Bone Health Presentation

Primary Prevention of Osteoporosis and Bone Health Michael Zanovec, CDT Research Associate LSU School of Human Ecology

Overview 

Osteoporosis is a skeletal disorder characterized by: 

Compromised bone strength  Reflects



bone density and bone quality

Increased susceptibility to fractures

Overview Normal bone

Osteoporosis causes weak bones. In this common disease, bones lose minerals like calcium.

Osteoporotic bone

They become fragile and break easily. 3 Source: The 2004 Surgeon General’s Report on Bone Health and Osteoporosis: What It Means to You at http://www.surgeongeneral.gov/library/bonehealth

Risk Factors       

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Female White/Caucasian Post menopausal woman Older adult Small body size Eating a diet low in calcium/vitamin D Physically inactive Female athlete triad

Osteoporosis Prevalence  

44 million Americans are at risk 10 million Americans have the disease   

~ 80% are women ~ 20% of Caucasians ~ 5% of African Americans

Bone Health and Osteoporosis: A Report of the Surgeon General, 2004

Osteoporosis can strike at any age! It is a myth that osteoporosis is only a problem for older women.

The “Silent Disease” 

Bone loss occurs without symptoms.

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A fracture may be the first sign.

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Collapsed vertebrae may cause pain, loss of height, or spinal deformities.

The 3 most common breaks in weak bones are in the: 1. hip 2. spine 3. wrist Source: The 2004 Surgeon General’s Report on Bone Health and8 Osteoporosis: What It Means to You at http://www.surgeongeneral.gov/library/bonehealth

Hip fractures account for 300,000 hospitalizations annually. People who break a hip might not recover for months or even years.

Source: The 2004 Surgeon General’s Report on Bone Health and9 Osteoporosis: What It Means to You at http://www.surgeongeneral.gov/library/bonehealth

1 in 5 people with a hip fracture end up in a nursing home within a year. Some people never walk again. Source: The 2004 Surgeon General’s Report on Bone Health and Osteoporosis: 10 What It Means to You at http://www.surgeongeneral.gov/library/bonehealth

A woman’s hip fracture risk equals her combined risk of breast, uterine and ovarian cancer.

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Source: National Osteoporosis Foundation Web site; retrieved July 2005 at http://www.nof.org

Burden of Bone Disease Economic cost - Estimated direct expenditures (hospitals and nursing homes) for osteoporotic and associated fractures:  

$17 billion in 2001 $47 million each day

Cost to the individual – osteoporosis causes frailty and reduced functional capacity

Bones are living organs 

Calcium is deposited and withdrawn from bones daily.

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Bones build to about age 30.

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We need to build up a healthy bone account while young and continue to make deposits with age.

Types of Bone 

Cortical bone 

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Lining or “bark”

Trabecular bone   

Structure “trab trab”” meaning beams or timber Spongy

Bone composition 

Cortical bone accounts for 80% of skeletal body mass 1/3 radius region of forearm: 100%  Femoral neck: 75% 

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Cancellous bone accounts for 20% of skeletal body mass Spine: 66%  Os calcis (heel): 95% 

Healthy Bones “Bone strength reflects the integration of two main features: bone density and bone quality.” quality.” NIH Consensus Development Panel. JAMA 2001:285:785 2001:285:785--795.

Evaluation of Bone Health 

Bone Density Dual-Energy XDualX-ray Absorptiometry (DXA) – “gold standard” for detecting osteoporosis

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Bone Quality Quantitative Ultrasound (QUS) – measures physical properties of bone

Bone Density DXA Apparatus  

Full-Size Table Models FullPeripheral DXA Devices

DXA BMD Reports

BMD T-score Risk Assessment The World Health Organization classifications for white women  Normal T-score greater than –1.0 

Osteopenia T-score between –1 and –2.5

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Osteoporosis T-score below –2.5

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Fracture Risk Doubles With Every SD Decrease in BMD 35 30

Relative Risk for Fracture

25 20 15 10 5 0 -5.0

-4.0

-3.0

-2.0

-1.0

Bone Density (T-score)

0.0

1.0

Quantitative Ultrasound  

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Peripheral site (usually the calcaneus; ~95% trabecular bone) Assesses without ionizing radiation Portable Less expensive Relatively new technology in the US 

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Approved by the FDA Center for Devices and Radiological Health (Achilles Express) in 1999.

DOES NOT MEASURE BONE DENSITY!

Why the heel? 

Considered the best peripheral site for fracture risk assessment    

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Easily accessible Metabolically active bone High trabecular content (~90%) Weight--bearing like the spine & Weight femur Allows early detection and intervention

Bone Characteristics in Terms of Ultrasound Velocity and Attenuation Measurements of Bone Quality: 1. Speed of Sound (SOS) 



2.

Bone elasticity and density

Broadband Ultrasound Attenuation (BUA) 

Trabecular density, spacing, and orientation

Stiffness Index Stiffness Index = BUA + SOS

SI = (0.67*BUA + 0.28*SOS)0.28*SOS)- 420) Clinical measure with a lower precision error than either variable alone

Stiffness Index T-score QUS printout

DXA printout What’s this person’s T-score?

Comparison of DXA and QUS BUA and DXA measurements are significant and independent predictors of hip fracture Fracture Risk/1000 women + DXA & + BUA = + DXA & - BUA = - DXA & + BUA = - DXA & - BUA =

2.7 6.2 11.8 19.6

+ = score above the mean - = score below the mean Hans et al, Lancet, 1996

Conclusions 

Bone health is a product of both bone density and bone quality.

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Quantitative ultrasound appears to be a effective bone quality screening tool.

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Quantitative ultrasound appears to be a better screening tool for African American women than for Caucasian females.

Nutrition and Osteoporosis

Build Your Bones! 

The amount of bone tissue can continue to grow until approximately 30 years of age.

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At that point, bones reach their maximum strength and density, known as peak bone mass.

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Attainment of peak bone mass is one of the most important strategies for preventing osteoporosis.

3 Keys to Bone Health 1.

Weight bearing physical activity

2.

Calcium

3.

Vitamin D

Exercise for Bone Health 

Weight bearing physical activity 

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Make your bones and muscles work against gravity with jogging, walking, stair climbing, dancing, and soccer.

Resistance 

Build your muscular strength with weight lifting

Exercise for Bone Health 

Moderate intensity exercise at least 30 minutes most days of the week to maintain health.

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Moderate intensity activity 60 minutes most days of the week to maintain weight and prevent future weight gain. U. S. Dietary Guidelines 2005

Eat Right for Bone Health 

Calcium – DRI Adequate Intake (AI)  1,000 mg/day for men and women 1919-50 yrs of age  1,200 mg/day for men and women 51 and older

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Vitamin D  200 IU/day for men and women 1919-50 yrs of age 

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(Sunshine 1010-15 min/day during the summer months)

400 IU/day for men and women 51 51--70 yrs of age 600 IU/day for men and women > 70 years of age

Fruits and vegetables (U. S. Dietary Guidelines, 2005)  2 cups/day (4 servings) of fruits  2.5 cups/day (5 servings) of vegetables

Keys to Bone Health Be physically active  Eat a wellwell-balanced diet rich in calcium and vitamin D  Get plenty of sunshine  Don’t smoke  If you drink alcohol do so in moderation 