musculoskeletal age related changes

osteoclast

breaks down bone

osteoblast

build up of bone and minerals

osteocyte

maintains bone

aging favors what?

catabolism

- bone breaks down as we age due to dec of osteoblast vs osteoclast efficiency

peak bone mass =

20-30 years of age

- followed by a progressive and slow decline

skeletal tissue and aging - women

- loss is more severe in postmenopausal women (dec estrogen)

- 2% of bone/year loss for the first few years

- bone loss slows to 1-1.5% /year later

skeletal tissue and aging - men

acceleration after the age of 75

men have what % of bone loss over their lifetime?

20-25%

women have what % of bone loss over their lifetime?

- 50% loss of trabecular bone

- 30% loss of cortical bone

women have an inc risk of what?

- osteoporosis

- osteopenia

- fractures

susceptible lifestyle factors contributing to bone health - nutrition

- dec vitamin D

- dec calcium

susceptible lifestyle factors contributing to bone health - activity

inactivity vs activity

- Wolf's law

- want to add osteogenic loading

what % of bone is lost from immobilization?

.5-1% lost

susceptible lifestyle factors contributing to bone health - hormones

- parathyroid

- calcitonin

- estrogen

- testosterone

- progesterone

what two hormones are independent mediators of bone health?

estrogen and testosterone

- breast CA and prostate CA have a direct impact on bone health

susceptible lifestyle factors contributing to bone health - disease

- cancer (bone, breast, prostate)

- diseases of malnutrition (IBS, anorexia, crohn's disease)

- systemic infections (osteomyelitis)

susceptible lifestyle factors contributing to bone health - medication

long term use of steroids

muscle tissue and aging causes changes in

- dec muscle fiber size

- dec type II muscle fibers (10-20% loss)

- structure/composition changes with inc adipose tissue

- dec contractile function with power movements

what does an inc in adipose tissue due to the muscle fiber structure

causes a low grade inflammation

dec contractile function due to what?

reduction in number of mitochondria and less calcium in sarcoplasmic reticulum

- results in dec muscle strength (power)

dec in muscle mass as you age

- .37 - .47%/year of muscle mass

- by 70, there is a 20-40% decrease

decrease in strength as you age

- 10% per decade at age 30

- 15% per decade after 60

- ** need to counteract using adequately dosed exercise

clinical importance

dec in velocity, force, strength, and power of movement

- dec in physical performance

- **adequately dosed physical activity/exercise can mitigate these changes

body composition

weight gain over time even without change in calorie intake or lifestyle

- dec lean body mass = inc fat mass

- dec lean body mass = dec resting metabolic rate

inc in visceral fat

- normal in aging

- in excess can be dangerous

inc inflammation due to inc in visceral fat

- cytokines

- C reactive protein

- leading to chronic low grade inflammation

inc risk for disease

- CV disease

- cancer

- DM II

- metabolic syndrome

metabolic syndrome

- HTN

- inc waist circumference

- inc triglycerides (low HDLs)

- impaired blood sugars

metabolic syndrome is an independent predictor of what?

mortality

inc visceral fat is an independent predictor of what?

CV disease and mortality

obesity

NOT a normal aspect of aging

- common in older population

- inc weight = inc stress on skeletal tissue

obesity impacts who?

all ages, genders, races, ethnicities

- inc in women and older adults

- inc adiposity impacts physical function

BMI is good to look at when?

during a chart review to see what equipment you may need

osteosarcopenic obesity syndrome

- osteopenia

- sarcopenia

- obesity

osteosarcopenic obesity syndrome is NOT what?

a normal aspect of aging

- visceral fat secretes inflammatory markers causing catabolic process

- bone will likely be weaker with diagnosis of obesity

connective tissue importance

- found everywhere

- loss of water

- inc collagen crosslinks

- loss of elastin fibers

connective tissue consists of

- collagen

- extracellular matrix

clinical consequences of loss of water

- dec ROM

- dec ability to absorb shock

- dec height from intervertebral discs

- dec articular cartilage

inc in crosslinks due to

dec rate of collagen turnover

clinical consequences of inc in crosslinks

inc in resistance to passive stretch

- "stiffer"

- end range of motion is affected

- more effort required to move

- dec endurance

dec in elastin

functions with collagen to return structures to their original shape after deformation

- dec 1%/year

clinical consequences of dec in elastin

- less tensile strength = injury

- aging skin

- organs no longer held in place as well

dec in elastin effects on organs

- tendency for uterine prolapse

- bladder issues

- constipation

- hernias

pathological conditions

- fractures (hip, pelvis, shoulder, forearm)

- arthritis (RA, OA in hip, hands, spine)

- osteoporosis

- cancer

- obesity

- rhabdomyolysis

- tendinitis

interventions to focus on

- strength (type II muscle fiber for power training)

- flexibility (end range to prevent loss of ROM)

- combatting bone loss

- education on lifestyle (nutrition, PA, lifestyle)