Osteoporosis

Definition:

A bone disease that occurs when the body loses too much bone, makes too little bone, or both. Without treatment it will get progressively worse so early diagnosis and intervention is paramount. 

Cause and scope for prevention:   

Many factors can increase the risk, some are genetic but others include: 

• Inactivity 
• Ageing
• Low calcium intake
• Low BMI
• Eating disorders such as anorexia and/or bulimia
• Heavy drinking and/or smoking
• Certain medications 

It can occur in all genders and at any age, however it is more prevalent in older people, especially postmenopausal women. 

Diagnosis:

The usual test is a DEXA scan which measures bone density, with the results being presented in the following way in this useful summary from the website of the Royal Osteoporosis Society:

The results of your scan tell your doctor how much bone tissue you have in the areas tested. This is also known as your bone density.

T-score

Results are given as a 'standard deviation', which is the number of units above or below the average bone density of a young and healthy person. This is known as your 'T score'.

Whatever score you receive, your risk of breaking a bone increases as you grow older. By the age of 75, 50% of the population has a bone density in the osteoporosis range.

What your T-score means

+1 to -1

Your bone density is in the normal range for a young and healthy person.

-1 to -2.5

Your bone density is slightly below the normal range for a young and healthy person, also known as osteopenia.

-2.5 and below

Your bone density is in the osteoporosis range.

If your T-score is in the osteoporosis range, it doesn't always need to be a cause for concern. It doesn't necessarily mean you will break a bone, or need a treatment. Having low bone density is one risk factor for osteoporosis and broken bones.

Your results from this test are usually used alongside a fracture risk assessment, which takes these other risk factors into account.

Z-score

You may be given your results as a Z-score, alongside your T-score.

A Z-score compares your bone density to people of the same age as you.

Having a low Z score may indicate that another condition or medicine is affecting your bone density levels. In this situation your doctor suggests further tests.

Standard medical therapy:

Medication. 

Benefit of exercise therapy:

Weight bearing exercises such as walking or resistance training increase the load on bones which leads to new bone formation and therefore stronger bones and can help prevent further decline.

Key references:

The National Osteoporosis Foundation's position statement on peak bone mass development and lifestyle factors: a systematic review and implementation recommendations.

Nonpharmacological interventions for osteoporosis treatment: Systematic review of clinical practice guidelines.

Key organisations:

Royal Osteoporosis Society.