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Flashcards in Adult & Elderly Deck (164)
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1
Q

What maturation milestones are reached in young adulthood?

A
  1. Sexual maturity (teens)

2. Physiological maturity (around 30)

2
Q

____ maturity is reached before ___ maturity

A

sexual

physiological

3
Q

True/False: When sexual maturity is reached, this indicates that growth has reached a maximum and will stop.

A

false; teens still growing, building bone mass

4
Q

What marks the point of physiological maturity? (2)

A

maximum height reached

maximum bone mass reached

5
Q

Why does growth and bone mass stop increasing? What happens after the maximum is reached?

A

rate of catabolism = anabolism (no more growth)

eventually catabolism > anabolism, will begin to DECREASE muscle and bone mass

6
Q

After the age of 30, humans enter a ____ phase.

A

catabolic

7
Q

When is peak strength reached?

A

5 years after max height reached

8
Q

Young adulthood describes the years:

A

20-35

9
Q

Middle adulthood is the years:

A

50-69

10
Q

As age increases, so does the rate of ____ , increasing the imbalance with _____.

A

catabolism

anabolism

11
Q

How does the metabolic changes in older adults affect body composition? What effects does this have?

A

less muscle mass -> lower BMR

gradually lower energy needs

12
Q

How is the average weight affected in aging people, and why?

A

average is increased
not accounting for lower energy needs, and more sedentary life -> more fat gain
(some will lose weight, but average is still gaining)

13
Q

weight tends to increase until age ____.

A

70

14
Q

What can help prevent muscle/bone loss?

A

resistance exercise & activity

15
Q

Fat gain with age tends to accumulate in the ____ area. What are the health effects?

A

abdominal; accelerates with age

increased risk of diabetes, hypertension, CVD

16
Q

How does decreased LBM contribute to obesity?

A

less LBM -> Higher % fat in body

17
Q

In terms of aging obesity, women have higher ____, but lower ____.

A

risk of obesity,

incidence

18
Q

At what point does morbidity from obesity become a concern? What are the risk for women

A

> 25 (overweight by more than 25lbs)

women: 2-3x greater risk for CHD

19
Q

How does obesity affect blood cholesterol?

A

overproduce LDL
less HDL
imbalance

20
Q

What are the health risks of obesity?

A

increased risk of chronic metabolic disease and morbidity

cancers, diabetes, heart disease, etc

21
Q

The leading causes of death and illness, such as __________, are closely associated with ___ and ___ factors.

A

major chronic disease: heart disease, cancer, stroke
also osteoporosis, dementia, HTN
LIFESTYLE & DIET

22
Q

What are some dietary factors that have increased the occurences of chronic disease?

A

shifting diet: more animal fat, less complex carbs and fibre

23
Q

What is a meta-analysis?

A

an unbiased review of multiple studies

put together data and analyze as 1 big cohort

24
Q

What was analyzed the the meta-analysis by Mozaffarian?

A

likelihood of developing CHD, Stroke, or diabetes from consumption patterns of many types of foods

25
Q

What needs to be considered when analyzing multiple data sets for a meta analysis?

A

results of each study
uncertainty
population size of each study (determine weight of results)
need to be unbiased, reliable

26
Q

How are results from multiple studies combined?

A

take the median or mean of results (account for weight % of each study, depending on population size)

27
Q

How do processed meats differ from normal meat?

A

higher sodium

nitrites and nitrates, nitrosamines as preservatives

28
Q

What two meat products were shown by the meta-analysis to have negative health effects, and why?

A

red meat: high in sat fat, high heat produces heterocyclic amines
processed meat: high salt, nitrates (even higher risk)

29
Q

foods found generally to be beneficial are:

A

fruit/veg, veg oil, fish, nuts, yogurt, beans, whole grains

30
Q

Foods found to be harmful and increase risk of chronic disease are:

A

refined grain/starch/sugar, high sodium, processed meat, trans fat (worst!)

31
Q

Foods that are somewhat neutral/inconclusive are:

A

dairy, eggs, poultry, red meat

32
Q

Are low fat diets found to be effective in reducing incidence of CHD?

A

Slightly; but much more effective was the mediterranean diet (small diet changes: use more EVOO, nuts)

33
Q

What did the PREDIMED study show about the mediterranean diet and fat consumption?

A

consumption of healthy fats (MUFA, PUFA) even if >35%, can still lead to decreased risk of CHD
so: should not focus diet on fat reduction!

34
Q

What is the key recommendation of the unified dietary guidelines? Why?

A

adequate fruit veg intake!

  • inadequate intake -> increase disease risk
  • higher intake -> protective effect against disease
35
Q

How can increased consumption of fruit and veg impact disease risk later in life, and what compounds are associated with this?

A

can reduce cancer risk (vitamin C, beta carotene, fibre, phytochemicals)

36
Q

What lifestyle/diet factors are found to increase chronic disease risk and accelerate aging? (8)

A
alcohol
smoking
sedentary
high stress
high sat fat
high Na
low fibre
high sugar
37
Q

what are the UNIFIED DIETARY GUIDELINES? (6)

A
  1. eat VARIETY of food
  2. choose mostly PLANT sources
  3. > 5 serves fruit/veg per day
  4. > 6 serves grains/starch per day
  5. less high-fat food (especially animal)
  6. minimal SIMPLE SUGARS
38
Q

The unified dietary guidelines were developed by:

A

American: Heart association, cancer society, academy of pediatrics, dietetics association
NIH

39
Q

What is happening to the age of the population in Canada? Why?

A

population is aging (higher % old people)

longer lifespan & lower birth rates

40
Q

Why is increasing age of the population problematic in terms of health? In terms of society?

A

living longer, but faced with chronic disease, loss of independence

less workforce, greater burden on nation to care for the elderly, need more funds for healthcare

41
Q

What is “usual aging,” vs “succesful aging?”

A

usual: normal deteriorative aging effects, accelerated by poor lifestyle/diet
succesful: still some normal aging effects, but NOT amplified because of poor lifestyle/diet

42
Q

What tends to decrease with age (physiological)?

A
muscle mass/function
BMR
organ mass/function
GI cells (less absorption)
43
Q

How do people who age “successfully” differ from those with usual aging?

A
exercise regularly
good nutrition
good control BP
no smoking or excess alcohol
not obese
44
Q

How is immune function affected by age?

A

may show decline = IMMUNOSENESCENCE

but not in everyone! so may be preventable

45
Q

The best characterized feature of immunosenescence:

A

declining T cell function

46
Q

What vitamin supplement can actually improve immune function, and by what mechanism?

A

vitamin E

  • high PE2 will inhibit T cell proliferation
    throws off balance of TH1 vs TH2; not enough TH1
    TH1 is interferon gamma, IL2 (cell-med immunity to kill pathogens)
  • also reduce IL2 receptor expression
    SO: high PE2 -> less immune response

vit E will inhibit prostaglandin E2 (PE2) from macrophages

47
Q

What is the best predictor of # of visits to doctor or hospital for elderly?

A

malnutrition

48
Q

Why are green vegetables beneficial in improving health of elderly?

A

high in vit C, E

improve/prevent cataracts, dementia, improve immunity

49
Q

How is folate related to dementia? (3)

A

deficiency increases risk (3x)
supplementation improve mental function
weight loss due to dementia may impact folate metabolism

50
Q

Supplementation with ___ and ____ can help prevent/improve symptoms of dementia

A

fish oil

folate

51
Q

Change in body composition with age is due to ____ and decrease in _____.

A

hormonal changes

decrease in activity

52
Q

How do the amounts of sex hormones change in old age, and how does this impact body composition?

A

less estrogen & testosterone
less estrogen -> decreased BMD
less testosterone -> can’t maintain protein stores -> less muscle

53
Q

What happens first, loss of BMD or loss of LBM?

A

LBM

54
Q

Why is BMI not a good indicator of obesity in elderly? What are better alternatives?

A

Does not indicate % fat; low weight but high fat is also dangerous

instead: PERCENT BODY FAT (PBF)
use BIA, MRI, CT, DXA, waist measure, electric impedement, TG levels in blood (can use combo)

55
Q

What is “HTW?”

A

hypertriglyceridemic waist

56
Q

How can excess fat mass be measured through blood?

A

measure TG levels

high visceral fat and fatty liver -> increased TG levels

57
Q

How does excess fat impact hormone action in the body?

A

high TG -> insulin resistance
high intromyocellular fat -> insulin resistance
changes in production and sensitivity of GROWTH HORMONE, INSULIN-LIKE GROWTH FACTOR 1, sex hormones, corticosteroids, insulin
-> affects muscle metabolism

58
Q

How does decreased PA affect muscle (describe hormone changes)

A

changes in production and sensitivity of GROWTH HORMONE, INSULIN-LIKE GROWTH FACTOR 1, sex hormones, corticosteroids, insulin

  • > affects catabolic/anabolic balance in muscle
  • > more intramuscular fat
59
Q

How does long term stress ultimately impact hormonal control?

A

repeated activation of HYPOTHALMIC PITUITARY ADRENAL ACCESS (HPAA) which is homeostatic response system; coordinate stress response hormones

too much activation -> generate many oxidative species, overwhelm neuron, cannot deal with oxidative stress (possibly less functional)

60
Q

What happens to muscle after age of 30? How does this affect the rest of the body? Can it be slowed/prevented?

A

decreased muscle mass (lose 3-5% every decade)
decreased function
increase % fat -> inflammation -> further decrease muscle mass/function

can slow/prevent with adequate cal/protein + phys activity

61
Q

More adipose tissue will result in more release of ___, which promote ______ and decrease muscle ____.

A

cytokines
myofibrillar breakdown
synthesis

62
Q

True/False: aging people should eat as much protein as possible to prevent muscle loss

A

False: excess protein is converted to fat, more fat will actually slow muscle synth

63
Q

The age related loss of muscle/function is known as: ____. What is a good lifestyle preventative measure?

A

sarcopenia

resistance training

64
Q

How are LBM and BMD related?

A

synergy between the two
better LBM -> better BMD
need muscle for mechanical stress on bone to maintain strength

65
Q

Can body composition and function be improved in old age? How?

A

yes; can revert changes by acting on muscle mass
physical activity -> less % body fat
phys activity increase muscle STRENGTH and MOBILITY

66
Q

Why are dietary interventions often necessary in elderly? What changes and effects take place?

A

chronic disease (CVD, cancer, diabetes, HTN, etc)

  1. required change in food habits -> less intake (unappetizing)
  2. drugs can affect (change metabolism, absorption)
  3. restrict access to food (decreased mobility)
67
Q

definition of “frailty”

A

fit 3+ of these criteria:

  1. muscle weakness
  2. slow walking
  3. exhaustion
  4. low activity
  5. unintended wt loss
68
Q

The risks associated with frailty:

A

increased fall risk -> fracture -> convalescence (bed rest), lack of movement, long recovery -> high morbidity (downward spiral)

69
Q

The theories of why we age: (6)

A
  1. Cellular mutations
  2. Decreased hormone secretions
  3. Cross-linking
  4. Free radicals
  5. Deteriorating Immunity
  6. Pre-programmed (genetic)
70
Q

How does cell mutation contribute to age?

A

accumulative over the years:
Exposure to UV, radiation, mutagens -> damage DNA repair ability -> cannot fix damage from enviromental stressors -> more “malfunction” cells -> cell death
(too many errors, incorrect proteins -> decrease function)

71
Q

How can DNA be studied to infer someone’s age? What else does it reveal?

A

methylation status (epigenetic modification, methyl on cytosine)

good predictor of how long going to live (higher methylation, higher mortality)

72
Q

How do hormonal changes contribute to aging?

A

less GH -> more fat, less LBM
less estrogen -> can’t maintain protein/bone
less testosterone -> Can’t maintain protein
less insulin -> less anabolism

73
Q

What is the theory of cross-linking and aging?

A

glycation -> linking of protein -> ADVANCED GLYCATION ENDPRODUCTS -> too many, cause APOPTOSIS

74
Q

What is the link between free radicals and aging?

A

environmental exposure: radiation, oxidation, breathing, etc -> cause macromolecular damage (oxidative damage)

75
Q

Can a reduced diet and therefore decreased oxidation rate in humans extend lifespan?

A

No; likely to become deficient in nutrients

76
Q

The deterioration of the immune system, called _____, impacts the __ and __ cells. What physiological change causes this? It will leads to what result?

A

immunosenescence
B & T
due to shrinking thymus -> less mature B and T cells produced
increased susceptibility to chronic inflammatory disease, autoimmune disorders
(dysregulated, lose function, etc)

77
Q

What is the theory of pre-programmed aging?

A

cells can only divide so many times;
TELOMERES at end of chromosomes w/ protective function, but get shorter with age!
- no more protection from telomeres, need DNA repair machinery
-p53 activated, stop proliferation, so can get fixed
*if not fixed -> cell death

old cells release detrimental chem to surrounding cells
slowing proliferation is bad for areas with high turnover (gut, blood)

78
Q

What are risk factors for malnutrition in elderly? (8)

A
  1. decrease body function
  2. chronic disease
  3. medication
  4. loss of mobility/independence
  5. tooth loss/oral pain
  6. eating poorly
  7. economic hardship
  8. less social contact
79
Q

What body functions tend to decrease, how does it impact nutrition in old age?

A

almost every system decreases
especially GI, liver, renal -> less absorption, detox ability
sensory impairment -> less appetizing food
decrease in oral health
decreased mobility
so: increased malnutrition risk

80
Q

How can medications impact elderly negatively?

A

interfere with appetite, absorption, excretion, etc

less detox ability -> easily overdose

81
Q

What factors can lead to loss of mobility and self-care ability in elderly, and possible malnutrition?

A

disability (eye problems, fractures)
surgery/injury/infection (less intake, but more nutrient needed!; anorexia)

less able to get food -> malnutrition -> even more weak -> more malnourished

82
Q

Oral problems in elderly increases risk of ____ and also ___.

A

malnutrition; choking

83
Q

Common features of elderly who eat poorly:

A

eliminate fruit/veg
poorly educated
change in living conditions (institutionalized, or alone)

84
Q

What are changes in organ function with aging? (9)

A
  1. less taste buds
  2. less saliva
  3. less esophageal function
  4. less gastric function/slow emptying
  5. less liver/biliary function
  6. less pancreatic secretion
  7. changed intestine morphology
  8. changed renal morphology
  9. less bladder control
85
Q

What are the changes that occur in the mouth, with age? What are the effects?

A

less taste buds -> decrease palatability -> less intake -> malnutrition

less saliva -> dry mouth (xerostomia); less protective enzymes
-> more infection/ulcers

86
Q

What is the importance of saliva, and what can decrease production?

A

lubricate food -> help swallow
contain IgA, lysozyme -> antibacterial

decreased by drug intake, disease

87
Q

swallowing dysfunction is known as:
What can cause this?
It increases risk of:

A

dysphagia
diabetic neuropathy, CNS changes, parkinson’s
risk of choking, pneumonia (food in lungs)
*need to restrict food types

88
Q

How does the stomach change with age? What negative effects does this cause?

A

decreased function/emptying

  • less acid production -> atrophic gastritis (can’t digest)
  • weaker lining, less parietal cells -> risk of ulcers, heartburn
  • can’t maintain healthy flora balance (low acid, other bacteria will colonize) -> overgrowth in small GI -> COMPETE FOR B VITAMINS
89
Q

the importance of gastric acid:

What 2 conditions arise if it is not enough?

A
  • digestion
  • barrier to bacteria

atrophic gastritis
hypochlorydria

90
Q

What does the stomach lining secrete to protect itself from the acid?

A

thicc mucus with Na bicarbonate

91
Q

What changes occur in the liver and biliary function with age, and what effects does it cause?

A

less bile -> more intolerant to foods (fat, raw veggies) -> gassy, diarrhea

less drug-metabolizing enzymes -> decreased detox ability -> more drug toxicity

92
Q

A decrease in function of the ____ results in less secretions of _____, leading to impaired nutrient absorption in the ____.

A

pancreas
digestive enzymes
small intestine

93
Q

How does intestinal morphology change with age?

A
  • slower movement-> constipation, diverticulosis
  • less enzymes -> lactose intolerance
    (can’t drink milk -> def in vit D, A, Ca, B2, protein)
94
Q

How is renal morphology changed by old age?

A

less function (lose nephrons, renal mass) -> less filtration ability -> can’t tolerate high load of protein or electrolyte

95
Q

How can high doses of drugs and vitamins affect kidneys in old age?

A

lead to GLOMERULONEPHRITIS
Can’t excrete; IgG and other complement bind to metabolites -> form depositions -> attract phagocytes (inflammation)

*type III hypersensitivity

96
Q

how can renal function loss lead to nutrient deficiencies? (3)

A

Can’t reabsorb water, glucose, AA -> excreted
impaired thirst mechanism -> dehydration
less able to activate vit D -> vit D deficiency

97
Q

How can drugs affect dietary intake? (2)

A

reduce/increase appetite

dry mouth, loss of taste, etc makes eating harder

98
Q

Drugs that impact vitamin status are known as ______. How does this occur? (5)

A

antivitamin drugs

  • inhibit absorption
  • bind and decrease bioavailability
  • more catabolism
  • more excretion
  • inhibit activation
99
Q

Multiple intakes of medical drugs (known as: _____), is a good predictor of ___ in elderly.

A

polypharmacy

malnutrition

100
Q

Do elderly bodies handle drugs differently than young adults? Why?

A

liver/renal systems decline; less able to metabolize and excrete drugs -> higher risk of toxicity and side-effects

101
Q

What is the general path of drugs through the body?

A

absorption
distribution
metabolism
excretion

102
Q

Why might the absorption of oral drugs be problematic?

A

intake of foods, supplements can interfere with absorption

103
Q

In blood, drugs are usually bound to _____. How do they behave differently from unbound drugs?

A

plasma proteins

only unbound drugs can leave bloodstream and affect target organs

104
Q

What does the “distribution” stage of drugs in the body consist of?

A

drugs leave systemic circulation to diff parts of body

105
Q

How could blood plasma composition affect drug effectiveness?

A

less serum albumin (carrier protein) -> more unbound drug -> more leaving circulation and into organs (more effective)

106
Q

the metabolism and ____ of drugs occurs primarily in the ____. It is facilitated by the enzyme system ____.

A

biotransformation
liver
P450

107
Q

What important role of drug metabolism is needed to facilitate excretion?

A

P450 in liver: convert FAT-SOLUBLE -> WATER SOLUBLE so can excrete out

108
Q

The major route of drug excretion:
The two affecting factors:
What other bodily fluid can it be excreted in?

A

renal
renal function; pH of urine
bile

109
Q

drugs may be excreted as ___ or ___.

A

drug metabolites; unchanged

110
Q

What is an example of a food that will affect drug metabolism, even when taken several hours earlier?

A

grapefruit juice
affect cytochrome p450, enzyme 3A4
(for anti-anxiety meds, Ca channel blockers, HMG CoA reductase inhibitors)

111
Q

____ is an antidepressant that will interact with “pressor agents in food, such as ______. What physiological effects can this have?

A

Monoamine oxidase inhibitors (MAOI)
tyramine, dopamine, histamine, phenylethylamine.

pressor agents increase BP; normally would be de-aminated (deactivate) by MAO (which is inhibited by drug)
so: if on drug + high intake of pressor agents -> hypertensive crisis

112
Q

How could intake affect the effectiveness of warfarin?

A

normally prevent conjugation of vit K -> active form; no clotting

but high vit K, vit E, garlic, other foods can overcome this

113
Q

What drugs might impact folate nutrition, and how can this be dealt with? (2)

A

methrotrexate (cancer or arthritis)
pyreethamine (malaria, toxoplasmosis)

folic acid ANTAGONISTS; folate not activated by DEHYDROFOLATE REDUCTASE

instead: use reduced form (FOLINIC ACID) to prevent deficiency (already active); or extra supplements

114
Q

Alcohol acts as a ____ on the gastric system. If it is combined with ____, it may cause ____.

A

irritant
other irritants (NSAIDS, hepatotoxic drugs)
gastric bleeding

115
Q

Define “drug-nutrient interactions,” and “food-drug interactions”

A

drug-nutrient: action between the 2, that would not happen with either alone

food-drug: broad term, includes drug-nutrient; effects on NUTRITIONAL STATUS

116
Q

What is cholestyramine drug used for, but what negative effects on nutrition occur?

A

reduce cholesterol by sequestering bile
BUT: “sticks” to fat soluble vitamins -> less is absorbed by body

if long term use, need vit supplements

117
Q

___ drugs may cause GI damage, by impacting microflora and also: ________.
What are the nutritional implcations?

A

antibiotic (ex: neomycin)
damage villi, microvilli, destroy mucosa, inhibit enzymes

lower absorption ability

118
Q

The anti-nutrition effects of anti-inflammatory drugs: (2)

A

inhibit lactase

damage gut -> less fat/micronutrient absorption

119
Q

Function of laxatives, and Antinutrient effects of laxatives:

A

help retain water in stool, speed up transit time

but: mineral oil dissolve fat + fat soluble vit -> excreted
shorter transit time -> less absorption Ca, K

120
Q

What drugs tend to impair absorption of minerals? Which minerals in particular?

A

NSAIDs, antiobiotics, chemotherapy
Ca, Fe
(also Mg, Zn)

121
Q

A diet high in ____ can bind and impair absorption of ____ drugs.

A

fibre

tricyclic antidepressants

122
Q

____ is taken to prevent ulcers. What is the mode of function, and what nutrition impacts happen?

A

cimetidine

lower HCl production -> less acidic
but: less B12 released from food! (so lower intrinsic B12 receptor secreted)
less absorption of Ca, Fe, beta-carotene, Folic acid

123
Q

How can use of diuretics impact the heart?

A

loop diuretics (for BP control) -> more THIAMINE excretion -> cardiac abnormalities

other diuretics -> more K excreted -> cardiac arrhythmia

124
Q

The effects of corticosteroids on renal function: (3)

A

DECREASE Na excretion
INCREASE K, Ca excretion
water retention

125
Q

What are 2 negative effects of aspirin?

A

irritant -> can cause gastric bleeding

INCREASE FOLATE EXCRETION (bind to folate site on carrier protein! more folate lost since can’t transport)

126
Q

Define diarrhea:

A

3+ unformed bowel movements in 24 hr

  • acute: <2 wks
  • chronic: 3-6 wks
127
Q

elderly are (more/less) susceptible to diarrhea. This is due to: ______.

A

more

immunosenescence; deteriorating GI tract/function; drug therapy (MOST COMMON!) - too high of a DOSE

128
Q

What are risks associated with diarrhea in elderly?

A

dehydration, illness, electrolyte imbalance, lower quality of life

129
Q

What are some osmotic drugs, and how do osmotic drugs impact GI function?

A

antacids, laxatives

cause osmotic diarrhea

130
Q

What is the meaning of “iatrogenic?” What is the most common iatrogenic cause of diarrhea in elderly?

A

treatment used for one condition will cause another problem

ANTIBIOTICS commonly cause diarrhea (alter microflora, damage mucosa)

131
Q

How can antibiotics cause osmotic diarrhea?

A

alter gut microflora -> less carb fermentation (carbs will act as osmotic agent)

132
Q

why does damaging gut microflora increase diarrhea risk?

A
  1. microflora needed to protect against diarrhea causing pathogens
  2. osmotic diarrhea, since more carbs unfermented
133
Q

What are factors that contribute to the negative effects of drugs?

A

polypharmacy
non-compliance (wrong dose, wrong time, etc)
self-medication
error with prescribing

134
Q

Anti-cancer drugs are known as _____ drugs. What is the damaging effect on the gut?

A

antineoplastic drugs

damage immature epithelial cells -> gut lining (mucosa) damaged -> less absorption ability -> diarrhea, malnutrition

135
Q

The replacement of old bone with new bone is known as ______. How does this occur?

A

bone remodeling

OSTEOCLASTS break down old bone with acid, PHAGOCYTES remove protein
OSTEOBLASTS synth new matrix

136
Q

Define osteoporosis

A
reduced bone (but normal composition)
<2SD below normal bone in young adults
137
Q

Bone loss is accelerated in women during the ______ period, which may lead to _____.

A
early postmenopausal  (50-70)
type I osteoporosis
138
Q

How do rates of bone resorption and formation change throughout life?

A

<30 yrs: formation > resorption -> bone mass increases
30: peak bone mass
>30: resorption > formation -> bone mass loss (-1% per yr)

139
Q

How do the rates of bone loss differ for men and women? why?

A

women: from 50-70 will have MORE rapid loss (3-5% per yr)
due to MENOPAUSE: lower level of estrogens
(less serum estrone & 17b estradione )
*eventually reach new setpoint -> loss will slow to same as men

140
Q

Can high Ca intake during youth prevent the gradual loss of bone with age?

A

No; but will make ample bone mass stores so that losses will not result in osteoporosis

141
Q

What is the main determinant of peak bone mass, and when does the maximum accretion occur?

A

Ca intake

puberty growth spurt

142
Q

Why are women more susceptible to osteoporosis?

A

smaller skeleton
hormonal changes during menopause
start bone loss earlier

143
Q

What are risk factors for osteoporosis?

A
Female
small/thin
old
genetics (race, family history)
postmenopausal
amenorrhea (low estrogen, no period)
anorexia nervosa (malnutrition, no hormones)
low Ca intake
hypogonadism (low levels of sex hormones)
inactivity
smoking/alcohol/drugs/medication
144
Q

Aging results in less secretion of hormone ____, which results in less ____ and ____, resulting in bone loss

A

GH

hepatic IGF1/IGF2, GF binding proteins

145
Q

_____ medications have what hormonal effects that affect bone?

A

steroid (glucocorticoids)

suppress IGF-1 synth, suppress bone growth

146
Q

____ exercise is recommended to strengthen skeleton

A

weight-bearing

147
Q

What part of bone contains Ca and responds to daily Ca intake?

A
TRABECULAR BONE (20%)
lacey inner part, contain Ca crystals
148
Q

The types of osteoporosis:

A

type I: postmenopausal - trabecular bone loss
- due to LOW ESTROGEN -> more osteoclast activity

type II: senile - cortical bone loss
- due to accumulation bone marrow fat -> less osteoblast

149
Q

true/false: senile osteoporosis will start in very old age, 70+

A

false; slow and steady process! begins around 40

150
Q

What is the role of estrogen in preventing bone loss? (3)

A
  1. promote breakdown of osteoclast precursors -> fewer osteoclasts
  2. less production of resorption cytokines (IL1, IL6, TNFa, MCSF)
  3. reduce Ca-releasing effects of PTH
151
Q

Which tends to begin sooner, Type I or Type II osteoporosis?

A

Type II

152
Q

A 40 year old man with low bone density would be classified as having ____ osteoporosis

A

idiopathic (cause unknown; not old enough for senile osteoporosis)

153
Q

What are the mechanisms of senile osteoporosis?

A
  1. more bone marrow adipocytes -> make adipokines, FA -> inhibit OB
  2. sarcopenia -> less muscle, less load/resistance on bone
  3. stem cells become adipocytes rather than OB
  4. estrogen deficiency (men and women!) -> OC Activity increase
  5. less Ca/vit D (lower absorption, activation) -> more PTH (hyperparathyroidism) -> more Ca release from bone
154
Q

Can Ca supplementation alone be used to prevent osteoporosis?

A

NO; But can help prevent; use with other treatments

high dose in first year menopause can help slow rapid bone loss

155
Q

What are preventative care measures for osteoporosis in different stages of life?

A
  1. acquire max bone mass in youth (adequate Ca, vit D)
  2. screen for osteopenia in premenopause
  3. slow bone loss in postmenopausal period
  4. lifestyle: exercise, avoid smoking/alcohol/drugs
156
Q

What is osteopenia?

A

bone loss >1SD (not yet osteoporosis)

157
Q

How can bone loss in postmenopausal period be slowed?

A
  1. supplement (Ca, vit D (calcitriol or alfacalcidol)
  2. HRT (hormone replacement therapy)
  3. lifestyle: exercise, avoid smoking/alcohol/drugs
158
Q

the predominant treatment to slow bone loss is: ____, used for ____ deficiencies in elderly, and other cases such as ______.
What is the optimal treatment period?

A

hormone replacement therapy
estrogen
anorexia, ovary removal, low-functioning ovaries
unknown optimal timing/duration

159
Q

HRT and similar therapy ____ have fallen out of favor due to increased risk of _______. What is the alternative?

A

SERMs (selective estrogen receptor modulators)
CVD, breast cancer

BISPHOSPHONATES - Less OC, more OB, less bone marrow fat

160
Q

How does vitamin D contribute to bone?

A

enhance Ca absorption in gut -> needed for bone mineralization
less bone resorption

161
Q

How is vit D activated, and how is this affected in elderly?

A

D2 -> D3 in kidney

as kidney declines -> less active vit D -> poor Ca absorption

162
Q

What are benefits and possible negatives of vit D supplementation?

A

improve Ca absorption -> better for bones

but can cause high Ca (hypercalcemia, hypercalciuria)

163
Q

A lifestyle/diet HIGH in _______, and LOW in _______ will increase osteoporosis risk

A

high in: smoking/alcohol/protein/caffeine/phosphorus

low in: Ca, vit D, exercise

164
Q

exercise will stimulate _____ in bones, and also reduces risk of fracture due to ______

A

osteogenesis

reduced bone loss, better coordination/muscle strength