CYP19A1 and obesity due to melanocortin 4 receptor deficiency: BMI is positively associated withtissue levels of estrogens.6 Thus, as fat mass increases in obesity, aromatase expression and,consequently, estrogen levels are also elevated, an effect that is more prominent inpostmenopausal women as after menopause adipose tissue is the primary source ofestrogen production in the body.94, –96 Adipose tissue can contributeup to 100% of circulating estrogen in postmenopausal women and 50% of circulatingtestosterone in premenopausal women.