Osteoporosis and fractures occur more commonly in women and can carry a significant risk of death and need for extended care. One in two women over the age of fifty will develop a fracture during her remaining life span. This often leads to the need for either extended care at home or admission to a nursing facility.
Bones are affected by hormonal, chemical and physical factors and undergo a constant process of removal of calcium. The building of bones begins in utero and reaches its peak when you are in your thirties. More than 10 million Americans have been diagnosed with osteoporosis and nearly four times more have been diagnosed with bone loss.
After menopause, when estrogen levels drop, a women will have approximately 2% yearly bone loss in the long bones like the femur and radius and up to 5% yearly bone loss in the spine and hips.
How is osteoporosis diagnosed?
The diagnosis and degree of bone loss is determined by the presence of a fragility fracture or diagnosis by dual-energy x-ray absorption (DEXA). DEXA measures the bone mineral density (BMD) of the lumbar spine and hip and is reported as a T and Z score. The T score is a comparison of a patient’s BMD with the average BMD of healthy young women. The Z score is a comparison of a patient’s BMD with individuals of similar age, sex, and race. The World Health Organization (WHO) has defined the following:
- A T score of -1.0 and higher / Normal
- A T score of -1.1 to -2.4 / Osteopenia
- A T score of lower than -2.5 / Osteoporosis
The scores assist in diagnosing the degree of bone loss and help your health care provider to identify treatment options. However, scores do not predict your risk for fracture.
The WHO developed a tool called the Fracture Risk Assessment Tool (FRAX) that can be used on men and women over 50 who have not had previous bone loss therapy. It looks at seven factors including body mass index, previous fragility fractures, smoking, alcohol use, history of arthritis, use of steroid medications and family history of fractures. This tool helps health care providers judge who may need therapy to reduce their risk of fractures.
There are many medical conditions and medications that can increase your risk of osteoporosis including endocrine conditions, intestinal diseases, kidney diseases, lupus, cystic fibrosis, excessive alcohol use, smoking, physical inactivity, steroids, lithium, certain birth control products, anti-seizure medications and gastric bypass surgery.
What are the therapies available for osteoporosis?
- Life style changes - Stop smoking, limit alcohol use to less than seven drinks per week and be sure to exercise including walking, running or aerobics. Balance and stability exercises such as yoga and tai chi can decrease your risk of falls.
- Calcium – The American Medical Association and the Institute of Medicine suggest that women over 50 should take in 1200-2000 mg of calcium daily. Recent studies show that a maximum of 500 mg of calcium can be absorbed at one time so divide the doses over the day.
- Vitamin D – A high percentage of adults in the US are deficient in Vitamin D. Vitamin D has been shown to be important in many of the body’s functions including the absorption of calcium from the intestines and redepositing of calcium into the bone.
- Hormonal therapies – Estrogen has been shown to stabilize the bones and decrease osteoclast activity. Recent studies have been reported that fracture rates were decreased by 30-40%. It is not indicated for treatment of osteoporosis but is used to help prevent osteoporosis.
- Bisphosphonates – This class of drugs decreases osteoclast activity and reduces spinal and hip fractures. The challenge with these drugs is that patients must wait 30-60 minutes after taking the medication before eating or drinking and remain sitting or standing for 30 minutes after taking the medication. The Fracture Intervention Trial study showed that one type of the bisphosphonates reduced the risk of vertebral fractures after using the medication for ten years.
- Estrogen Agonists – This family of medications has only one medication approved for bone action. Raloxifene (Evista) reduces the risk of estrogen-receptor-positive breast cancer and reduces the risk of vertebral fractures but no decrease in hip fractures.
- Parathyroid hormone – This anabolic hormone increases bone mineral density in the spine but only slightly in the hip.
- Rank-inhibitor agents – Denosumab is a human immunoglobulin antibody that decreases the function of osteoclasts. Studies have shown that three-year therapy has decreased vertebral and hip fractures.
- Calcitonin – This hormone is manufactured by the parathyroid gland that stimulates the osteoblasts to rebuild the bone. Studies have shown reductions in both vertebral and hip fractures but the medication is usually very expensive.
At present different groups around the US suggest all women should have a DEXA scan either after age fifty or within five years of menopause. Discuss the need for the scan and an evaluation approach with your physician.