Women with higher lifetime exposure to estrogen have lower stroke risk

Researchers found that higher levels of lifetime estrogen exposure in women were associated with a lower risk of stroke.

A stroke occurs when blood is blocked from reaching the brain or a blood vessel in the brain bursts. Stroke is the second-leading cause of death around the world, and its incidence increased substantially between 1990 and 2019 globally, including a 70% increase in the number of incident, or first-ever, strokes.

Some studies suggest that higher estrogen levels may protectagainst stroke. Research shows, for example, that young womenhave a lower stroke risk than men, and that this risk increases after menopause, when estrogen production reduces.

Understanding more about stroke risk factors could improve preventative care and lead to improved treatment options.

Recently, researchers examined the link between lifetime cumulative estrogen exposure and stroke risk among postmenopausal women in China.

They found that women with the highest lifetime estrogen exposure had the lowest stroke risk.

For the study, researchers examined healthcare data from 122,939 postmenopausal women without prior stroke at baseline from the study. Participants were aged between 40 and 79 years and were followed for an average of 8.9 years.

They were asked to provide information about their reproductive history, including the age of puberty onset, the age at which menopause started, and the number of pregnancies they had. They also provided information on their use of contraceptive pills.

The women were then split into four groups according to their reproductive lifespan (RL), or the number of years between puberty onset and menopause. Those in the shortest RL group had up to 31 reproductive years, whereas those in the longest RL group had 36 years or more.

The researchers also collected data on stroke incidence. During the study, they recorded 15,139 cases of new-onset stroke.

The researchers found that 13.2% of women in the longest RL group had a stroke, compared to 12.6% of women in the shortest RL group.