Abstract 2195: Early Menopause and the Risk of Silent Brain Infarction in Community-dwelling Elderly Subjects

Abstract

Background and Purpose: Brain infarction is more common in men. Our previous study showed the male predominance of silent brain infarction (SBI), which was largely due to higher prevalence of alcohol habit and smoking in men than in women (Hypertens Res. 2010;33:748). However, early menopause could be a risk factor for SBI. Methods: We conducted a population-based analysis of brain magnetic resonance imaging (MRI) findings to examine whether early menopause contribute to SBI. The subjects (n=712) were living independently at home without apparent dementia. The National Hospital Organization Hizen Psychiatric Center Institutional Review Board approved the study, and written informed consent was obtained from all subjects. Participants underwent a structured clinical interview, a neurological examination, general hematology tests, biochemistry tests, and electrocardiograms. Natural menopause was considered to occur if a woman had ceased menstruating naturally for at least 1 year. Early menopause was defined as menopause before age 40. Women were also queried as to the cause of menopause (natural, surgical, other), whether a hysterectomy was performed, number of ovaries removed, the use of hormone replacement therapy, the total number of children, and the age at giving birth to her last child. T1-weighted, T2-weighted, and FLAIR images were obtained with a MRI (1.0T, Shimadzu Magnex XP). SBI was shown as low signal intensities on T1-weighted images, and their size was 5 mm or larger. The data were analyzed with the IBM SPSS Statistics 18 software for Windows (SPSS Japan Inc.). Results: Among 303 female subjects aged 60 years or older, the median age at menopause was 50 years, the median number of children was 3, and the median age at the last parity was 30 years. Early menopause (total or natural) was more frequent in subjects with SBI. Age at natural menopause, number of children, and age at the last parity were not significantly associated with SBI. In the 712 subjects (283 men and 429 women with a mean age of 67.1 years), SBI, DWMLs and PVHs were detected in 89 (12.5%), 240 (33.7%) and 154 (21.6%) of 712 participants, respectively. The prevalence of SBI was more frequent in men (15.5%) than in women (10.5%). In the forward stepwise method of logistic analysis, natural early menopause (OR 4.239, 95% CI1.060-16.960), age (OR 2.447/10y, 95% CI 1.849-3.240), hypertension (OR 4.045, 95% CI 2.413-6.780), alcohol intake (OR 2.091, 95% CI 1.230-3.553), and smoking (OR 2.936, 95% CI 1.520-5.671) were significant factors concerning SBI. Conclusions: The present study showed “natural” early menopause as one of the potential risk factors for SBI. Although the prevalence of natural early menopause was low (3.3% of 303 female subjects aged 60 years or older), natural menopause before the age of 40 years may be the basis for SBI or small vessel disease of the brain.