Testosterone is increasingly recognized as an environmentally driven exposure because of our biological imperative to get our genes into the next generation, potentially with a role in many non-communicable chronic diseases. The role of testosterone in ischemic heart disease is controversial because the observational evidence suggests benefit, but the limited experimental evidence suggests harm. Given the very different pattern of non-communicable chronic diseases in East Asian compared with the U.S., i.e., high rates of diabetes in relatively non-obese populations but low rates of ischemic heart disease, CUNY School of Public Health researchers compared testosterone in young men from the U.S. and China.