Soccer fans' testosterone and cortisol levels go up when watching a game, but don't further increase after a victory, according to a study published in the open access journal PLoS ONE. The study was conducted with 50 Spanish soccer fans watching the finals between Spain and the Netherlands in the 2010 World Cup. The researchers, led by Leander van der Meij of the University of Valencia in Spain and VU University Amsterdam in the Netherlands, measured testosterone and cortisol levels for fans of different ages, genders, and degree of interest in the game. They found that the increase in testosterone was independent of all these factors, but the increase in cortisol level was more pronounced for dedicated, young, male fans. The authors write that the testosterone effect is in agreement with the "challenge hypothesis, " as testosterone levels increased to prepare for the game, and the cortisol effect is consistent with the "social self-preservation theory, " as higher cortisol secretion among young and greater soccer fans suggests that they perceived a particularly strong threat to their own social esteem if their team didn't win.
Testosterone supplements helped heart failure patients breathe better and exercise more, according to research in Circulation Heart Failure, an American Heart Association journal. Researchers analyzed four randomized clinical trials of patients with moderate to severe chronic heart failure. Patients were given commercial testosterone supplements by injection, patch or gel. Based on the analysis of these studies, those who received supplemental testosterone scored 50 percent better in a six-minute walking test than those receiving placebo. Also, in two of the studies, the severity of heart failure as measured by the New York Heart Association classification system improved one to two grades in 35 percent of treated patients compared to 9.8 percent of those who didn't receive the supplements.
Understanding the damage that pollution causes to both wildlife and human health is set to become much easier thanks to a new green-glowing zebrafish. Created by a team from the University of Exeter, the fish makes it easier than ever before to see where in the body environmental chemicals act and how they affect health. The fluorescent fish has shown that oestrogenic chemicals, which are already linked to reproductive problems, impact on more parts of the body than previously thought. The research by the University of Exeter and UCL (University College London) is published in the journal Environmental Health Perspectives. Numerous studies have linked 'endocrine-disrupting' chemicals, used in a wide range of industrial products and contraceptive pharmaceuticals, to reproductive problems in wildlife and humans.
People who have irregular sleep patterns and/or do not sleep enough have a higher risk of developing metabolic syndrome and diabetes, researchers from Harvard Medical School, and Brigham and Women's Hospital in Boston, reported in the journal Science Translational Medicine. Orfeu Buxton, PhD. and team examined healthy volunteers over a 29-day period. They were made to sleep less and at varying bedtimes; sleeping patterns similar to those experienced by shift-workers. They found that the shift-like sleep patterns led to poorer glucose regulation and metabolism. The authors explained that eventually, over time, the raised risk of obesity and diabetes became apparent. Previous observational studies had associated disrupted sleep patterns with a higher risk of developing diabetes and metabolic syndrome, especially among night-shift workers.
Testosterone, the primary male sex hormone, appears to have antidepressant properties, but the exact mechanisms underlying its effects have remained unclear. Nicole Carrier and Mohamed Kabbaj, scientists at Florida State University, are actively working to elucidate these mechanisms. They've discovered that a specific pathway in the hippocampus, a brain region involved in memory formation and regulation of stress responses, plays a major role in mediating testosterone's effects, according to their new report in Biological Psychiatry. Compared to men, women are twice as likely to suffer from an affective disorder like depression. Men with hypogonadism, a condition where the body produces no or low testosterone, also suffer increased levels of depression and anxiety. Testosterone replacement therapy has been shown to effectively improve mood.