Bone Health Basics

Bone Health Basics

Session Content

Skeleton and Bones - function

Bone Development and Growth

Osteoporosis and Bone Loss

- risk factors for bone loss

- diagnosis of OP

Elements for Good Bone Health

OP Medications

Falls (the ultimate test of bone strength).

Functions of Skeleton/Bones

Mechanical: structure

protection of vital organs

movement

sound transduction

Synthetic: blood cell production

Metabolic: mineral & growth factor storage

fat storage (energy reserves)

preserve ph balance

detoxification.

Bone Development in Utero

Early after conception our bones begin to develop.

Week 4 – cells differentiate – early spine

Week 5 – cartilage framework develops, limb buds

Week 6 – arms and legs lengthen, muscle tissues develop

Week 8 – teeth begin to form

- wrist & ankle joints, muscles function

Week 11 – fingers and toes separate

Week 15 – legs longer than arms, all joints/muscles work

Week 17 – skeleton begins to harden into early bone.

From the Womb to ……

At birth we have 270 bones.

These fuse and harden into 206 adult bones.

Eg skull sutures will not fuse completely

until three years of age to allow for the

birth process and for brain growth.

Our bones continue to grow longer and stronger.

When they have reached their adult length, they are still

able to grow ‘outwards’ until late adolescence – this

allows them to support the growing mass of the body.

How Bone Tissues Develop

Flexible cartilage - grows and strengthens into bone.

This process is called ossification.

This hardened bone develops in three stages:

i. tissues form a mesh of collagen fibres

ii. body creates molecules of a substance like cement

iii. calcium crystals are deposited to form hard bone.

Changes in Cartilage Pattern

Adult MSK Cartilage Sites

Ossification continues until the only cartilage is located:

• ends of the bones in joints (articular)*

• bridge of the nose

• ear structure (auricular)

• ribs

* Sites of damage in osteo and inflammatory arthritis.

Inside the Bone

Two types of bone tissue –

i. Cortical (outer) bone

= compact bone – strong and dense

ii. Trabecular (inner) bone.

= spongy bone

This combination is very efficient > light & strong.

Kilo for kilo, bone is much stronger than steel.

An adult has 10kg of bone = 400kg of steel to be as strong.

But steel is not as resilient and cannot heal itself.

Bone Growth and Maintenance

To maintain bone – a process called remodelling continues

throughout our whole life.

Two types of bone cells are responsible for remodelling:

• osteoblasts - build up new bone tissue

• osteoclasts – clean away, ‘resorb’ old bone

Approx 10-12% is replaced per year in a healthy adult.

The Calcium ‘Bank’

Bones store minerals such as phosphorous, collagen

and calcium.

They store 99% of the calcium supply - other 1% is

released by the bones to be used by the body.

Calcium helps:

• blood vessels to move our blood

• nerves to send messages

• muscles to contract

• hormones and enzymes to be released.

The Calcium ‘Bank’

Each day the body makes ‘withdrawals’ of calcium from

the bones.

This means we may lose calcium at the ‘expense’ of the

bones – making them less strong.

After the age of 30 years – we ‘lose’ more bone than our

body can ‘deposit’ each day.

Although calcium is the most abundant mineral in the

body, the bones may become deficient.

Leading to the condition called osteoporosis.

Peak Bone Mass

The point at which bones of an individual are at their

strongest/most dense.

Greater a person’s bone mass at this time - the greater

their protection from OP in later life.

Osteoporosis [OP]

‘osteo’ = bone + ‘por’ = passage

As bones become porous, they become more fragile.

Osteoporosis

is the ‘Silent Disease’

this is because most people don’t know they have it -

until they sustain a fracture.

The WHO estimates 77% of people with OP

do not know that they have it.

Osteoporosis in History

No evidence of OP in hunter/gatherer societies.

Evidence of anatomical changes consistent

with OP do exist in ancient Egyptian mummies.

It is an example of a very ‘early’ sedentary lifestyle

disease.

Impact of OP on the Body

• compromises bone integrity

– risk of fracture

• compression of vertebrae

- affects discs and/or nerves

• postural changes

– distortion of spinal column

• compression of internal organs.

Impact of OP on Posture

The ‘Fracture Cascade’

OP fractures - called fragility or minimal trauma fractures

Approx. 50% with an OP fracture will have another

Risk increases exponentially with each subsequent #

2+ fractures = 9 times greater risk of further fractures

Women with a vertebral fracture are 4x more likely to have

another within 12 months (than those who haven’t)

The fracture cascade results in pain, deformity, disability

and possibly even death.

Common OP Fracture Sites

Spinal fractures are the most common OP fracture (46%)

2/3 will be asymptomatic - may occur spontaneously

Wrist – most common in women in their 50’s (16%)

Rib fractures may result from sneezing, bending over

Hip (15%) > most common fracture site over 75 years -

may result in increased morbidity and residential care

The hip, wrist and vertebrae all have a high percentage of

trabecular (spongy) bone.

OP Risk Factors - Non Modifiable

• age (advancing)

• heredity – strong genetic predisposition

• very small build – small bones

• low levels of oestrogen-women

• extended periods of no menstruation

• early menopause (including surgical)

• low levels of testosterone- men

• chronic conditions – inflammatory arthritis, crohn’s & coeliac diseases, haemochromatosis

• medications – long term steroids.

OP Risk Factors - Modifiable

• low calcium intake

• inadequate vitamin D exposure/intake

• physical inactivity or excessive exercise

• smoking

• excessive alcohol

• consumption of cola drinks

• diet high in salt

• eating disorders

• diet high in animal protein (?)

Diagnosing Osteoporosis

Dr will assess: age/medical history/lifestyle factors

If indicated refer for Bone Mineral Density Test (BMD).

Bone densitometry – gold standard is dual energy X-ray

absorptiometry (DXA) scan of the hip & lower spine.

A blood test is not a good indication.

Medicare will only rebate DXA for:

• those over 70 years* of age

• who have had a (common to OP) fracture.

* Having a baseline earlier is optimal.

Osteoporosis is diagnosed when the bone mineral density is -

less than or equal to 2.5 standard deviations below that of a young

(30–40 year old), healthy adult women reference population.

This is translated as a T-score.

World Health Organisation Definitions Based on Bone Density Levels

Level Definition

NormalBone density is within 1 SD (+1 or −1) of the young adult

mean.

Low bone mass

(osteopenia)

Bone density is between 1 and 2.5 SD below the young adult

mean (−1 to −2.5 SD).

OsteoporosisBone density is 2.5 SD or more below the young adult

mean (−2.5 SD or lower) = a T Score of -2.5 or lower

Severe

(established)

osteoporosis

Bone density is more than 2.5 SD below the young adult

mean, and there have been one or more osteoporotic

fractures.

When you have a T Score

T Score Result What is the Outcome?

1 to -1 Normal Ensure that you have adequate calcium, Vitamin D and

regular exercise.

-1 to - 2.5 Osteopenia -

at risk of

developing OP

Take immediate action to minimise further bone loss.

Your Dr will ensure that your calcium and Vitamin D levels

are adequate.

-2.5 or

lower

Osteoporosis –

fracture risk is

high

Your Dr will discuss commencement on specific OP

medications and ensure adequate calcium and Vitamin D

intake.

Your Dr should discuss possible medical causes and risk

factors with you.

Follow-up tests to monitor bone health and treatment.

How Common is OP?

4.74m Australians (66% of the population over 50 yrs) -live with compromised bone density.

$33.6b = total (indirect & direct) cost of OP, osteopenia and fractures in Australia (2013–2022)

In 2012 this meant 140,882 fractures

By 2022 projected to reach 183,105 fractures

On a personal level – someone is admitted to hospital every 3.6 minutes in Australia, with an osteoporotic fracture.

Maintaining/Enhancing

Bone Health

Move Here!!

Bone Health

We need to actively build strong bones in childhood,

then manage ‘bone health’ along the age continuum.

This includes:

• calcium

• Vitamin D

• exercise

• BMD testing (baseline and ongoing)

• medical management if diagnosed.

Dietary Calcium

Recommendations for adequate calcium intake:

Less than 50% of Australians get their recommended daily intake of calcium.

Category Age (yrs) Dietary Intake / per day

Children 1 -3 500 mg

4 - 8 700mg

Girls and Boys 9 - 11 1 000mg

Teens 12 - 18 1 300mg

Adults 19+ 1 000mg

Increasing to:

Women Over 50 1 300mg

Men Over 70 1 300mgNational Health & Medical Research Council of Australia

Calcium

The best (and safest) way to consume the recommended

daily intake is to eat a diet rich in calcium.

Calcium is more concentrated in and easily

absorbed from dairy than other food groups.

People who dislike or cannot tolerant dairy will require

serves of other high calcium-containing foods

eg calcium rich vegetables, tinned sardines

or tinned salmon (including the bones), nuts and fruits; and calcium fortified foods.

For example:

Women 50+ =

1 300mg per day

Calcium Absorption

Not all of the calcium we consume is absorbed by the

digestive system (we normally excrete some).

Some factors that lead to abnormally low absorption of

calcium include:

• excessive consumption of alcohol

• excessive consumption of caffeine

• diets high in oxalates (spinach or rhubarb)

• diets high in phytates (some cereals or brans)

• some medical conditions eg coeliac disease.

Getting More Calcium from Your Diet

• choose hard cheeses rather than soft

• add milk or skim milk powder to soups or casseroles

• use yoghurt in soups, salads and desserts

• choose soy products such as calcium set tofu and

brands of soy milk with added calcium•

• eat more broccoli, bok choy, silverbeet, cucumber,

celery, chick peas

• snack on almonds, dried figs and dried apricots

• look for products fortified with calcium, eg some

breads, fruit juices – this calcium is deemed dietary.

Calcium Supplementation

The safest and recommended way to obtain your required

calcium intake is from your diet.

When this is not possible and supplement is required - a

maximum dose of 600mg per day is recommended.

The most common supplements are calcium carbonate,

calcium citrate or hydroxyapatite.

Supplements may take the form of:

• oral (swallowed) tablets,

• chewable tablets,

• effervescent tablets, or

• soluble powder.

Issues with Calcium Supplementation

• not everyone can tolerate calcium supplements

• may cause reflux

• current concern that they may pose a heart attack risk

– more research required

• also a possible link with prostate cancer

• may cause bloating and gas

• may cause constipation (calcium carbonate)

• may interact with many different prescription medications

including blood pressure medications, synthetic thyroid

hormones, bisphosphonates, antibiotics and calcium

channel blockers.

Vitamin D

Vitamin D plays an essential role in bone health.

By improving the absorption of calcium for the intestine,

vitamin D is important to the growth and maintenance of

strong bones

Vitamin D also helps to regulate calcium levels in the

blood and helps to maintain muscle strength

Sunshine is the main source of vitamin D

Two thirds of Tasmanians are deficient in winter.

Recommend 1000-2000iu of supplementation daily.

Risk Factors for Vitamin D Deficiency

People who:

• elderly/those in institutional or residential care

• wear modest dress

• have dark skin

• have chronic medical problems:

- that cause malabsorption of calcium/vitamins

- medications that break down vitamin D eg those

for epilepsy.

• live in Tasmania.

Exercise and OP

Regular physical activity plays an important role in

building and maintaining strong & healthy bones.

When the skeleton is exposed to loads greater than

‘normal’ the bones deform slightly (causing microscopic

fractures) – this is a signal to the bone to ‘remodel’

This is called ‘osteogenic’ exercise.

Varying the types of exercise and loading

ensure continual stimulation of bone growth.

Exercise also keeps muscles strong thus

reducing the risk of having a fall.

Exercise and OP

Exercises recommended for bone health:

• weight bearing aerobic exercise

• progressive resistance training

• moderate to high impact exercise

• balance & mobility exercises (fracture risk reduction).

Hip fractures have been found to be as much as 45%

lower in people who have been physically active.

Exercise and OPThe impact of selected exercises on bone health:

*Osteogenic exercise = applies specific stress on the bone.

Highly

Osteogenic*

Moderately

Osteogenic*

Low

Osteogenic*

Non-Osteogenic*

Basketball/Netball Running/Jogging Leisure Walking Swimming

Impact Aerobics Brisk / Hill Walking Lawn Bowls Cycling

Dancing / Gymnastics Resistance Training Yoga

Tennis Stair Climbing Pilates

Jumping Rope Tai Chi

Exercise for Bone Health

Aim for at least 3 times per week, up to 40 mins per day.

Moderate exercise including back muscle strengthening

excluding loaded forward flexion.

• low to moderate impact aerobics

• stair climbing/descending

• line dancing

• Tai Chi

• standing on one leg, stepping sideways over objects.

Also engage in a variety of lower intensity activities

designed to optimise balance, strength & endurance.

Medical Management of OP

The Dr will ensure that lifestyle factors are maximised.

If diagnosed with OP or assessed as being a high fracture

risk – medications may be prescribed.

OP medications work by making the cells that break

down bone (osteoclasts) less active while allowing the

cells that form new bone (osteoblasts) to remain active.

The overall result is a reduction in bone loss and a

gradual increase in bone strength (density).

Medications are grouped into ‘classes’ based on their

active ingredients.

Medicines for OP

There are a range of osteoporosis medicines available.

The GP, Rheumatologist or

Endocrinologist) will determine the

appropriate treatment for an individual

situation and take into consideration

any other medical conditions.

Some are not covered by the PBS.

Compliance on some of the therapies is very low due to

side effects.

* Sometimes they do not result in obvious BMD increases

but do positively influence fracture risk

When to Seek Advice

If you:

• are over 50 and have experienced a fracture as a

result of a minor incident

• Have rib or back pain – may be spinal/rib fracture

especially if the pain disappears in 6-8 weeks.

Signs that this type of fracture may have occurred:

• loss of height (more than 3 cm, 1 inch)

• sudden, severe, unexplained back pain

• developing a ‘dowager’s hump’ or curve in the spine.

Falls and OP

Falls put bone density and strength to the test.

Minimal trauma fractures are the hallmark of OP.

Talk to doctors or health professionals, about:

• nutrition and hydration

• any medical conditions that cause dizziness

• continence issues

• eye health and vision

• making the home and garden safe

Falls Prevention

Falls are not inevitable.

Many things that you can do to avoid having a fall:

• have an annual eye examination (or more regularly as

necessary)

• wear your glasses at all times when moving around

• wear sunglasses and a hat to reduce sun glare

• exercise:

– for strength, balance, coordination and flexibility.

You need to have a Plan

Bone health needs active management.

My Goal How I Will Achieve the Goal

Calcium Increase my dietary calcium - by adding an additional two serves of

calcium rich food per day.

Vitamin D Supplement with one tablet per day: Summer & Autumn

Supplement with two tablets per day: Winter and Spring.

Exercise Do one strength and resistance training class per week.

Go for a (brisk) walk twice a week.

Do a Tai Chi session twice per week.

Falls Prevention Organise an Occupational Therapy assessment of your home.

Clear up any clutter/hazards around the house/paths/garden.

Install brighter light globes for corridors, stairs, bathroom.

Replace shoes regularly.

Have an eye check annually.

Implications for our young people

Approximately 40% of our Peak Bone Mass is acquired

during puberty.

A teenager’s health behaviours can influence their long-

term bone health depending on their:

• diet:

- lack of dairy

- consumption of cola drinks

- vegan

• exercise habits

• sun exposure (Vitamin D).

OP and our Girls

Please help to build bone in the young

women in your family.

Encourage:

• exercise

– lots of different types and lots of it

• sunlight (without burning)

• calcium rich foods

OP Considerations in Aged Care

Research shows that people living in residential aged

care are at considerably higher risk of sustaining a

fracture than older people in a community setting.

80% of RACF residents will have OP.

40% of all hip fractures occur in this setting.

Recommend* - all people entering residential care

should be assessed for fracture risk to ensure effective

fracture prevention measures are put in place.

* Medical Journal of Australia – Consensus Recommendations for Fracture Prevention in Residential Aged Care

OP Considerations in Aged Care

Recommendations*:

• All residents should be on Vitamin D therapy.A meta-analysis found that vitamin D supplementation appears to reduce the risk of

falls among institutionalised older people with stable health by more than 20%.

• Sunlight exposure should be actively encouraged.

• Dietary calcium intake should be optimised and

supplemented if inadequate.

• Whilst most residents are at risk of fracture – only a

minority receive treatment according to level of risk.

* Medical Journal of Australia – Consensus Recommendations for Fracture Prevention in Residential Aged Care

Risk Factors for Fracture

In older person living in care >

• Male

• Low serum Vitamin D

• Bowel, bladder incontinence

• Cognitive impairment

• Poor balance

• Ambulatory

• Use anti-anxiety agents.

OP Considerations in Aged Care

Falls Prevention:

• All residents should be screened for falls risk on

admission / 6 monthly intervals / in the event of a

fall.

• Medication/s should be reviewed to identify risk of

medication related problems (pharmacist & GP).

• Education of residents & staff re alternative methods

to enhance sleep quality.

• Exercise should be part of a multifactorial approach >

it should challenge balance and be undertaken

regularly.

OP Considerations in Aged Care

Falls Prevention:

• Assess residents’ footwear/glasses.

• Environmental assessment should be

constant to identify risks and eliminate them.

• Hip protectors should be used – targeted

approach to identify candidate residents.

• Physical / mechanical and chemical restraint

never recommended as a falls prevention

strategy.

OP Considerations in Aged Care

Physical activity in residential care:

Residents should be given the opportunity to participate

in exercise/activity programs for physiological and

psychological health.

For bone health and OP the activity should:

• Offer incremental increases in resistance / strength,

• Challenge balance and coordination (safely).

Remember…

People with compromised bone density may

experience spontaneous vertebral fractures from

activities such as coughing, sneezing and bending

forward.

If a person complains about pain in the back or ribs,

OP and a possible fracture should be considered.

Postural changes may cause abdominal discomfort

as organ space is compromised.