Background

Alzheimer's Disease Facts & Figures




Adapted from Alzheimer's Association, 2018
  • Alzheimer's Disease is a complex and fatal neurodegenerative disorder.

  • While we do not understand the cause of AD, we know that risk and pathology are driven by 3 universal biological variables:

    • Age (Old age)

    • APOE genotype (APOE4)

    • Sex (Female)

  • Approximately 5.8 million people have AD today.

    • Familial AD (early onset < age 65) affects only 0.2 million people in the U.S., caused by the overexpression of Aβ42.

    • Sporadic AD (Late onset > age 65) affects 5.6 million people in the U.S.

  • By 2050, ~14 million people will have Alzheimer's Disease.

  • There is no cure available, only symptom management .

  • While mortality for other diseases has fallen, mortality for Alzheimer's disease has increased.

  • $425 million go into AD research from the National Institute of Health alone.

  • Biggest hurdle: there is no reliable biomarker for diagnosis.

Hallmarks of Alzheimer's disease

  • Alzheimer’s disease is not normal aging.

  • It is a fatal disease that slowly destroys the brain and the ability to learn, reason and carry out daily activities.

  • Two main pathological hallmarks of Alzheimer's disease:

    • Aβ42 plaques

    • Tau tangles

Universal Biological Variables: Age, APOE genotype, and Sex

Adapted from Herbert et al, Neurol., 2013

Age

  • Age is the greatest risk factor for Alzheimer's Disease.

  • Progression potentially occurs without symptoms for 20 years before onset.

APOE

  • APOE4 is the greatest genetic risk factor of Alzheimer's disease.

  • 60% of the Alzheimer's population has APOE4.

  • APOE4 is associated with accelerated Aβ42 accumulation.

Adapted from Farrer et al, JAMA, 1997

Sex

  • AD risk is increased 2-fold in females compared to males.

Adapted from Farrer et al, JAMA, 1997

Sex and APOE

  • Female APOE4 carriers have a greater lifetime risk for developing AD compared to male APOE4 carriers.

  • The mechanism behind the interactive effects of sex and APOE4 on AD risk is not understood.

Modifiable Risk Factors/Suggestions to Reduce AD Risk