c-peptide and Prostatic-Neoplasms

The association between serum C-peptide concentration and prostate cancer remains unexplored. Therefore, we conducted a meta-analysis to assess whether C-peptide serum concentrations are associated with increased prostate cancer risk.. Several databases were searched to identify relevant original research articles published before November 2017. Random-effects models were used to summarize the overall estimate of the multivariable-adjusted odds ratios (ORs) with 95% confidence intervals (CIs).. Nine observational studies involving 11,796 participants were identified. The findings of the meta-analysis indicated that the association between serum C-peptide concentration and prostate cancer was not significant (OR: 1.15, 95% CI: 0.85-1.54; for highest versus lowest category C-peptide concentrations, P = .376). The associations were inconsistent, as indicated by subgroup analyses.. Although our findings provided no support for the hypothesis that serum C-peptide concentration is associated with excess risk of prostate cancer, people must pay attention to this aspect and increase physical activity or modify dietary habits to constrain insulin secretion, which possibly lead to decreased incidence of prostate cancer. Hence, well-designed observational studies involving different ethnic populations are still needed.

Topics: C-Peptide; Humans; Male; Observational Studies as Topic; Prostatic Neoplasms; Risk Factors

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.

Topics: Androgens; C-Peptide; Diabetes Mellitus, Type 2; Glycated Hemoglobin; Humans; Male; Prostate-Specific Antigen; Prostatic Neoplasms; Risk Factors; United States

Obesity is associated with a higher risk of aggressive prostate cancer and alters circulating levels of insulin and adiponectin, two hormones that influence biologic processes implicated in carcinogenesis. Results of some studies showed associations of circulating levels of adiponectin, insulin, and c-peptide (a marker of insulin secretion) with aggressive prostate cancer, but the size of these studies was limited.. A nested case-control study of 272 aggressive prostate cancer cases [Gleason score ≥ 7 (4+3) or T3-T4] and 272 age- and race-matched controls from the Cancer Prevention Study II Nutrition Cohort was conducted to determine the associations of prediagnostic plasma levels of c-peptide and adiponectin with risk of aggressive prostate cancer.. Neither circulating adiponectin nor c-peptide was associated with risk of aggressive prostate cancer. In analyses of the highest-risk aggressive prostate cancer (Gleason score ≥ 8 or T3-T4), the highest quartile of c-peptide, compared with the lowest, was associated with an OR of 1.41 [95% confidence interval (CI), 0.72-2.78].. Our findings provide no support for the hypothesis that adiponectin is associated with risk of aggressive prostate cancer but a possible association of high levels of c-peptide with particularly high-risk prostate cancer cannot be ruled out.. These results indicate that changes in circulating levels of adiponectin and c-peptide do not play an important role in risk of aggressive prostate cancer.

Topics: Adiponectin; Aged; Biomarkers; C-Peptide; Case-Control Studies; Cohort Studies; Follow-Up Studies; Humans; Insulin; Male; Neoplasm Staging; Nutritional Status; Obesity; Prognosis; Prostate; Prostatic Neoplasms; Risk Factors

Hyperinsulinemia and obesity-related metabolic disturbances are common and have been associated with increased cancer risk and poor prognosis. To investigate this issue in relation to prostate cancer, we conducted a nested case-control study within the Prostate Cancer Prevention Trial (PCPT), a randomized, placebo-controlled trial testing finasteride versus placebo for primary prevention of prostate cancer. Cases (n = 1,803) and controls (n = 1,797) were matched on age, PCPT treatment arm, and family history of prostate cancer; controls included all eligible non-whites. Baseline bloods were assayed for serum C-peptide (marker of insulin secretion) and leptin (an adipokine) using ELISA. All outcomes were biopsy determined. Logistic regression calculated odds ratios (OR) for total prostate cancer and polytomous logistic regression calculated ORs for low-grade (Gleason <7) and high-grade (Gleason >7) disease. Results were stratified by PCPT treatment arm for C-peptide. For men on placebo, higher versus lower serum C-peptide was associated with a nearly 2-fold increased risk of high-grade prostate cancer (Gleason >7; multivariate-adjusted OR, 1.88; 95% confidence interval, 1.19-2.97; P(trend) = 0.004). When C-peptide was modeled as a continuous variable, every unit increase in log(C-peptide) resulted in a 39% increased risk of high-grade disease (P = 0.01). In contrast, there was no significant relationship between C-peptide and high-grade prostate cancer among men receiving finasteride. Leptin was not independently associated with high-grade prostate cancer. In conclusion, these results support findings from other observational studies that high serum C-peptide and insulin resistance, but not leptin, are associated with increased risk of high-grade prostate cancer. Our novel finding is that the C-peptide-associated risk was attenuated by use of finasteride.

Topics: C-Peptide; Case-Control Studies; Enzyme Inhibitors; Enzyme-Linked Immunosorbent Assay; Finasteride; Humans; Insulin Resistance; Leptin; Male; Middle Aged; Prostatic Neoplasms; Risk Factors

The association between plasma C-peptide concentration and prostate cancer is unclear. Inconsistency of results from previous studies motivates this study. Using the Japan Public Health Center-based Prospective study, 201 prostate cancer cases and 402 controls were matched by age, public health center area, residence, date and time of blood collection, and fasting duration before blood collection. Odds ratios (OR) and 95% confidence intervals (CIs) were estimated by conditional logistic regression models. Out of 201 cases, 144 were localized and 48 were advanced. The overall association between median plasma C-peptide concentration and prostate cancer was not significant (OR for the highest tertile=0.81, 95% CI: 0.43-1.56, P-trend=0.54). Although stratification of prostate cancer by stage indicated different effects of plasma C-peptide on localized and advanced cases, there was no association between plasma C-peptide concentration and advanced prostate cancer (OR=2.82, 95% CI: 0.30-26.36 for the highest category, P-trend=0.37) and localized cases (OR=0.49, 95% CI: 0.23-1.04 for the highest category, P-trend=0.06) for patients fasting at the time of blood collection. The association between plasma C-peptide concentration and prostate cancer risk differed by cancer stage. Differentiation of localized and advanced prostate cancer cases is crucial when investigating the association between plasma C-peptide concentration and the risk of prostate cancer.

Topics: Adult; C-Peptide; Case-Control Studies; Humans; Japan; Logistic Models; Male; Middle Aged; Neoplasm Staging; Odds Ratio; Prospective Studies; Prostate; Prostatic Neoplasms; Risk Factors

Obesity and age, key risk factors for aggressive prostate cancer, are associated with insulin resistance. Glucose-related parameters in patients with aggressive prostate cancer were compared with 2 reference groups: men of similar age and body mass index (BMI) without cancer, and healthy young men. Acute changes in these parameters following radiation treatment were also evaluated.. Nine patients with aggressive prostate cancer underwent metabolic assessments prior to treatment (baseline), 7 and 33 weeks post-baseline (post-treatment initiation). Baseline measures were compared with the 2 reference groups. Evaluations included: 1) fasting and oral glucose tolerance test (OGTT) blood samples for glucose, C-peptide, and insulin, 2) fasting blood samples for triglycerides, cholesterols, leptin, adiponectin, IL-6, and TNF-α, 3) body composition, 4) nutrition, and 5) physical activity.. At baseline, patients had normal fasting glucose concentrations (<5.6 mM; 4.9 ± 1.2 mM) but impaired 2-h OGTT glucose concentrations (>7.8 mM; 8.7 ± 2.9 mM). Both reference groups had normal fasting (matched males: 4.2 ± 0.5 mM; young males: 3.7 ± 0.4 mM) and 2-h OGTT glucose concentrations (matched males: 5.6 ± 1.8 mM; young males: 3.1 ± 0.1 mM) that were significantly lower than patient values. During the OGTT, patients had higher insulin (120 min) and C-peptide (45, 60, 90, 120 min) concentrations compared to the matched males. At 7 weeks, 2-h OGTT glucose concentrations in patients improved to healthy ranges without changes in insulin, C-peptide, IGF-1, IGFBP-3 or other metabolic parameters.. At baseline patients with aggressive prostate cancer demonstrated impaired glucose tolerance compared with men of similar age and body size. Following treatment, glucose tolerance improved in the absence of changes in expected modifiers of glucose metabolism. These improvements may be related to treatment.

Topics: Adult; Age Factors; Aged; Blood Glucose; Body Mass Index; C-Peptide; Case-Control Studies; Glucose Intolerance; Humans; Insulin-Like Growth Factor I; Male; Middle Aged; Obesity; Prostatic Neoplasms; Young Adult

Prostate cancer development is associated with numerous lifestyle factors (i.e., physical activity, nutrition intake) and metabolic perturbations. These factors have been studied independently; here, we used an integrative approach to characterize these lifestyle and metabolic parameters in men undergoing diagnostic prostate biopsies.. We prospectively evaluated 51 consecutive men for body composition, metabolic factors including glucose- and lipid-related measures, as well as lifestyle factors prior to prostate biopsy. Evaluations were performed in a blinded manner and were subsequently related to biopsy outcomes for: (i) presence or absence of cancer; and (ii) where cancer was present, Gleason score.. Serum C-peptide concentrations were significantly greater in participants with Gleason scores ≥4 + 3 (2.8 ± 1.1 ng/ml) compared to those with Gleason 3 + 3 (1.4 ± 0.6 ng/ml) or Gleason 3 + 4 (1.3 ± 0.8 ng/ml, P = 0.002), suggesting greater insulin secretion despite lack of differences in fasting glucose concentrations. Central adiposity, measured by waist circumference, was significantly greater in participants with Gleason ≥4 + 3 (110.1 ± 7.4 cm) compared to those with Gleason 3 + 4 (102.0 ± 9.5 cm, P = 0.028). Men with Gleason ≥4 + 3 also had significantly greater leptin concentrations than those with lower Gleason scores (Gleason ≥4 + 3: 15.6 ± 3.3 ng/ml vs. Gleason 3 + 4: 8.1 ± 8.1 ng/ml, P < 0.05) and leptin:adiponectin ratio (Gleason ≥4 + 3: 9.7 ± 6.1 AU, Gleason 3 + 4: 2.9 ± 3.2, Gleason 3 + 3: 2.4 ± 2.1 AU, P = 0.013).. We profiled a cluster of obesity-related metabolic perturbations (C-peptide, central adiposity, leptin, and leptin:adiponectin ratios) which may associate with more aggressive prostate cancer histology. Prostate 77:211-221, 2017. © 2016 Wiley Periodicals, Inc.

Topics: Adipokines; Aged; Aged, 80 and over; Biomarkers, Tumor; Body Composition; C-Peptide; Humans; Male; Middle Aged; Neoplasm Grading; Obesity, Abdominal; Prospective Studies; Prostatic Neoplasms; Risk Factors; Waist Circumference

Hyperinsulinemia is hypothesized to influence prostate cancer risk. Thus, we evaluated the association of circulating C-peptide, which is a marker of insulin secretion, and leptin, which is secreted in response to insulin and influences insulin sensitivity, with prostate cancer risk.. We identified prostate cancer cases (n = 1,314) diagnosed a mean of 5.4 years after blood draw and matched controls (n = 1,314) in the Health Professionals Follow-up Study. Plasma C-peptide and leptin concentrations were measured by ELISA. Odds ratios (ORs) and 95 % confidence intervals (CI) were estimated taking into account the matching factors age and history of a PSA test before blood draw and further adjusting for body mass index, diabetes, and other factors.. Neither C-peptide (quartile [Q]4 vs. Q1: OR 1.05, 95 % CI 0.82-1.34, p-trend = 0.95) nor leptin (Q4 vs. Q1: OR 0.85, 95 % CI 0.65-1.12, p-trend = 0.14) was associated with prostate cancer risk. Further, neither was associated with risk of advanced or lethal disease (n = 156 cases; C-peptide: Q4 vs. Q1, OR 1.18, 95 % CI 0.69-2.03, p-trend = 0.78; leptin: Q4 vs. Q1, OR 0.74, 95 % CI 0.41-1.36, p-trend = 0.34).. In this large prospective study, circulating C-peptide and leptin concentrations were not clearly associated with risk of prostate cancer overall or aggressive disease. Well into the PSA era, our findings do not appear to be supportive of the hypothesis that hyperinsulinemia influences risk of total or aggressive prostate cancer.

Topics: Aged; C-Peptide; Case-Control Studies; Cell Growth Processes; Cohort Studies; Follow-Up Studies; Humans; Incidence; Leptin; Male; Middle Aged; Prospective Studies; Prostatic Neoplasms; Risk Factors; Surveys and Questionnaires

Diabetes, characterized by perturbations in insulin production and signaling, is inversely associated with prostate cancer risk irrespective of stage. Obesity, a diabetes risk factor, is inversely associated with localized disease but positively associated with advanced disease. To understand the complex association between hyperinsulinemia and prostate cancer, we evaluated the association of plasma C-peptide, an insulin secretion marker, with prostate cancer risk in a case-control study nested in a prospective community cohort. Prostate cancer cases (n = 264) and matched controls (n = 264) were identified in the CLUE II cohort between 1989 (baseline) and 2002. C-peptide concentration was measured in baseline plasma by ELISA. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated using conditional logistic regression, adjusting for being overweight or obese and family history. Median C-peptide concentration was lower in cases (1,180 pmol/L) than in controls (1,365 pmol/L; P = 0.03). Men in the highest (versus lowest) fourth of C-peptide had a lower risk for prostate cancer (OR, 0.65; 95% CI, 0.37-1.14; P-trend = 0.08), primarily localized disease (OR, 0.44; 95% CI, 0.19-1.03; P-trend = 0.04). Associations were similar to overall, when excluding cases diagnosed during the first 5 years of follow-up, men with diabetes, or men who had not had a prostate-specific antigen test. C-peptide concentration was inversely associated with subsequent diagnosis of prostate cancer, primarily localized disease, similar to the association for obesity. However, we cannot rule out detection bias that might result if men with higher C-peptide have lower prostate-specific antigen irrespective of whether prostate cancer is present or not.

Topics: Aged; Aged, 80 and over; Body Mass Index; C-Peptide; Case-Control Studies; Cohort Studies; Enzyme-Linked Immunosorbent Assay; Humans; Hyperinsulinism; Incidence; Male; Middle Aged; Neoplasm Staging; Obesity; Prostatic Neoplasms; Risk Factors

Rye whole grain and bran intake has shown beneficial effects on prostate cancer progression in animal models, including lower tumor take rates, smaller tumor volumes, and reduced prostate specific antigen (PSA) concentrations. A human pilot study showed increased apoptosis after consumption of rye bran bread. In this study, we investigated the effect of high intake of rye whole grain and bran on prostate cancer progression as assessed by PSA concentration in men diagnosed with prostate cancer. Seventeen participants were provided with 485 g rye whole grain and bran products (RP) or refined wheat products with added cellulose (WP), corresponding to ~50% of daily energy intake, in a randomized controlled, crossover design. Blood samples were taken from fasting men before and after 2, 4, and 6 wk of treatment and 24-h urine samples were collected before the first intervention period and after treatment. Plasma total PSA concentrations were lower after treatment with RP compared with WP, with a mean treatment effect of -14% (P = 0.04). Additionally, fasting plasma insulin and 24-h urinary C-peptide excretion were lower after treatment with RP compared with WP (P < 0.01 and P = 0.01, respectively). Daily excretion of 5 lignans was higher after the RP treatment than after the WP treatment (P < 0.001). We conclude that whole grain and bran from rye resulted in significantly lower plasma PSA compared with a cellulose-supplemented refined wheat diet in patients with prostate cancer. The effect may be related to inhibition of prostate cancer progression caused by decreased exposure to insulin, as indicated by plasma insulin and urinary C-peptide excretion.

Topics: C-Peptide; Dietary Fiber; Humans; Insulin; Male; Prostate-Specific Antigen; Prostatic Neoplasms; Secale; Triticum

Recent epidemiologic studies have identified obesity as a risk factor for benign prostatic hyperplasia (BPH). We examined whether adiponectin, leptin, and C-peptide were associated with incident, symptomatic BPH and whether these factors mediate the relationship between obesity and BPH risk.. Data are from Prostate Cancer Prevention Trial placebo arm participants who were free of BPH at baseline. Incident BPH (n = 698) was defined as treatment, two International Prostate Symptom Score (IPSS) values > 14, or an increase of >or=5 in IPSS from baseline documented on at least two occasions plus at least one score >or=12. Controls (n = 709) were selected from men reporting no BPH treatment or IPSS > 7 during the 7-year trial. Baseline serum was analyzed for adiponectin, C-peptide, and leptin concentrations.. Neither C-peptide nor leptin was associated with BPH risk. The odds ratio [95% CI] contrasting highest to lowest quartiles of adiponectin was 0.65[0.47, 0.87] P(trend) = 0.004. Findings differed between levels of physical activity: there was a strong inverse association between adiponectin and BPH among moderately/very active men OR = 0.43 [0.29, 0.63], and no association among sedentary/minimally active men OR = 0.92 [0.65, 1.30] P(interaction) = 0.005. Adiponectin concentrations explained only a moderate amount of the relationship between obesity and BPH risk.. High adiponectin concentrations were associated with reduced risk of incident, symptomatic BPH. This association was limited to moderately/very active men; suggesting the relationship between obesity and BPH involves a complex interaction between factors affecting glucose uptake and insulin sensitivity. However, adiponectin is likely not the only mechanism through which obesity affects BPH risk.

Topics: Adiponectin; Aged; C-Peptide; Case-Control Studies; Disease Progression; Humans; Insulin Resistance; Leptin; Male; Middle Aged; Obesity; Prostatic Hyperplasia; Prostatic Neoplasms; Risk Factors; Washington

Excess body-mass index (BMI) has been associated with adverse outcomes in prostate cancer, and hyperinsulinaemia is a candidate mediator, but prospective data are sparse. We assessed the effect of prediagnostic BMI and plasma C-peptide concentration (reflecting insulin secretion) on prostate cancer-specific mortality after diagnosis.. This study involved men diagnosed with prostate cancer during the 24 years of follow-up in the Physicians' Health Study. BMI measurements were available at baseline in 1982 and eight years later in 1990 for 2546 men who developed prostate cancer. Baseline C-peptide concentration was available in 827 men. We used Cox proportional hazards regression models controlling for age, smoking, time between BMI measurement and prostate cancer diagnosis, and competing causes of death to assess the risk of prostate cancer-specific mortality according to BMI and C-peptide concentration.. Of the 2546 men diagnosed with prostate cancer during the follow-up period, 989 (38.8%) were overweight (BMI 25.0-29.9 kg/m(2)) and 87 (3.4%) were obese (BMI >/=30 kg/m(2)). 281 men (11%) died from prostate cancer during this follow-up period. Compared with men of a healthy weight (BMI <25 kg/m(2)) at baseline, overweight men and obese men had a significantly higher risk of prostate cancer mortality (proportional hazard ratio [HR] 1.47 [95% CI 1.16-1.88] for overweight men and 2.66 [1.62-4.39] for obese men; p(trend)<0.0001). The trend remained significant after controlling for clinical stage and Gleason grade and was stronger for prostate cancer diagnosed during the PSA screening era (1991-2007) compared with during the pre-PSA screening era (1982-1990) or when using BMI measurements obtained in 1990 compared with those obtained in 1982. Of the 827 men with data available for baseline C-peptide concentration, 117 (14%) died from prostate cancer. Men with C-peptide concentrations in the highest quartile (high) versus the lowest quartile (low) had a higher risk of prostate cancer mortality (HR 2.38 [95% CI 1.31-4.30]; p(trend)=0.008). Compared with men with a BMI less than 25 kg/m(2) and low C-peptide concentrations, those with a BMI of 25 kg/m(2) or more and high C-peptide concentrations had a four-times higher risk of mortality (4.12 [1.97-8.61]; p(interaction)=0.001) independent of clinical predictors.. Excess bodyweight and a high plasma concentration of C-peptide both predispose men with a subsequent diagnosis of prostate cancer to an increased likelihood of dying of their disease. Patients with both factors have the worst outcome. Further studies are now needed to confirm these findings.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Body Mass Index; C-Peptide; Case-Control Studies; Follow-Up Studies; Humans; Hyperinsulinism; Kaplan-Meier Estimate; Male; Middle Aged; Multivariate Analysis; Obesity; Physicians; Proportional Hazards Models; Prostate-Specific Antigen; Prostatic Neoplasms; Risk Factors; United States

Topics: C-Peptide; Humans; Hyperinsulinism; Life Style; Male; Obesity; Prostatic Neoplasms

Prior studies report slightly lower prostate-specific antigen (PSA) levels among obese men. To understand this effect, we investigated the association between PSA and blood HbA1c, C-peptide, leptin and adiponectin levels in African-American (AA) (n=121) and Caucasian (CA) (n=121) men. Among AA men, PSA levels decreased with increasing C-peptide levels (PSA=0.99, 0.93, 0.75 and 0.53 ng ml(-1) across quartiles of C-peptide, respectively; P(trend)=0.005). Among CA men, PSA levels decreased with increasing HbA1c (PSA=0.84, 0.73, 0.77 and 0.45 ng ml(-1) across quartiles of HbA1c, respectively; P(trend)=0.005). This may suggest that metabolic disturbances related to metabolic syndrome or diabetes affect the ability to detect early-stage prostate cancer.

Topics: Adiponectin; Adult; Aged; Black or African American; Body Mass Index; C-Peptide; Cohort Studies; Diabetes Complications; Early Diagnosis; Glycated Hemoglobin; Humans; Leptin; Male; Metabolic Syndrome; Middle Aged; Prostate-Specific Antigen; Prostatic Neoplasms; White People

Previous studies suggest men with diabetes may be at reduced risk for prostate cancer as compared to men without diabetes. To investigate potential biological mechanisms, hormonal profiles of diabetic men and non-diabetic controls were compared.. In the Health Professionals Follow-Up Study, plasma levels of C-peptide, testosterone, sex-hormone binding globulin, insulin-like growth factor-1, and insulin-like growth factor binding protein-3 were determined in 171 diabetic men and 3,001 non-diabetic controls. Multiple linear regression analysis was conducted and least square means were calculated for hormones of interest.. Plasma levels of several hormones either < or =1, 1.1-6, 6.1-14.9, or > or =15 years after diagnosis with diabetes were examined. As time since diabetes diagnosis increased, plasma levels of C-peptide and IGFBP-3 significantly decreased (p for trend: C-peptide =.05, IGFBP-3 =.03). While testosterone and SHBG levels both significantly increased with increasing time since diabetes diagnosis (p for trend: testosterone =.02, SHBG =.002), the ratio of testosterone to SHBG decreased, suggesting a reduction in bioavailable testosterone. Plasma IGF-1 levels were lower in diabetics than non-diabetics, but no significant time trend was noted.. This study of hormonal profiles of diabetic versus non-diabetic men identified changes in diabetic men that may be consistent with reduced prostate cancer risk.

Topics: Adult; Aged; C-Peptide; Case-Control Studies; Diabetes Mellitus; Humans; Insulin-Like Growth Factor Binding Protein 3; Insulin-Like Growth Factor I; Linear Models; Male; Middle Aged; Prospective Studies; Prostatic Neoplasms; Risk; Sex Hormone-Binding Globulin; Surveys and Questionnaires; Testosterone; Time Factors

Factors related to insulin resistance have been implicated in prostate cancer development, however, few analytical studies support such an association. We performed a case control study on 392 prostate cancer cases and 392 matched controls nested in a prospective cohort in Northern Sweden. Plasma concentrations of C-peptide, leptin, glycated haemoglobin (HbA1c) and fasting and post-load glucose were analysed and homeostatic model assessment of insulin resistance (HOMA-IR) was calculated. Conditional logistic regression analyses were used to calculate odds ratios (OR) of prostate cancer. High levels of C-peptide, HOMA-IR, leptin and HbA1c were associated with significant decreases in risk of prostate cancer, with ORs for top vs. bottom quartile for C-peptide of 0.59 (95% Confidence Interval [CI], 0.40-0.89; p(trend) = 0.008), HOMA-IR 0.60 (95% CI, 0.38-0.94; p(trend) = 0.03), leptin 0.55 (95% CI, 0.36-0.84; p(trend) = 0.006) and HbA1c 0.56 (95% CI, 0.35-0.91; p(trend) = 0.02). All studied factors were strongly inversely related to risk among men less than 59 years of age at blood sampling, but not among older men, with a significant heterogeneity between the groups for leptin (p(heterogeneity) = 0.006) and fasting glucose (p(heterogeneity) = 0.03). C-peptide and HOMA-IR were strongly inversely related to non-aggressive cancer but were non-significantly positively related to risk of aggressive disease (p(heterogeneity) = 0.007 and 0.01, respectively). Our data suggest that androgens, which are inversely associated with insulin resistance, are important in the early prostate cancer development, whereas insulin resistance related factors may be important for tumour progression.

Topics: Blood Glucose; Body Mass Index; C-Peptide; Case-Control Studies; Fasting; Glycated Hemoglobin; Homeostasis; Humans; Insulin; Insulin Resistance; Leptin; Logistic Models; Lymphatic Metastasis; Male; Odds Ratio; Prospective Studies; Prostate-Specific Antigen; Prostatic Neoplasms; Risk Factors; Sweden

Topics: Biomarkers, Tumor; C-Peptide; Case-Control Studies; Dehydroepiandrosterone; Early Diagnosis; Follow-Up Studies; Humans; Male; Prostatic Neoplasms; Regression Analysis; Risk Factors; Statistics as Topic; Testosterone

Excessive energy intake tends to increase circulating levels of insulin and free insulin-like growth factor-1 (IGF-I), which may increase risk of some cancers that are common in Western countries. However, the relative importance of these hormonal factors during pre-adulthood and adulthood is unknown.. We prospectively examined height, as a marker of pre-adult IGF-I bioactivity, and modifiable adult determinants of insulin secretion, in relation to risk of cancer, particularly Western-related cancers (colon, pancreas, kidney, and aggressive prostate cancers) in 47,690 male health professionals. Information about dietary and lifestyle factors for these men was collected at baseline (1986) and was updated periodically. A C-peptide score, representing insulin secretion, was created by using body mass, physical activity, and diet in a stepwise linear regression to predict C-peptide level, in a sample of 263 cohort members.. From 1986 to 1998, we documented 3270 incident cancers (excluding the less aggressive prostate cancers). Greater body mass index, lower physical activity, and a Western dietary pattern were independent predictors of higher plasma C-peptide levels in the sample. A C-peptide score, based on these variables, was positively related to risk of Western-related cancers, but not to other cancer types in the entire cohort. Height was also only related to Western-related cancers. For Western-related cancers, 29% (95% CI: 16%, 48%) were attributed to C-peptide scores above the first decile, 30% (95% CI: 11%, 58%) to heights >or=66 inches, and 49% (95% CI: 30%, 69%) to both factors combined. For total cancers, 29% (95% CI: 16%, 46%) were attributable to both factors.. Maximal growth in the pre-adult period and hyperinsulinaemia during adulthood may largely underlie the excess risk of some cancers that are common in Western populations. A substantial proportion of these cancers may be modifiable in adulthood, through alterations in body weight, sedentary behaviour, and dietary patterns that stimulate hyperinsulinaemia.

Topics: Adult; Aged; Body Height; Body Mass Index; C-Peptide; Diet; Exercise; Humans; Insulin; Insulin-Like Growth Factor I; Male; Middle Aged; Neoplasms; Prospective Studies; Prostatic Neoplasms; Risk Factors; United States

Topics: Aged; C-Peptide; Diabetes Complications; Diabetes Mellitus; Disease Progression; Follicle Stimulating Hormone; Hormone Antagonists; Humans; Luteinizing Hormone; Male; Orchiectomy; Progesterone; Prostatic Neoplasms

A series of 229 patients with urogenital carcinomas were investigated for aberrant peptide hormone activities. Serum TSH and prolactin were frequently measured in elevated levels and showed some relation to the stage of disease. Ectopic production of beta-HCG was not observed in any of the cases, thyroid and steroid hormones did not exceed the normal ranges.

Topics: Adenocarcinoma; Antibodies; C-Peptide; Cross Reactions; Female; Follicle Stimulating Hormone; Humans; Kidney Neoplasms; Luteinizing Hormone; Male; Peptides; Pituitary Hormones; Prolactin; Prostatic Hyperplasia; Prostatic Neoplasms; Thyrotropin; Urinary Bladder Neoplasms; Urogenital Neoplasms

Patients with benign hyperplasia of the prostate and with anaplastic carcinoma have similar activities in their cells in staining for acid phosphatase. After therapy with estrogens the acid phosphatase is significantly inhibited, leucin amino peptidase and succinate dehydrogenase appear to be reactivated in the cells of anaplastic carcinoma. Serum TSH is decreased distinctly, serum levels of LH and prolactin are significantly elevated especially in patients with anaplastic carcinoma of the prostate in comparison to that of patients with treated benign hyperplasia.

Topics: Acid Phosphatase; C-Peptide; Carcinoma; Enzymes; Estrogens; Fibrinolysin; Follicle Stimulating Hormone; Hormones; Humans; Leucyl Aminopeptidase; Luteinizing Hormone; Male; Prolactin; Prostatic Hyperplasia; Prostatic Neoplasms; Succinate Dehydrogenase; Thyrotropin