Fixed risk factors
Fixed risk factors determine whether an individual is at heightened risk of osteoporosis and, unlike modifiable risk factors, are factors which we can’t change, including age, gender, and family history.
In addition people may have secondary risk factors (see below) which cannot be changed. These include disorders that weaken bone or disorders and/or medications that affect mobility and balance (i.e. heightened risk of falling and breaking a bone).
Low bone mineral density, one of the most important indicators that a person is at risk of a fracture, is considered both a ‘fixed’ and ‘modifiable’ factor since it is determined by a wide range of factors including both family history, age, and secondary or lifestyle factors.
Although fixed risk factors cannot be changed, people need to be aware of these risks so that they can take steps to reduce bone mineral loss as early as possible.
Fixed risks for osteoporosis include:
Age:
The vast majority of hip fractures (90%), for example, occur in people aged 50
and older. This is partly because of reduced bone mineral density − as people
reach middle age the bone remodeling balance tips in favour of bone mineral loss, bringing with it an increased risk of fracture. But age can also be a risk factor that is independent of bone mineral density. In other words, even older adults with normal BMD are more likely to suffer a fracture than younger people.
Female gender;
Women, particularly post-menopausal women, are more susceptible to bone
loss than men, because their bodies produce less estrogen. This hormone
supports osteoblast survival and tips the balance of bone remodeling in favour of
bone formation.
Women are more likely to sustain any osteoporotic fractures than men. Lifetime risk of
any fracture ranges between 40-50% in women whereas it ranges between 13-22% in men.
Family history:
A parental history of fracture (particularly a family history of hip fracture) is associated with an increased risk of fracture that is independent of bone mineral density (BMD).
Previous fracture:
A previous fracture increases the risk of any fracture by 86%, compared with people without a prior fracture. Both men and women are almost twice (1.86 times) as likely to have a second fracture compared to people who are fracture free. This increased risk cannot be explained by bone mineral density alone, because low BMD accounts for only about 8% of the increased risk.
Race/ethnicity:
Osteoporosis is more common in Caucasian and Asian populations and the incidence of osteoporosis and fractures of the hip and spine is lower in black than in white people.
Menopause/hysterectomy:
Hysterectomy, if accompanied by removal of the ovaries, may also increase the risk for osteoporosis because of estrogen loss. Post-menopausal women, and those who have had their ovaries removed, must be particularly vigilant about their bone health.
Long term glucocorticoid therapy:
Long-term corticosteroids use is a very common cause of secondary osteoporosis and is associated with an increased risk of fracture.
Rheumatoid arthritis:
Rheumatoid arthritis and diseases of the endocrine system can take a heavy toll on bones. Hyperparathyroidism, for example, results in elevated levels of parathyroid hormone, which signals bone cells to release calcium from bone into the blood.
Primary/secondary hypogonadism in men:
Like estrogen deficiency in women (which is observed in case of primary or secondary amenorrhea and premature menopause), androgen deficiency in men, (primary or secondary hypogonadism) increases the risk of fracture.
At any age, acute hypogonadism, such as that resulting from orchidectomy for prostate cancer, accelerates bone loss to a similar rate as seen in menopausal women. The bone loss following orchidectomy is rapid for several years, then reverts to the gradual loss that normally occurs with aging.
Secondary risk factors
Secondary risk factors are less prevalent but they can have a significant impact on bone health and fracture incidence. These risk factors include other diseases that directly or indirectly affect bone remodelling and conditions that affect mobility and balance, which can contribute to the increased risk of falling and sustaining a fracture. Read about secondary osteoporosis
Disorders that affect the skeleton:
• Asthma
• Nutritional/gastrointestinal problems
(Crohn’s disease etc.)
• Rheumatoid arthritis
• Haematological disorders/malignancy
• Some inherited disorders
• Hypogonadal states (Turner syndrome/Kleinfelter syndrome, amenorrhea etc.)
• Endocrine disorders (Cushing’s syndrome, hyperparathyroidism, diabetes, etc.)
• Immobility
• Certain drugs (see below)
Medical treatments affecting bone health
Some medications may have side effects that directly weaken bone or increase the risk of fracture due to fall or trauma. Patients taking any of the following medications
should consult with their doctor about increased risk to bone health.
• Glucocorticosteroids − oral or inhaled
• Certain immunosuppressant
(calmodulin/calcineurine phosphatase inhibitors)
• Thyroid hormone treatment (L-Thyroxine)
• Certain steroid hormones (medroxyprogesterone
acetate, leutenising hormone releasing hormone
agonists)
• Aromatase inhibitors
• Certain antipsychotics
• Certain anticonvulsants
• Certain antiepileptic drugs
• Lithium
• Methotrexate
• Antacids
• Proton pump inhibitors
