Influence of hormonal replacement therapy on the regional cerebral blood flow in postmenopausal women.

Objectives: The aim of this study was evaluation of the influence of hormonal replacement therapy (HRT) on the regional cerebral blood flow in postmenopausal women.

Methods: The study group were 20 postmenopausal women, mean age 48.7 years (S.D. +/- 4.9 years). The control group were ten regularly menstruating women, mean age 32.6 years (S.D. +/- 13.2 years). In the studied group we measured the severity of climacteric syndrome with the use of Kupperman index and serum FSH and 17beta-estradiol level with the use of radioimmunological method. Cerebral blood flow was measured at rest using Single Photon Emission Computed Tomography (SPECT). Tracer accumulation evaluation was performed in three slices defined as: cerebellar slice, thalamic slice and ventricular slice, the reference region was delineated in the cerebellum. In ten women with an impairment in the cerebral blood flow at the beginning of the study all the tests were repeated after 12 months of HRT.

Results: Before HRT mean value of the Kupperman index in the study group was 29.8 points (S.D. +/- 7.1 points); 17beta-estradiol 27 pg/ml (S.D. +/- 2 pg/ml); FSH 56 IU/l (S.D. +/- 49.5 IU/l); SPECT study revealed cerebral blood flow impairment in ten women. In all the studied slices cerebral blood flow was lower in the study group than in the controls. After 12 months of HRT the mean value of the Kupperman index in the study group was 13.2 points (S.D. +/- 2.1 points) (P < 0.05); 17beta-estradiol 44 pg/ml (S.D. +/- 25 pg/ml); FSH 36.4 IU/l (S.D. +/- 57.3 ng/ml); we found cerebral blood flow increase in all studied slices: right cerebellar slice: 5.2%; left cerebellar slice: 4.1%; right thalamic slice: 3.8%; left thalamic slice: 3.3%; right ventricular slice: 7.5%*; left ventricular slice: 6.7%* (* P < 0.05).

Conclusions: Cerebral blood flow is lower in the postmenopausal women than in regularly menstruating women. HRT increases regional cerebral blood flow and this improvement coexists with an increase of serum 17beta-estradiol level.