Effects of norethisterone acetate addition to estradiol in long term HRT

OBJECTIVE: The aim of this study was to evaluate the efficacy and tolerability of hormone replacement therapy (HRT) among postmenopausal women living in the Lund area of Southern Sweden and to analyze treatment effects in different types or routes of HRT administration, as well as to compare with unopposed estrogen therapy. METHOD: in an ongoing, large population-based, prospective cohort study, this interim analysis included 3900 women. Of them, 693 postmenopausal women were eligible in the present analyses as they continued to use one of the four commercial HRT products for at least 2-3 years, i.e. continuous oral estradiol (E(2)) 2 mg+norethisterone acetate (NETA) 1 mg (CON-O), sequential oral estradiol 2 mg + norethisterone acetate 1 mg (CYC-O), sequential transdermal estradiol 50 microg + norethisterone acetate 250 microg (CYC-TRANS) and estradiol monotherapy. These women completed one generic questionnaire and one specific 'hormonal' questionnaire, as well as a personal interview pertaining to socio-demographics, detailed status of HRT use, and therapeutic efficacy and untoward side-effects by HRT. RESULTS: comparing the three combined E(2)+NETA groups with E(2) monotherapy, the beneficial effects on sexual desire and emotional well-being were significantly less in the combined groups than in E(2) monotherapy group. There was no significant difference regarding the negative side-effects between the groups. No significant difference was found between CON-O and CYC-O groups either in positive effects or in negative side-effects. A higher prevalence of positive effects was found in CYC-TRANS group than that in CYC-O group, especially in amelioration of sleep and urinary symptoms. Higher odd ratios of negative effects by HRT, such as irregular bleeds, weight gain, food craving and skin disorders were also found in CYC-TRANS group. CONCLUSION: in long-term HRT administration, the addition of a progestogen in HRT could compromise the beneficial effects of estradiol, particularly, the effects on women's emotional well being and psychosexual functioning. Administration of NETA continuously and sequentially had similar therapeutic efficacy and tolerability. More marked positive effects, such as improving of sleep and urinary symptoms, as well as nuisance side-effects, i.e. irregular bleeds, weight gain, food craving and skin disorders were encountered by the women using sequential transdermal regime