Body Composition, Abdominal Fat Distribution, and Prostate-Specific Antigen Test Results

Business Travel and Behavioral and Mental Health

OBJECTIVE

Assess associations between business travel and behavioral and mental health.

METHODS

Cross-sectional analyses of de-identified electronic medical record data from EHE International, Inc. a provider of corporate wellness programs.

RESULTS

Higher levels of business travel were associated with poorer outcomes. Compared with traveling 1 to 6 nights/mo for work, those who traveled 21+ nights were more likely to: smoke (prevalence ratio [PR] = 3.74, 95% confidence interval [CI] 2.56, 5.46), report trouble sleeping (PR = 1.37, 95% CI 1.09, 1.71), be sedentary (PR = 1.95, 95% CI 1.56, 2.43), and score above clinical thresholds for alcohol dependence (CAGE score >1: PR = 2.04, 95% CI 1.26, 3.29), and mild or worse anxiety (Generalized Anxiety Scale [GAD-7] score >4: PR = 1.69, 95% CI 1.29, 2.21), and depression symptoms (Patient Health Questionnaire [PHQ-9] score >4: PR = 2.27, 95% CI 1.70, 3.03).

CONCLUSIONS

Employers should provide programs to help employees manage stress and maintain health while traveling for work.

Estrogens and prostate cancer

BACKGROUND

Hormonal influences such as androgens and estrogens are known contributors in the development and progression of prostate cancer (CaP). While much of the research to the hormonal nature of CaP has focused on androgens, estrogens also have critical roles in CaP development, physiology as well as a potential therapeutic intervention.

METHODS

In this review, we provide a critical literature review of the current basic science and clinical evidence for the interaction between estrogens and CaP.

RESULTS

Estrogenic influences in CaP include synthetic, endogenous, fungi and plant-derived compounds, and represent a family of sex hormones, which cross hydrophobic cell membranes and bind to membrane-associated receptors and estrogen receptors that localize to the nucleus triggering changes in gene expression in various organ systems.

CONCLUSIONS

Estrogens represent a under-recognized contributor in CaP development and progression. Further research in this topic may provide opportunities for identification of environmental influencers as well as providing novel therapeutic targets in the treatment of CaP.

Body mass index as a classifier to predict biochemical recurrence after radical prostatectomy in patients with lower prostate-specific antigen levels

Prostate cancer, one of the most common malignant tumors among men, is closely associated with obesity and, thus far, several studies have suggested the association between obesity and aggressive pathological characteristics in the United States. However, the effect of obesity on prostate cancer mortality is controversial, and it remains unclear whether obesity contributes to the aggressiveness of prostate cancer in Asian patients. The aim of the present study was to investigate the association between body mass index (BMI) and the clinicopathological characteristics of prostate cancer in 2,003 Japanese patients who underwent radical prostatectomy. There was a significant association between higher BMI and higher Gleason score (GS). The multivariate analysis also revealed that BMI was an independent indicator for GS ≥8 at surgery. Moreover, among patients with lower prostate-specific antigen levels, biochemical recurrence-free survival was significantly worse in those with higher BMI. These results suggest that BMI may be a classifier for predicting adverse pathological findings and biochemical recurrence after radical prostatectomy in Japanese patients.

Comparison of anthropometric and body composition measures as predictors of components of the metabolic syndrome in a clinical setting

PROBLEM

The use of body mass index (BMI) to assess obesity and health risks has been criticized in scientific and lay publications because of its failure to account for body shape and inability to distinguish fat mass from lean mass. We sought to determine whether other anthropometric measures (waist circumference (WC), waist-to-height ratio (WtH), percent body fat (%BF), fat mass index (FMI), or fat-free mass index (FFMI)) were consistently better predictors of components of the metabolic syndrome than BMI is.

METHODS

Cross-sectional measurements of height, weight, waist circumference and percent body fat were obtained from 12,294 adults who took part in annual physical exams provided by EHE International, Inc. Blood pressure was measured during the exam and HDL, LDL, and fasting glucose were measured from blood samples. Pearson correlations, linear regression, and adjusted Receiver Operator Characteristic (ROC) curves were used to relate each anthropometric measure to each metabolic risk factor.

RESULTS

None of the measures was consistently the strongest predictor. BMI was the strongest predictor of blood pressure, measures related to central adiposity (WC and WtH) performed better at predicting fasting glucose, and all measures were roughly comparable at predicting cholesterol levels. In all, differences in areas under ROC curves were 0.03 or less for all measure/outcome pairs that performed better than BMI.

CONCLUSION

Body mass index is an adequate measure of adiposity for clinical purposes. In the context of lay press critiques of BMI and recommendations for alternative body-size measures, these data support clinicians making recommendations to patients based on BMI measurements.

Obese men have more advanced and more aggressive prostate cancer at time of surgery than non-obese men after adjusting for screening PSA level and age: results from two independent nested case-control studies

BACKGROUND:

It remains unclear whether the hemodilution effect of body mass index (BMI) on PSA levels translates to inappropriate prostate cancer (PCa) screening in obese men. To address this, we conducted two nested case–control studies within prospective cohorts of men undergoing radical prostatectomy for newly diagnosed PCa.

METHODS:

We identified 1817 men with BMI ⩾30 kg m⁻² (cases) and 1244 men with BMI <25 kg m⁻² (controls) who underwent surgery to treat PCa at Mayo Clinic in Rochester between 2000 and 2009. Cases and controls were frequency matched on age and PSA level. In a similar manner, we identified 206 cases and 133 controls treated at Mayo Clinic in Florida between 2006 and 2011. We employed logistic regression models to evaluate the association of pathologic features of aggressiveness with obesity status.

RESULTS:

After adjusting for age and PSA level, we noted that obese men in the Rochester population are more likely to present with Gleason grade 8–10 tumors (OR= 1.50; 95% CI 1.14–1.96; P=0.003) and pT3, pT4, pTxN+ stage disease (OR=1.30; 95% CI 1.05–1.62). We noted a similar association seminal vesicle involvement (OR= 1.41; 95% CI 1.03–1.92; P=0.03). Results from the smaller Florida population supported these same associations but did not achieve conventional statistical significance.

CONCLUSIONs:

Obese men present with more aggressive PCa tumors compared with non-obese men of similar age and PSA screening values. If confirmed, this would support the need to explore PSA-based screening in obese men to possibly account for a hemodilution effect.

The prognostic value of pathologic prostate-specific antigen mass ratio in patients with localized prostate cancer with negative surgical resection margins

OBJECTIVE

To investigate potential predictors of biochemical recurrence (BCR) in patients with localized prostate cancer with negative surgical resection margin (SRM).

MATERIALS AND METHODS

Data from 582 consecutive patients diagnosed with localized prostate cancer with negative SRM who underwent only radical prostatectomy between November 2003 and April 2010 were reviewed. Pathologic prostate-specific antigen (PSA) mass ratio was defined as total circulating PSA protein per surgical prostate volume. Cox regression models tested the association between clinicopathologic variables and BCR-free survival.

RESULTS

Mean age at surgery was 64.9 ± 6.9 years and mean PSA was 8.3 ± 4.4 ng/mL. The mean follow-up period was 40.7 ± 7.9 months. Pathologic stage was T2a in 113 of 582 patients (19.3%), T2b in 4 of 582 (0.7%), and T2c in 465 of 582 (79.9%). Surgical Gleason score was ≤6 in 215 of 582 patients (37.0%), 7 in 342 of 582 (58.8%), and ≥8 in 25 of 582 (4.3%). Mean pathologic prostate volume and pathologic PSA mass ratio were 42.4 ± 15.8 mL (14.6-176.0 mL) and 0.48 ± 0.37 μg/mL (0.03-2.62 μg/mL), respectively. Five-year BCR-free survival rate was 90.9%. PSA, surgical Gleason score, and pathologic PSA mass ratio were significantly associated with BCR-free survival in univariate analysis. In multivariate analysis, surgical Gleason score (P <.001, hazards ratio = 9.804) and pathologic PSA mass ratio (P = .037, hazards ratio = 3.753) were independent predictors of BCR-free survival.

CONCLUSION

In patients with localized prostate cancer and negative SRM after radical prostatectomy, surgical Gleason score and pathologic PSA mass ratio were significant prognostic indicators of BCR-free survival.

Relationship between prostate-specific antigen, age, and body mass index in a prostate cancer screening population

BACKGROUND

Recent studies questioning the benefit of prostate-specific antigen (PSA) screening have increased the need for evaluating factors contributing to variance in levels and their clinical relevance. An inverse relationship between body mass index (BMI) and PSA has been illustrated, however the clinical implications have not been specified. We performed a retrospective review of patients screened through our free screening clinic to delineate any relationship between PSA and BMI in an attempt to understand its possible clinical significance.

METHODS

The authors retrospectively reviewed data collected in relation to PSA values and patient characteristics from a community outreach program supplying information and screening for prostate cancer between June of 2003 and August of 2009.

RESULTS

Mean BMI of our patient population was 28.7 m/kg(2) (SD 5.4) and our mean PSA value was 1.28 (SD 1.77). Our data indicate a small, but statistically significant decrease in PSA for an increasing BMI with a 0.026 decrease in PSA for every unit increase in BMI.

CONCLUSIONS

Our study confirms the previously reported inverse relationship between PSA value and BMI. The significance of this finding and its impact on the value do not seem to indicate a rationale to change the accepted abnormal value in obese patients and should be used in the context of the clinical scenario and other PSA altering factors.

Which obesity index best correlates with prostate volume, prostate-specific antigen, and lower urinary tract symptoms?

OBJECTIVE

To determine which measurement variable, waist circumference (WC), body mass index (BMI), or waist-to-hip ratio (WHR) is most closely related to the prostate volume (PV), prostate-specific antigen (PSA), and lower urinary tract symptoms (LUTS).

METHODS

Between January 2010 and September 2011, 1632 consecutive ostensibly healthy Korean men aged 40-69 years who visited our clinic for a prostate checkup were enrolled into the study. Exclusion criteria included pyuria, history of lower urinary tract disorder influencing urination, and a high PSA level of >3.0 ng/mL. All men underwent a detailed clinical evaluation using the International Prostate Symptom Score (I-PSS) questionnaire. Anthropometric measurements were determined. Serum PSA, urinalysis, and transrectal ultrasound were also performed.

RESULTS

Data from 1601 men were analyzed. The mean age was 51.6 years, WC 83.7 cm, BMI 24.8 kg/m(2), PV 24.6 mL, and the mean PSA level was 1.07 ng/mL. Using multivariate analysis, PV most positively associated with WC (P < .001), while PSA level had negatively associated with BMI (P = .036) and no significant association with WC or WHR was noted. There was no significant relationship between various obesity indexes and I-PSS.

CONCLUSION

Our data showed that PV positively associated with central obesity, as represented by WC. In contrast, serum PSA negatively associated with BMI, which represented overall obesity (ie, hemodilution). Our data also suggested that obesity is not associated with lower urinary tract symptoms in Korean men.

Prostate cancer in elderly Croatian men: 5-HT genetic polymorphisms and the influence of androgen deprivation therapy on osteopenia--a pilot study

BACKGROUND

The aim of this study was to determine the relationship between body mass index, biochemical parameters, and 5-hydroxytryptamine (5-HT) genetic polymorphisms and prostate dysfunction in an elderly general male population.

RESULTS

One hundred and seventeen elderly male subjects [60 men without symptoms of prostate hyperplasia, 42 men with untreated benign prostatic hyperplasia (BPH), and 15 men with prostate cancer (PCa)] treated with finasteride or flutamide were included. Multiple comparisons showed significant difference in age, T-score, concentration of phosphorus, calcium, C-reactive protein, and prostate-specific antigen (PSA) between the groups. T-score was the lowest and phosphorus concentration was the highest in the PCa group. Highest PSA, proteins, calcium, and Hekal's formula score were found in the BPH group. Patients with PCa were more frequent GG+GA carriers of 5-HT1B 1997A/G gene polymorphism (p=0.035). Univariate regression analysis showed association of PCa-treated subjects with age (p=0.010) and 5-HT1B genetic polymorphism (p=0.018). Antiandrogen therapy affects T-score (p=0.017), serum phosphorus (p=0.008), glucose (p=0.036), and total proteins (p=0.050). Multivariate-stepwise logistic regression analysis showed the significant association of treated PCa with age (p=0.028) and inorganic phosphorus (p=0.005), and a marginal association with ultrasonographic T-score (p=0.052).

CONCLUSIONS

Antiandrogen therapy might induce bone mineral loss in elderly PCa patients. Preliminary data imply that the genetic variants of the 5-HT1B receptor might be associated with PCa.

Obesity and prostate cancer aggressiveness among African and Caucasian Americans in a population-based study

BACKGROUND

This study evaluated obesity and prostate cancer aggressiveness relationship in a population-based incident prostate cancer study.

METHODS

The North Carolina-Louisiana Prostate Cancer Project includes medical records data for classification of prostate cancer aggressiveness at diagnosis by using clinical criteria for 1,049 African American (AA) and 1,083 Caucasian American (CA) participants. An association between prostate cancer aggressiveness and obesity, measured using body mass indices (BMI) and waist-to-hip ratio (WHR), was assessed using ORs and 95% CIs adjusted for confounders.

RESULTS

A significantly positive association was found between prostate cancer aggressiveness and obesity. The ORs for high aggressive prostate cancer among prediagnosis obese and severely obese were 1.48 (95% CI = 1.02-2.16) and 1.98 (95% CI = 1.31-2.97), respectively, compared with normal weight research subjects. Race-stratified results suggested the association is stronger among CAs. Interaction model showed that normal weight AAs had more aggressive prostate cancer than normal weight CAs (OR = 2.69, 95% CI = 1.36-5.30); severe obesity was associated with aggressive disease in AAs (OR = 3.90, 95% CI = 1.97-7.75). WHR > 0.98 among all research subjects adjusted for race was significantly associated with high aggressive prostate cancer (OR = 1.42, 95% CI = 1.00-2.00) when compared with WHR < 0.90. The stratified result is less clear among AAs.

CONCLUSIONS

This study shows a positive association between obesity and aggressive prostate cancer. AAs have more aggressive prostate cancer in general than CAs even at normal weight. Therefore, the association between obesity and aggressiveness is not as evident in AAs as in CAs.

IMPACT

This study provides a unique opportunity to examine impact of race on obesity and high aggressive prostate cancer relationship.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Modeling the effects of obesity and weight gain on PSA velocity

BACKGROUND

Hemodilution theory states that higher blood volume in obese men effectively dilutes circulating PSA levels resulting in lower PSA test results. Here we apply hemodilution theory to model the effect of weight gain on PSA velocity.

METHODS

Hemodilution formulas were used to model PSA velocity for a series of plausible scenarios in which initial weight and weight gain were varied. The formulas were also applied to published summary data on weight, weight change and PSA velocity from the Prostate Cancer Prevention Trial (PCPT).

RESULTS

Under hemodilution theory, PSA velocity is understood to be influenced by total circulating PSA mass (ng of PSA) and BMI at the initial test and total circulating PSA mass and BMI at the subsequent test. PSA velocity in a man with a stable BMI of 35 is estimated to be 13% lower than in a man with a stable BMI of 25. A gain of 4 BMI units is predicted to attenuate PSA velocity by as much as 25%. When applied to summary data from the PCPT, the formulas estimate that a 10 pound weight gain causes a -0.028 ng/ml change in PSA, which closely matches PCPT results where a 10 pound weight gain caused a -0.024 ng/ml change in PSA. We provide software to implement the hemodilution formulas to model PSA velocity for different weights and changes in weight through time (http://www.eheintl.com/psa.jsp).

CONCLUSION

Stable obesity and weight gain both independently attenuate PSA velocity, potentially obscuring clinically relevant changes in circulating PSA.

Prostate-specific antigen-based screening for prostate cancer in the third millennium: useful or hype?

Prostate cancer is the most prevalent malignancy in men and the third leading cause of cancer deaths worldwide. Although the wide-spread introduction of total prostate-specific antigen (tPSA) testing has revolutionized the approach to the managed care of this disease, there are some biological, analytical, clinical, and economical issues that argue against the cost-effectiveness of tPSA-based population screening for early identification of cancer. The on-going standardization/harmonization efforts, along with the outcomes of recent epidemiological investigations, demonstrate that the current tPSA thresholds might be revised and possibly recalculated according to several demographical variables, such as age, ethnicity, genotype, family history, and body mass index. A major shortcoming of tPSA screening is the lack of reliable evidences of reduction in prostate cancer-associated mortality, due to the large lead-time because of the indolent growth rate, the impossibility to differentiate high-grade from indolent cancers, and the treatment-associated morbidity. Since no single tPSA cut-off was proven able to efficiently identify men at higher risk of death, the jeopardy of over-diagnosis and over-treatment is also tangible. The large expenditure is an additional source of concern. Finally, a wide-spread population screening also carries several ethical, social, and psychological implications, which might overwhelm the potential benefits.