Female-specific factors are associated with cognition in the UK Biobank cohort

Abstract

Background: Relative to males, females are at a higher risk of developing age-related neurocognitive disorders including Alzheimer's disease. Emerging evidence suggests that reproductive life events such as pregnancy and hormone use may influence female's cognition later in life. Yet, female's health has historically been understudied, and little is known about the relationship between female-specific factors and cognition. Methods: Using multiple linear regression, we investigated the associations between reproductive history, exogenous hormone use, apolipoprotein (APOE) ε4 genotype and cognition in 221,124 middle- to older-aged (mean age 56.2 ± 8.0 years) females from the UK Biobank. Performance on six cognitive tasks was assessed, covering four cognitive domains: episodic visual memory, numeric working memory, processing speed, and executive function. Results: A longer reproductive span, older age at menopause, older age at first and last birth, and use of hormonal contraceptives were positively associated with cognitive performance later in life. Number of live births, hysterectomy without oophorectomy and use of hormone therapy showed mixed findings, with task-specific positive and negative associations. Effect sizes were generally small (Cohen's d < 0.1). While APOE ε4 genotype was associated with reduced processing speed and executive functioning, in a dose-dependent manner, it did not influence the observed associations between female-specific factors and cognition. Conclusion: Our findings support previous evidence of associations between a broad range of female-specific factors and cognition. The positive association between a history of hormonal contraceptive use and cognition later in life showed the largest effect sizes (max. d = 0.1). Future research is needed to investigate the effects of sex hormone exposure and cognition to develop a better understanding of female's brain health.

The importance of female reproductive history on self-reported sleep quality, mood, and urogenital symptoms in midlife

“…In contrast, Wang et al 9 investigated a Chinese population of 512,891 adults and determined that each additional child was associated with a 4% decreased probability of insomnia in later life. In support, current studies indicate that women with breastfeeding history, and particularly those with more than 12 weeks of total breastfeeding; older age at first and last childbirths; and use of hormonal contraceptives maintained higher midlife cognition ability 26,33 …”

“…In support, current studies indicate that women with breastfeeding history, and particularly those with more than 12 weeks of total breastfeeding; older age at first and last childbirths; and use of hormonal contraceptives maintained higher midlife cognition ability. 26,33 The complex underlying associations between women's reproductive history and psychosomatic symptoms are largely due to great diversity in personal biological selections and longterm socioeconomic health impacts. 34 Therefore, sufficient analytic covariates are required to elucidate associations and objective results.…”