Background: postmenopausal women are more susceptible to insulin resistance. Many studies reported that estrogen (E2) contributes in insulin sensitivity improvement. As a result of postmenopausal estrogen replacement therapy (ERT) hazards, tamoxifen (TAM) as an alternative to estrogen are now applicable. There are no published data distinguishing the effects of TAM on insulin sensitivity in non-diabetic post menopause women.
Objectives: Test whether TAM acts as E2 in improving insulin sensitivity in post- menopausal period and to what extent the effect would be similar for both, together with exploring the underlying mechanism.
Material & method: Forty female albino rats were divided into 4 groups (10 rats each): sham (SH), ovariectomized (OV), ovariectomized E2 (OVE) treated and ovariectomized TAM (OVT) treated groups. At the end of experiment, blood samples were taken for estimation of fasting blood glucose (FBG), serum concentration of insulin, homeostasis model assessment of insulin resistance (HOMA-IR), lipid parameters and tumour necrosis factor α (TNFα), then adipose tissues were removed for measurement of MDA and SOD. Also, histopathological and immunohistochemical examination of adipose tissue were done.
Results: Ovariectomy worsened glycemic state, insulin resistance and lipid profile. TAM was like E2 induced glucose metabolic improvement, decreased insulin resistance alongside with lipid profile improvement. These metabolic changes might assert to oxidative state and inflammatory response improvement accompanying apparent histopathological and immunohistochemical changes on adipose tissue.
Conclusion: TAM can counterbalance the metabolic disorders in postmenopausal period and this may improve metabolic disorders as E2 with avoiding the undesired effects of ERT.