Presence of existing minimal trauma fractures
The single most easily recognised risk factor for osteoporotic fracture is the presence of any spinal or non-spinal minimal trauma fracture (a fracture occurring as a result of a fall from standing height or less). This also applies to vertebral fractures that are coincidentally detected on radiographs. It should be noted that not all vertebral deformities result from minimal trauma. A review of trauma history may guide interpretation of vertebral deformities. Dual energy X-ray absorptiometry (DXA) may be useful to determine if the patient has reduced bone mineral density (BMD) with a higher likelihood of sustaining an osteoporotic vertebral fracture.
Relative fracture risk approximately doubles for each unit (standard deviation) decrease in T-score, as measured by DXA. Postmenopausal women and men older than 50 years of age with osteoporosis (T-score ≤–2.5) are already at increased risk of minimal trauma fracture. Absolute fracture risk increases with both increasing age and decreasing BMD. The absolute risk for fracture is therefore high in postmenopausal women and men aged 70 years or older with a T-score ≤–2.5 (without fracture) and even higher in those with T-score ≤–3.0.
Fracture risk is strongly affected by age for both sexes. With each decade the risk of minimal trauma fracture approximately doubles. Age as a fracture risk is independent of both BMD and clinical risk factors, such as risk of falling, which also increase with age and contribute to fracture risk.
Calcium and vitamin D status
Suboptimal dietary calcium intake and vitamin D deficiency are important public health problems in Australia. Vitamin D deficiency is associated with a higher risk of falling as well as with a lower BMD. Routine screening of vitamin D levels should not be carried out. Testing should be restricted to those with suspected or proven osteoporosis, conditions or medications known to decrease vitamin D levels, deeply pigmented skin, or severe lack of sun exposure due to cultural, medical, occupational or residential reasons.
Paternal or maternal history of hip fractures
Paternal or maternal history of hip fractures is regarded as the most reliable indicator of genetic risk of minimal trauma fracture. However, family history of other types of minimal trauma fracture should also be considered.
At each age group, men are at approximately 50% lower fracture risk than women: for every three fractures, two will occur in women and one in a man. However, once a man has experienced a fracture, his risk of a subsequent fracture is equivalent to that of a woman of comparable age who has also experienced a fracture.
A history of falls increases the risk of peripheral minimal trauma fractures for postmenopausal women and men of comparable age. This applies to falls without external cause that have occurred more than once in the past 12 months. Risk factors for falling include poor quadriceps strength, body sway, vitamin D deficiency, medications, visual impairment and environmental hazards.
For both women and men, smoking is a moderate risk factor for vertebral and non-vertebral (including hip) minimal trauma fractures. The determination of a gradation of risk depending on the number of cigarettes is still inaccurate. However, smokers generally have a higher fracture risk than non-smokers.
Low levels of physical activity or prolonged immobility
Lack of physical activity is a risk factor for hip fractures and vertebral fractures. Immobility (ie mobility limited to such a degree that the person cannot leave their home or cannot do any housework) may be associated with, and compounded by, low or no exposure to sunlight and subsequent vitamin D deficiency. The inability of a patient to rise from a chair without using their arms (a marker of loss of lower extremity strength and power) is associated with increased risk of minimal trauma fracture.
Low body weight and weight loss
Low body weight (body mass index <20) doubles the relative risk of a hip fracture for both women and men. An increased risk has also been demonstrated for spine and peripheral fractures. Unintentional weight loss is also associated with an increased risk of minimal trauma fracture. Anorexia nervosa is associated with increased risk of developing osteoporosis.
Loss of height
Some loss of height is typical with advancing age and can be due to disc degeneration and/or scoliosis. Accurate measurement and recording of height is important; loss of 3 cm or more, as measured by stadiometer, requires exclusion of vertebral deformity or fractures by X-ray. The greater the height loss, in the absence of obvious scoliosis, the greater the likelihood of vertebral fractures.
High alcohol intake
In this context, high alcohol intake is considered to be greater than two standard drinks per day for both men and women. For more information, refer to the evidence statement for Recommendation 8.
Medications associated with increased risk of minimal trauma fracture include, but are not limited to, glucocorticoids, excessive thyroid hormone replacement, anti-androgen therapy, anti-oestrogen treatments (aromatase inhibitors), selective serotonin reuptake inhibitors, thiazolidenediones, proton pump inhibitors, certain anti-epileptic drugs and certain anti-psychotics. However, it is not always possible to distinguish the effects on bone health of the drug treatments from the effect of the underlying condition that required their use.
Medical conditions that increase fracture risk (secondary osteoporosis)
Medical conditions that increase bone loss or lead to lower BMD at an earlier age include, but are not limited to, rheumatoid arthritis, Cushing syndrome (endogenous or exogenous), hyperparathyroidism, hyperthyroidism or thyroxine excess, chronic kidney disease, chronic liver disease, premature menopause, male hypogonadism, coeliac disease or other malabsorption disorder, depression, organ or bone marrow transplantation, myeloma or monoclonal gammopathies, human immunodeficiency virus (HIV) infection and diabetes mellitus. These conditions are associated with an increase in the age-specific risk for osteoporosis and minimal trauma fractures. Multiple myeloma may also present with pathologic fractures.
There is strong multinational randomised controlled trial (RCT) evidence that mild (Grade 1: 20–25% vertebral height loss) vertebral fractures are a significant risk factor for future vertebral fractures.6 The risk of new vertebral fracture increases progressively with the grade of the initial vertebral fracture; a severe initial fracture is associated with a six-fold increase in the risk of new vertebral fractures in the following three years.6 A moderate increase in the risk of non-vertebral fractures is also seen following moderate to severe vertebral fracture, a finding that is independent of BMD.6 The Dubbo Osteoporosis Epidemiology Study found that all fracture types, except ankle and rib fractures, are associated with increased subsequent fracture risk, with even a minor initial fracture resulting in an increased risk of major or hip fracture.7 Approximately half of re-fractures occurred in the first two years, and the risk persists for up to 10 years.7