OSTEOPOROSIS

Introduction

When people age – particularly women – there often comes a loss of height and weight, and the development of stooped posture. A bone-thinning disease called osteoporosis often causes these body changes. Osteoporosis is characterized by loss of bone mass and structural deterioration of bone tissue. This leads to bone fragility and increased susceptibility to fractures of the spine, hip, and wrist. Spinal fractures are the most common type of osteoporotic fractures. Forty percent of all women will have at least one spinal fracture by the time they are 80 years old. These vertebral fractures can permanently alter the shape and strength of your spine.

Most women are likely to feel some effects of osteoporosis in their lifetime, but the good news is that much can be done to reduce and even prevent loss of bone mass and fractures. New treatments for this disease are being discovered each year. You can actively work to decrease your chances of suffering the effects of osteoporosis. The key is prevention and intervention.

Causes

Loss of bone mass begins at around age 30. Although men can be affected by osteoporosis, the typical sufferers are older women, particularly those who are past menopause. Bone loss becomes worse in women after menopause because of the body’s lack of estrogen. When bones lose mass they tend to weaken and become fragile. This increases the risk of fracture under stress or because of a fall, particularly in your spine and hip. Falls in elderly women are often the result, rather than the cause, of hip fractures. In other words, a fragile hip bone may simply fracture, causing you to fall. In severe cases of osteoporosis, your bones can fracture with any kind of slight movement, which could leave you bedridden.

Doctors use two types to classify osteoporosis, primary and secondary. Primary osteoporosis is further divided into “primary type I” and “primary type II” osteoporosis.

Primary (Type I) Osteoporosis

Most people think of this type when talking about osteoporosis. It’s the form that mainly affects women after menopause. Primary type I osteoporosis is six times more common in women than men, occurring in women 15 to 20 years after menopause. The loss of bone is linked to an estrogen deficiency in women and a testosterone deficiency in men. These hormones tend to become deficient with age.

Primary type I osteoporosis is sometimes called high-turnover osteoporosis because it causes a rapid loss of the spongy inner part of the bones (called trabecular bone). Normally there is a large amount of trabecular bone in the vertebral bodies of the spine and in the end of the long bones, like your wrist. People who lose trabecular bone have a higher risk of spine and wrist fractures.

Primary (Type II) Osteoporosis

Type II osteoporosis is only two times more common in women than men. It typically occurs once people reach their 70s and 80s. It is also thought to be the result of a deficiency in dietary calcium, age-related Vitamin D decline, or increased activity of the parathyroid glands (secondary hyperparathyroidism). With primary type II osteoporosis there is a simultaneous loss of both the outer bone and the spongy tissue inside the bone. Because the rate of bone turnover is much lower in this type of osteoporosis, primary type II osteoporosis is also called low-turnover osteoporosis. Hip fractures are the most common result of this type of osteoporosis.

Secondary Osteoporosis

This form of osteoporosis develops when another problem in the body increases the rate of bone remodeling, leading to a loss of bone mass. Bone turnover is caused by two functions: (1) the production of new bone, and (2) the loss (resorption) of old bone. The amount of bone mass you have depends on the balance between these functions, which is your bone turnover rate. If bone production is less than the amount of bone being resorbed, the risk of developing osteoporosis increases.

Secondary osteoporosis can occur from an imbalance in hormones.

  • Hyperparathyroidism is increased activity of your parathyroid glands.
  • Hyperthyroidism is an excessive secretion of your thyroid glands.
  • Diabetes is a disease where the body does not produce or use insulin correctly. This leads to hyperglycemia,which is an increase in blood sugar that increases your risk of getting an infection and getting glycosuria, which is glucose in your urine.
  • Hypercortisolism is a result of systemic illness or long-term use of oral corticosteroid.

Secondary osteoporosis can also occur from disorders where the bone marrow cavity expands at the expense of the trabecular bone. The trabecular bones have a honeycomb appearance and large marrow spaces. If a trabecular bone is affected by increased bone marrow cavities, it loses some of its strength.

Other causes of secondary osteoporosis include:

  • Thalassemia – a hereditary form of anemia (a problem where your have too few red blood cells).
  • Multiple myeloma – a condition where there are multiple tumors within your bone and bone marrow.
  • Leukemia – a serious disease that is characterized by unrestrained growth of white blood cells in your tissues.
  • Metastatic bone disease – a condition that occurs when malignant tumor cells spread from one part of the body to another. The disease travels through your blood and settles in your bones.

Risk Factors

Osteoporosis does not affect everyone. There are risk factors that may predict your chances of developing it. Some risk factors are genetic, meaning you inherited them from your biological parents. Some risks are due to medical conditions that you may not be able to avoid, such as use of particular medications. Risk factors that are considered “lifestyle-related” are the ones that you have the most opportunity to control.

Biological and Medical Risk Factors for Osteoporosis

  • Biological Sex– Women have a greater chance of developing osteoporosis.
  • Race– Caucasians and Asians are at greater risk of having osteoporosis.
  • Age– Since bone loss begins at around age 30, the risk of osteoporosis increases with age.
  • Family History– If others in your family have experienced hip or spine fractures or become hunched over as they aged, you are at greater risk of experiencing the same symptoms.
  • Body Frame– A thin body frame with low body weight for height will increase your risk of osteoporosis.
  • Post Menopause– Women who are past menopause have reduced estrogen, so their chances of losing bone mass increase.
  • Low Estrogen– There is more risk for women if they have had a low rate of estrogen over their lifetime. The deficiency can be the result of late onset of puberty/getting their period, early menopause (before 40), or an absence or suppression of menstruation.
  • Medication Use– Certain medications increase your risk for osteoporosis because they contribute to loss of bone mass when used long term. These drugs include steroids, inhaled steroids, antiepileptic drugs, immunosuppressants, anticoagulants, and thyroid hormone suppressive therapy.
  • Nutritional Conditions– Conditions such as anorexia nervosa, chronic liver disease, malabsorption syndromes, or malnutrition can increase your risk for osteoporosis.
  • Endocrine Disease or Metabolic Causes– These could include thalassemia, diabetes, or hemochromatosis.
  • Other Medical Disorders– Conditions such as Down syndrome, mastocytosis, myeloma and some cancers, renal tubular acidosis, rheumatologic disorders, and immobilization add to the risks.

Lifestyle Risk Factors for Osteoporosis

  • Low Calcium Intake– Consumption below 300 mg per day (which is equal to one glass of milk) is considered low.
  • Low (or no) Vitamin D in Your Diet– Vitamin D comes from sunlight and foods such as egg yolks, fortified milk and cereals, and some types of fish.
  • High Caffeine Intake– More than two to three cups of caffeinated coffee each day is considered high if you have a low calcium intake.
  • Tobacco Use– This includes current use as well as past use of tobacco.
  • Alcohol Use– More than 7 oz. of alcohol per week can slightly increase your risk of hip fracture.
  • Low Activity– Your activity rate is considered low if you do not walk or exercise regularly.

Symptoms

Perhaps the most common symptoms of osteoporosis are fractures – particularly vertebral compression fractures and hip fractures. The compression fractures in the spine that are caused by weakened vertebrae can lead to pain in the mid back, also called your thoracic spine. These fractures often stabilize by themselves and the pain eventually goes away. But the pain may persist if the crushed bone continues to move around and break.

In severe cases of osteoporosis, actions as simple as bending forward can be enough to cause a “crush fracture” in a vertebra. This type of vertebral fracture causes loss of body height and a humped back, especially in elderly women. This disorder (called kyphosis) is an exaggeration in the curve of your mid back. It causes the shoulders to slump forward and the top of your back to look enlarged and humped.

Consult your doctor if you have symptoms of osteoporosis. Older women should discuss their risks with their doctor, even if they are not currently showing any signs of osteoporosis. All women should be aware of the many preventive steps that can lower their risk of developing osteoporosis.

Diagnosis

Diagnosis of osteoporosis generally begins with aphysical exam that measures height, weight, and arm span. This gives your doctor a rough estimate of what your original height might have been in your young adult life. Your posture and vertebral tenderness will also be checked.

Your doctor may ask you to have a bone mineral density test. Bone densitometry measures the density of your bone mass. This test is not part of a routine screening, but it will be done if osteoporosis is suspected or if you are at high risk for getting it. The test uses an X-ray beam to analyze bone density. The results are placed on a graph. A T-score shows how your bone density compares to the density of a healthy person who is 30 years old. Normal bone is between 0 and 1. Bones with T-scores between 1 and 2.5 are called osteopenic, meaning “too little bone”. A T-score that is more than 2.5 below ideal levels indicates osteoporosis. Doctors also compare your scores to people your same age and sex. This is called a Z-score.

People at risk for osteoporosis can benefit by getting a bone mineral density test done earlier. The results can help identify if a problem exists so proper treatment can begin sooner.

Lab tests are conducted to rule out any secondary disorders that might be causing your osteoporosis. Tests of urine and serum are used to look for concentrations of calcium, serum protein, inorganic phosphorus, alkaline phosphates, or complete blood cell count (CBC). A CBC with a separate white cell count can be used to rule out other diseases. Biochemical measures of bone turnover and other clinical information can be considered. Elderly people should have thyroid function tests, serum, and urinary protein electrophoresis to rule out hyperthyroidism and multiple myeloma.

X-rays might be taken if your doctor suspects a fracture. An X-ray can also show whether there are problems with bone content. An X-ray may detect problems with osteoporosis if the bones have lost 40 percent or more of their normal substance.

Treatment Options

There is still no cure for osteoporosis. But in recent years many effective treatments and prevention plans have been discovered. The best treatment for osteoporosis continues to be prevention.

Physical Therapy

Your doctor may have you work with a physical therapist. A well-rounded rehabilitation program assists in calming pain and inflammation, improving your mobility and strength, and helping you do your daily activities with greater ease and ability.

Physical therapists design treatment programs to improve your flexibility, strength, and posture. Exercises are chosen to help stabilize your spine while preventing bent positions of your spine. Therapists evaluate your balance and strength to make sure you are not at risk of having a fall. Therapy sessions may be scheduled two to three times each week for up to six weeks.

The goals of physical therapy are to help you:

  • Learn correct posture and body movements to counteract the effects of osteoporosis
  • Perform a routine of safe weight bearing and resistance exercise
  • Use safe lifting practices to avoid straining your spine
  • Improve your balance to prevent you from falling down
  • Learn ways to manage your condition

Preventive Treatment Options

Calcium

The most fundamental suggestion is to increase your calcium intake, either through dietary changes or supplemental pills. It is best for people to begin adequate calcium intake at an early age, as bone mass begins to decrease around the age of 30. After age 30, calcium helps decrease bone loss, strengthen bones, and decrease your risk of fractures.

The recommended daily intake for women aged 25 to 50, and for women over age 50 who take hormone replacements, is 1,000 mg (milligrams) or calcium per day. Women over 50 who do not take hormone replacements should take 1,500 mg of calcium per day. Men aged 25 to 65 should have 1,500 mg of calcium per day. Men and women over 65 years old should have 1,500 mg of calcium per day.

If you take calcium supplements, make sure they contain Vitamin D, as this helps with absorption. Calcium citrate is absorbed better than calcium carbonate. If you take the carbonate form, make sure to take it with food.

Vitamin D

A vitamin D deficiency may contribute to bone loss and fracture. At least 800 mg of vitamin D per day is recommended for all adults. Many calcium supplements contain vitamin D. You can also get vitamin D through foods such as egg yolks, fish, and fortified milk and cereals. Fish sources include halibut, mackerel, sardines, shrimp, pink salmon, and cod liver oil.

Exercise

Exercising five days a week for at least 30 minutes each day helps reduce bone loss. The best exercises for maintaining bone mass are weight-bearing exercises like walking, low-impact aerobics, and safe forms of dancing.

Medications

Currently, four medications have approval from the US Food and Drug Administration (FDA) for helping to prevent osteoporosis:

Hormone (estrogen) replacement therapy (HRT) is used for both prevention and treatment of osteoporosis. HRT can reduce bone loss, increase bone density in your spine and hips, and reduce the risk of hip and spinal fractures in postmenopausal women.

HRT is usually given as a pill or skin patch. It is effective even when started after age 70. Estrogen taken alone can increase the risk of developing endometrial cancer (cancer of the uterine lining). For this reason another hormone called progestin is usually prescribed in combination with estrogen for women whose uterus is intact.

Side effects of HRT can include nausea, bloating, breast tenderness, and high blood pressure. Some studies indicate a relationship between estrogen use and breast cancer, while other studies do not. Make sure to discuss the pros and cons of estrogen replacement therapy with your doctor.

These compounds inhibit breakdown of bone and slow down bone resorption. They’ve been shown to increase bone density and decrease the risk of hip and spine fractures. Alendronate is the bisphosphonate that has been approved by the FDA for preventing and treating osteoporosis in postmenopausal women. The strongest side effect of alendronate is gastrointestinal problems. To avoid these problems it should be taken on an empty stomach. Also take it with a full glass of water and remain in an upright position for at least thirty minutes afterward. More recently, long-term bisphosphonates usage has been linked to unusual femur (thigh bone) fractures. It is theorized that slowing the natural turnover of bone prevents the body from being able to heal micro-cracks that may occur over time. This could lead to a weakening of some bones. However, this type of fracture is rare and the overall reduction in the risk of fracture as a result of bisphosphonate treatment remains.1

PTH is a hormone that occurs naturally in the body and plays a role in regulating the levels of calcium and phosphate. Teriparatide is a synthetic form of PTH that has been shown to increase the number of bone building cells in the body. This drug has been shown to increase bone mass and prevent future fractures. Teriparatide is administered via daily self-injection. Most common side effects of teriparatide include nausea, joint aches and leg cramps.2

Calcitonin is used for women who cannot or choose to not take estrogen. For women who are at least five years past menopause, calcitonin can increase spinal bone density and slow bone loss. Calcitonin is a protein, so it cannot be taken orally because it would digest before it goes to work. It is available as an injection or nasal spray.

SERMs are compounds that have effects similar to estrogen in some parts of your body, such as your spine and hip. SERMs seem to prevent bone loss in your spine, hip, and throughout your body. Raloxifene is the SERM drug currently approved by the FDA for prevention of osteoporosis. Its impact on the spine does not appear to be as powerful as either estrogen replacement therapy or alendronate. There are no common side effects with raloxifene. Some women have experienced hot flashes and deep vein thrombosis (DVT).

1Schilcher, J., MichaĆ«lsson, K., Aspenberg, P. 2011. “Bisphosphonate Use and Atypical Fractures of the Femoral Shaft.” N Engl J Med, 364:1728-37.

2“About FORTEO.” Osteoporosis Medication -FORTEO [teriparatide (rDNA Origin) Injection]. Lilly USA, LLC, n.d. Web. Retrieved November 1. 2013 from, http://www.forteo.com/Pages/osteoporosis-medication.aspx”

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