Osteoporosis is the medical term for low bone density “osteo-” refers to bone and “-porosis” means filled with small holes. The bones in patients with osteoporosis are weak due to low levels of minerals, such as calcium, that normally give the bones their strength.
This condition most often affects postmenopausal women but may also occur in elderly men and in the setting of other diseases. Osteoporosis usually does not cause symptoms in of itself but significantly increases the risk of bone fractures.
Elderly patients with osteoporosis often develop hip fractures after falls – this is a very debilitating complication of osteoporosis that can result in impaired mobility and inability to carry out daily activities. Patients with hip fractures are also at an increased risk for blot clot development in the legs – which can travel to the lungs and result in death.
Osteoporosis occurs due to decreased bone mineral density. This may occur in postmenopausal women as a result of decreased estrogen levels. It may also affect elderly men with low testosterone levels. The disease often runs in families and has a strong genetic component. Other conditions that may lead to osteoporosis include:
- Chronic alcohol use
- Overactive thyroid (hyperthyroidism)
- Nutritional deficiencies – low calcium and vitamin D
- Medications – long-term use of corticosteroids (eg. prednisone) or proton-pump inhibitors (e.g. Prilosec)
When the bones become thin and fragile, they are susceptible to fracture – this is especially common in the hip, spine, and upper arms.
Osteoporosis is very common, approximately 16% of American women aged 50 or greater have osteoporosis of the hip or lower spine. In contrast, about 4% of men aged 50 or greater have hip or low back osteoporosis. This condition frequently goes unrecognized until a fracture occurs or a routine screening test is performed.
The risk of osteoporosis differs significantly between patients of African descent and those of Caucasian descent. African American women in particular have a much higher baseline bone density making them far less likely to suffer from osteoporosis later in life. The bone density of Asian, Hispanic, and Caucasian Americans is thought to be similar.
Osteoporosis has no real signs or symptoms, only when it results in an unexpected fracture do symptoms present. These fractures may result in obvious deformity in the injured area, inability to use the injured area, and severe pain. The most common areas affected by these fractures are:
- Spine – compression fracture of the vertebrae
- Hip – fractures of the hip/thigh, especially after falls
- Forearms – radial bone fracture (Colle’s fracture) when falling on an outstretched arm
In severe cases of osteoporosis, fractures can result from extremely minor trauma. This is most common in elderly individuals and generally results from soft impacts with furniture, stepping down from stairs or street curbs, and tripping on rugs or small obstacles.
Osteoporosis is diagnosed based on a DEXA scan (dual-energy x-ray absorptiometry). This is a type of bone scan that evaluates bone density. Patients will receive a T-score based on their bone density in comparison to young healthy individuals. Scores between negative 1.5-2.5 are diagnostic of osteopenia – or mild thinning of the bone. Scores less than -2.5 are diagnostic of osteoporosis, severe thinning of the bone.
Plain x-rays may also show evidence of bone thinning and osteopenia, these x-rays are not sufficient for the diagnosis of osteoporosis but may be suspicious enough for your doctor to refer you for formal DEXA testing.
Your doctor will likely order blood tests, including a comprehensive metabolic panel, calcium, phosphate, vitamin D, PTH (parathyroid hormone), TSH (thyroid-stimulating hormone), and thyroid hormone levels. They may also check testosterone levels in men. These tests are used to check for conditions that may contribute to or even cause osteoporosis. Low levels of calcium, vitamin D, or severe hypothyroidism are common culprits.
The treatment of osteoporosis begins with increasing physical activity, which has been shown to increase bone density. Smoking cessation, alcohol avoidance, and the treatment of other medical conditions such as kidney disease and thyroid disease are also likely to result in increases in bone density.
Weight-bearing exercise specifically is beneficial in osteoporosis, the added stress on the bones helps to stimulate increased bone density. The increased strength of the muscles also helps to prevent fractures even in the setting of low bone density.
Your doctor will also likely recommend increased intake of calcium and vitamin D to maintain proper bone health. The recommended daily intake of calcium is about 1000mg. Most experts recommend that patients also receive about 800-1000 U of vitamin D daily. Vitamin D is usually supplemented in the form of vitamin D3 (ergocalciferol).
There are many over-the-counter supplements that include a combination of calcium and vitamin D. However, if you have vitamin D deficiency, your doctor will likely prescribe a higher dose of ergocalciferol – one common prescription is 50,000 IU per week for 6 weeks.
Patients with low bone mineral density may also benefit from a class of medications called bisphosphates. Bisphosphates are usually reserved for patients with osteoporosis and those with osteopenia and other risk factors (eg. family history, prior history of hip fracture, or long-term corticosteroid use).
These medications work by promoting bone growth and increasing bone density. Some of the most commonly prescribed drugs include:
- Fosamax (alendronate)
- Reclast (zoledronate)
- Actonel (risedronate)
- Boniva (ibandronate)
- Aredia (pamidronate)
Your doctor may also recommend a newer medication called Prolia (denosumab) an artificial antibody that decreases the natural breakdown of bone.
Oral bisphosphonates should generally be used with caution in patients with gastrointestinal reflux disease as it can worsen reflux symptoms. Studies show that a minority of patients using bisphosphonates can develop an increased risk of atypical fractures and jaw necrosis. The benefits of bisphosphonate therapy – reduced risk of hip fracture – likely outweighs the risk of its use, especially in patients with severe disease.
- Bernabei R, Martone A, Ortolani E, et al. Screening, diagnosis and treatment of osteoporosis: a brief review. Clin Cases Miner Bone Metab. 2014 Sep-Dec; 11(3): 201–207. – https://www.ncbi.nlm.nih.gov/pubmed/25568654
- Kling J, Clarke B, Sandhu N. Osteoporosis Prevention, Screening, and Treatment: A Review. J Womens Health (Larchmt). 2014 Jul 1; 23(7): 563–572. – https://www.liebertpub.com/doi/abs/10.1089/jwh.2013.4611