17. sarcopenia and sarcopenic obesity Flashcards Preview

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Flashcards in 17. sarcopenia and sarcopenic obesity Deck (16):
1

sarcopenia definition

sarco = muscle
penia = lack of

- loss of muscle and strength

2

sarcopenia leads to

- neuromuscular impairment
- loss mobility
- balance problems
- increase falls
- hospitalization (causes more muscle loss)
* viscous cycle

3

sarcopenia normal vs disease

occurs naturally with aging

clinical problem once a threshold in muscle loss and strength

4

body composition methods to quantify sarcopenia

CT / MRI / DXA
- to charaterize specific tissue mass and changes in tissue

5

defining sarcopenia

2 standard deviations below mean for young health adult
- sex specific


* definition evolving

6

sarcopenia: muscle mass vs strength

mass easier to define

strength no accepted criteria
- but easier to measure and is important
- mass doesnt equal strength

7

aging sarcopenia - mass vs strength

strength decrease higher rate than mass
- quality of muscle
- force per unit cross sectional area
- decrease fiber size and number
- contratile activity in intact fibers
- fat infilltration
- impaired neurlogical modulation
and
**decreased metabolic quality

8

high quality of muscle
- metablic perspective

high oxidative capacity
high capacity of glucose transport and lipid transport

9

metabolic syndrom

cluster of metabolic abnormalities in a person that increases CVD risk

relate back to insulin resistance
- hypertension
- dyslipidemia
- diabetes

10

sarcopenic obesity
- why is it new

aging population
more obesity

*** silent condition
- increase fat while decrease muscle
- minimal change in BMI

11

"normal" age-related changes in body composition

- increase fat mass from birth (peak 60-75)
- difference in partitioning of adipose
- visceral fat and intramuscular fat increase
- subcutaneous same or decrease
- fat inflitration into muscle -> lowers strength

12

muscle and fat mass relation

more fat, need more muscle
- mechanical loading effect
- 1kg increase adipose needs 0.1 kg (women) or 0.24kg (men) skeletal muscle
- muscle mass and strength decline steadily around 30y (accelerate around 50-60y)
- 1-2% per y past 50

13

problem with aging and sarcopenic obesity

excess fat with low muscle mass and strength
- obesity in elderly acts "synergistally" with sarcopenia to maximize disability

14

factors implicated in sarcopenic obesity

nutrition
- low protein = sarcopenia
- increased kcal = obesity

physical activity
- atrophy from not using
- reduced kcal expenditure

low grade inflamation
- cytokines/adipokines obesity related insulin resistance
- proinflammatory cytokines = muscle catabolism

insulin resistance
- decrease resp to anabolic stim
- vasodilatory - aminos to muscle for prot syn

hormonal
- decreased growth hormone and testosterone

15

muscle fat relation during weight gain

adipose tissue
- adiponectin decrease
- leptin increase
- TNFa increase
- IL-6 increase
- MCP-1 increase
causes macrophage recruitment
- increase inflammation
- increase adipokin release

effect on muscle
- increase inflammation
- increase fat infiltration
- causes weakness
- decrease exercise

*viscous cycle

16

intervention target for sarcopenic obesity

increase muscle while decrease fat
- strength and aerobic exercise

target low grade inflammation