U.S. arms now reportedly being delivered to Syrian rebel groups Estrogen importance in men a highlight of new study A new study in the New England Journal of Medicine finds that symptoms of so-called male menopause may be triggered not only by declines in testosterone, but in the female hormone estrogen, as well. Dr. Abraham Morgentaler, an associate clinical professor of urology at Harvard Medical School, discusses the study with the "CBS This Morning" co-hosts.