Selenium (Se) is a trace element which plays an important role in adipocyte hypertrophy and adipogenesis. Some studies suggest that variations in serum Se may be associated with obesity. However, there are few studies examining the relationship between dietary Se and obesity, and findings are inconsistent. We aimed to investigate the association between dietary Se intake and a panel of obesity measurements with systematic control of major confounding factors. A total of 3214 subjects participated in the study. Dietary Se intake was determined from the Willett food frequency questionnaire. Body composition was measured using dual-energy X-ray absorptiometry. Obese men and women had the lowest dietary Se intake, being 24% to 31% lower than corresponding normal weight men and women, classified by both BMI and body fat percentage. Moreover, subjects with the highest dietary Se intake had the lowest BMI, waist circumference, and trunk, android, gynoid and total body fat percentages, with a clear dose-dependent inverse relationship observed in both gender groups. Furthermore, significant negative associations discovered between dietary Se intake and obesity measurements were independent of age, total dietary calorie intake, physical activity, smoking, alcohol, medication, and menopausal status. Dietary Se intake alone may account for 9%–27% of the observed variations in body fat percentage. The findings from this study strongly suggest that high dietary Se intake is associated with a beneficial body composition profile.

The immune landscape plays an important role in various pituitary diseases, ranging from hypophysitis to pituitary neuroendocrine tumors. Moreover, the use of immune checkpoint inhibitors (ICIs) has dramatically altered the landscape of cancer treatment by improving prognosis and overall survival in a multitude of advanced-staged malignancies, though their use in pituitary neuroendocrine tumors has remained limited. In this review, we will focus on selected topics to highlight the impact of the immune microenvironment on the function of the pituitary gland, namely, animal models of autoimmune hypophysitis, including ICI-induced hypophysitis as a common adverse event, and the importance of its early recognition in patients treated with ICIs. Using a case, we will provide an overview on the epidemiology, pathogenesis, clinical spectrum, diagnosis, predictors, and management of ICI-induced hypophysitis. We will also summarize the role of the immune microenvironment in pituitary neuroendocrine tumors with programmed cell death ligand 1 as a biomarker for treatment. Lastly, we will review the role of ICIs in the management of 40 patients with aggressive and metastatic pituitary neuroendocrine tumors. Current knowledge gaps in these topics will also be highlighted.