PARIS, April 6 (Benin News) –
Life events that influence levels of the female hormone estrogen may be linked to risk of dementia in adulthood, according to a new study published in the journal ‘PLoS Medicine’.
The analysis found that certain reproductive events – such as early or late onset of menstruation, early menopause and hysterectomy – were associated with an increased risk of dementia, while having ever been pregnant or having had an abortion and late menopause were associated with a lower risk.
But childbearing is not one of them, as a similar relationship has been observed between the number of children and the risk of dementia in both men and women.
Lead author Jessica Gong, of the George Institute for Global Health in Australia, notes that while it appears that reproductive events linked to changes in women’s hormone levels may be involved in dementia risk, the exact relationship is still unknown.
“Although the risk of developing dementia increases with age, we don’t yet know if the higher rates seen in women are simply due to them living longer,” she explains. But it’s possible that female-specific reproductive factors could account for some of the gender differences.
Dementia is fast becoming a global epidemic, currently affecting some 50 million people worldwide. This number is expected to triple by 2050, mainly due to the aging of the population. The rates of dementia and associated death are known to be higher in women than in men.
Estradiol is the most predominant form of estrogen during reproductive life (from onset of menstruation to menopause) and estriol is the major estrogen during pregnancy. The use of hormones from outside the body, such as oral contraceptives during the reproductive years, and hormone replacement therapy (HRT) at older ages can also influence estrogen levels.
To examine these relationships in more detail, researchers at the George Institute analyzed data from a total of 273,240 women without dementia who were enrolled in the UK Biobank, a large-scale biomedical database.
After adjusting for other factors that may have influenced the results, they found that early or late onset of menstruation, early age at first childbirth, and hysterectomy, particularly nonablation hysterectomy, surgery to one or both ovaries, or if the hysterectomy took place after removal of the ovaries, were associated with an increased risk of dementia.
On the other hand, the factors associated with a lower risk were the fact of having already been pregnant, having already had an abortion, having had a longer reproductive life and a later menopause.
“With regard to external hormones, oral contraceptive pill use was associated with a lower risk of dementia, but the results of our study failed to confirm an association between HRT and dementia risk. notes Gong.
The authors proposed that the variation in risk in women is not associated with childbearing, as a similar pattern was observed between the number of children fathered and the risk of dementia in a similar number of men in the same study. .
“We found that the increased risk of dementia associated with early menopause (natural and artificial) was more pronounced in women of lower socioeconomic status,” she adds. Social deprivation is likely to be an important determinant of dementia risk, as well as other aspects of women’s health.
Faced with the increase in the number of dementias and the absence of significant advances in treatment, attention has focused on reducing the risk of developing the disease.
“Further research is needed to understand whether these differences are associated with lifetime exposure to the body’s own estrogen, and whether the use of external hormones may influence the risk of developing dementia,” suggests Gong. Our results may be useful in identifying high-risk women to participate in future clinical trials aimed at evaluating preventive measures and possible treatments.