Is there a non-linear relationship between dietary protein intake and prostate-specific antigen: proof from the national health and nutrition examination survey (2003-2010)

Interaction between smoking status and dietary selenium intake affects PSA: A cross-sectional study

BACKGROUND

Conflicting results regarding the impact of selenium on reducing prostate cancer have been reported. The current analysis aimed to understand whether there are potential factors affecting the relationship between selenium and prostate cancer.

OBJECTIVE

To clarify the relationship between dietary selenium intake and prostate cancer, we evaluated the correlation between dietary selenium intake and prostate-specific antigen (PSA) based on the National Health and Nutrition Examination Survey (NHANES) database.

METHODS

After screening the NHANES survey data from 2005 to 2010, data for 3,614 of 31,034 participants were considered suitable to include in our study. Dietary selenium intake was the independent variable of our study, while PSA was the dependent variable. We stratified participants into current, former, and never smokers and performed an interaction test on the relationship between selenium intake and PSA using multivariable logistic regression for each smoking-status subgroup.

RESULTS

For our subgroup analysis, we grouped participants based on smoking status and investigated the association between dietary selenium intake and PSA levels. Among the 242 participants with a PSA level of 4 or higher, the mean age was 58.5 years (±12.1). After adjusting for covariates, we did not find a significant association between dietary selenium and the odds of having a high PSA level. However, we observed a significant interaction between smoking status and dietary selenium in relation to PSA levels (P = .007). Specifically, smokers had lower odds of having high PSA levels, while nonsmokers had higher odds. This suggests that smoking status may modify the effect of dietary selenium on PSA levels.

CONCLUSION

Our findings suggest that smoking status affects the relationship between dietary selenium intake and PSA and that smokers are at lower odds of having a high PSA level.

Age-specific percentile-based prostate-specific antigen cutoff values predict the risk of prostate cancer: A single hospital observation

Background

Testing for prostate-specific antigen (PSA) is often recommended for men with a potential risk of prostate cancer (PCa) before requiring advanced examination. However, the best PSA cutoff value remains controversial.

Object

We compared the predictive performance of age-specific percentile-based PSA thresholds with a conventional cutoff of >4 ng/mL for the risk of PCa.

Methods

We included men who received PSA measurements between 2003 and 2017 in a medical center in Taiwan. Logistic regression modeling was used to assess the association between age-specific percentile-based PSA thresholds and PCa risk in age subgroups. We further applied C-statistic and decision curve analysis to compare the predictive performance of age-specific percentile-based PSA with that of a conventional cutoff PSA.

Results

We identified 626 patients with PCa and 40 836 patients without PCa. The slope of PSA in patients >60-year-old was almost 3 times that of those <60-year-old (0.713 vs 0.259). The risk effect sizes of the 75th percentile PSA cutoff (<60-year-old: 2.19; 60-70-year-old: 4.36; >70-year-old: 5.84 ng/mL) were comparable to those observed based on the conventional cutoff in all age groups. However, the discrimination performance of the 75th percentile PSA cutoff was better than that of the conventional cutoff among patients aged <60-year-old (C-statistic, 0.783 vs. 0.729, p < 0.05). The 75th percentile cutoffs also correctly identified an additional 2 patients with PCa for every 100 patients with PSA screening at the threshold probability of 20%.

Conclusions

Our data support the use of the 75th percentile PSA cutoff to facilitate individualized risk assessment, particularly for patients aged <60-year-old.

Quantifying the Contributions of Environmental Factors to Prostate Cancer and Detecting Risk-Related Diet Metrics and Racial Disparities

The relevance of nongenetic factors to prostate cancer (PCa) has been elusive. We aimed to quantify the contributions of environmental factors to PCa and identify risk-related diet metrics and relevant racial disparities. We performed a unique analysis of the Diet History Questionnaire data of 41 830 European Americans (EAs) and 1282 African Americans (AAs) in the PLCO project. The independent variables in the regression models consisted of age at trial entry, race, family history of prostate cancer (PCa-fh), diabetes history, body mass index (BMI), lifestyle (smoking and coffee consumption), marital status, and a specific nutrient/food factor (X). P < .05 and a 95% confidence interval excluding zero were adopted as the criteria for determining a significant difference (effect). We established a priority ranking among PCa risk-related genetic and environmental factors according to the deviances explained by them in the multivariate Cox-PH regression analysis: age > PCa-fh > diabetes ⩾ race > lifestyle ⩾marital-status ⩾BMI > X. We confirmed previous studies showing that (1) high protein and saturated fat levels in diet were related to increased PCa risk, (2) high-level supplementary selenium intake was harmful rather than beneficial for preventing PCa, and (3) supplementary vitamin B6 was beneficial for preventing benign PCa. We obtained the following novel findings: high-level organ meat intake was an independent predictor for increased aggressive PCa risk; supplementary iron, copper and magnesium increased benign PCa risk; and the AA diet was "healthy" in terms of the relatively lower protein and fat levels and was "unhealthy" in that it more commonly contained organ meat. In conclusion, we established a priority ranking among the contributing factors for PCa and identified several risk-related diet metrics and the racial disparities. Our findings suggested some new approaches to prevent PCa such as restriction of organ meat intake and supplementary microminerals.

The relationship between serum albumin and prostate-specific antigen: A analysis of the National Health and Nutrition Examination Survey, 2003-2010

Background

Previous studies have shown that serum albumin is associated with prostate cancer (PCa), but not with prostate-specific antigen (PSA) levels in populations without PCa history. Therefore, we analyzed secondary data provided by the National Health and Nutrition Examination Survey (NHANES) (2003-2010).

Methods

In total, 5,469 participants were selected from the NHANES database (2003-2010). Serum albumin and PSA levels were serially considered independent and dependent variables, serially. A number of covariates were included in this study, including demographic, dietary, physical examination, and comorbidity data. Using weighted linear regression model and smooth curve fitting, the linear and non-linear relationship between serum albumin and PSA was investigated.

Results

After modulating underlying interference factors, the weighted multivariate linear regression analysis revealed that serum albumin did not independently predict PSA levels (β = -0.009 95%CI: -0.020, 0.002). Nevertheless, a non-linear relationship was found between serum albumin and PSA, with a point of 41 g/L. Left of the inflection point, the effect size, 95%CI, and P-value were 0.019 (log2 transformation) (-0.006, 0.043) and 0.1335, respectively. We found a negative association between serum albumin and PSA on the right side of the inflection point, with effect size, 95%CI, and a P-value of -0.022 (log2 transformation) (-0.037, -0.007), 0.0036.

Conclusion

In summary, serum albumin and PSA levels are not linearly related. When serum albumin levels exceed 41 g, serum albumin levels are negatively associated with PSA levels.

Assessing volatile organic compounds exposure and prostate-specific antigen: National Health and Nutrition Examination Survey, 2001–2010

Background

Volatile organic compounds (VOCs) are a large group of chemicals widely used in people's daily routines. Increasing evidence revealed the VOCs' accumulating toxicity. However, the VOCs toxicity in male prostate has not been reported previously. Thus, we comprehensively evaluated the association between VOCs and prostate-specific antigen (PSA).

Methods

A total of 2016 subjects were included in our study from the National Health and Nutrition Examination Survey with VOCs, PSA, and other variables among U.S. average population. We constructed XGBoost Algorithm Model, Regression Model, and Generalized linear Model (GAM) to analyze the potential association. Stratified analysis was used to identify high-risk populations.

Results

XGBoost Algorithm model identified blood chloroform as the most critical variable in the PSA concentration. Regression analysis suggested that blood chloroform was a positive association with PSA, which showed that environmental chloroform exposure is an independent risk factor that may cause prostate gland changes [β, (95% CI), P = 0.007, (0.003, 0.011), 0.00019]. GAM observed the linear relationship between blood chloroform and PSA concentration. Meanwhile, blood chloroform linear correlated with water chloroform in the lower dose range, indicating that the absorption of water may be the primary origin of chloroform. Stratified associations analysis identified the high-risk group on the chloroform exposures.

Conclusion

This study revealed that blood chloroform was positively and independently associated with total PSA level, suggesting that long-term environmental chloroform exposure may cause changes in the prostate gland.

Dietary protein intake and prostate cancer risk in adults: A systematic review and dose-response meta-analysis of prospective cohort studies

OBJECTIVE

This study aimed to conduct a comprehensive systematic review and dose-response meta-analysis to summarize available findings on the associations between dietary protein intake and prostate cancer risk as well as the dose-response associations of total, animal, plant, and dairy protein intake with prostate cancer risk.

METHODS

This study followed the 2020 PRISMA guideline. We conducted a systematic search in the online databases of PubMed, Scopus, ISI Web of Science, and Google Scholar to detect eligible prospective studies published to October 2021 that assessed total, animal, plant, and dairy protein intake in relation to prostate cancer risk.

RESULTS

Overall, 12 articles containing prospective studies with a total sample size of 388,062 individuals and 30,165 cases of prostate cancer were included. The overall relative risks (RRs) of prostate cancer, comparing the highest and lowest intakes of total, animal, plant, and dairy protein intake, were 0.99 (95% CI: 92-1.07, I² =12.8%), 0.99 (95% CI: 95-1.04, I² =0), 1.01 (95% CI: 96-1.06, I² =0), and 1.08 (95% CI: 1.00-1.16, I² =38.1%), respectively, indicating a significant positive association for dairy protein intake (P = 0.04) and non-significant associations for other protein types. However, this positive association was seen among men who consumed ≥ 30 gr/day of dairy protein, such that a 20 g/d increase in dairy protein intake (equal to 2.5 cups milk or yogurt) was associated with a 10% higher risk of prostate cancer (Pooled RR: 1.10, 95% CI: 1.02-1.20, I² = 42.5%). Such dose-response association was not seen for total, animal, and plant protein intake.

CONCLUSION

Overall, dairy protein intake may increase the risk of prostate cancer in men who consumed > 30 gr/day of dairy protein. Larger, well-designed studies are still required to further evaluation of this association.

Impact of Plant-Based Diet on PSA Level: Data From the National Health and Nutrition Examination Survey

OBJECTIVE

To determine the potential association between plant-based dietary content and PSA levels among men enrolled in the National Health and Nutrition Examination Survey (NHANES).

METHODS

Data on demographics, diet, and PSA levels was acquired from the NHANES database. Plant-based diet index (PDI) and healthful plant-based diet index (hPDI) were calculated using food frequency questionnaires. A higher score on PDI and hPDI indicates higher consumption of plant foods or healthy plant foods, respectively. Multivariable-adjusted logistic regression analysis was performed to determine the association between elevated PSA, clinical variables, demographics, and plant-based diet indices.

RESULTS

A total of 1399 men were included in the final cohort. Median age of participants was 54 [46-63] years. Median PSA level was 0.9 [0.6-1.5] ng/dL, and 69 (4.9%) men had a PSA level ≥4 ng/dL. Although there was no association between elevated PSA and PDI, on multivariable analysis patients with higher consumption of healthy plant-based diet (high hPDI scores) had a decreased probability of having an elevated PSA (OR = 0.47, 95% CI: 0.24-0.95; P = .034).

CONCLUSION

There is a significant association between increased consumption of a healthy plant-based diet and lower PSA levels. This finding may be incorporated into the shared-decision making process with patients to promote healthier lifestyle choices to reduce the likelihood of prostate biopsy and potential treatment-related morbidity.

Association of Total Dietary Intake of Sugars with Prostate-Specific Antigen (PSA) Concentrations: Evidence from the National Health and Nutrition Examination Survey (NHANES), 2003-2010

BACKGROUND

There is increasing evidence that dietary intake of sugars may be a risk factor for prostate cancer (PCa) and elevate the concentration of serum prostate-specific antigen (PSA). However, there is limited evidence of the correlation between total dietary intake of sugars and serum PSA concentrations for adult American males. Herein, we evaluated the association between total dietary intake of sugars and serum PSA concentrations in men without a malignant tumor diagnosis in the United States (US) National Health and Nutrition Examination Survey (NHANES) database. Material and Methods. In this secondary data analysis, a total of 6,403 men aged ≥40 years and without malignant tumor history were included from 2003 to 2010. The independent variable of this study was the total dietary intake of sugars, and the dependent variable was serum PSA concentrations. Covariates included dietary, comorbidity, physical examination, and demographic data.

RESULTS

The average age of participants included in this study was 58.1 years (±13.6). After adjusting for the dietary, comorbidity, physical examination, and demographic data, we observed that a dietary intake increase of one gram of total dietary intake of sugars was associated with an increase of serum PSA concentrations by 0.003 ng/mL (after log2 transformed, 95% CI: 0.001 to 0.005) with a P value for trend less than 0.05. Sensitivity analysis using the generalized additive model (GAM) supported the linear association between total dietary intake of sugars and serum PSA concentrations.

CONCLUSION

The total dietary intake of sugars is independently and positively associated with serum PSA concentrations in adult American males who are without a personal history of malignant tumors.