Objective Preclinical studies indicate that oxytocin is anorexigenic and has beneficial metabolic effects. Oxytocin effects on nutrition and metabolism in humans are not well defined. We hypothesized that oxytocin would reduce caloric intake and appetite, and alter levels of appetite-regulating hormones. We also explored metabolic effects of oxytocin. Methods We performed a randomized, placebo-controlled crossover study of single-dose intranasal oxytocin (24 IU) in 25 fasting healthy men. After oxytocin/placebo, subjects selected breakfast from a menu, and were given double portions. Caloric content of food consumed was measured. Visual analogue scales were used to assess appetite and blood was drawn for appetite-regulating hormones, insulin, and glucose before and after oxytocin/placebo. Indirect calorimetry assessed resting energy expenditure (REE) and substrate utilization. Results Oxytocin reduced caloric intake with a preferential effect on fat intake and increased levels of the anorexigenic hormone cholecystokinin without affecting appetite or other appetite-regulating hormones. There was no effect of oxytocin on REE. Oxytocin resulted in a shift from carbohydrate to fat utilization and improved insulin sensitivity. Conclusions Intranasal oxytocin reduces caloric intake and has beneficial metabolic effects in men without concerning side effects. The efficacy and safety of sustained oxytocin administration in the treatment of obesity warrants investigation.

Background: Osteocytes, the most abundant cells in adult bone, express PPR. Results: Mice with constitutive PPR deletion in osteocytes demonstrate blunted anabolic and catabolic bone responses and the inability to recruit osteoblasts and osteoclasts upon PTH administration. Conclusion: PPR in osteocytes is needed for a full skeletal response to PTH administration. Significance: PPR signaling in osteocytes is necessary for PTH-driven anabolic effects during osteoporosis therapy.

Background: Former American football players have a higher prevalence of cognitive impairment than that of the US general population. It remains unknown what aspects of playing football are associated with neuropsychiatric outcomes. Hypothesis: It was hypothesized that seasons of professional football, playing position, and experience of concussions were associated with cognition-related quality of life (QOL) and indicators of depression and anxiety. Study Design: Descriptive epidemiology study. Methods: The authors examined whether seasons of professional football, playing position, and experience of concussions, as measured by self-report of 10 symptoms, were associated with cognition-related QOL and indicators of depression and anxiety in a cross-sectional survey conducted 2015 to 2017. Cognition-related QOL was measured by the short form of the Quality of Life in Neurological Disorders: Applied Cognition–General Concerns. The Patient Health Questionnaire–4 measured depression and anxiety symptoms. Of 13,720 eligible men with apparently valid contact information, 3506 players returned a questionnaire at the time of this analysis (response rate = 25.6%). Results: Seasons of professional play (risk ratio [RR] per 5 seasons = 1.19, 95% CI = 1.06-1.34) and playing position were associated with cognition-related QOL. Each 5 seasons of play was associated with 9% increased risk of indicators of depression at borderline statistical significance ( P = .05). When compared with former kickers, punters, and quarterbacks, men who played any other position had a higher risk of poor cognition-related QOL, depression, and anxiety. Concussion symptoms were strongly associated with poor cognition-related QOL (highest concussion quartile, RR = 22.3, P < .001), depression (highest quartile, RR = 6.0, P < .0001), and anxiety (highest quartile, RR = 6.4, P < .0001), even 20 years after last professional play. Conclusion: The data suggest that seasons of play and playing position in the NFL are associated with lasting neuropsychiatric health deficits. Additionally, poor cognition-related QOL, depression, and anxiety appear to be associated with concussion in the long term.