Disease: Alzheimer's Epidemiology, Determinants and Prevention
Stefanie B. Marquez, MS HP200 October 27, 2009
Lecture Outline
Video Importance of Alzheimer's Disease (AD) awareness How we define AD Epidemiology: Who gets AD? Symptoms Diagnosis Risk Factors Treatment Prevention Lasting effects of AD: cost and caregiver stress Role of HPDP
Awareness of Alzheimer's is Important Because...
Someone develops AD every 70 seconds AD/dementia triple healthcare costs in persons aged 65 and older 9.9 million unpaid caregivers AD is the 6th leading cause of death in US
(source: WHO)
The total cost per year: $148 billion 3.5 million more health care workers needed by 2030
Percentage Changes in Selected Causes of Death, 2000 and 2006
Cause
Heart disease Breast cancer Prostate cancer Stroke Alzheimer's disease 2000 710,760 41,200 31,900 167,661 49,558 2006 629,191 40,970 27,350 137,265 72,914 Percentage Change -11.5 -0.6 -14.3 -18.1 +47.1
Source: Alzheimer's Association Executive Summary, 2009.
Famous people who have suffered from AD/dementia
Ronald Reagan
Margaret Thatcher
Rita Hayworth
Charlton Heston
James "Scotty" Doohan E.B. White
Rosa Parks
Sugar Ray Robinson
What is Alzheimer's Disease?
Named after Alois Alzheimer, who "discovered" the disease in 1906. Progressive, neurodegenerative disorder Most common cause of dementia (50-60% of total cases) Characterized by memory loss Long-term vs. short-term memory Death usually occurs 8-10 yrs. after Dx
Types of AD
Familial forms (5-10% of total cases)
Caused by genetic mutations
Sporadic (majority of AD cases)
Multifactorial with genetic components
MCI (mild cognitive impairment)
Sometimes progresses to AD, but not always
Epidemiology
Prevalence of dementia is <1% in individuals aged 60-64 but... In individuals who are >85, prevalence is 24-33% in the Western world 5.3 million Americans with AD In 2006: ~ 26 million people worldwide By 2050: this will quadruple to 104 million (1 in 85!!!)
Symptoms
Problems with executive function (e.g. decision-making) Language difficulties (e.g. word-finding) long-term memory is increasingly impaired Inability to learn new things Irritability, aggression, apathy, sleep disturbances Neuropsychiatric manifestations (e.g. delusions) 40% have symptoms of depression
How is AD Diagnosed?
Clinical Dx: based on cognitive tests (MMSE), history, brain scans... Biomarkers in blood and CSF Need to rule out other causes of dementia Dx confirmed at autopsy: plaques and tangles in the brain; extensive cell death
MMSE (Mini Mental State Exam)
A score of less than 24/30 or a marked decline from a previous score--indicates some type of dementia MCI: 24-25 Advanced AD/dementia: patients no longer capable of completing the test
Gross Pathology of the Brain
AD
Normal
Note the enlargement of the ventricles.
Risk Factors
Advanced age (>65) Reduced brain size Low education/occupation levels Head injury: does it initiate disease process or reduce just brain reserve? Genetics (DNA) Gender: women>men Ethnicity: African-Americans > Hispanics > Caucasians > Asians Down Syndrome (25% over age 35) Vascular disease and its assoc. risk factors
Treatment Options
FDA has approved 5 drugs that lessen symptoms
Namenda (memantine) Reminyl (galantamine) Aricept (donepezil) Exelon (rivastigmine) Cognex (tacrine)
They do NOT cure, stop or slow progression of AD Benefits usually last 6-12 mos. Only work in ~50% of suspected AD patients
Does AD Cause Death?
Common causes of death: pneumonia, stroke, infections, falls, heart disease, organ failure A severely damaged AD brain can shut down the body Difficulty with feeding & swallowing Inability to correctly process sensory perceptions (e.g. urinary bladder control)
Preventive Drugs
NSAIDs (e.g. naproxen vs. ibuprofen) Cholesterol-lowering drugs Vitamins C, E, B12 and folate Estrogen (women): is it protective? Testosterone (men) Antioxidants Diet: curcumin; omega-3-fatty acids (fish oil) Moderate alcohol intake (esp. wine)
Other Mechanisms of Prevention
ID biomarkers for earlier detection prevention of progression AD vaccine? Keeping your brain "fit" (e.g. crossword puzzles) Exercise
Promotes neurogenesis in the brain
Financial Effects: How much AD Costs
Average Per Person Payments by Source for Healthcare and Long-term Care Services, Medicare Beneficiaries Aged 65 and Older, 2004
No AD/dementia AD/Dementia
Total payments Medicare Medicaid Private insurance Other payers HMO Out of pocket Uncompensated
$10,603 5,272 718 1,466 211 704 1,916 201
$33,007 15,145 6,605 1,847 519 410 2,464 261
Source: Alzheimer's Association
AD and other dementias cost Medicare $91 billion per year and Medicaid $21 billion. These numbers will increase dramatically as baby boomers reach age 65. How will the government handle this increase?
What does AD Cost to the Caregiver?
87% caregivers are relatives of an AD patient 9.9 million Americans are unpaid caregivers 2008: 8.5 billion hours of unpaid service = $94 billion dollar contribution to the nation 50% of caregivers spend $200/month out of pocket
Caregiver Stress
~40% caregivers report "high" or "very high" stress levels ~33% have symptoms of depression Caregivers more likely to have:
Reduced immune function Slow wound-healing New hypertension New coronary artery disease
Disparity of Health Beliefs
A recent study: whites vs. AfricanAmericans Marked racial differences in factual knowledge about AD
Risks and concerns over AD Effectiveness of treatment/prevention
AA>whites: significant memory loss and AD are normal parts of aging
Role of HPDP
Ensure all populations are educated about AD/dementia: "tailored" education Need to disseminate accurate info about AD to avoid misconceptions Make info accessible to general public: websites (e.g. Mayo Clinic, alz.org), The Alzheimer's Project on HBO Research: recruitment for clinical trials and post-mortem studies