Geriatrics Flashcards
Current life expectancy (2013)
82 for women vs. 77 for men
Average is 80
Aging statistics
Currently 13% of US population is > age 65
20% by 2030
Human life-span
~ 110 years
Oldest recorded age is 122
Changes in the brain with aging
Brain volume decreases by 10% from age 35 to 60 due to loss of white matter
Lipofuscin
“Wear and tear pigment” - the product of peroxidation of unsaturated fatty acids; accumulates in heart and liver with age
Diseases associated with aging
Cancer Atherosclerosis Cerebrovascular disease Diabetes Thromboembolism Alzheimer's and Parkinson's Disease
Clock theory of aging - Basic idea
Somatic cells are “programmed” to die due to inevitable shortening of telomeres, which limits the number of mitotic divisions each cell can undergo
Telomeres decrease in length by 50 bp/year such that by age 100 they are only 1/2 of their original length
Telomeres
Long tandem TTAGGG repeats at the ends of chromosomes
Telomerase
Regenerates TTAGGG telomere repeats at the ends of chromosomes; found in stem cells only (not somatic cells)
Telomerase mutations
Individuals with mutations in any component of the telomerase complex (TERT, TERC, DSC1) develop early bone marrow failure, skin disease, and organ fibrosis
Dyskeratosis Congenita
Due to mutation of DSC1 enzyme of telomerase complex
Mucucutaneous triad of nail dystrophy + skin hyper/hypopigmentation, leukoplakia
Progeria
Dominant mutation in Laminin A gene, an intermediate filament important for maintaining chromatin stability
Presents with accelerated aging; death usually occurs by 10 years due to cardiac / cerebrovascular disease
Werner Syndrome
Caused by mutation in DNA helicase resulting in faulty DNA replication / damage repair
Presents with early onset cataracts, aging changes in skin and hair, DM, osteoporosis, cancer, ASCVD; death by ~ 50 years
age-1
Inactivation of age-1 gene in nematodes increases life span by 30% by “slowing down” metabolism
IGF receptor gene mutations may have a similar effect
Supports Rust Theory
SIR-2
Histone deacetylase that functions in chromatin remodeling / stabilization; also suppresses BAX and apoptosis
Expression of Sir-2 is induced by caloric restriction, and over-expression of Sir2 increases life-span up to 30%
mTOR
mTOR coordinates growth and survival to the availability of nutrients
Treatment of mice with rapamycin (mTOR inhibitor) increases life span; mTOR is also inhibited by caloric restriction
Rust Theory of Aging - Basic Idea
Aging occurs as a result of the accumulation of somatic mutations and oxidative damage in cellular macromolecules over time
Evidence: Increased percentage of oxidized protein with age, accumulation of somatic mutations in mtDNA leading to decreased capacity for oxidative phosphorylation in somatic cells with age
Sarcopenia
Progressive decrease in fat-free mass (bone and muscle) with age; increased percentage of adipose
What are the two most important causes of morbidity related to secondary aging?
Tobacco
Physical inactivity
Exercise recommendations for elderly
Walking 30 - 40 minutes/day (4x/week)
10 weight-bearing exercises, 10-15 reps each (2x/week)
Renal changes related to age
Decreased GFR (10mL / decade)
Decreased ADH sensitivity > reduced response to hypovolemia
Decreased sodium excretion response to hypervolemia
Cardiovascular changes with age
Increased arterial and ventricular stiffness > increased systolic and diastolic pressure
Decreased maximum HR and CO
Pulmonary changes with aging
Declining VO2 max such that regular activity (“walking”) requires a greater percentage of total energy expenditure; i.e. “functional reserve” declines
Vital capacity, elasticity decrease
Residual capacity increases
Metabolic changes with aging
Metabolic syndrome =
Insulin resistance / hyperinsulinemia
Gucose intolerance / DM
HTN
Dyslipidemia
How is fever diagnosed in the elderly?
Single temp > 100
or repeated temp > 99
or rise > 2 over baseline
ADLs
Bathing - usually first need for help Dressing Transferring (i.e. bed to chair) Toileting Grooming Feeding
Instrumental activities of Daily Life (IADLs)
Using the telephone Shopping Food prep Housekeeping Laundry
Get Up and Go Test
Rise from hard chair without use of arms, walk 10 feet, turn, return, and sit back down
Time > 10 seconds = increased fall risk
Time > 20 seconds - consider therapy referral
Depression - 2 Question screen
- “During the past 2 weeks, have you felt down, depressed, or hopeless?”
- “During the past 2 weeks have you felt little interest or pleasure in doing things?”
Cognitive screening methods in geriatrics (2)
- MMSE (30 point screen)
2. MIni-cog = 3 item re-call + clock test
Approach to assessment of ADLs and IADLs
- Ask
- Observe - corroborate responses with patient appearance, verify accurary with family members
- Intervene - determine and correct underlying cause of deficit
- Refer - to case management, PT, social services, etc.
