Acta Pharmacologica Sinica (2009) 30: 1065-1070; doi: 10.1038/aps.2009.81

Aim: To apply 3.0 magnetic resonance imaging (MRI) to study the effects of long-term, low dose hormone replacement therapy (HRT) on the brain parenchyma of postmenopausal women. 

Methods: A total of 155 postmenopausal healthy female medical staff members from Peking Union Medical College Hospital were enrolled.  The HRT group was composed of 71 subjects who had been given a low dose of HRT for over 4 years, while 84 women who had never been given HRT were enrolled in the control group.  The Mini-Mental State Examination (MMSE) was used to evaluate mental state, and an Enzyme-Linked ImmunoSorbent Assay (ELISA) was used to detect plasma levels of sex hormones.  In addition, all participants were subjected to an MRI, including axial T2 weighted imaging (T2WI), fluid-attenuated inversion recovery (FLAIR), T1 weighted imaging (T1WI, oblique coronal, vertical to the hippocampus, slice thickness 3 mm without gaps), and a 3D image of the whole brain.

Results: The ELISA showed that the plasma level of estradiol in the HRT group was significantly higher than that in the control group (P<0.05).  No differences were observed in the MMSE between the two groups.  In participants older than 70 years of age, the number of deep white matter hyperintensities (DWMHs) in the control group was significantly higher than that in the HRT group (P=0.0013); however, in other age subgroups, no statistical differences were observed.  Finally, no significant difference in periventricular hyperintensity (PVH) between the two groups was observed.

Conclusion: We found that a high plasma level of estradiol in postmenopausal women receiving long-term HRT was correlated with the survival of brain parenchyma.

Keywords: postmenopausal women; hormone replacement therapy; estrogen; magnetic resonance imaging; deep white matter hyperintensity