In total , 99 postmenopausal women were included in this double-blind , randomized clinical trial and divided into three groups : Group A used estrogen therapy alone ( 2.0 mg of 17-estradiol ) , Group B received estrogen-progestin therapy ( 2.0 mg of 17 - estradiol +1.0 mg of norethisterone acetate ) and Group C received a placebo ( control ) .