What are the Risk Factors for Fragility Fracture?
The most important risk factors for fragility fracture are:
- Age: Incidence of fragility fractures increases with age and peak incidence occurs between the ages of 60 and 75 years, with vertebral fractures peaking in the over 70s and hip fractures peaking in the over 80s.
- Gender: Fragility fractures are twice as common in women as in men.
- Low bone mineral density (BMD): Risk of fracture increases progressively with reduction in BMD. Every 1 standard deviation reduction in BMD equates approximately to a doubling of the relative risk of fracture. The majority of fragility fractures occur in those with a BMD T-score above the osteoporosis threshold of 2.5 or less (i.e. within the osteopenic range) rather than those with osteoporosis (i.e. with a T-score of ≤ −2.5). This is attributable to the population of patients with osteopenia being more numerous than those with osteoporosis and the osteopenic range covering a broad spectrum of fracture risk.
- Parental history of hip fracture: Maternal and paternal history of hip fracture is the most reliable indicator of genetic risk of fragility fracture.
- Low body mass index (BMI): BMI of ≤ 19 kg/m2 is associated with an increase in the risk of hip fracture (and probably other fractures) in both women and men.
- Hormones: Premature menopause (in women under the age of 45) - whether natural or induced by surgery, chemotherapy, radiotherapy or endocrine therapy - increases risk. Risk is increased in men who have had orchidectomy or androgen deprivation therapy.
- Medical conditions associated with bone loss: These include rheumatoid arthritis, inflammatory bowel disease (e.g. Crohn's disease, ulcerative colitis), malabsorption (e.g. coeliac disease, pancreatic insufficiency), cystic fibrosis, hyperthyroidism, hyperparathyroidism, vitamin D insufficiency, immobilisation (e.g. resulting from CVA or Parkinson's disease), chronic obstructive pulmonary disease, diabetes mellitus type 1 and chronic renal and hepatic disease.
- Drug treatments associated with bone loss: These include oral corticosteroids, aromatase inhibitors, androgen deprivation therapy, some anti-epileptic medications and glitazones.
- Lifestyle factors: Smoking and alcohol intake ≥ 3 units per day increase fracture risk.
- Falls: Non-vertebral fragility fractures usually result from a fall in an individual with compromised bone strength; thus, the risk factors for falls should be routinely considered in older patients, as advocated by NICE guidance