Selenium is an antioxidant trace element linked to cardiovascular disease and cancer. Although diet is a major source, relatively little else is known about independent determinants of selenium levels in free-living humans. In this study, we aimed to investigate the independent demographic, lifestyle, and dietary determinants of selenium levels in 1,997 men and 1,905 women in two large prospective U.S. cohorts. Toenail selenium levels were quantified using neutron activation analysis. Diet, geographic residence, demographic, and environmental factors were assessed by validated self-administered questionnaires. Multivariate generalized linear models were conducted to assess the independent relations of these factors with toenail selenium levels, correcting for measurement error in the diet. In multivariable-adjusted analyses, independent predictors of higher selenium were male gender (6.3% higher levels); living in West and Northern-Midwest U.S. regions (8.9% and 7.4% higher than Southern-Midwest regions, respectively); consumption of beef and bread products (between 0.7 - 2.5% higher per daily serving); and selenium supplement use (6.9% higher than non-users); whereas cigarette smoking (5-10% lower than never smokers) , older age (0.6% lower per 5 years), and consumption of eggs, white rice, dairy products, coffee, and alcohol (between 0.1 to 2.0% lower per daily serving) were associated with lower selenium. Multiple dietary and non-dietary factors independently predicted selenium levels, suggesting that both consumption and non-dietary processes (e.g., related to oxidant status) may affect levels. Significant geographic variation in selenium levels exists in the US.
Bread ; Cardiovascular Diseases ; Coffee ; Cohort Studies ; Dairy Products ; Diet ; Eggs ; Female ; Humans ; Life Style ; Linear Models ; Male ; Nails ; Neutron Activation Analysis ; Ovum ; Prospective Studies ; Surveys and Questionnaires ; Selenium ; Smoking

Purpose: Prostate cancer (PCa) screening can lead to potential over-diagnosis/over-treatment of indolent cancers. There is a need to optimize practices to better risk-stratify patients. We examined initial longitudinal outcomes of mid-life men with an elevated baseline prostate-specific antigen (PSA) following initiation of a novel screening program within a system-wide network. Materials and Methods: We assessed our primary care network patients ages 40 to 49 years with a PSA measured following implementation of an electronic health record screening algorithm from 2/2/2017–2/21/2018. The multidisciplinary algorithm was developed taking factors including age, race, family history, and PSA into consideration to provide a personalized approach to urology referral to be used with shared decision-making. Outcomes of men with PSA ≥1.5 ng/mL were evaluated through 7/2021. Statistical analyses identified factors associated with PCa detection. Clinically significant PCa (csPCa) was defined as Gleason Grade Group (GGG) ≥2 or GGG1 with PSA ≥10 ng/mL. Results: The study cohort contained 564 patients, with 330 (58.5%) referred to urology for elevated PSA. Forty-nine (8.7%) underwent biopsy; of these, 20 (40.8%) returned with PCa. Eleven (2.0% of total cohort and 55% of PCa diagnoses) had csPCa. Early referral timing (odds ratio [OR], 4.58) and higher PSA (OR, 1.07) were significantly associated with PCa at biopsy on multivariable analysis (both p<0.05), while other risk factors were not. Referred patients had higher mean PSAs (2.97 vs. 1.98, p=0.001). Conclusions Preliminary outcomes following implementation of a multidisciplinary screening algorithm identified PCa in a small, important percentage of men in their forties. These results provide insight into baseline PSA measurement to provide early risk stratification and detection of csPCa in patients with otherwise extended life expectancy. Further follow-up is needed to possibly determine the prognostic significance of such mid-life screening and optimize primary care physician-urologist coordination.