Public Health

Area of Science:

• Neuroscience
• Gerontology
• Public Health

Background:

• Women exhibit higher dementia prevalence than men, with midlife risk factors inadequately explaining this disparity.
• Estrogen's neuroprotective role suggests menopause timing may impact cognitive function, necessitating further research, especially cross-nationally.
• Limited evidence exists on menopause age and cognitive function in China and India, with no prior cross-national comparisons.

Purpose of the Study:

• To investigate the association between age at menopause and cognitive function in postmenopausal women.
• To compare this association across two distinct populations: China and India.
• To identify potential differences in menopause timing and its cognitive impact between these countries.

Main Methods:

• Analysis of nationally representative samples of postmenopausal women aged 45+ from China (CHARLS) and India (LASI).
• Categorization of menopause age into <40, 40-44, 45-49, 50-55, and >55 years.
• Assessment of cognitive function using composite scores from neuropsychological tests and linear regression models, adjusting for demographics and country interactions.

Main Results:

• Indian women had earlier mean menopause ages and higher education than Chinese women.
• Premature (<40) and early (40-44) menopause were more prevalent in India; late menopause (50-55) was more common in China.
• Earlier menopause (<50) correlated with poorer cognition globally. In China, late menopause (>55) was linked to worse cognitive function, unlike in India.

Conclusions:

• Earlier menopause is significantly associated with diminished cognitive function in women.
• Indian women bear a higher burden from premature and early menopause, impacting cognitive health.
• Chinese women face additional risks from late menopause, which is also linked to poorer cognitive outcomes.