologous to the Na⁺-dependent K⁺-Cl^- cotransport system for which the molecular identity had already been uncovered. Not long after, the three other isoforms were once again identified in the EST databank. Among those, KCC4 has generated much interest a few years ago when it was shown to sustain distal renal acidification and hearing development in mouse. As will be seen in this review, many additional roles were ascribed to this isoform, in keeping with its wide distribution in animal species. However, some of them have still not been confirmed through animal models of gene inactivation or overexpression. Along the same line, considerable knowledge has been acquired on the mechanisms by which KCC4 is regulated and the environmental cues to which it is sensitive. Yet, it is inferred to some extent from historical views and extrapolations.

The Correlation between Body Mass Index and Routine Parameters in Men Over Fifty

Purpose

This study aimed to investigate the relationships between body mass index (BMI) and prostate-specific antigen (PSA) levels, international prostate symptom score (IPSS), quality of life (QoL), and prostate volume (PV).

Materials and Methods

Height, weight, PSA levels, PV, and IPSS were analyzed in 15,435 patients who underwent a prostate examination between 2001 and 2014. Patients aged <50 years or with a PSA level ≥10 ng/mL were excluded. The relationships between BMI and PSA, IPSS, QoL, and PV were analyzed by a scatter plot, one-way analysis of variance, and the Pearson correlation coefficient.

Results

The mean age was 71.95±7.63 years, the mean BMI was 23.59±3.08 kg/m², the mean PSA level was 1.45±1.45 ng/mL, the mean IPSS was 15.53±8.31, the mean QoL score was 3.48±1.25, and the mean PV was 29.72±14.02 mL. PSA, IPSS, and QoL showed a tendency to decrease with increasing BMI, and there were statistically significant differences for each parameter (p≤0.001). PV showed a significant tendency to increase with BMI (p<0.001). In the correlation analysis, BMI showed a statistically significant correlation (p<0.001) with PSA, IPSS, and QoL, although the correlations were very weak. In contrast, BMI showed a significant correlation with PV (p<0.001), with a meaningful Pearson correlation coefficient of 0.124.

Conclusions

Higher BMI was associated with lower PSA levels and higher IPSS and QoL scores. Meanwhile, PV increased with BMI. Although obese individuals had a greater PV, obesity did not aggravate lower urinary tract symptoms.

Tall height and obesity are associated with an increased risk of aggressive prostate cancer: results from the EPIC cohort study

BACKGROUND

The relationship between body size and prostate cancer risk, and in particular risk by tumour characteristics, is not clear because most studies have not differentiated between high-grade or advanced stage tumours, but rather have assessed risk with a combined category of aggressive disease. We investigated the association of height and adiposity with incidence of and death from prostate cancer in 141,896 men in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort.

METHODS

Multivariable-adjusted Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). After an average of 13.9 years of follow-up, there were 7024 incident prostate cancers and 934 prostate cancer deaths.

RESULTS

Height was not associated with total prostate cancer risk. Subgroup analyses showed heterogeneity in the association with height by tumour grade (P heterogeneity = 0.002), with a positive association with risk for high-grade but not low-intermediate-grade disease (HR for high-grade disease tallest versus shortest fifth of height, 1.54; 95% CI, 1.18-2.03). Greater height was also associated with a higher risk for prostate cancer death (HR = 1.43, 1.14-1.80). Body mass index (BMI) was significantly inversely associated with total prostate cancer, but there was evidence of heterogeneity by tumour grade (P heterogeneity = 0.01; HR = 0.89, 0.79-0.99 for low-intermediate grade and HR = 1.32, 1.01-1.72 for high-grade prostate cancer) and stage (P heterogeneity = 0.01; HR = 0.86, 0.75-0.99 for localised stage and HR = 1.11, 0.92-1.33 for advanced stage). BMI was positively associated with prostate cancer death (HR = 1.35, 1.09-1.68). The results for waist circumference were generally similar to those for BMI, but the associations were slightly stronger for high-grade (HR = 1.43, 1.07-1.92) and fatal prostate cancer (HR = 1.55, 1.23-1.96).

CONCLUSIONS

The findings from this large prospective study show that men who are taller and who have greater adiposity have an elevated risk of high-grade prostate cancer and prostate cancer death.

Association of Obesity-Related Hemodilution of Prostate-Specific Antigen, Dihydrotestosterone, and Testosterone

BACKGROUND

Prostate-specific antigen (PSA) hemodilution is the leading theory for lower PSA values in obese men. However, testosterone and dihydrotestosterone (DHT), which are necessary for PSA production, are reduced in obese men. We assessed the relationship of body mass index (BMI) and PSA, taking into consideration the effect of testosterone and DHT.

METHODS

Among 8,122 participants in Reduction by Dutasteride of Prostate Cancer Events (REDUCE), complete data were available for 7,275. BMI was categorized as normal (<25 kg/m² ), overweight (25-29.9 kg/m² ), obese (30-34.9 kg/m² ), or moderate + severely obese (≥35 kg/m² ). Associations between BMI, testosterone, and DHT and the outcome variable of PSA were examined using linear regression.

RESULTS

There were 1,964 (27.0%) normal weight, 3,826 (52.6%) overweight, 1,200 (16.5%) obese, and 285 (3.9%) moderately + severely obese patients. With increasing BMI, there was a progressive decrease in PSA (P = 0.02), increase in prostate volume (P < 0.001), and decrease in both testosterone (P < 0.001) and DHT (P < 0.001). Using linear regression, increasing BMI was associated with decreasing serum PSA values. Furthermore, BMI remained inversely associated with PSA after individually adjusting for testosterone and DHT, as well as when adjusting for testosterone and DHT in the same model. Decreased androgen levels accounted for only 19% of the lower PSA in men with higher BMI.

CONCLUSIONS

Only a fraction of lower PSA in obese men could be attributed to testosterone and DHT levels. The remaining factors explaining lower PSA are unaccounted for, presumably secondary to hemodilution associated with increased plasma volume in obese men. Prostate 77:466-470, 2017. © 2016 Wiley Periodicals, Inc.

Does Inflammation Mediate the Obesity and BPH Relationship? An Epidemiologic Analysis of Body Composition and Inflammatory Markers in Blood, Urine, and Prostate Tissue, and the Relationship with Prostate Enlargement and Lower Urinary Tract Symptoms

BACKGROUND

BPH is a common disease associated with age and obesity. However, the biological pathways between obesity and BPH are unknown. Our objective was to investigate biomarkers of systemic and prostate tissue inflammation as potential mediators of the obesity and BPH association.

METHODS

Participants included 191 men without prostate cancer at prostate biopsy. Trained staff measured weight, height, waist and hip circumferences, and body composition by bioelectric impedance analysis. Systemic inflammation was estimated by serum IL-6, IL-1β, IL-8, and TNF-α; and by urinary prostaglandin E2 metabolite (PGE-M), F2-isoprostane (F2iP), and F2-isoprostane metabolite (F2iP-M) levels. Prostate tissue was scored for grade, aggressiveness, extent, and location of inflammatory regions, and also stained for CD3 and CD20 positive lymphocytes. Analyses investigated the association between multiple body composition scales, systemic inflammation, and prostate tissue inflammation against BPH outcomes, including prostate size at ultrasound and LUTS severity by the AUA-symptom index (AUA-SI).

RESULTS

Prostate size was significantly associated with all obesity measures. For example, prostate volume was 5.5 to 9.0 mls larger comparing men in the 25th vs. 75th percentile of % body fat, fat mass (kg) or lean mass (kg). However, prostate size was not associated with proinflammatory cytokines, PGE-M, F2iP, F2iP-M, prostate tissue inflammation scores or immune cell infiltration. In contrast, the severity of prostate tissue inflammation was significantly associated with LUTS, such that there was a 7 point difference in AUA-SI between men with mild vs. severe inflammation (p = 0.004). Additionally, men with a greater waist-hip ratio (WHR) were significantly more likely to have severe prostate tissue inflammation (p = 0.02), and a high WHR was significantly associated with moderate/severe LUTS (OR = 2.56, p = 0.03) among those participants with prostate tissue inflammation.

CONCLUSION

The WHR, an estimate of centralized obesity, was associated with the severity of inflammatory regions in prostate tissue and with LUTS severity among men with inflammation. Our results suggest centralized obesity advances prostate tissue inflammation to increase LUTS severity. Clinically targeting centralized fat deposition may reduce LUTS severity. Mechanistically, the lack of a clear relationship between systemic inflammatory or oxidative stress markers in blood or urine with prostate size or LUTS suggests pathways other than systemic inflammatory signaling may link body adiposity to BPH outcomes.

Analysis of the height dependence of site-specific cancer risk in relation to organ mass

BACKGROUND

Cancer risks at multiple cancer sites have been shown to correlate positively with height. An existing idea is that taller people have more cells and thus more prone to mutations that will lead to cancer, and the hypothesis is that cancer risk is proportional to the organ mass. In this study we quantitatively test this hypothesis.

METHODS

We perform an analysis of large-scale data on the height dependence of site-specific cancer risks. We also perform an analysis of the height dependence of measured organ masses. We then compare the cancer risk data with the expectations based on the organ mass hypothesis. Our study includes 16 cancer sites of women and 14 cancer sites of men.

RESULTS

For the relative risk (RR) per 10 cm increase in height for cancer incidence, the averaged expected value is within the 95% confidence interval (CI) of the averaged cancer risk data for 8 out of the 15 cancer sites for which the comparison can be made. Also, a large proportion of the sex difference of cancer risks for pancreas and lungs could come from the sex difference of the organ mass.

CONCLUSIONS

The hypothesis that cancer risk is proportional to the organ mass partially explains the height dependence of cancer risks. It also helps explain the sex difference of cancer risks, especially for pancreas and lungs.

Genetic Determinants of Metabolism and Benign Prostate Enlargement: Associations with Prostate Volume

Prostate enlargement leading to clinical benign prostatic hyperplasia (BPH) is associated with metabolic dysregulation and obesity. The genetic basis of this association is unclear. Our objective was to evaluate whether single nucleotide polymorphisms (SNPs) previously associated with metabolic disorders are also associated with prostate volume (PV). Participants included 876 men referred for prostate biopsy and found to be prostate cancer free. PV was measured by transrectal ultrasound. Samples were genotyped using the Illumina Cardio-MetaboChip platform. Multivariable adjusted linear regression models were used to evaluate SNPs (additive coding) in relation to natural-log transformed (log) PV. We compared SNP-PV results from biopsy-negative men to 442 men with low-grade prostate cancer with similar levels of obesity and PV. Beta-coefficients from the discovery and replication samples were then aggregated with fixed effects inverse variance weighted meta-analysis. SNP rs11736129 (near the pseudo-gene LOC100131429) was significantly associated with log-PV (beta: 0.16, p-value 1.16x10^-8) after adjusting for multiple testing. Other noteworthy SNPs that were nominally associated (p-value < 1x10^-4) with log-PV included rs9583484 (intronic SNP in COL4A2), rs10146527 (intronic SNP in NRXN3), rs9909466 (SNP near RPL32P31), and rs2241606 (synonymous SNP in SLC12A7). We found several SNPs in metabolic loci associated with PV. Further studies are needed to confirm our results and elucidate the mechanism between these genetic loci, PV, and clinical BPH.

Higher body mass index increases the risk for biopsy-mediated detection of prostate cancer in Chinese men

Objective

To investigate the relationship between body mass index (BMI) and prostate cancer (PCa) risk at biopsy in Chinese men.

Patients and Methods

We retrospectively reviewed the records of 1,807 consecutive men who underwent initial multicore (≥10) prostate biopsy under transrectal ultrasound guidance between Dec 2004 and Feb 2014. BMI was categorised based on the Asian classification of obesity as follows: <18.5 (underweight), 18.5–22.9 (normal weight), 23–24.9 (overweight), 25–29.9 (moderately obese), and ≥30 kg/m2 (severely obese). The odds ratios (OR) of each BMI category for risk of PCa and high-grade prostate cancer (HGPCa, Gleason score ≥4+3) detection were estimated in crude, age-adjusted and multivariate-adjusted models. Prevalence ratios and accuracies of PSA predicted PCa were also estimated across BMI groups.

Results

In total, PCa was detected by biopsy in 750 (45.4%) men, and HGPCa was detected in 419 (25.4%) men. Compared with men of normal weight, underweight men and obese men were older and had higher prostate specific antigen levels. The risk of overall PCa detection via biopsy presented an obvious U-shaped relationship with BMI in crude analysis. Overall, 50.0%, 37.4%, 45.6% 54.4% and 74.1% of the men in the underweight, normal weight, overweight, moderately obese and severely obese groups, respectively, were diagnosed with PCa via biopsy. In multivariate analysis, obesity was significantly correlated with a higher risk of PCa detection (OR = 1.17, 95%CI 1.10–1.25, P<0.001). However, higher BMI was not correlated with HGPCa detection (OR = 1.03, 95%CI 0.97–1.09, P = 0.29). There were no significant differences in the accuracy of using PSA to predict PCa or HGPCa detection across different BMI categories.

Conclusion

Obesity was associated with higher risk of PCa detection in the present Chinese biopsy population. No significant association was detected between obesity and HGPCa.

Association between obesity, prostate-specific antigen level and prostate-specific antigen density in men with a negative prostate biopsy

OBJECTIVE

To determine the association between body mass index (BMI), serum prostate-specific antigen (PSA) level and PSA density (PSAD) in patients with an elevated serum PSA level but a negative prostate biopsy.

METHODS

This retrospective study enrolled men with a negative prostate biopsy but a serum PSA level of 3.0-10 ng/ml. All men underwent anthropometric measurements, serum PSA determination and transrectal ultrasound examination. BMI was grouped according to the Asia-Pacific obesity criteria: nonobese (<25 kg/m(2)) versus obese (≥ 25 kg/m(2)). Partial correlation and linear regression models between PSA, PSAD and BMI were conducted after adjusting for age.

RESULTS

A total of 907 men were enrolled in this study. On multivariate analyses, PSA showed no significant correlation with age or BMI, whereas PSAD had a negative correlation with age and BMI. Similar results were obtained when patients were categorized as having low (3.0 < PSA  ≤ 6.5 ng/ml) or high PSA (6.5 < PSA ≤ 10.0 ng/ml) levels.

CONCLUSION

PSAD, but not PSA, demonstrated a significant negative correlation with BMI. This indicates that a new strategy including PSAD rather than simple PSA levels should be adopted in the study of obesity-adjusted PSA cut-offs.

Obesity is associated with larger prostate volume but not with worse urinary symptoms: analysis of a large multiethnic cohort

OBJECTIVE

To evaluate the associations between body mass index (BMI) and prostate volume (PV) and lower urinary tract symptoms in a multiethnic cohort.

METHODS

A cohort of men without prostate cancer seen at our institution was assembled, excluding those with previous transurethral resection of the prostate. Height and weight were measured to compute BMI, PV was measured by transrectal ultrasound, and the International Prostate Symptom Score (IPSS) questionnaire was administered. After stratified bivariate analyses, multiple linear regression and ordinal logistic regression models were used to assess the independent effect of BMI on PV and IPSS, respectively.

RESULTS

The cohort included 1613 patients, and mean BMI was 27.1 kg/m(2). Patients with a BMI of <25.0, 25.0-29.9, and 30.0-34.9 had a median PV of 44.0 mL, 48.0 mL, and 52.0 mL, respectively. The African ethnicity subgroup generally had larger median PVs than European and Asian subgroups and had the largest differences in median PV between normal and obese men. There were no significant differences in IPSS or usage of benign prostatic hyperplasia medications between BMI categories. In multivariable analyses, higher BMI was associated with larger PV (P <.001) but not IPSS (P = .91). On the basis of our model, given a PV of 40 mL, 50 mL, and 60 mL, each 5 kg/m(2) increase in BMI was associated with a 2.19 mL, 2.74 mL, and 3.29 mL increase in PV, respectively. Body weight (P <.001) but not height (P = .13) was associated with PV.

CONCLUSION

Higher BMI is associated with larger PV but not worse lower urinary tract symptoms (measured using IPSS). Usage rate of alpha blockers or 5 alpha reductase inhibitors was not significantly different between BMI categories.

Why are diabetics at reduced risk for prostate cancer? A review of the epidemiologic evidence

A large body of epidemiologic evidence provides strong support for the notion that type-2 diabetics are at decreased risk for prostate cancer. In this review article, we summarize the epidemiologic literature that explores the role of diabetes mellitus and related biomarkers in prostate cancer risk and detection, in order to create a better understanding of the potential mechanisms that underlie this inverse association. The bulk of the data supporting this association comes from the USA, as evidence for this association is less consistent in many other regions of the world. The relationship between diabetes and prostate cancer is suspected to be causal due to evidence of decreasing prostate cancer risk with increasing diabetes duration and lack of evidence for any confounding of this association. Hypothesized mechanisms for decreased prostate cancer risk among diabetics include (1) decreased levels of hormones and other cancer-related growth factors among diabetics, (2) the impact of diabetes on detection-related factors, such as prostate size, circulating prostate-specific antigen (PSA), and health-care seeking behaviors, (3) protective effects of diabetes medications, and (4) a protective effect of diabetes-induced vascular damage in the prostate. The evidence for screening-related factors is compelling, as diabetics appear to have reduced PSA and lower levels of health-care seeking behavior compared with nondiabetics. Furthermore, the inverse association between diabetes and prostate cancer is much less apparent in populations that do not perform biopsies based on PSA levels and in studies restricted to biopsied individuals. The inverse association appears to be stronger for low-grade disease, as compared with high-grade (Gleason >7), which is consistent with the observation that among patients receiving biopsy or prostate cancer treatment, diabetics are more likely to have high-grade disease as compared to nondiabetics, potentially resulting in worse outcomes for diabetics. Epidemiological research has reveals a great deal regarding the relationship between diabetes and prostate cancer risk, but additional research is needed to further clarify the mechanisms underlying this inverse association.

Diabetes mellitus and prostate cancer risk of different grade or stage: a systematic review and meta-analysis

AIM

Prior studies have reported that diabetes mellitus might reduce the overall prostate cancer risk. We examined this association by conducting a detailed meta-analysis of the studies published in peer-reviewed literature on the association between diabetes mellitus and prostate cancer risk of different stage or grade.

METHODS

A comprehensive search for articles of MEDLINE and EMBASE databases and bibliographies of retrieved articles published up to October 23, 2012 was performed. Methodological quality assessment of the trials was based on the Newcastle-Ottawa Scale. Meta-analysis was performed using STATA 12.0.

RESULTS

We included 9 studies in the meta-analysis (5 studies examining the relation of different stage only, 2 studies for grade only, and 2 studies for both grade and stage), and found an inverse association between diabetes mellitus and prostate cancer of different stage or grade. The relative risk (RRs) was moderately stronger for low grade (RR 0.74, 95% confidence interval (CI), 0.64-0.86) and localized disease (RR 0.72, 95% CI 0.67-0.76) compared with high grade (RR 0.78, 95% CI 0.67-0.90) and advanced disease (RR 0.85, 95% CI 0.75-0.97).

CONCLUSION

This study suggests an inverse relationship between diabetes mellitus and prostate cancer of different stage or grade. Possible biases underlying this association are discussed.

Association between percent-free prostate-specific antigen and glomerular filtration rate in transrectal ultrasound-guided biopsy-proven patients with prostate-specific antigen levels ranging from 4 to 10 ng/ml

PURPOSE

The aim of this study was to investigate the relationship between percent-free prostate-specific antigen (PSA) and estimated glomerular filtration rate (GFR) in men whose PSA level was 4-10 ng/ml with biopsy-proven prostate status.

METHODS

Between 2004 and 2010, the medical records of 495 cases (404 cases without prostate cancer and 91 cases with prostate cancer) who underwent prostate biopsy were reviewed and their GFR was calculated using the Cockcroft-Gault equation, adjusted for body surface area. Correlation and multivariate regression analyses were conducted among percent-free PSA, body mass index, prostate size, and GFR in patients with and without prostate cancer, respectively.

RESULTS

The mean patient age was 64.6 years, and the median PSA and free PSA were 5.64 and 0.87 ng/ml. The mean GFR was 61.02 mL/min/1.73 m2, and mean percent-free PSA was 18.9%. Correlation analysis showed that percent-free PSA was correlated with GFR, age, and prostate size in the non-cancer cohort and correlated with only prostate size in the cancer cohort. Multivariate regression analysis showed that percent-free PSA was influenced by GFR (p < 0.001) and prostate size (p < 0.001) independently in the non-cancer cohort, while only by prostate size (p = 0.008) in the cancer cohort.

CONCLUSIONS

Percent-free PSA has a negative relationship with GFR in the benign prostate group, while it does not in the prostate cancer group. Screening with current cutoff value of percent-free PSA can be applied to the patients with impaired renal function.

Association between biomarkers of obesity and risk of high-grade prostatic intraepithelial neoplasia and prostate cancer--evidence of effect modification by prostate size

Prostate enlargement is common with aging and obesity. We investigated the association between obesity and prostate cancer controlling for differential detection related to prostate enlargement. In an analysis of 500 men, we found body mass index, waist-hip ratio, and blood leptin levels were significantly associated with high-grade PC, but only among men without prostate enlargement. Leptin was also significantly associated with high-grade prostatic intraepithelial neoplasia (HGPIN) in the absence of prostate enlargement. Our results suggest obesity advances prostate carcinogenesis, and that detection biases at prostate biopsy may explain past inconsistencies in the association between obesity and PC.

The impact of obesity on the predictive accuracy of PSA in men undergoing prostate biopsy

PURPOSE

Obese men have been reported to have lower serum PSA values relative to normal-weight men in population-based studies, screening cohorts, and in men with prostate cancer (CaP) treated with surgery. There are concerns that PSA may be less accurate in detecting prostate cancer in men with increased body mass index (BMI). We determine whether the diagnostic potential of PSA is negatively influenced by obesity by comparing its operating characteristics across BMI categories among men undergoing prostate biopsy.

METHODS

Demographic, clinical, and histopathological data on 917 men who underwent trans-rectal ultrasound-guided prostate needle biopsy from 2002 to 2010 at a University hospital in Italy were used in the study. Men were categorized for BMI as follows: <25 kg/m(2) (normal weight), 25-29.9 kg/m(2) (overweight), and ≥ 30 kg/m(2) (obese). Receiver operator characteristics (ROC) curves were used to assess PSA accuracy for predicting prostate cancer overall and then stratified according to digital rectal examination (DRE) findings using the area under the ROC curve (AUC).

RESULTS

The obesity rate of the study cohort was 21 %. There was no statistically significant difference in the overall AUCs of PSA for predicting CaP among normal-weight (AUC = 0.56), overweight (AUC = 0.60), and obese men (AUC = 0.60; p = 0.68) in either DRE-positive or negative men.

CONCLUSIONS

In a cohort of Italian men undergoing prostate biopsy, the performance accuracy of PSA as a predictor of CaP is not significantly altered by BMI. Obesity does not negatively impact the overall ability of PSA to discriminate between CaP and benign conditions.

Association between physical activity, lower urinary tract symptoms (LUTS) and prostate volume

OBJECTIVES

To determine the association between lower urinary tract symptoms (LUTS) severity and physical activity (PA) across workplace, home, and leisure domains. To determine the mediating role of prostate enlargement on LUTS severity and PA.

PATIENTS AND METHODS

The study included 405 men without prostate cancer or prostatic intraepithelial neoplasia. LUTS severity was ascertained using the American Urological Association Symptom Index and prostate size by ultrasonography. PA was assessed using validated questionnaires, with conversion to metabolic equivalent of task (MET)-h/week to estimate leisure-time PA energy expenditure. Analysis used multivariable linear regression, controlling for body mass index (BMI), age, race, and treatment for benign prostatic hyperplasia, cardiovascular disease and diabetes.

RESULTS

Higher leisure-time PA energy expenditure and light housework activities were significantly associated with lower LUTS severity. Prostate volume was not significantly associated with PA in adjusted analyses, and controlling for prostate volume did not affect the association between LUTS severity and PA. Stratification by BMI showed a moderate interaction (P = 0.052), suggesting that PA was more strongly associated with LUTS severity among obese men.

CONCLUSIONS

In this cross-sectional analysis, leisure-time and home-time PA was inversely associated with LUTS severity. The association between PA and LUTS severity was stronger for irritative symptoms and among obese men, and was not mediated through changes in prostate size. Our results indicate the need for further detailed investigation of PA and LUTS.

Obesity, body composition, and prostate cancer

Background

Established risk factors for prostate cancer have not translated to effective prevention or adjuvant care strategies. Several epidemiologic studies suggest greater body adiposity may be a modifiable risk factor for high-grade (Gleason 7, Gleason 8-10) prostate cancer and prostate cancer mortality. However, BMI only approximates body adiposity, and may be confounded by centralized fat deposition or lean body mass in older men. Our objective was to use bioelectric impedance analysis (BIA) to measure body composition and determine the association between prostate cancer and total body fat mass (FM) fat-free mass (FFM), and percent body fat (%BF), and which body composition measure mediated the association between BMI or waist circumference (WC) with prostate cancer.

Methods

The study used a multi-centered recruitment protocol targeting men scheduled for prostate biopsy. Men without prostate cancer at biopsy served as controls (n = 1057). Prostate cancer cases were classified as having Gleason 6 (n = 402), Gleason 7 (n = 272), or Gleason 8-10 (n = 135) cancer. BIA and body size measures were ascertained by trained staff prior to diagnosis, and clinical and comorbidity status were determined by chart review. Analyses utilized multivariable linear and logistic regression.

Results

Body size and composition measures were not significantly associated with low-grade (Gleason 6) prostate cancer. In contrast, BMI, WC, FM, and FFM were associated with an increased risk of Gleason 7 and Gleason 8-10 prostate cancer. Furthermore, BMI and WC were no longer associated with Gleason 8-10 (OR_BMI = 1.039 (1.000, 1.081), OR_WC = 1.016 (0.999, 1.033), continuous scales) with control for total body FFM (OR_BMI = 0.998 (0.946, 1.052), OR_WC = 0.995 (0.974, 1.017)). Furthermore, increasing FFM remained significantly associated with Gleason 7 (OR_FFM = 1.030 (1.008, 1.052)) and Gleason 8-10 (OR_FFM = 1.044 (1.014, 1.074)) after controlling for FM.

Conclusions

Our results suggest that associations between BMI and WC with high-grade prostate cancer are mediated through the measurement of total body FFM. It is unlikely that FFM causes prostate cancer, but instead provides a marker of testosterone or IGF1 activities involved with retaining lean mass as men age.

Impact of diabetes mellitus on the detection of prostate cancer via contemporary multi (≥ 12)-core prostate biopsy

BACKGROUND

Currently, controversy continues regarding the association between diabetes mellitus (DM) and prostate cancer (PCa). We investigated the impact of DM in PCa detection among men who underwent contemporary multi-core prostate biopsy.

METHODS

In this retrospective study, we reviewed records of 3,925 men who underwent multi (≥ 12)-core prostate biopsy at our institution. Biopsy outcomes were analyzed with respect to various variables, including DM, patient age, body mass index (BMI), prostate-specific antigen (PSA), digital rectal exam (DRE) finding, ultrasound finding, and prostate volume.

RESULTS

Among 3,925 subjects, 607 (15.5%) reported having DM at biopsy. Overall PCa was detected from biopsy in 1,387 (35.3%) patients, and high grade (biopsy Gleason score ≥ 7) PCa in 781 (19.9%). In multivariate analysis incorporating variables of patient age, BMI, PSA, DRE finding, ultrasound finding, and prostate volume, DM was observed to be significantly associated with higher odds of overall PCa detection via contemporary prostate biopsy (OR = 1.46, P = 0.019). When analyzed by tumor grade, DM was significantly associated with higher rate of high grade PCa detection from biopsy in multivariate analysis (OR = 1.54, P = 0.036) whereas DM and detection of low grade (biopsy Gleason score ≤ 6) PCa demonstrated no significant association (OR = 1.11, P = 0.558).

CONCLUSIONS

Our results showed DM was independently associated with the detection of high grade PCa via contemporary multi-core prostate biopsy. Further investigations would be needed to elucidate exact biologic basis of relationship between the two diseases.

Abdominal obesity as risk factor for prostate cancer diagnosis and high grade disease: a prospective multicenter Italian cohort study

OBJECTIVE

To evaluate the association between abdominal obesity and prostate cancer (CaP) diagnosis and grade in patients undergoing prostate biopsy.

MATERIALS AND METHODS

Between 2008 and 2011, we prospectively enrolled patients referred to 3 clinics in Italy who were scheduled for transrectal ultrasound (TRUS) guided prostate biopsy. Before biopsy, digital rectal examination (DRE), prostate specific antigen (PSA), body mass index (BMI), and waist circumference (WC) were measured. Men were categorized in 4 groups of body habitus, according to BMI and waist circumference values. Crude and adjusted logistic regressions were performed to assess the association of BMI (continuous), waist circumference (continuous), body habitus (categorical), and CaP diagnosis and grade.

RESULTS

Six hundred sixty-eight patients were enrolled. CaP was detected in 246 patients (38%), of whom 136 had low-grade (Gleason score ≤ 6) and 110 high-grade cancer (Gleason score ≥ 7). Logistic regression multivariate analysis showed that BMI (OR 1.05 per unit, CI 95% 1.00-1.10 P = 0.033) and waist circumference (OR 1.02 per cm, CI 95% 1.00-1.04 P = 0.026) were significant predictors of CaP diagnosis. BMI (OR 1.11 95% CI 1.04-1.18 P = 0.001) and WC (OR 1.04 95% CI 1.02-1.06 P = 0.001) were also associated with high-grade CaP. Furthermore, obesity with central adiposity (BMI ≥ 30 kg/m(2) and WC ≥ 102 cm) was significantly associated with CaP diagnosis (OR 1.66, CI 95% 1.05-2.63, P = 0.03) and high-grade disease (OR 2.56, CI 95% 1.38-4.76, P = 0.003).

CONCLUSIONS

Obesity defined by BMI and WC seems to be associated with CaP and, more specifically, with high-grade disease at the time of biopsy. The relationship between obesity and CaP is complex and remains to be further addressed.

PPARγ: a molecular link between systemic metabolic disease and benign prostate hyperplasia

The emergent epidemic of metabolic syndrome and its complex list of sequelae mandate a more thorough understanding of benign prostatic hyperplasia and lower urinary tract symptoms (BPH/LUTS) in the context of systemic metabolic disease. Here we discuss the nature and origins of BPH, examine its role as a component of LUTS and review retrospective clinical studies that have drawn associations between BPH/LUTS and type II diabetes, inflammation and dyslipidemia. PPARγ signaling, which sits at the nexus of systemic metabolic disease and BPH/LUTS through its regulation of inflammation and insulin resistance, is proposed as a candidate for molecular manipulation in regard to BPH/LUTS. Finally, we introduce new cell and animal models that are being used to study the consequences of obesity, diabetes and inflammation on benign prostatic growth.

The associations between statin use and prostate cancer screening, prostate size, high-grade prostatic intraepithelial neoplasia (PIN), and prostate cancer

OBJECTIVE

Prior studies report statins may reduce the risk of advanced prostate cancer. This study investigates the association between statin use and the likelihood of having a PSA or DRE test, blood PSA levels, prostate volume, and the severity of lower urinary tract symptoms. We also describe the association between statin use and prostate cancer and high-grade prostatic intraepithelial neoplasia (PIN) before and after controlling for prostate cancer screening indices associated with statin use.

METHODS

The Nashville Men's Health Study used a multicenter, rapid recruitment protocol to collect clinical, biologic, behavioral, and body measurement data from 2,148 men 40 years or older scheduled for diagnostic prostate biopsy. Medication use and other data were ascertained by research survey, clinical interview, and chart review.

RESULTS

Approximately 37% of participants were taking a statin. Statin use was significantly associated with a 12% lower PSA levels and 8% smaller prostate volume after controlling for age, race, BMI, WHR, aspirin use, and other comorbidity. Simvastatin was more strongly associated with prostate volume, while atorvastatin was associated with PSA. Statin use was marginally associated with increasing PSA test frequency among men with undiagnosed cancer. Statin use was not associated with the frequency or results of digital rectal exams, lower urinary tract symptom severity, high-grade (Gleason > 6) prostate cancer (OR = 0.95 (0.73, 1.24)), low-grade (Gleason = 6) prostate cancer (OR = 1.11 (0.86, 1.42)) or PIN (OR = 0.82, (0.57, 1.17)). Additional control for the number of prior PSA tests, PSA levels, and prostate volume did not alter these results.

CONCLUSION

These results suggest selective referral for biopsy associated with statin use is an essential element to address in further understanding the potential for statins to prevent prostate cancer.

The effects of body mass index on changes in prostate-specific antigen levels and prostate volume over 15 years of follow-up: implications for prostate cancer detection

OBJECTIVE

To investigate the association of body mass index (BMI) and BMI change with change in prostate-specific antigen (PSA) level and to assess the possible roles of PSA hemodilution and prostate volume in explaining the obesity and PSA association.

METHODS

In 1990, a randomly selected cohort of Caucasian men, aged 40 to 79 years, from Olmsted County, Minnesota, completed questionnaires ascertaining demographic characteristics, current medical conditions, and medications biennially, with a subset undergoing blood draws and clinical examinations. Linear mixed models were used to predict annual changes and intercepts of individual changes in BMI, PSA, prostate volume, plasma volume, and PSA mass, adjusting for age in 545 men with at least 2 serial PSA, BMI, and prostate volume measurements.

RESULTS

Baseline BMI was inversely associated with the annual percent change in PSA, adjusting for age, baseline PSA, and prostate volume and for the rates of change in BMI and prostate volume (β=-0.003, 95% CI: -0.006 to -0.0003). Baseline obesity was positively associated with mean baseline levels and the rate of change in prostate volume (P=0.002) and plasma volume (both P<0.001) but was not associated with either the mean baseline values or the rate of change in PSA mass.

CONCLUSIONS

Baseline obesity was associated with baseline PSA and prostate volume and with the rate of change in PSA over 15 years of follow-up.

IMPACT

The inverse association of obesity with prostate cancer diagnosis may be at least partly due to detection bias, which is due to larger prostate volumes and PSA hemodilution in obese men.

Body mass index and serum lipid profile influence serum prostate-specific antigen in Chinese men younger than 50 years of age

This study is to assess the potential factors that could affect the serum prostate-specific antigen (PSA) level in healthy younger men. We evaluated the associations of age, body mass index (BMI) and serum lipid profile with serum PSA level in 6774 Chinese men (aged 20-49 years) who received a routine health examination. Eligible men were classified into 10-year age groups. BMI was categorized as underweight (<18.5), normal (18.5-22.9), overweight (23.0-24.9), obese (25.0-29.9) and very obese (>30) according to the redefined World Health Organization (WHO) criteria for the Asia-Pacific region. PSA levels were compared among groups as well. In multiple linear regression analysis, PSA was positively correlated with age (P<0.0001). Negative correlations existed between PSA and BMI (P<0.0001) and triglyceride level (P=0.01). No relationship could be found between PSA and serum cholesterol (P=0.711) or high-density lipoprotein (HDL; P =0.665). In addition, we found that serum PSA levels increased with age and decreased with BMI. Our study demonstrates that age, BMI and triglyceride levels influence the PSA level in men <50 years of age.

Relationship between changes in haemoglobin A1C and prostate-specific antigen in healthy men

BACKGROUND

Although many studies have shown an inverse relationship between diabetes and prostate cancer, it still remains unclear why diabetes may reduce the risk of prostate cancer. An inverse association between haemoglobin A(1C) (HbA(1C)) and prostate-specific antigen (PSA) also has been reported in previous studies that assessed the association cross-sectionally. To fully understand the relationship between diabetes and prostate cancer, it is essential to examine the association in a longitudinal design. The effect of plasma volume should also be considered in examining the PSA level. The aim of this study was to determine whether changes in HbA(1C) were associated with PSA levels, independent of plasma volume changes, as indicated by haematocrit and weight.

METHODS

We investigated 5917 Japanese men aged 50 and over who visited St. Luke's International Hospital, Tokyo for routine health check-ups in 2006 and 2007. We performed a multiple linear regression analysis to examine any association between changes in HbA(1C) and PSA over 1 year.

RESULTS

Adjusting for age, body mass index at baseline and changes in weight and haematocrit, the increases in HbA(1C) and PSA were concordant (5.7% increase per 1-unit HbA(1C) change; 95% confidence interval, 2.8-8.5%; p<0.001).

CONCLUSIONS

In contrast to previous cross-sectional observations showing an inverse association between HbA(1C) and PSA, longitudinal observations suggest a positive association between the two. Further studies are needed to investigate the association between diabetes and prostate cancer.

PSA and body composition by dual X-ray absorptiometry (DXA) in NHANES

BACKGROUND

Obese men are at higher risk for advanced prostate cancer and have a poorer prognosis following treatment. Several studies also report that obese men have lower blood PSA levels, suggesting that obesity may be interfering with the ability to detect early-stage prostate cancer.

METHODS

Dual X-ray absorptiometry (DXA) is considered a gold-standard measurement of body composition. We investigated the association between PSA levels and body composition measured by DXA among 1,360 men participating in NHANES (2001-2004), a representative sample of the U.S. male population.

RESULTS

After controlling for age, race, and other factors, PSA concentration was approximately 15% lower for men with the highest level of total mass, lean mass, fat mass, trunk lean mass, and trunk fat mass (all P for trend <0.05). We then multiplied PSA concentration by estimated plasma volume to calculate the amount of PSA in circulation (i.e., PSA mass). Total body fat mass and fat mass located in the body trunk were not significantly associated with PSA mass, however, PSA mass was approximately 10-15% higher across low versus high categories of total body lean mass and bone mineral content (all P-trend <0.05).

CONCLUSION

Our results using DXA to measure body composition confirm that a greater body mass, not just fat mass, is associated with a lower PSA concentration. This is consistent with PSA hemodilution within men with a higher body mass index. The separate associations between measured lean and fat mass on calculated PSA mass require further investigation.

Effect of population trends in body mass index on prostate cancer incidence and mortality in the United States

Concurrent with increasing prostate cancer incidence and declining prostate cancer mortality in the United States, the prevalence of obesity has been increasing steadily. Several studies have reported that obesity is associated with increased risk of high-grade prostate cancer and prostate cancer mortality, and it is thus likely that the increase in obesity has increased the burden of prostate cancer. In this study, we assess the potential effect of increasing obesity on prostate cancer incidence and mortality. We first estimate obesity-associated relative risks of low- and high-grade prostate cancer using data from the Prostate Cancer Prevention Trial. Then, using obesity prevalence data from the National Health and Nutrition Examination Survey and prostate cancer incidence data from the Surveillance, Epidemiology, and End Results program, we convert annual grade-specific prostate cancer incidence rates into incidence rates conditional on weight category. Next, we combine the conditional incidence rates with the 1980 prevalence rates for each weight category to project annual grade-specific incidence under 1980 obesity levels. We use a simulation model based on observed survival and mortality data to translate the effects of obesity trends on prostate cancer incidence into effects on disease-specific mortality. The predicted increase in obesity prevalence since 1980 increased high-grade prostate cancer incidence by 15.5% and prostate cancer mortality by between 7.0% (under identical survival for obese and nonobese cases) and 23.0% (under different survival for obese and nonobese cases) in 2002. We conclude that increasing obesity prevalence since 1980 has partially obscured declines in prostate cancer mortality.

Height and prostate cancer risk: a large nested case-control study (ProtecT) and meta-analysis

BACKGROUND

Height, a marker of childhood environmental exposures, is positively associated with prostate cancer risk, perhaps through the insulin-like growth factor system. We investigated the relationship of prostate cancer with height and its components (leg and trunk length) in a nested case-control study and with height in a dose-response meta-analysis.

METHODS

We nested a case-control study within a population-based randomized controlled trial evaluating treatments for localized prostate cancer in British men ages 50 to 69 years, including 1,357 cases detected through prostate-specific antigen testing and 7,990 controls (matched on age, general practice, assessment date). Nine bibliographic databases were searched systematically for studies on the height-prostate cancer association that were pooled in a meta-analysis.

RESULTS

Based on the nested case-control, the odds ratio (OR) of prostate-specific antigen-detected prostate cancer per 10 cm increase in height was 1.06 [95% confidence interval (95% CI): 0.97-1.16; p(trend) = 0.2]. There was stronger evidence of an association of height with high-grade prostate cancer (OR: 1.23; 95% CI: 1.06-1.43), mainly due to the leg component, but not with low-grade disease (OR: 0.99; 95% CI: 0.90-1.10). In general, associations with leg or trunk length were similar. A meta-analysis of 58 studies found evidence that height is positively associated with prostate cancer (random-effects OR per 10 cm: 1.06; 95% CI: 1.03-1.09), with a stronger effect for prospective studies of more advanced/aggressive cancers (random-effects OR: 1.12; 95% CI: 1.05-1.19).

CONCLUSION

These data indicate a limited role for childhood environmental exposures-as indexed by adult height-on prostate cancer incidence, while suggesting a greater role for progression, through mechanisms requiring further investigation.

Diabetes mellitus and prostate cancer risk in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial

Objective

A history of diabetes has been fairly consistently related to a reduced prostate cancer risk, but previous investigations have not always addressed whether the relation with diabetes varies by prostate cancer aggressiveness or the association between diabetes and prostate cancer is modified by physical activity level and body mass, variables closely related to glucose metabolism.

Methods

We prospectively examined the diabetes–prostate cancer risk relationship among 33,088 men in the screening arm of the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial.

Results

During 8.9 years follow-up, we ascertained 2,058 incident prostate cancer cases. Diabetes history was related to decreased risk of total prostate cancer (RR = 0.80, 95% CI = 0.68–0.95). The apparent protection afforded by diabetes was primarily due to the inverse relation with non-aggressive disease (i.e., the combination of low grade (Gleason sum <8) and low stage (clinical stages I or II); RR = 0.75; 95% CI = 0.62–0.91). In contrast, no association was noted between diabetes and aggressive disease (i.e., high grade or high stage (Gleason sum ≥8 or clinical stages III or IV); RR = 1.04, 95% CI = 0.74–1.45). In further analyses, the association between diabetes and aggressive prostate cancer was suggestively positive for men who were lean (RR = 1.64, 95% CI = 0.87–3.07; BMI < 25 kg/m²) and it was positive for men who were the most physically active (RR = 1.63; 95% CI = 1.07–2.62; 3+ hours vigorous activity/week). By comparison, no relations of diabetes to aggressive prostate cancer were noted for their heavier or physically less active counterparts (p-value for tests of interaction = 0.10 and 0.03 BMI and physical activity, respectively).

Conclusion

In this study, diabetes showed divergent relations with prostate cancer by tumor aggressiveness. Specifically, diabetes was inversely associated with early stage prostate cancer but it showed no relation with aggressive prostate cancer. Exploratory analyses suggested a positive association between diabetes and aggressive prostate cancer in the subgroup of men with a low BMI.

Body composition and serum prostate-specific antigen: review and findings from Flint Men's Health Study

Recent studies have suggested that obesity is associated with lower serum prostate-specific antigen levels, perhaps influencing the recommendation for prostate biopsy and potentially explaining part of the observed poorer prognosis among obese men. African-American men have the greatest rates of prostate cancer and are more likely to die of the disease, making early detection a priority in this group. We present findings from the Flint Men's Health Study, a study of African-American men, that are consistent with most studies suggesting that overweight men have prostate-specific antigen levels that are 0.15 to 0.30 ng/mL lower than those who are not overweight. We have coupled our results with a systematic review of publications in this area.