The beneficial effect of hormone therapy may be due to the presence of estrogen and estrogen receptors in the central nervous system, which is involved in sleep regulation[36–37].In addition, obesity may have a negative impact on sleep quality, as was shown by results from Finland on postmenopausal women, which reported impaired sleep quality in women with high BMI [18]. This evidence concerns the gene ESR1 and obesity due to melanocortin 4 receptor deficiency.