PLOD1 and obesity due to melanocortin 4 receptor deficiency: It has also been postulated that obesity alters 17-20-lyase activity, the enzyme that converts 17-OH progesterone into testosterone, causing an elevated 17-OH progesterone/testosterone ratio with both decreased 17-OH progesterone and testosterone levels with respect to healthy subjects after LH/hCG stimulation [15], a fact that could reinforce the connection between both androgens.