Serum prostate-specific antigen levels in men with type 2 diabetes

Poor Glycemic Control Affecting Screening of Prostate Carcinoma

Introduction Diabetes and cancer are commonly linked together. The possible links include insulin resistance, hyperinsulinemia, hyperglycemia, oxidative stress, and chronic inflammation. These are factors that have potential promoting effects on the progression of cancer in many ways. Measurement of prostate-specific antigen (PSA) is widely applied for early detection of prostate cancer. However, several factors influence serum PSA levels in men including age, benign prostatic hyperplasia, prostatitis, and body mass index (BMI). The risk of several malignancies is increased in diabetes but the risk of prostate carcinoma in diabetic patients is reduced secondary to lowering of testosterone levels during the state of hyperinsulinemia. A negative association between serum PSA levels and metformin use is also an explanation of low cancer prostate incidence with diabetes. Objective The study aims to evaluate the PSA levels in diabetic patients with poor glycemic control i.e., glycated hemoglobin (HbA1c) ≥ 7%) vs good glycemic control (HbA1c < 7%). Materials and methods Samples of PSA in diabetic patients collected in the Department of Biochemistry at Indira Gandhi Institute of Medical Sciences (IGIMS), Patna, were included. The observational study was carried out on clinically diagnosed 318 cases of diabetes attending both the outpatient and inpatient Department, IGIMS, Patna. Six ml venous blood samples were collected from patients after obtaining informed consent and ethical clearance. Patient details regarding age, complete clinical details, and general physical examinations were recorded. Serum levels of PSA, fasting plasma glucose (FPG) and HbA1c were analyzed and values were compared. The serum level of PSA was estimated by the chemiluminescent immunoassay (CLIA) method on an automated immunoassay analyzer in the Department of Biochemistry, maintaining all the quality control precautions using a control, calibrator, and reagent kit. HbA1c estimation was by chromatography technique. Fasting plasma glucose was estimated using the hexokinase method on an automated chemistry analyzer. Statistical analyses were performed using SPSS software, version 16.0 (SPSS Inc., Chicago). The median and interquartile range were calculated for numerical variables. Covariance analysis was used in the comparisons among groups. The Mann-Whitney U test was applied to detect the comparison between the two groups. Significance was determined by the P value. P value<0.05 was considered significant. Result Serum PSA value was found to be higher in (the good glycemic control group) with a median of 0.99 with an interquartile range of 3.14, than in (the bad glycemic control group) with a median of 0.49 with an interquartile range of 3.9, and the difference is statistically significant. The difference is also statistically significant in the subgroup (i) with PSA value <4 ng/ml. In subgroups (ii) and (iii), PSA values 4 ng/ml-8 ng/ml and PSA values >8 ng/ml respectively, no significant differences were found. Conclusion It was found that serum prostate-specific antigen levels have been lower in diabetic patients with poor glycemic control than in good glycemic control. Future studies with a larger sample size and detailed information on diabetes duration and management are recommended.

Statins may increase the risk of being diagnosed with prostate cancer

BACKGROUND

Although statins are known to protect against cardiovascular accidents, their anti-inflammatory features could play a role in preventing tumorigenesis. We investigated the association between statin intake and prostate cancer (PCa) diagnosis and aggressiveness.

METHODS

A retrospective analysis was performed. Our dataset on patients undergone systematic prostate biopsy from December 2008 to December 2022 was searched for histopathologic and clinical data. Prognostic Grade Group ≥3 tumors were defined as high-grade (HG). The association between Metabolic Syndrome (MetS), statin use and PCa diagnosis and HG disease was assessed using logistic regression analyses.

RESULTS

Data on 1685 patients were collected; MetS affected 344 (20.4%) men and 138 (36.5%) were taking statins at least for 6 months at the time of biopsy. Among the 671 (39.8%) men diagnosed with PCa, 327 (48.7%) presented with a HG disease. Tumor incidence was higher among men taking statins, compared to controls (46.8% vs. 37.8%; P=0.002); also, high grade diseases were more common in the former group, but the difference did not reach statistical significance (49.1% vs. 48.6%; P=0.89). Statin intake (OR 1.44; 95% CI [1.05-1.98]; P=0.02) independently predicted PCa diagnosis but not high-grade disease (P=0.8).

CONCLUSIONS

Statin use may be associated with an increased risk of PCa diagnosis.

Association of TyG index with prostate-specific antigen (PSA) in American men: results from NHANES, 2003-2010

BACKGROUND

In recent years, triglyceride-glucose index (TyG) was a new indicator of insulin resistance, and it has been widely reported that it may be associated with serum prostate-specific antigen (PSA) concentrations.

AIMS

We intended to investigate the possible connection between serum PSA concentration and the TyG index.

METHODS

This is a cross-sectional study of adults with complete data on TyG and serum PSA concentrations (ng/ml) from the NHANES, 2003-2010. The TyG index is obtained by the formula below: TyG = Ln [triglycerides (mg/dL) × fasting glucose(mg/dL)/2]. Multivariate regression analysis and subgroup analysis were used to examine the connection between the TyG index and serum PSA levels.

RESULTS

Multiple regression analysis of the weighted linear model showed that individuals with a higher TyG index had lower PSA levels. Subgroup analyses and interaction tests showed no apparent dependence on age, race/ethnicity, BMI, household income ratio, education level, and marital status on this negative association (all interactions p > 0.05).

CONCLUSIONS

TyG index is related to lower serum PSA concentrations in adult men from the USA. Further comprehensive prospective studies are needed to confirm our findings.

Physical Inactivity, Metabolic Syndrome and Prostate Cancer Diagnosis: Development of a Predicting Nomogram

Insufficient physical activity (PA) may be a shared risk factor for the development of both metabolic syndrome (MetS) and prostate cancer (PCa). To investigate this correlation and to develop a nomogram able to predict tumor diagnosis. Between 2016 and 2018, a consecutive series of men who underwent prostate biopsy at three institutions were prospectively enrolled. PA was self-assessed by patients through the Physical Activity Scale for the Elderly (PASE) questionnaire; MetS was assessed according to Adult Treatment Panel III criteria. A logistic regression analyses was used to identify predictors of PCa diagnosis and high-grade disease (defined as International Society of Uro-Pathology grade >2 tumors). A nomogram was then computed to estimate the risk of tumor diagnosis. A total of 291 patients were enrolled; 17.5% of them (n = 51) presented with MetS. PCa was diagnosed in 110 (38%) patients overall while 51 presented high-grade disease. At multivariable analysis, age (OR 1.04; 95%CI: 1.00−1.08; p = 0.048), prostate volume (PV) (OR 0.98; 95%CI: 0.79−0.99; p = 0.004), suspicious digital rectal examination (OR 2.35; 95%CI: 1.11−4.98; p = 0.02), total PSA value (OR 1.12; 95%CI: 1.05−1.2; p < 0.001), and PASE score (OR 0.99; 95%CI: 0.98−0.99; p = 0.01) were independent predictors of tumor diagnosis. The latter two also predicted high-grade PCa. MetS was not associated with PCa diagnosis and aggressiveness. The novel nomogram displayed fair discrimination for PCa diagnosis (AUC = 0.76), adequate calibration (p > 0.05) and provided a net benefit in the range of probabilities between 20% and 90%. reduced PA was associated with an increased risk of PCa diagnosis and high-grade disease. Our nomogram could improve the selection of patients scheduled for prostate biopsy at increased risk of PCa.

Metabolic Syndrome and Physical Inactivity May Be Shared Etiological Agents of Prostate Cancer and Coronary Heart Diseases

Simple Summary

As metabolic syndrome (MetS) and a sedentary lifestyle are associated with an increased risk of prostate cancer (PCa) and cardiovascular diseases (CVDs), the 2 conditions may share common causes. We investigated the association between CVDs and PCa. Clinical data from patients undergone prostate biopsy were collected, physical activity (PA) was assessed and coronary heart diseases (CHDs) recorded. PCa was diagnosed in 395/955 men and 238 were aggressive tumors. Although CHDs were more common among PCa-patients (9.4% vs. 7.5%) the difference was not statistically significant and no difference was observed between low- and high-grade subgroups (9.5% vs. 9.2%). PA significantly reduced the risk of PCa diagnosis and aggressiveness while MetS only increased the risk of being diagnosed with cancer. CHDs were associated neither with tumor diagnosis nor aggressiveness. MetS and PA are strong predictors of PCa. We failed to prove a significant association between PCa and CHDs.

Abstract

As metabolic syndrome (MetS) and a sedentary lifestyle have been associated with an increased risk of developing both prostate cancer (PCa) and cardiovascular diseases (CVDs), the 2 conditions may share a common etiology. We aimed at investigating the association between CVDs and PCa. A retrospective analysis was performed. Our dataset on patients undergone systematic prostate biopsy was searched for histopathologic and clinical data. The physical activity (PA) scale for the elderly (PASE) was collected. Coronary heart diseases (CHDs) were recorded. Prognostic Grade Group ≥3 tumors were defined as high-grade (HG). The association between MetS, PA, CHDs and PCa was assessed using logistic regression analyses. Data on 955 patients were collected; 209 (22%) presented with MetS, 79 (8%) with CHDs. PCa was diagnosed in 395 (41.3%) men and 60% (n = 238) presented with an high-grade tumor. CHDs were more common among PCa-patients (9.4% vs. 7.5%; p = 0.302) but the difference was not statistically significant. No difference was observed between low- and high-grade subgroups (9.5% vs. 9.2%; p = 0.874). PASE independently predicted PCa diagnosis (OR: 0.287; p = 0.001) and HG-PCa (OR: 0.165; p = 0.001). MetS was an independent predictor of HG-PCa only (OR: 1.50; 95% CI: 1.100–2.560; p = 0.023). CHDs were not associated with tumor diagnosis and aggressiveness.

Biomarkers of glucose homeostasis and inflammation with risk of prostate cancer: A case-cohort study

BACKGROUND

Few prospective studies have examined biomarkers of glucose homeostasis or inflammation with prostate cancer risk by tumor stage or grade.

METHODS

We conducted a case-cohort study to examine associations of pre-diagnosis hemoglobin A1c (HbA1c), c-peptide, and c-reactive protein (CRP) with prostate cancer risk overall and stratified by tumor stage and grade. The study included 390 non-aggressive (T1-2, N0, M0 and Gleason score <8) and 313 aggressive cases (T3-4, or N1, or M1, or Gleason score 8-10) diagnosed after blood draw (1998-2001) and up to 2013, and a random sub-cohort of 1,303 cancer-free men at blood draw in the Cancer Prevention Study-II Nutrition Cohort. Prentice-weighted Cox proportional hazards regression models were used to estimate hazards ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

In the multivariable-adjusted model without body mass index (BMI), HbA1c was inversely associated with non-aggressive prostate cancer (HR per unit increase: 0.89, 95% CI: 0.80-1.00, P=0.04). Analyses stratified by tumor stage and grade separately showed that HbA1c was inversely associated with low-grade prostate cancer (HR per unit increase: 0.89, 95% CI: 0.80-1.00) and positively associated with high-grade prostate cancer (HR per unit increase: 1.15, 95% CI: 1.01-1.30). C-peptide and CRP were not associated with prostate cancer overall or by stage or grade.

CONCLUSIONS

The present study suggests that associations of hyperglycemia with prostate cancer may differ by tumor grade and stage.

IMPACT

Future studies need to examine prostate cancer by tumor stage and grade, and to better understand the role of hyperglycemia in prostate cancer progression.

Epidemiology and Prevention of Prostate Cancer

CONTEXT

Worldwide, prostate cancer (PCa) represents the second most common solid tumor in men.

OBJECTIVE

To assess the geographical distribution of PCa, epidemiological differences, and the most relevant risk factors for the disease.

EVIDENCE ACQUISITION

Estimated incidence, mortality, and prevalence of PCa for the year 2020 in 185 countries were derived from the IARC GLOBOCAN database. A review of English-language articles published between 2010 and 2020 was conducted using MEDLINE, EMBASE, and Scopus to identify risk factors for PCa.

EVIDENCE SYNTHESIS

In the year 2020, there were over 1414000 estimated new cases of PCa worldwide, with an age-standardized rate (ASR) incidence of 31 per 100000 (lifetime cumulative risk: 3.9%). Northern Europe has the highest all-age incidence ASR (83), while the lowest ASR was in South-Central Asia (6.3). In the year 2020, there were over 375000 estimated deaths worldwide, and the overall mortality ASR was 7.7 per 100000, with the highest ASR in the Caribbean (28) and the lowest in South-Central Asia (3.1). Family history, hereditary syndromes, and race are the strongest risk factors for PCa. Metabolic syndrome was associated with the risk of developing PCa, high-grade disease, and adverse pathology. Diabetes and exposure to ultraviolet rays were found to be inversely associated to PCa incidence. Cigarette smoking and obesity may increase PCa-specific mortality, while regular physical activity may reduce disease progression. Although 5-alpha reductase inhibitors are known to be associated with a reduced incidence of PCa, available studies failed to show an effect on overall mortality.

CONCLUSIONS

Family history, race, and hereditary syndromes are well-established risk factors for PCa. Modifiable risk factors may impact the risk of developing PCa and that of dying from the disease, but little evidence exist for any clear indication for prevention other than early diagnosis to reduce PCa mortality.

PATIENT SUMMARY

Prostate cancer (PCa) rates vary profoundly worldwide, with incidence and mortality rates being highest in Northern Europe and Caribbean, respectively. South-Central Asia has the lowest epidemiological burden. Family history, race, and hereditary syndromes are well-established risk factors for PCa. Modifiable risk factors may impact the risk of developing PCa and that of dying from the disease itself, but little evidence exist for any clear indication for prevention other than early diagnosis to reduce PCa mortality.

Association between serum prostate-specific antigen concentrations and the risk of developing type 2 diabetes mellitus in Chinese men: A cohort study

AIMS/INTRODUCTION

The current literature suggests that men with diabetes have a lower prostate-specific antigen concentration than men without diabetes, but the causal association remains unclear. We aimed to investigate the association between serum prostate-specific antigen concentrations and the risk of type 2 diabetes mellitus in a cohort study of a Chinese population.

MATERIALS AND METHODS

We designed a cohort study that comprised 16,811 initially non-diabetic Chinese men who received annual health checkups between 2009 and 2016. The outcome of this study was type 2 diabetes mellitus, identified by medical diagnosis, self-reportage, medication use, fasting glucose, 2-h post oral glucose or glycated hemoglobin measurements. Cox proportional hazards models were carried out to evaluate the association.

RESULTS

During a median follow-up period of 3.8 years (interquartile range 1.91-5.73 years), 1,260 participants developed incident type 2 diabetes mellitus. The multivariable model, adjusted for various potential confounders, showed that serum prostate-specific antigen concentrations were inversely related to type 2 diabetes mellitus risk (P for trend = 0.014). Compared with the lowest quartile of serum prostate-specific antigen, the hazard ratio and 95% confidence intervals of type 2 diabetes mellitus risk for quartile 2-4 were 0.84 (0.66-1.07), 0.75 (0.59-0.94) and 0.77 (0.62-0.96), respectively. Subgroup analyses suggested the inverse relationship was more prominent in overweight or obese participants (P for interaction = 0.013).

CONCLUSIONS

High serum prostate-specific antigen concentration was associated with a low risk of type 2 diabetes mellitus in Chinese men. Future studies are required to confirm these findings and investigate underlying mechanisms.

A national observation study of cancer incidence and mortality risks in type 2 diabetes compared to the background population over time

We examined changing patterns in cancer incidence and deaths in diabetes compared to the background population. A total of 457,473 patients with type 2 diabetes, included between 1998 and 2014, were matched on age, sex, and county to five controls from the population. Incidence, trends in incidence and post-cancer mortality for cancer were estimated with Cox regression and standardised incidence rates. Causes of death were estimated using logistic regression. Relative importance of risk factors was estimated using Heller’s relative importance model. Type 2 diabetes had a higher risk for all cancer, HR 1.10 (95% CI 1.09–1.12), with highest HRs for liver (3.31), pancreas (2.19) and uterine cancer (1.78). There were lesser increases in risk for breast (1.05) and colorectal cancers (1.20). Type 2 diabetes patients experienced a higher HR 1.23 (1.21–1.25) of overall post-cancer mortality and mortality from prostate, breast, and colorectal cancers. By the year 2030 cancer could become the most common cause of death in type 2 diabetes. Persons with type 2 diabetes are at greater risk of developing cancer and lower chance of surviving it. Notably, hazards for specific cancers (e.g. liver, pancreas) in type 2 patients cannot be explained by obesity alone.

Untangling the association between prostate-specific antigen and diabetes: a systematic review and meta-analysis

Objectives

Several studies have shown an inverse association between diabetes mellitus and prostate cancer (PCa). Some researchers suggest that this relationship is due to reduced PCa detection in diabetics due to lower prostate-specific antigen (PSA) levels compared to non-diabetics. Our objective is to analyze the impact of diabetes on PSA in asymptomatic men without known prostate pathology and without prior prostate intervention.

Methods

We searched Medline (via PubMed), Embase and Scopus. We included studies that reported the relationship between serum PSA levels and diabetes or diabetes treatment in asymptomatic adult men without known prostate pathology, and without prior prostate intervention. Pooled mean differences were compared between diabetics and non-diabetics.

Results

Of 2,392 screened abstracts, thirteen studies met the inclusion criteria and 8 (62%) reported appropriate measures that could be included in a meta-analysis. Eleven (85%) examined the influence of diabetes on PSA levels and 8 (62%) evaluated the influence of diabetes treatments on PSA levels. Overall diabetics had a significantly lower PSA level compared to non-diabetics (mean difference: -0.07 ng/mL; 95% CI -0.10, -0.04).

Conclusions

Diabetes and related factors (such as disease duration, severity and treatment) were significantly associated with lower PSA levels among asymptomatic men, yet differences were small and are unlikely to influence PCa detection in a screening setting.

Prostate-Specific Antigen Within the Reference Range, Subclinical Coronary Atherosclerosis, and Cardiovascular Mortality

RATIONALE

Although PSA (prostate-specific antigen)-a tumor marker for prostate cancer-has been reported to be associated with cardiovascular disease (CVD) risk factors, studies on the association of PSA with subclinical and clinical CVD remain limited.

OBJECTIVE

We examined the association of total serum PSA within the reference range with coronary artery calcium (CAC) score and CVD mortality.

METHODS AND RESULTS

A cross-sectional study was performed in 88 203 Korean men who underwent a health checkup exam including cardiac tomography estimation of CAC score. Logistic regression model was used to calculate odds ratios with 95% CIs for prevalent CAC. PSA levels were inversely associated with the presence of CAC. After adjusting for potential confounders, multivariable-adjusted odds ratio (95% CIs) for prevalent CAC comparing PSA quartiles 2, 3, and 4 to the first quartile were 0.96 (0.90-1.01), 0.88 (0.83-0.93), and 0.85 (0.80-0.90), respectively ( P for trend, <0.001). A cohort study was performed in 243 435 Korean men with a mean age of 39.3 years, PSA values of <4.0 ng/mL, and without known CVD or prostate disease who were followed up with for ≤14 years for CVD mortality (median, 7.3 years). CVD deaths were ascertained through linkage to national death records. Hazard ratios and 95% CIs for CVD mortality were estimated using Cox proportional hazards regression analyses. During 1 829 070.1 person-years of follow-up, 336 CVD deaths were identified. After adjustment for potential confounders, multivariable-adjusted hazard ratios (95% CIs) for CVD mortality comparing PSA quartiles 2, 3, and 4 to the lowest quartile were 0.90 (0.66-1.22), 0.79 (0.58-1.08), and 0.69 (0.51-0.93), respectively.

CONCLUSIONS

Serum total PSA levels within the reference range showed an inverse association with subclinical atherosclerosis and CVD mortality in young and middle-aged Korean men, indicating a possible role of PSA as a predictive marker for subclinical and clinical CVD.

Review: Diabetes, Obesity, and Cancer-Pathophysiology and Clinical Implications

Obesity and diabetes have both been associated with an increased risk of cancer. In the face of increasing obesity and diabetes rates worldwide, this is a worrying trend for cancer rates. Factors such as hyperinsulinemia, chronic inflammation, antihyperglycemic medications, and shared risk factors have all been identified as potential mechanisms underlying the relationship. The most common obesity- and diabetes-related cancers are endometrial, colorectal, and postmenopausal breast cancers. In this review, we summarize the existing evidence that describes the complex relationship between obesity, diabetes, and cancer, focusing on epidemiological and pathophysiological evidence, and also reviewing the role of antihyperglycemic agents, novel research approaches such as Mendelian Randomization, and the methodological limitations of existing research. In addition, we also describe the bidirectional relationship between diabetes and cancer with a review of the evidence summarizing the risk of diabetes following cancer treatment. We conclude this review by providing clinical implications that are relevant for caring for patients with obesity, diabetes, and cancer and provide recommendations for improving both clinical care and research for patients with these conditions.

Association Between Antidiabetic Medications and Prostate-Specific Antigen Levels and Biopsy Results

IMPORTANCE

Diabetic men appear to have a lower risk of prostate cancer. Whether antidiabetic medications are protective or potentially mask prostate cancer by lowering prostate-specific antigen (PSA) levels is unclear.

OBJECTIVE

To examine the associations of antidiabetic medication use with (1) PSA levels, (2) frequency of PSA testing, (3) receipt of biopsy following elevated PSA results, and (4) prostate cancer detection at biopsy.

DESIGN, SETTING, AND PARTICIPANTS

Population-based cohort study using data from the Stockholm PSA and Biopsy Register. Participants were all prostate cancer-free men aged 40 to 79 years residing in Stockholm County, Sweden, between January 1, 2006, and December 31, 2015. Data were analyzed from November 2018 to March 2019.

EXPOSURES

One or more prescription for metformin, sulfonylurea, or insulin, as recorded in Sweden's National Prescribed Drug Register.

MAIN OUTCOMES AND MEASURES

Levels of PSA following first exposure to antidiabetic medications were assessed using multivariable linear regression. Frequency of PSA testing was assessed via multivariable Poisson regression. Biopsy following elevated PSA (≥3.0 ng/mL) and prostate cancer detection at biopsy were assessed via multivariable logistic regression.

RESULTS

The cohort of 564 666 men (median [range] age, 65 [40-79] years) consisted of 4583 men initially exposed to metformin, 1104 exposed to sulfonylurea, and 978 exposed to insulin who were age matched with unexposed men (1:5). Exposed men had lower median (interquartile range) PSA levels before starting antidiabetic medications compared with unexposed men (1.2 [0.7-2.5] vs 1.6 [0.8-3.2] ng/mL). After accounting for baseline differences, PSA levels did not vary from those of unexposed men following exposure to antidiabetic medications. Frequency of PSA testing was higher for those receiving metformin (rate ratio, 1.07; 95% CI, 1.06-1.09) and sulfonylurea (rate ratio, 1.06; 95% CI, 1.03-1.08) but was lower for those receiving insulin (rate ratio, 0.79; 95% CI, 0.77- 0.81). Likelihood of biopsy after elevated PSA was lower among men receiving metformin (odds ratio, 0.87; 95% CI, 0.80-0.96) and insulin (odds ratio, 0.83; 95% CI, 0.74-0.93). There were no differences in prostate cancer detection at biopsy, regardless of PSA levels that triggered the biopsy.

CONCLUSIONS AND RELEVANCE

This study's findings do not support the hypothesis that the inverse association between diabetes and prostate cancer is mediated through antidiabetic medications lowering PSA levels to mask prostate cancer. They do suggest potential detection bias due to fewer biopsies among men receiving antidiabetic medications, which may explain the lower prostate cancer risk in men with diabetes.

Association between serum prostate-specific antigen level and diabetes, obesity, hypertension, and the laboratory parameters related to glucose tolerance, hepatic function, and lipid profile: implications for modification of prostate-specific antigen threshold

BACKGROUND

Previous studies indicated inverse relationships between body mass index (BMI), diabetes and prostate-specific antigen (PSA) concentration besides an established positive relationship between age and PSA. Other causal relationships between clinical parameters including hypertension, hepatic function, tests, lipid profile and PSA were also suggested. Thus, we incorporated these parameters all together into the analysis to identify possible determinants of PSA concentration to improve the accuracy of PSA tests.

METHODS

Associations between PSA and the above-mentioned clinical parameters were examined among 14,486 men who visited our hospital for a routine health checkup, using linear regression analyses.

RESULTS

Total of 1403 (9.7%) and 784 (5.4%) men were classified as diabetes and obesity, respectively. After adjusting age, significant PSA reductions were found in diabetic men, especially for men taking antidiabetics. Such association was seen when the diabetic status was represented by hemoglobin A1c (HbA1c) and fasting blood sugar (FBS) levels. That is, PSA levels were significantly reduced in men with higher HbA1c and FBS levels. Obesity was also associated with a reduction in PSA levels. Moreover, PSA levels were significantly decreased with increased ALT levels.

CONCLUSIONS

PSA test results should be carefully interpreted especially for men with diabetes and obesity, in whom a substantial reduction in PSA concentration is likely to occur.

Age-Specific Reference Ranges of Prostate-Specific Antigen among Saudi Men as a Representation of the Arab Population

OBJECTIVE

To describe the reference ranges of serum prostate-specific antigen (PSA) in Saudi men. Materials/Subjects and Methods: Saudi males, aged 30 and above, were invited to participate in the study. Blood samples were taken from each subject to determine serum levels of PSA. Blood sugar levels, lipid profile, and anthropometric measurements were also obtained.

RESULTS

Our cohort consisted of 7,814 men; their mean PSA level was 1.24 ng/mL. The majority (90.5%) had PSA values between 0 and 2.5 ng/mL. The median PSA and the 95th percentile increased steadily with age. There was a sharp increase in the 95th percentile, from 3.8 ng/mL in men between 60 and 70 years old to 6.9 ng/mL in men over 71 years old. The 95th percentiles of PSA serum levels were lower in Saudi men than in the general population.

CONCLUSIONS

PSA serum levels in Saudi men are lower than in other communities. Creating age-specific reference ranges could improve the sensitivity of the PSA tests by allowing the detection of treatable tumors in younger men if the threshold of 4.0 ng/mL is lowered. Furthermore, unnecessary biopsies among older men may be avoided if the threshold is increased.

Association of diabetes mellitus with prostate cancer grade and prostate-specific antigen in Chinese biopsy population

AIMS

To investigate the association of diabetes mellitus with prostate cancer (PCa) grade and prostate-specific antigen (PSA) in Chinese biopsy population.

METHODS

We retrospectively evaluated data from 2032 patients who underwent prostate biopsies from 2010 to 2016 at our hospital. All diabetes cases were divided into sub-groups according to HbA1c (<6.5%, 6.5%-7.49% and ≥7.5%) and diabetes duration (0-5 years, 6-10 years and >10 years).

RESULTS

Among 2032 men, 467 (23.0%) were diabetic and 674 (33.2%) were diagnosed with PCa. Diabetes increased the overall risk of PCa (OR = 1.51, 95%CI: 1.12-2.05, P = 0.007), especially high-grade PCa (OR = 2.30, 95%CI: 1.47-3.61, P < 0.001), but was not associated with low- or intermediate-grade PCa. High-grade PCa risk was markedly increased in patients with increased diabetic duration and HbA1c. Moreover, diabetics had a 22.8% lower geometric mean PSA level than non-diabetics (6.42 vs. 8.31 ng/mL, P < 0.001) and the difference increased with diabetic duration.

CONCLUSIONS

Diabetes was associated with a higher risk of PCa detection, especially high-grade disease in Chinese biopsy patients. We speculate that low PSA levels in diabetics might delay and/or interfere with PCa detection, eventually leading to higher degree PCa on diagnosis.

Fasting blood glucose, glycaemic control and prostate cancer risk in the Finnish Randomized Study of Screening for Prostate Cancer

Background

Diabetic men have lowered overall risk of prostate cancer (PCa), but the role of hyperglycaemia is unclear. In this cohort study, we estimated PCa risk among men with diabetic fasting blood glucose level.

Methods

Participants of the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC) were linked to laboratory database for information on glucose measurements since 1978. The data were available for 17,860 men. Based on the average yearly level, the men were categorised as normoglycaemic, prediabetic, or diabetic. Median follow-up was 14.7 years. Multivariable-adjusted Cox regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (95% CIs) for prostate cancer overall and separately by Gleason grade and metastatic stage.

Results

In total 1,663 PCa cases were diagnosed. Compared to normoglycaemic men, those men with diabetic blood glucose level had increased risk of PCa (HR 1.52; 95% CI 1.31–1.75). The risk increase was observed for all tumour grades, and persisted for a decade afterwards. Antidiabetic drug use removed the risk association. Limitations include absence of information on lifestyle factors and limited information on BMI.

Conclusions

Untreated diabetic fasting blood glucose level may be a prostate cancer risk factor.

Impact of poor glycemic control of type 2 diabetes mellitus on serum prostate-specific antigen concentrations in men

BACKGROUND

To evaluate the impact of poor glycemic control of type 2 diabetes mellitus (T2DM) on serum prostate-specific antigen (PSA) concentrations in men.

METHODS

We performed a prospective analysis of 215 consecutive patients affected by erectile dysfunction (ED). ED was evaluated using the IIEF-5 questionnaire and the poor glycemic control (PGC) of T2DM was assessed according to the HbA1c criteria (International Diabetes Federation). Patients were divided into PGC group (HbA1c ≥ 7%) and control group (CG) (HbA1c < 6%). Correlations between serum HbA1c levels and various variables were evaluated and multivariate logistic regression analyses were carried out to identify variables for PGC.

RESULTS

We compared 110 cases to 105 controls men ranging from 44 to 81 years of age, lower PSA concentrations were observed in men with PGC (PGC mean PSA: 0.9 ng/dl, CG mean PSA: 2.1 ng/dl, p < 0.001). Also mean prostate volume was 60% was smaller among men with PGC compared with men with CG (PGC mean prostate volume: 26 ml, CG prostate volume: 43 ml, p < 0.001). A strong negative correlation was found between serum HbA1c levels and serum PSA (p < 0.001 and r = -0.665) concentrations in men with PGC. We also found at the multivariate logistic regression model that PSA, prostate volume and peak systolic velocity were independent predictors of PGC.

CONCLUSION

Our results suggest that there is significant impact of PGC on serum PSA levels in T2DM. Poor glycemic control of type 2 diabetes was associated with lower serum PSA levels and smaller prostate volumes.

Prostate-specific antigen rising in Iranian men in correlation with body mass index, fasting blood sugar and blood lipid profile

Background

Prostate-specific antigen (PSA) is a serine protease that is secreted by prostate cells and it is useful as a tumor marker for prostate cancer.

Objectives

In this study, the relationship between some of metabolic factors and serum PSA level was investigated.

Materials and Methods

In this cross-sectional study, patients with urinary symptoms or for screening of the prostate cancer (after 50 years of age or 40 years with a family history of prostate cancer), were evaluated. Collected data included metabolic syndrome factors such as cholesterol (Chol), triglycerides (TG), fasting blood sugar (FBS), and body mass index (BMI), serum PSA level, prostate volume and age.

Results

481 patients were enrolled to this study with the average age of 60.69 ± 9.72 years and the average PSA level of 1.70 ng/ml. Data analysis showed that there was a significant relationship between serum PSA level with age (P < 0.001, r = 0.30) and prostate volume (P < 0.001, r = 0.29). There were not significant relationship between serum PSA level with TG (P = 0.57, r = 0.026), Chol (P = 0.57, r = -0.025), FBS (P = 0.054, r = 0.088), and BMI (P = 0.89, r = 0.006).

Conclusions

This study showed that, with increasing age and prostate volume, serum PSA level increased, and an increase in the levels of cholesterol, TG, FBS and BMI did not have significant effect on serum PSA level.

Investigating the prostate specific antigen, body mass index and age relationship: is an age-BMI-adjusted PSA model clinically useful?

PURPOSE

Previous studies indicate a possible inverse relationship between prostate-specific antigen (PSA) and body mass index (BMI), and a positive relationship between PSA and age. We investigated the associations between age, BMI, PSA, and screen-detected prostate cancer to determine whether an age-BMI-adjusted PSA model would be clinically useful for detecting prostate cancer.

METHODS

Cross-sectional analysis nested within the UK ProtecT trial of treatments for localized cancer. Of 18,238 men aged 50-69 years, 9,457 men without screen-detected prostate cancer (controls) and 1,836 men with prostate cancer (cases) met inclusion criteria: no history of prostate cancer or diabetes; PSA < 10 ng/ml; BMI between 15 and 50 kg/m2. Multivariable linear regression models were used to investigate the relationship between log-PSA, age, and BMI in all men, controlling for prostate cancer status.

RESULTS

In the 11,293 included men, the median PSA was 1.2 ng/ml (IQR: 0.7-2.6); mean age 61.7 years (SD 4.9); and mean BMI 26.8 kg/m2 (SD 3.7). There were a 5.1% decrease in PSA per 5 kg/m2 increase in BMI (95% CI 3.4-6.8) and a 13.6% increase in PSA per 5-year increase in age (95% CI 12.0-15.1). Interaction tests showed no evidence for different associations between age, BMI, and PSA in men above and below 3.0 ng/ml (all p for interaction >0.2). The age-BMI-adjusted PSA model performed as well as an age-adjusted model based on National Institute for Health and Care Excellence (NICE) guidelines at detecting prostate cancer.

CONCLUSIONS

Age and BMI were associated with small changes in PSA. An age-BMI-adjusted PSA model is no more clinically useful for detecting prostate cancer than current NICE guidelines. Future studies looking at the effect of different variables on PSA, independent of their effect on prostate cancer, may improve the discrimination of PSA for prostate cancer.

Diabetes, prostate cancer screening and risk of low- and high-grade prostate cancer: an 11 year historical population follow-up study of more than 1 million men

AIMS/HYPOTHESIS

An inverse association has consistently been shown between diabetes and prostate cancer incidence. We investigated whether lower prostate cancer incidence among men with diabetes is attributable to lower detection due to prostate cancer screening patterns.

METHODS

We studied a population-based historical cohort of 1,034,074 Israeli men aged 21-90 years, without a previous history of cancer. The cohort was followed-up from 2002 to 2012, according to diabetes morbidity, for frequency of prostate-specific antigen (PSA) testing, mean PSA values and detection of prostate cancer, after adjustment for age, ethnic origin, socioeconomic status and PSA testing.

RESULTS

In January 2002, 74,756 men had prevalent diabetes. During the 11 year follow-up, 765,483 (74%) remained diabetes-free and 193,835 developed diabetes. Approximately 10% more PSA screening was performed in men with than without diabetes, but the rate of PSA positivity (>4 μg/l) was 20% lower in men with diabetes. PSA values were already significantly lower in men who developed diabetes than in those who did not, 3 years before diabetes diagnosis. Reduced prostate cancer risk was observed among men with incident diabetes only for low-moderate grade tumours (Gleason score 2-6: adjusted HR 0.83; 95% CI 0.77, 0.89). No association was observed for high-grade tumours (Gleason score 7-10: HR 0.99; 95% CI 0.88, 1.11).

CONCLUSIONS/INTERPRETATION

Our findings suggest that diabetes comorbidity is a factor to be considered in prostate cancer screening strategies, and specifically in the interpretation of PSA levels. Furthermore, our demonstration of reduced incidence of low-moderate grade but not high-grade prostate cancer tumours among men with diabetes supports the possibility that low PSA levels, rather than lower tumour risk, explains the observed reduced incidence of prostate cancer in men with diabetes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02072902.

Association between baseline serum glucose, triglycerides and total cholesterol, and prostate cancer risk categories

Lifestyle-related risk factors such as hyperglycemia and dyslipidemia have been associated with several cancers. However, studies exploring their link with prostate cancer (PCa) clinicopathological characteristics are sparse and inconclusive. Here, we investigated the associations between serum metabolic markers and PCa clinicopathological characteristics. The study comprised 14,294 men from the Swedish Apolipoprotein MOrtality RISk (AMORIS) cohort who were diagnosed with PCa between 1996 and 2011. Univariate and multivariable logistic regression were used to investigate the relation between glucose, triglycerides and total cholesterol and PCa risk categories, PSA, Gleason score, and T-stage. Mean age at time of PCa diagnosis was 69 years. Men with glucose levels >6.9 mmol/L tend to have PSA<4 μg/L, while those with glucose levels of 5.6-6.9 mmol/L had a greater odds of PSA>20 μg/L compared to PSA 4.0-9.9 μg/L. Hypertriglyceridemia was also positively associated with PSA>20 μg/L. Hyperglycemic men had a greater odds of intermediate- and high-grade PCa and advanced stage or metastatic PCa. Similarly, hypertriglyceridemia was positively associated with high-grade PCa. There was also a trend toward an increased odds of intermediate risk localized PCa and advanced stage PCa among men with hypertriglyceridemia. Total cholesterol did not have any statistically significant association with any of the outcomes studied. Our findings suggest that high serum levels of glucose and triglycerides may influence PCa aggressiveness and severity. Further investigation on the role of markers of glucose and lipid metabolism in influencing PCa aggressiveness and severity is needed as this may help define important targets for intervention.

Metabolic syndrome-like components and prostate cancer risk: results from the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) study

OBJECTIVE

To evaluate the relationship between number of metabolic syndrome (MetS)-like components and prostate cancer diagnosis in a group of men where nearly all biopsies were taken independent of prostate-specific antigen (PSA) level, thus minimising any confounding from how the various MetS-like components may influence PSA levels.

SUBJECTS/PATIENTS AND METHODS

We analysed data from 6426 men in the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) study with at least one on-study biopsy. REDUCE compared dutasteride vs placebo on prostate cancer risk among men with an elevated PSA level and negative pre-study biopsy and included two on-study biopsies regardless of PSA level at 2 and 4 years. Available data for MetS-like components included data on diabetes, hypertension, hypercholesterolaemia, and body mass index. The association between number of these MetS-like components and prostate cancer risk and low-grade (Gleason sum <7) or high-grade (Gleason sum >7) vs no prostate cancer was evaluated using logistic regression.

RESULTS

In all, 2171 men (34%) had one MetS-like component, 724 (11%) had two, and 163 (3%) had three or four. Men with more MetS-like components had lower PSA levels (P = 0.029). One vs no MetS-like components was protective for overall prostate cancer (P = 0.041) and low-grade prostate cancer (P = 0.010). Two (P = 0.69) or three to four (P = 0.15) MetS-like components were not significantly related to prostate cancer. While one MetS-like component was unrelated to high-grade prostate cancer (P = 0.97), two (P = 0.059) or three to four MetS-like components (P = 0.02) were associated with increased high-grade prostate cancer risk, although only the latter was significant.

CONCLUSION

When biopsies are largely PSA level independent, men with an initial elevated PSA level and a previous negative biopsy, and multiple MetS-like components were at an increased risk of high-grade prostate cancer, suggesting the link between MetS-like components and high-grade prostate cancer is unrelated to a lowered PSA level.

Poor glycemic control is associated with reduced prostate specific antigen concentrations in men with type 1 diabetes

PURPOSE

Previous studies have revealed lower prostate specific antigen concentrations in men with type 2 diabetes, paralleling the reported lower prevalence of prostate cancer in diabetic men. Data are lacking on prostate specific antigen in men with type 1 diabetes whose insulin and obesity profiles differ from those with type 2 diabetes mellitus. In this study we examined the relationship between long-term glycemic control and prostate specific antigen in men with type 1 diabetes mellitus.

MATERIALS AND METHODS

Total prostate specific antigen was measured at one time in 639 men in the EDIC, the observational followup of participants in the DCCT. The relationship between DCCT/EDIC weighted mean hemoglobin A1c and log prostate specific antigen was assessed using linear regression modeling after adjusting for age, body mass index, total testosterone, statin and thiazide medication use, diabetes duration, and DCCT randomization arm and cohort.

RESULTS

Median subject age was 52 years, body mass index was 28.4 kg/m(2) and DCCT/EDIC time-weighted hemoglobin A1c was 7.9%. Median prostate specific antigen was 0.64 ng/ml (IQR 0.43, 1.05). Prostate specific antigen increased significantly with age (p <0.0001) and with lower time-weighted hemoglobin A1c (p <0.0001). Each 10% increase in hemoglobin A1c was accompanied by an 11% reduction in prostate specific antigen (p=0.0001).

CONCLUSIONS

Prostate specific antigen decreases as hemoglobin A1c increases in men with type 1 diabetes mellitus. This relationship is independent of age, body mass index, androgen levels, medication use and measures of diabetes severity, which suggests that factors related to glycemia may directly affect prostate specific antigen levels.

Diabetes mellitus and prostate cancer risk; a nationwide case-control study within PCBaSe Sweden

BACKGROUND

Diabetes mellitus (DM) increases the risk for cancer at almost all sites, but data on the association with prostate cancer are inconsistent.

METHODS

We assessed the risk of a prostate cancer diagnosis among men with type 2 (T2)DM in a nationwide population-based case-control study including 44,352 men with prostate cancer identified through the Prostate Cancer data Base Sweden (PCBaSe) between 2002 and 2006 and 221,495 age-matched men from the general population.

RESULTS

Overall, the risk of prostate cancer among men with T2DM was lower than among men without T2DM [OR, 0.80; 95% confidence interval (CI), 0.76-0.85]. The risk decreased with longer disease duration and was observed across all tumor risk categories, although most clearly among men with low risk tumors (OR, 0.71; 95% CI, 0.64-0.80). The risk for prostate cancer was reduced among diabetic men on dietary treatment only (OR, 0.89; 95% CI, 0.80-0.99) but more markedly among men on oral hypoglycemic agents (OR, 0.80; 95% CI, 0.74-0.87) and insulin (OR, 0.72; 95% CI, 0.69-0.81). Obese diabetic men (BMI > 30 kg/m(2)) showed a reduced risk (OR, 0.72; 95% CI, 0.65-0.80) compared with men without diabetes. There was a trend of decreasing risk with increasing levels of HbA1c (P < 0.05).

CONCLUSIONS

This nationwide study confirmed a reduced risk of being diagnosed with prostate cancer among men with T2DM, especially for low-risk tumors. An altered hormonal milieu is a plausible explanation, although the possibility of decreased prostate cancer detection among diabetic men cannot be ruled out.

IMPACT

This is the largest study to examine the association between T2DM and prostate cancer accounting for tumor risk group and diabetes treatment.

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.

New players for advanced prostate cancer and the rationalisation of insulin-sensitising medication

Obesity and type 2 diabetes are recognised risk factors for the development of some cancers and, increasingly, predict more aggressive disease, treatment failure, and cancer-specific mortality. Many factors may contribute to this clinical observation. Hyperinsulinaemia, dyslipidaemia, hypoxia, ER stress, and inflammation associated with expanded adipose tissue are thought to be among the main culprits driving malignant growth and cancer advancement. This observation has led to the proposal of the potential utility of "old players" for the treatment of type 2 diabetes and metabolic syndrome as new cancer adjuvant therapeutics. Androgen-regulated pathways drive proliferation, differentiation, and survival of benign and malignant prostate tissue. Androgen deprivation therapy (ADT) exploits this dependence to systemically treat advanced prostate cancer resulting in anticancer response and improvement of cancer symptoms. However, the initial therapeutic response from ADT eventually progresses to castrate resistant prostate cancer (CRPC) which is currently incurable. ADT rapidly induces hyperinsulinaemia which is associated with more rapid treatment failure. We discuss current observations of cancer in the context of obesity, diabetes, and insulin-lowering medication. We provide an update on current treatments for advanced prostate cancer and discuss whether metabolic dysfunction, developed during ADT, provides a unique therapeutic window for rapid translation of insulin-sensitising medication as combination therapy with antiandrogen targeting agents for the management of advanced prostate cancer.

Diabetes predicts metastasis after radical prostatectomy in obese men: results from the SEARCH database

OBJECTIVE

To examine the association between diabetes and metastasis risk after radical prostatectomy (RP) and to determine if race or obesity modifies this relationship.

PATIENTS AND METHODS

Patients comprised 2058 US veterans with prostate cancer (PCa) enrolled in the Shared Equal-Access Regional Cancer Hospital (SEARCH) database and treated with RP between 1988 and 2010. The association of diabetes with metastasis risk or secondary treatment rates was examined using Cox proportional hazards, adjusting for preoperative and, separately, clinical and postoperative findings. The effect modification by race (black vs white) and obesity (body mass index [BMI] ≥30 vs <30 kg/m(2) ) was tested via interaction terms.

RESULTS

Men with diabetes had higher BMIs and were more likely to be non-white (all P ≤ 0.001). On multivariable analysis, diabetes was not associated with metastasis risk (P ≥ 0.45), but, among men with diabetes, longer diabetes duration was associated with higher metastasis risk (P ≤ 0.035). When stratified by obesity, diabetes was linked with higher metastasis risk in obese but not in non-obese men (P-interaction ≤ 0.037), but there was no significant interaction with race (P-interaction ≥ 0.56). Diabetes also predicted more aggressive secondary treatment among obese men but less aggressive treatment among non-obese men (hazard ratio 1.39 vs 0.63, P-interaction = 0.006). Where applicable, results were similar for both pre- and postoperative models.

CONCLUSIONS

Diabetes was not associated with metastasis risk overall. Stratification by obesity yielded significant differences, with diabetes linked to a fourfold higher metastasis risk in obese men, despite predicting more aggressive secondary treatment. Longer diabetes duration was also associated with increased metastasis risk.

Dynamics of Prostate-Specific Antigen Levels During Treatment with Testosterone Undecanoate in Patients with Type 2 Diabetes Mellitus

Objectives. Prostate-specific antigen (PSA) is the most used and validated marker ofprostate cancer risk. The aim of this study was to assess PSA levels during treatmentwith testosteronum undecanoat in patients with type 2 diabetes (T2DM). Material and Methods. We evaluated 38 T2DM patients aged between 48 and 61 years withconfirmed hypogonadism. 1000 mg testosterone undecanoate was injectedintramuscular every 10 to 14 weeks. Total testosterone and PSA levels were assessedat baseline and after 6, 12, 24 months of treatment. Results. The average age was55.03 ± 2.40 years and 3 patients (7.89%) had a family history of prostate cancer.Treatment with testosterone undecanoate generated significant changes in serumtotal testosterone (482.29±50.78 ng/dl vs. 246.66±51.50 ng/dl, p < 0.001) but not inserum PSA levels (2.11±.0.49 ng/ml vs. 2.09±0.47 ng/ml, p - NS). Conclusion.Testosterone replacement therapy may normalize serum androgen levels but appearsto have little effect on PSA levels.

Obesity, type 2 diabetes, and cancer: the insulin and IGF connection

Epidemiological studies suggest a positive association between obesity and type 2 diabetes mellitus (T2D) with the risk of cancer and cancer-related mortality. Insulin resistance, hyperinsulinemia, increased levels of IGF, elevated levels of steroid and peptide hormones, and inflammatory markers appear to play a role in the connection between these different diseases. Medications, such as metformin and exogenous insulin, used to treat T2D may affect the risk of cancer and cancer-related mortality. Newer therapies targeting the insulin and IGF1 systems are being developed for use in cancer therapy.

Diabetic nephropathy is associated with prostate-specific antigen levels in type 2 diabetes mellitus

PURPOSE

Type 2 diabetes is associated with reduced risk of prostate cancer and low prostate-specific antigen levels for uncertain reasons. Recently, two studies demonstrated the time course of diabetes with prostate-specific antigen levels, which would be explained by the chronic renal complication. Therefore, we conducted a retrospective study to determine whether diabetic nephropathy is associated with prostate-specific antigen levels.

METHODS AND RESULTS

Eligible patients were men aged ≥40 years, with type 2 diabetes and a recorded prostate-specific antigen level. Patients with a prior history of prostate cancer or prostatectomy or prostate-specific antigen level ≥10 ng/mL and patients with end-organ damage were excluded. Of the 247 patients included in the adjusted analysis, 51 (20.8 %) were diagnosed with diabetic nephropathy. A significant association of diabetic nephropathy with log-transformed prostate-specific antigen level was detected (Spearman's correlation coefficient -0.201, p = 0.003; adjusted for all other correlated variables) and fit into a linear regression model (B-coefficient -0.331, p = 0.003). Comparing diabetic nephropathy group with non-diabetic nephropathy group, the difference in log-transformed prostate-specific antigen levels was also significant (p = 0.002).

CONCLUSION

The results indicated that patients with diabetic nephropathy have low prostate-specific antigen levels, suggesting fewer prostate cancers being detected or fewer incidences among this group.

The Interactions between Insulin and Androgens in Progression to Castrate-Resistant Prostate Cancer

An association between the metabolic syndrome and reduced testosterone levels has been identified, and a specific inverse relationship between insulin and testosterone levels suggests that an important metabolic crosstalk exists between these two hormonal axes; however, the mechanisms by which insulin and androgens may be reciprocally regulated are not well described. Androgen-dependant gene pathways regulate the growth and maintenance of both normal and malignant prostate tissue, and androgen-deprivation therapy (ADT) in patients exploits this dependence when used to treat recurrent and metastatic prostate cancer resulting in tumour regression. A major systemic side effect of ADT includes induction of key features of the metabolic syndrome and the consistent feature of hyperinsulinaemia. Recent studies have specifically identified a correlation between elevated insulin and high-grade PCa and more rapid progression to castrate resistant disease. This paper examines the relationship between insulin and androgens in the context of prostate cancer progression. Prostate cancer patients present a promising cohort for the exploration of insulin stabilising agents as adjunct treatments for hormone deprivation or enhancers of chemosensitivity for treatment of advanced prostate cancer.

Serum prostate specific antigen changes in cynomolgus monkeys (Macaca fascicularis) on a high sugar high fat diet

BACKGROUND

An inverse relationship between serum prostate specific antigen (PSA) levels and body mass index (BMI) has been reported in men but not in any animal model.

METHODS

Serum PSA in a colony of cynomolgus monkeys was assayed and correlated to body weight, prostate weight, and age. In addition, 15 animals were selected and fed a high sugar high fat (HSHF) diet for 49 weeks to increase their BMI and correlate it to PSA RESULTS: Serum PSA levels were positively correlated to prostate weight (r = 0.515, P = 0.025) and age (r = 0.548, P = 0.00072) but was not significantly correlated to body weight (r = -0.032, P = 0.419). For the animals on the HSHF diet, body weight, lean mass, fat mass, and BMI were significantly higher at 49 weeks than at baseline (P < 0.01). PSA was not significantly correlated to body weight and insulin at both baseline and 49 weeks. PSA was negatively correlated to BMI and insulin resistance (HOMA-IR) at 49 weeks but not at baseline. In addition, we observed hepatic steatosis and increases in serum liver enzymes.

CONCLUSIONS

Increases in BMI in cynomolgus monkeys as a result of consuming a HSHF diet resulted in PSA changes similar to those in humans with increased BMI. Cynomolgus monkeys are a useful model for investigating the relationship between obesity, diabetes, and PSA changes resulting from prostate gland pathology.

The influence of antidiabetic medications on the development and progression of prostate cancer

BACKGROUND

The development of prostate tumors has been linked to co-morbid diabetes mellitus (DM) in several studies, potentially through the stimulation of insulin-like growth factor receptor (IGFR). This study evaluates the effect of anti-diabetic medication use on the development of high grade tumors and time to tumor progression compared to non-diabetics.

METHODS

This retrospective, nested case control study identified patients with prostate cancer (PCa) from the Kentucky Medicaid Database. Cases were diagnosed with PCa and DM and using at least one of the following antidiabetic medications; sulfonylureas, insulin, metformin or TZDs. Cases were further stratified on their insulin exposure resulting from therapy. Controls were those with PCa without DM or any anti-diabetic medications.

RESULTS

The use of metformin or TZDs trended toward decreased odds of high-grade tumors and decreased risk of progression, while sulfonylureas and high-dose insulin tended toward an increased odds of high-grade tumors and increase the risk of progression compared to non-diabetics.

CONCLUSIONS

Future studies should be conducted to further evaluate the effects of anti-diabetic medications on tumor grade and time to prostate cancer progression.

The effect of demographic and clinical factors on the relationship between BMI and PSA levels

INTRODUCTION

Studies have reported lower prostate specific antigen (PSA) levels in men with a higher body mass index (BMI). Additional factors such as diabetes mellitus, benign prostatic hyperplasia (BPH) and certain medications may also affect PSA levels and confound the PSA-BMI association. In this study we evaluated the potential confounding effect of these factors on the obesity-PSA relationship and evaluated the association between these factors and PSA level.

METHODS

The study cohort consisted of 770 population-based controls without a history of prostate cancer (PCa) who participated in a prior PCa study. Demographic, anthropometric, and medical history data were obtained, and PSA level was determined from blood drawn at the time of interview. Linear regression was performed to evaluate the PSA-BMI relationship, adjusting for potential confounders. Finally, a forward stepwise algorithm was used to determine which factors were independently associated with PSA values.

RESULTS

With increase in BMI (<25, 25-29, ≥30), the geometric mean PSA level declined (1.18, 1.13, and 0.94, respectively); obese men had a 17% (95% CI 0.70-0.99) lower age-adjusted PSA level compared to normal weight men. However, this relationship was non-significant (P = 0.17) in the multivariate model. Independent predictors of PSA level included age (β = 1.03, 95% CI 1.02-1.04), history of BPH (β = 1.48, 95% CI 1.27-1.72), current statin (β = 0.85, 95% CI 0.74-0.98), and NSAID use (β = 0.84, 95% CI 0.72-0.98).

CONCLUSION

The relationship between obesity and PSA is confounded by a number of factors, which likely explain the observed inverse association previously reported. These results should help in interpreting PSA values in men screened for PCa.

Defining the molecular nexus of cancer, type 2 diabetes and cardiovascular disease

The metabolic syndrome is characterized by a state of metabolic dysfunction resulting in the development of several chronic diseases that are potentially deadly. These metabolic deregulations are complex and intertwined and it has been observed that many of the mechanisms and pathways responsible for diseases characterizing the metabolic syndrome such as type 2 diabetes and cardiovascular disease are linked with cancer development as well. Identification of molecular pathways common to these diverse diseases may prove to be a critical factor in disease prevention and development of potential targets for therapeutic treatments. This review focuses on several molecular pathways, including AMPK, PPARs and FASN that interconnect cancer development, type 2 diabetes and cardiovascular disease. AMPK, PPARs and FASN are crucial regulators involved in the maintenance of key metabolic processes necessary for proper homeostasis. It is critical to recognize and identify common pathways deregulated in interrelated diseases as it may provide further information and a much more global picture in regards to disease development and prevention. Thus, this review focuses on three key metabolic regulators, AMPK, PPARs and FASN, that may potentially serve as therapeutic targets.

Prostate cancer mortality in Taiwanese men: increasing age-standardized trend in general population and increased risk in diabetic men

BACKGROUND

To evaluate the trend of prostate cancer mortality in Taiwanese general population and the association between diabetes and prostate cancer mortality.

MATERIALS AND METHODS

In the general population during 1995-2006, the trends of prostate cancer mortality were evaluated, followed by calculation of age-specific mortality rates for age 40-64, 65-74, and ≥ 75 years. A cohort of 102,651 diabetic men aged ≥ 40 years recruited in 1995-1998 was followed prospectively.

RESULTS

The trends of crude and age-standardized mortality from prostate cancer in the general population increased significantly (P < 0.0001). In the general population, 7,966 men aged ≥ 40 years died of prostate cancer, and aging was associated with increased risk. Age-specific prostate cancer mortality suggested significantly increasing trend for ages 65-74 and ≥ 75 years. A total of 321 diabetic men died of prostate cancer (crude mortality rate 41.9/100,000 person-years). Mortality rate ratios (95% confidence interval) showed higher risk of prostate cancer mortality in the diabetic patients, with magnitude increased with decreasing age: 1.55 (1.29-1.86), 2.68 (2.29-3.13), and 6.84 (5.34-8.75) for age ≥ 75, 65-74, and 40-64 years, respectively.

CONCLUSIONS

Prostate cancer mortality in the Taiwanese general population is increasing. Diabetic patients have a higher risk of prostate cancer mortality, which is more remarkable with decreasing age.

The effects of type 2 diabetes and hypertension on changes in serum prostate specific antigen levels: results from the Olmsted County study

OBJECTIVE

Men with type 2 diabetes have lower concomitant prostate-specific antigen (PSA) levels; however, the influence of metabolic conditions on PSA changes over time remains unknown. Therefore, the goal of this study was to assess associations between type 2 diabetes and hypertension and changes in serum PSA levels.

METHODS

In 1990, a randomly selected cohort of Caucasian men, ages 40-79, from Olmsted County, MN completed questionnaires ascertaining demographic characteristics, current medical conditions and medications biennially, with 633 men undergoing blood draws. Men with a physician diagnosis of diabetes or hypertension at baseline, or who reported using medications to treat these conditions prior to baseline were considered exposed. Men with at least two serum PSA measurements (n = 569) were included in this analysis. Linear mixed models were used to estimate the annual percent change in serum PSA levels associated with diabetes and hypertension, adjusting for baseline age.

RESULTS

The overall mean change in serum PSA levels was 3.6% per year and increased with age (P = .009). Men with diabetes experienced less annual change in serum PSA levels (1.1%) than did non-diabetic men (3.7%), adjusting for age (P = .02). Age-adjusted change in serum PSA levels differed little by hypertension status (3.7% vs. 3.6%; P = .49).

CONCLUSIONS

Our results suggest that Caucasian men with type 2 diabetes experience smaller increases in serum PSA levels as they age compared to men without diabetes. Additional research is needed to elucidate whether this difference results in a relatively lower incidence of prostate cancer or less cancer detection among diabetic men.

Prostate cancer and PSA among statin users in the Finnish prostate cancer screening trial

Decreased risk of advanced prostate cancer has been reported among men using statins. However, the evidence on overall prostate cancer risk is conflicting. We compared the relative risk between current users and non-users of statins or other cholesterol-lowering medications in a population undergoing systematical prostate cancer screening. The study cohort comprised of 23,320 men participating in the screening arm of the Finnish prostate cancer screening trial during 1996-2004. Information on medication use was obtained from a comprehensive national prescription database. Cox proportional hazards regression was used to calculate multivariable adjusted hazard ratios (HRs) for prostate cancer. Serum prostate-specific antigen (PSA) level was compared between current users and non-users of cholesterol-lowering drugs. Compared with medication non-users, the overall prostate cancer incidence was decreased among statin users [HR 0.75, 95% confidence interval (CI) 0.63-0.89]. The inverse association was dose-dependent with cumulative amount of statin use, and strongest for low-grade and early stage tumors. The incidence was nonsignificantly lower also among users of other types of cholesterol-lowering drugs (HR 0.62, 95% CI 0.28-1.38), but without dose-dependence. Age-adjusted median serum PSA tended to be lower among users of cholesterol-lowering drugs, but the relative risk decrease among statin users was not related to decreased PSA. Overall incidence of prostate cancer was lowered among statin users when bias due to differential PSA testing between medication users and non-users was eliminated by systematical prostate cancer screening. Cholesterol-lowering with statins seems beneficial for prostate cancer prevention.

Association of diabetes and body mass index with levels of prostate-specific antigen: implications for correction of prostate-specific antigen cutoff values?

BACKGROUND

In a recent study, an inverse association between diabetes and prostate-specific antigen (PSA) levels was observed, and several studies reported lower PSA levels in groups with higher body mass index. However, all of the studies were conducted in populations with intensive PSA screening and the role of diabetes severity, duration, and therapy are yet to be explored.

METHODS

Associations of diabetes duration and treatment, hemoglobin A1c, and BMI with PSA levels were assessed among 778 men ages 50 to 74 years, randomly chosen from the 2000 to 2002 baseline recruitment of a large population-based cohort study in Germany (prevalence of diabetes, 17%), using linear regression analyses.

RESULTS

PSA values were significantly reduced in men with insulin treatment (-39%; P = 0.006) and oral diabetic medication (-24%; P = 0.030), and in men with elevated (6.1-6.9%) and highly (> or =7%) elevated hemoglobin A1c values (-15%, P = 0.004 and -29%, P = 0.003, respectively). PSA reduction was not associated with duration of diabetes. Obesity was possibly associated with a reduction of PSA levels (-14%; P = 0.096).

CONCLUSIONS

Our study suggests that more severe forms of diabetes are associated with lower PSA levels and confirms the magnitude of reduction in PSA levels in diabetic men overall. The observed PSA reduction parallels reported risk reduction of prostate cancer among diabetic men.

Association of diabetes with prostate cancer risk in the multiethnic cohort

Among men of European ancestry, diabetics have a lower risk of prostate cancer than do nondiabetics. The biologic basis of this association is unknown. The authors have examined whether the association is robust across populations in a population-based prospective study. The analysis included 5,941 prostate cancer cases identified over a 12-year period (1993-2005) among 86,303 European-American, African-American, Latino, Japanese-American, and Native Hawaiian men from the Multiethnic Cohort. The association between diabetes and prostate-specific antigen (PSA) levels (n = 2,874) and PSA screening frequencies (n = 46,970) was also examined. Diabetics had significantly lower risk of prostate cancer than did nondiabetics (relative risk = 0.81, 95% confidence interval (CI): 0.74, 0.87; P < 0.001), with relative risks ranging from 0.65 (95% CI: 0.50, 0.84; P = 0.001) among European Americans to 0.89 (95% CI: 0.77, 1.03; P = 0.13) among African Americans. Mean PSA levels were significantly lower in diabetics than in nondiabetics (mean PSA levels, 1.07 and 1.28, respectively; P = 0.003) as were PSA screening frequencies (44.7% vs. 48.6%; P < 0.001); however, this difference could explain only a small portion ( approximately 20%) of the inverse association between these diseases. Diabetes is a protective factor for prostate cancer across populations, suggesting shared risk factors that influence a common mechanism.

Effect of ageing and body mass index on prostate-specific antigen levels among Chinese men in Singapore from a community-based study

OBJECTIVE To assess the effect of ageing and body mass index (BMI) on prostate-specific antigen (PSA) among Chinese men from the results of the 2005 Prostate Awareness Week in Singapore. SUBJECTS AND METHODS In all, 2714 men participated in the programme, consisting of 2431 Chinese, 114 Malays, 117 Indians and 52 'others'. Of these, 2410 Chinese men who had a PSA level of <20 ng/mL and were aged >50 years but <80 years were included in the analysis. Height and weight were used to calculate the BMI. The relationship between age and PSA levels was analysed using linear regression and bivariate correlation, and the associations among different groups of BMI and PSA levels were analysed using analysis of variance and covariance. RESULTS PSA levels were significantly correlated with age (correlation coefficient, r = 0.27, P < 0.001). Analyses showed a significant inverse association between PSA level and BMI; mean PSA levels decreased with increasing BMI for both standards (standard classification; geometric mean, GM, PSA of 1.08, 1.06, 0.96, 0.83 ng/mL for a BMI of <18.5, 18.5-24.9, 25-29.9 and > or =30 kg/m(2), respectively, P trend <0.01; and for Asian classification, GM PSA 1.08, 1.09, 0.96, 0.91 ng/mL for a BMI of <18.5, 18.5-22.9, 23-27.5 and > or =27.5, respectively, P trend <0.001). There were significant differences (P < 0.05) in the age-adjusted GM PSA levels for the groups with BMI <25 (1.05 ng/mL) and BMI > or =25 kg/m(2) (0.97 ng/mL). Similarly, there were significant differences (P < 0.05) in the age-adjusted GM PSA levels in those with a BMI of <30 (1.03 ng/mL) and > or =30 kg/m(2) (0.85 ng/mL). CONCLUSION These data suggest that the BMI in Chinese men in Singapore is significantly associated with PSA levels, especially among the obese men aged 70-79 years.

Prioritizing risk pathways: a novel association approach to searching for disease pathways fusing SNPs and pathways

MOTIVATION

Complex diseases are generally thought to be under the influence of one or more mutated risk genes as well as genetic and environmental factors. Many traditional methods have been developed to identify susceptibility genes assuming a single-gene disease model ('single-locus methods'). Pathway-based approaches, combined with traditional methods, consider the joint effects of genetic factor and biologic network context. With the accumulation of high-throughput SNP datasets and human biologic pathways, it becomes feasible to search for risk pathways associated with complex diseases using bioinformatics methods. By analyzing the contribution of genetic factor and biologic network context in KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways, we proposed an approach to prioritize risk pathways for complex diseases: Prioritizing Risk Pathways fusing SNPs and pathways (PRP). A risk-scoring (RS) measurement was used to prioritize risk biologic pathways. This could help to demonstrate the pathogenesis of complex diseases from a new perspective and provide new hypotheses. We introduced this approach to five complex diseases and found that these five diseases not only share common risk pathways, but also have their specific risk pathways, which is verified by literature retrieval.