Effects of long-term,low-dose sex hormone replacement therapy on hippocampus and cognition of postmenopausal women of different apoE genotypes

摘要

＜正＞ Aim:To study the effects of long-term,low-dose sex hormone replacement therapy（HRT）on the volume and biochemical changes of the hippocampus in postmeno-pausal women carrying apolipoprotein E（apoE）gene ε3 or ε4.Methods:Eighty-three postmenopausal women who had used a low dose of HRT for over 4 yearswere selected as the HRT group,and 99 postmenopausal women with matchedage and education were enrolled as the control group.ApoE alleles were analyzedby PCR.Magnetic resonance imaging was performed to determine the volume ofthe brain hippocampus.Proton magnetic resonance spectroscopy was used todetect the biochemical changes in the anterior cingulate cortex and hippocampusin apoE ε4 and ε3 carriers.Six common cognitive tests were used to make anoverall evaluation of cognitive function.Results:Analysis with the apoE ε4carriers showed that the volume of the hippocampus of the control group weresignificantly lower than those of the HRT group.The biochemical analysis showedthat there was an increase of N-acetylaspartate（NAA）/total creatine（tCr）and adecrease of myoinositol（mI）/tCr in the hippocampus of apoE ε4 carriers in theHRT group,compared with the control group.For the apoE ε3 carriers,the leastsquares means（LSMEAN）of the HRT group was higher than that of the controlgroup.Conclusion:This study showed that long-term,low dose HRT might bebeneficial for reducing the risk of AD development in vulnerable postmenopausalwomen.Meanwhile,HRT could increase the LSMEAN of apoE ε3 carriers.