"... an accurate diagnosis, which is relatively simple, can save people from a lot of suffering, fractures and emotional damage."
Carmen Sanchez, Spain, osteoporosis patient
People with osteoporosis suffer from a reduction in their bone mass and bone quality- put simply, their bones become fragile, leading to an increased risk of fractures. Bone density loss is usually gradual and without noticeable symptoms. The only reliable way to determine loss of bone mass is to have a bone mineral density (BMD) test.
Who should be tested?
Strong risk factors for osteoporosis include:
- Oestrogen deficiency:
- Early menopause (age <45 years)
- Absence or cessation of menstrual periods (amenorrhoea >1 year)
- Primary or secondary hypogonadism in both genders
- Prolonged corticosteroid therapy (prednisolone, or equivalent, 7.5 mg or more daily with an expected use of 3 months or more)
- Maternal family history of hip fracture
- Low body mass index (<19 kg/m2)
- Chronic disorders associated with osteoporosis: anorexia nervosa, malabsorption syndromes including chronic liver disease and inflammatory bowel disease, primary hyperparathyroidism, post-transplantation, chronic renal failure, hyperthyroidism, prolonged immobilisation, Cushing's syndrome
- Previous fragility fracture, particularly of the hip, spine or wrist
- Loss of height, thoracic kyphosis (widows hump)
Other risk factors:
- Female (women are more at risk than men)
- Asian or Caucasian
- Poor diet low in calcium
- Lack of exercise
- Regular and excessive alcohol consumption
People with a strong risk of osteoporosis are advised to consult their doctors for a bone mineral density test. In the USA, for example, guidelines recommend that all women aged 65 and up should have a BMD test and that postmenopausal women under age 65 who have one or more risk factors (in addition to being postmenopausal and female) should have a BMD test.
To check your risk
Take the IOF One-Minute Risk test
How osteoporosis is diagnosed
The most common diagnostic tool is a bone mineral density (BMD) test. This is a painless and noninvasive scan which, depending on the technology, measures bone density in the hip, spine, wrist, heel or hand.
According to World Health Organization (WHO) guidelines, a BMD score in a postmenopausal Caucasian woman that is more than 2.5 standard deviations below the average for the young healthy female population implies a diagnosis of osteoporosis. For every standard deviation (SD) below peak bone mineral density fracture risk increases by 50% to 100%. The same BMD values are being provisionally used for men because currently data on BMD and fracture in men is scarce.
Summary of WHO definitions of osteoporosis based on bone density levels*:
BMD is within +1 or -1 SD of the young adult mean.
Osteopenia (low bone mass):
BMD is between -1 and -2.5 standard deviations below young adult mean.
BMD is -2.5 SD or more than the young adult mean.
Severe (established) osteoporosis:
BMD is more than -2.5 SD and one or more osteoporotic fractures have occurred.
*based on DXA measurement at hip or spine
Methods of Diagnosis
A variety of methods is available to assess bone density. All are painless and noninvasive. The most common types of tests are listed below:
(Dual Energy X-Ray Absorptiometry)
DXA is a special low radiation X-ray capable of detecting quite low percentages of bone loss. DXA scans are the most commonly used method of BMD measurement. They are used to measure spine and hip bone densities.
(Peripheral Dual Energy X-ray Absorptiometry)
pDXA measures the forearm, finger and heel
(Single-Energy X-Ray Absorptiometry)
SXA measures the heel
(Quantitative Computed Tomography)
QCT scans the trabecular bones of the lower spine - these are bones that change as you grow older. pQCT measures the forearm.
QUS uses sound waves to measure density at the heel, shin and finger.
The importance of early diagnosis
Through early detection, people with osteopenia (low bone mass) or osteoporosis, can take action to stop the progressive loss of bone mass. By making positive lifestyle changes (see prevention) and following appropriate treatment strategies in consultation with a doctor (see treatment), osteoporotic fractures can be prevented.