Adverse reproductive factors plus unhealthy lifestyle tied to higher risk of cognitive decline

In Chinese postmenopausal women, adverse reproductive factors combined with unhealthy lifestyle behaviours appear to be associated with increased likelihood of cognitive decline, as reported in a study.

The study included 1,379 cognitively normal postmenopausal women aged ≥60 years who were residing in Shanghai, China. All participants were followed for 1.8 years on average.

Researchers obtained data on reproductive factors such as menopausal age, menarche age, parity, age at first live birth, and breastfeeding duration. These factors were examined in relation to the study outcome of cognitive decline, defined as an annual decline in Mini-Mental State (MMSE) Examination score exceeding mean decline by 1.0 standard deviation (SD).

The odds of cognitive decline were increased for women who underwent menopause at a younger age (<46 vs >55 years: odds ratio [OR], 2.55; 45–50 vs >55 years: OR, 2.32). The odds were also higher for women with longer vs short breastfeeding duration (>35 vs <12 months: OR, 2.15; 24–35 vs <12 months: OR, 2.31).

Notably, the likelihood of cognitive decline was higher among women with early menopause (≤50 years) plus insufficient vegetable intake (OR, 1.84), physical inactivity (OR, 2.11), suboptimal sleep duration (OR, 2.15), or an unfavourable composite lifestyle index (CLI) (OR, 1.76) relative to those with late menopause (>50 years) and favourable lifestyle behaviour.

Similarly, the odds of cognitive decline were higher among women with prolonged breastfeeding duration (>23 months) combined with physical inactivity (OR, 2.10), suboptimal sleep (OR, 2.11), or an unfavourable CLI (OR, 2.16) compared with those who had short breastfeeding duration (≤23 months) and favourable lifestyle behaviour.

Further analysis showed additive interactions between early menopause and physical inactivity (relative excess risk due to interaction [RERI], 1.08; attributable proportion due to interaction [AP], 0.51), as well as between prolonged breastfeeding duration and physical inactivity (RERI, 0.89; AP, 0.42).