High estrogen and diabetes a recipe for dementia in women

The combination of higher estrogen levels and a diabetes diagnosis is associated with 14 times the risk of developing dementia for older women, according to a study published Jan. 29 in Neurology.

Higher blood estrogen levels alone accounted for double the risk of dementia for postmenopausal women after accounting for other risk factors.

The dramatic numbers come from a new study by a team of researchers including Laure Carcaillon, PhD, with the French National Institute of Health and Medical Research (INSERM) and CESP Centre for Research in Epidemiology and Population Health, Hormones and Cardiovascular Disease at the University Paris Sud in Villejuif, France.  The prospective study was undertaken to evaluate factors of higher dementia risk in women aged 65 and older. A total of 543 cognitively normal women and 132 women diagnosed with dementia were screened for higher endogenous estradiol (E2) levels, and other risk factors including diabetes, elevated blood pressure and atypical blood clotting.  

“While it was long believed that estrogens (endogenous or therapy) were good for women's health especially for heart and brain, this study, together with other current data, challenge this dogma,” study co-author Pierre-Yves Scarabin, MD, told Molecular Imaging. “Beliefs are largely based on experimental data but findings from animal models do not necessarily apply to women. Studies of dementia in women are urgently needed.”

Estrogen levels of women with diabetes were found to be 70 higher than others, leading to the 14-fold increased risk for this population of women. In fact, no other cardiovascular risk factors studied led to increased risk of developing neurodegenerative disease.

Interestingly, lower levels of E2 also were associated with increased risk of dementia, but the researchers believe that reverse causation could be the culprit in this case. Further research is needed to fully understand the link between E2 and dementia risk.