Gender, sex steroid hormones, and Alzheimer's disease

Abstract

Age-related loss of sex steroid hormones is an established risk factor for the development of Alzheimer’s disease (AD) in women and men. While the relationships between the sex steroid hormones and AD are not fully understood, findings from both human and experimental paradigms indicate that depletion of estrogens in women and androgens in men increase vulnerability of the aging brain to AD pathogenesis. We review evidence of a wide range of beneficial neural actions of sex steroid hormones that may contribute to their hypothesized protective roles against AD. Both estrogens and androgens exert general neuroprotective actions relevant to a several neurodegenerative conditions, some in a sex-specific manner, including protection from neuron death and promotion of select aspects of neural plasticity. In addition, estrogens and androgens regulate key processes implicated in AD pathogenesis, in particular the accumulation of β-amyloid protein. We discuss evidence of hormone-specific mechanisms related to the regulation of the production and clearance of β-amyloid as critical protective pathways. Continued elucidation of these pathways promises to yield effective hormone-based strategies to delay development of AD.

Polysomnography, brain volumetry, and mismatch negativity as early biomarkers of amnestic mild cognitive impairment progression

“…1 Hypnogram of a 63-year female progressive amnestic mild cognitive impairment patient showing decreased sleep efficiency, delayed rapid eye movement sleep latency, reduced REM % of total sleep time, and increased N3 non-rapid eye movement % of TST dementia. Vest and Pike (2013) also agreed with these results and stated that AD disproportionately has higher female incidence due to the rapid tapering of gonadal sex hormones after menopause in comparison to the slow male andropause with loss of their potent neurotrophic anti-AD action. Medical researches stated a bidirectional relationship between MCI and sleep disturbances.…”

Sex Hormones and Alzheimer’s Disease

“…Estrogen actions seem to be age dependent with obvious dysregulation in old-aged people. At the same time, estrogens have neuroprotective actions through increasing the expression of antiapoptotic Bcl-xL and Bcl-w and suppressing the expression of proapoptotic Bim, which lead to prevention of neuronal loss from Aβ toxicity [77][78][79][80].…”

“…Male andropause occurs very slowly over a long period of time where total androgen level starts to decline in thirties in a rate of 0.2-1% per year, while free testosterone decreases in a higher rate (2-3% yearly). This slowly gradual andropause relative to the rapid menopause may be one of the explanations of decreased male gender AD risk, delayed male MCI/AD conversion and slower AD cognitive deterioration [78,95].…”

Alzheimer’s Disease: An Epidemiologic Disaster From Nutritional Perspective

“…The share of population aged 65 and over is increasing in every EU member state: In 2014 the 65-79 years age group represented 13.4% of the population, while the rate of people aged 80 years Evidence suggests that AD pathogenesis is regulated by estrogen and progesterone in females, but primarily by androgens in males [12,13].…”