Highest bone density is reached around age of 35 years and bone loss occurs with varying rates depending on the subject and gender. Bone density decreases in all people as age advances; however, “osteoporosis” develops when decrease is faster and fragility is higher than expected.
How is osteoporosis diagnosed? It is diagnosed by bone mineral density measurement, but there are many methods. World Health Organization (WHO) established “Dual Energy X-ray absorptiometry (DEXA)” as a standard method for post-menopausal women. Blood and urine tests are used for differential diagnosis as there are many diseases leading to bone loss.
Osteoporosis may stay asymptomatic until fracture occurs and it may be accidentally diagnosed when X-ray graph is ordered for another purpose. Pain occurs only when fracture develops. Contrary to the common belief; when generalized muscle, joint and bone pain occurs for a long period of time, like months, other diseases and medical conditions should be considered and tested. Sometimes body height shorting more than expected or increased back curve-kyphosis may be indicative. When fracture occurs due to a simple fall or impact or when your doctor think you are under risk of osteoporosis, s/he may order tests and evaluate your bone density.
Researches and discussion continue on which patient and whether healthy subjects should undergo tests measuring bone density. Bone mineral density measurement tests are recommended for postmenopausal women fulfilling a risk factor, women aged above 65 years and men aged above 70 years.
What are risk factors for reduced bone strength and density? History of fracture at adult age due to a simple fall, familial history of hip fracture due to a simple fall, long-term use of several drugs (cortisone, anti-epileptic, heparin etc.), lean subjects (body weight below 50 kg), diabetes, thyroid problems, deficiency of female (estrogen) and male (testosterone) sex hormones, premature menopause (onset before age of 40 years), other hormonal problems, rheumatoid diseases with severe course such as rheumatoid arthritis, intestinal and renal problems influencing normal nutrition etc.
How can we keep our bones healthy? We should keep ourselves healthy in all respects, take account of healthy life style recommendations during younger ages and early adulthood. Most important preventive measures are: increasing activity during daily life, preferring foods rich in calcium and vitamin D (green-leaved vegetables, meat, milk and dairy products, fish, cereals etc.), avoiding smoking and limiting alcohol consumption.
There are different views on how and when to use calcium and vitamin D drugs, dose of supplementation and whether to add into foods or not. Excess consumption of alcohol (over 3 units per day) may lead to malnutrition and increase risk of accidents/falls. Debates about the influences of caffeine (from tea or coffee) and salt consumption are not clear.
Exercise during adolescence will increase healthy bone. Peak bone mass for women before menopause reduces risk of postmenopausal fracture. Active life style, minimum 30-min jogging for 3-5 days a week, exercises supporting vertical posture and flexibility as well as personally preferred exercises (yoga, pilates, dance etc.) which support muscle strength and balance are recommended for postmenopausal period and advanced age.
How can we prevent bone fracture? We should all have a care plan for not falling at home, work etc especially at advanced age. Preventive measures against domestic accidents may include: preventing risk of stumbling on carpet edges or door sill, using special anti-slip materials (supportive materials placed under carpet, special floor covering etc.), avoiding cable mass on walking routes, adequate illumination, night lamps, avoiding to walk on slippery surfaces, preferring orthopedic and fit shoes and slippers, attending ophthalmic control visits regularly, having knowledge on side effects of current medications and consulting to doctor on use of drugs causing dizziness/confusion.
Can osteoporosis be treated? Yes. There are drugs which reduce bone loss and enhance partially new bone gain. Non-medication measures protecting bone health should always be considered. When treatment is planned, all personal medical history, habits and familial history are taken into account. Control visits can be planned in order to determine efficiency of treatment by measuring bone density once in 1, 2 or 5 year(s). Bone screening, blood and urine tests can be repeated in order to measure efficiency of the therapy or make differential diagnosis again. If any, treatment will be based on features of the fracture and surgical treatment may be required.
What are the tests measuring bone density?
Dual-energy X-ray absorptiometry (DXA) – This is the most reliable test. Dose of radiation is low. Different body regions: spine, hip and forearm can be tested. The device screens your body when you lie on a table, no discomfort, no drug is administered and there is not a cover used over the patient. It usually lasts for 5-10 minutes. The test result is compared with mean bone density results of age-matched subjects and young individuals which are previously saved in the computer system and the differences are expressed as “T-score” and “Z-score”. This is a statistical evaluation.
Ultrasonography: The measurement is made on heel bone. This test is used for screening and identifying risks; it is not be used for final diagnosis.
Quantitative computerized tomography (CT): It is not often preferred for scientific researches due to exposure to high radiation dose.
What would the bone density test mean? For postmenopausal women, results obtained from bone density measurements are compared with mean values as “standard deviation”. T-score is used.
- Normal bone density: T-score: +1 and -1
- Osteopenia: T score: -1.1 and -2.4. Osteoporosis had not developed yet; bone density is lower than normal ranges. Patient can be followed up for osteoporosis. Medical treatment can be considered when there is a risk identified.
- Osteoporosis: T score: ≤-2.5. A treatment is planned for reducing risk of bone fracture.
Medical treatment of osteoporosis: When there is a treatment plan with drug medication adequate calcium and vitamin D supplementation is also required. Preventive measures should be maintained and comorbidities of the patient should be taken into account.
Who should take drug medication? Medical treatment is recommended for subjects with high risk of fracture. The algorithm, consensus decisions or rules can be established by medical societies, Ministry of Health and Social Security Institutions. Medical drug treatment is advised if hip and spine fracture occurs in postmenopausal women and elderly men and for subjects with T-score ≤ - 2.5 indicated by a bone density test.
How is the treatment of pre-menopausal women? For premenopausal women (women with active menstrual cycles), there is not a clear indication on relationship between bone density measurement and fracture risk and possible candidates of treatment. Differential diagnosis for other diseases which may possibly influence bone health should be evaluated. If there is only a test result showing low bone density may not indicate increase risk of fracture, the patient can be followed up, especially during menopause.
Types of Drugs:
Bisphosphonates: They target decelerating bone resorption. They are commonly used for prevention and actual treatment. There are daily, weekly, monthly and annual regimes (alendronate, risedronate, ibdandronate, zoledronic acid). They may be administrated via oral, intra-muscular or intravenous routes. No serious side effect is expected; gastric discomfort is the most common one and there are rare reports for jaw bone lesions.
Drugs “resembling estrogen hormone”: These are drugs which are not actually estrogen hormone, but acts like the hormone on bones. Selective estrogen receptor modulator – they are also referred as SERMs (raloxifen, tamoxifen) reduce post-menopausal bone loss and risk of breast cancer.
Estrogen/progestin therapy: They were commonly used for post-menopausal women in the past; however, considering side effects, they are not currently preferred for treatment of osteoporosis. They may be preferred for a post-menopausal patient on special conditions, if there is pre-menopausal hormone deficiency and early menopause (starting before age of 40 years).
Calcitonin: It is a type of natural hormone which is secreted from thyroid gland and influences bones. Synthetic form can be used as a nasal spray or subcutaneously. It is preferred for fracture associated with pain.
Parathyroid hormone (PTH): It is a hormone which has influences on bone. It is injected in daily regime: it is preferred for severe osteoporosis.
Denosumab: It is a new drug which is an antibody for a substance in bone metabolism (RANKL); we don’t have the long term results yet. It is administered in daily regime.