Decreased sexual activity, desire may lead to decline in serum testosterone in older men In Gynaecology & andrology, Sexual dysfunctionMarch 13, 20151 Min Read D Public Release: 7 Mar 2015 In older men, decreased sexual activity and desire, not erectile dysfunction, may cause serum testosterone to decline, a new study from Australia finds. Read more here erection hormones libido men older men sexual activity sexual desire sexual dysfunction testosterone FacebookXReddit