Exposure to heavy metal elements may significantly increase serum prostate-specific antigen levels with overdosed dietary zinc.

BACKGROUND: Serum prostate-specific antigen (PSA) is a primary metric for diagnosis and prognosis of prostate cancer (PCa). Exposure to heavy metals, such as lead, cadmium, mercury, and zinc can impact PSA levels in PCa patients. However, it is unclear whether this effect also occurs in men without PCa, which may lead to the overdiagnosis of PCa. METHOD: Data on a total of 5089 American men who had never been diagnosed with PCa were obtained from the National Health and Nutrition Examination Survey performed from 2003-2010. The relationship between serum PSA levels (dependent variable) and concentrations of lead (µmol/L), cadmium (nmol/L), and mercury (µmol/L) were investigated with dietary zinc intake being used as a potential modifier or covariate in a weighted linear regression model and a generalized additive model. A series of bootstrapping analyses were performed to evaluate sensitivity and specificity using these models. RESULTS: Regression analyses suggested that, in general, lead, cadmium, or mercury did not show an association with PSA levels, which was consistent with the results of the bootstrapping analyses. However, in a subgroup of participants with a high level of dietary zinc intake (≥14.12 mg/day), a significant positive association between cadmium and serum PSA was identified (1.06, 95% CI, P = 0.0268, P for interaction=0.0249). CONCLUSIONS: With high-level zinc intake, serum PSA levels may rise in PCa-free men as the exposure to cadmium increases, leading to a potential risk of an overdiagnosis of PCa and unnecessary treatment. Therefore, environmental variables should be factored in the current diagnostic model for PCa that is solely based on PSA measurements. Different criteria for PSA screening are necessary based on geographical variables. Further investigations are needed to uncover the biological and biochemical relationship between zinc, cadmium, and serum PSA levels to more precisely diagnose PCa.

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.

Dietary phosphorus intake and serum prostate-specific antigen in non-prostate cancer American adults: A secondary analysis of the National Health and Nutrition Examination Survey (NHANES), 2003-2010.

BACKGROUND AND OBJECTIVES: Previous study has reported phosphorus intake is associated prostate cancer (PCa), but the association between phosphorus intake and serum prostate specific antigen (PSA) levels hasn't been reported in non-history of PCa population. Therefore, we performed a secondary data analysis based on existing data from the public Nutrition Examination Survey (NHANES) (2003-2010) database. METHODS AND STUDY DESIGN: Totally 6403 participants were selected from NHANES (2003-2010) database. The interested independent and dependent variables were considered as dietary phosphorus intake and PSA level, respectively. Covariates included demographic data, dietary data, physical examination data, and comorbidities. Weighted linear regression and generalized additive models were used to addressing the linear and non-linear link of phosphorus intake to PSA level. RESULTS: Linear association between phosphorus intake and PSA was not detected [ß=0.016 (95% Confidence Interval (CI) -0.012, 0.045)]. But we found an existing nonlinearity. By the recursive algorithm, the inflection point was 1151 mg. On the left side of the inflection point, we did not find the correlation between dietary phosphorus intake (per 100 change) and PSA level [ß=-0.04 (95% CI -0.11, 0.02), p=0.2155], while dietary phosphorus intake (per 100 change) positively associated with PSA [ß=0.05 (95% CI 0.01, 0.09) p=0.0293] on the right side of inflection point. CONCLUSIONS: There is a non-linear correlation between dietary phosphorus intake and PSA. Dietary phosphorus intake was positively associated with increased PSA when dietary phosphorus intake is beyond 1151 mg after adjusting other covariates. Over 1151 mg per day dietary phosphorus intake may be the risk factor for PSA increasing.