Neuroprotective role of estrogens: relationship with insulin/IGF-1 signaling.

Postmenopausal women have an elevated risk of developing a neurodegenerative disease. These clinical observation supported by basic research, suggest that estrogens are neuroprotective. Insulin resistance represents an independent factor in the etiology of age-associated disease and metabolic syndrome should be considered as a contributing factor to the higher post-menopausal vulnerability to neurological disorders. Elucidating the relationship between insulin resistance associated with aging in females, and the cross-talk between estradiol, insulin, and insulin-like growth factor (IGF-1) signaling pathways, will lead to a more complete understanding of the mechanism underlying estradiol-mediated neuroprotection. In past decades, estrogen replacement therapy (ERT) was commonly used as a palliative therapy during menopause, but the mid-term and long-term effects of estrogen as possible promoters of breast cancer and the increased risk of coronary illness or stroke, has limited current usage. A deeper understanding of the molecular mechanisms common to all forms of neurodegenerative diseases may hasten the development of protective strategies against chronic age-related deterioration and acute illness, ultimately providing a better quality of life for the elderly.