Different Types of Osteoporosis

Beautiful Bones without Hormones: The All-New Natural Diet and Exercise Program to Reduce the Risk of Osteoporosis and Keep Your Bones Healthy and Strong
by Leon Root, M.D.

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Osteoporosis is divided into two basic categories: primary and secondary. Primary osteoporosis occurs when bone loss is due to a problem within the bone itself, usually as the result of a disruption in the normal bone remodeling (removal) cycle. Secondary osteoporosis refers to diseases in other parts of the body that also cause bone loss. In this case the bone loss is secondary to some other disease.

There are three types of primary osteoporosis:

Type I: Postmenopausal osteoporosis (PMO)

Obviously this affects only women, because it is mainly associated with the loss of estrogen that occurs after menopause. It primarily affects the trabecular (porous, spongy) bone in the vertebrae and in the wrist, where much of the metabolically active trabecular bone is located. It is because of this type of bone loss that many postmenopausal women will have a spine or wrist fracture within five to ten years of their last menstrual period.

Type II: Age-related osteoporosis (sometimes called senile osteoporosis)

This affects both men and women. It differs from postmenopausal osteoporosis in that bone loss occurs in the cortical areas of the skeleton as well as in the trabecular areas. Because of the loss in both types of bone, people with Type II osteoporosis also suffer fractures of the hip as well as the wrist and spine. In women, Type II osteoporosis usually shows up about ten years later than Type I, and it is thought to be caused by calcium and vitamin D deficiency as well as by the age-related changes associated with loss of estrogen and the malfunctioning of the remodeling process.

Idiopathic osteoporosis: adult and juvenile

The word "idiopathic" refers to a disease that arises spontaneously from an unknown or uncertain cause. In other words, doctors do not know the cause of the disease. This is the case with idiopathic osteoporosis.

It is a rare form of primary osteoporosis, and when it occurs in children it is usually around the time of puberty. Fortunately, it often resolves itself after puberty, and the young adult goes on to live a completely bone-healthy life. When idiopathic osteoporosis occurs in adults, the bones become fragile and break, just as they do in people with Type I and Type II osteoporosis. But with these patients, we simply don't know what has caused the disease.

Secondary osteoporosis is either caused by medications or medical conditions that affect the calcium balance or the microarchitectural integrity of the bones. Fewer than 5% of people with osteoporosis have secondary osteoporosis. Some of its most common causes include:

Medications: corticosteroids, dilantin, phenobarbitol, lithium, aluminum antacids, gonadotropin-releasing hormone agonists, loop diuretics, methotrexate, excessive thyroid medication.

Hereditary diseases of the skeleton: rickets, hypophosphatasia, osteogenesis imperfecta.

Endocrine conditions and metabolic diseases: Cushing syndrome, asicosis, Gaucher's disease, hypogonadism, hyperparathyroidism, Turner's syndrome, Klinefeltner's syndrome, prolactinoma, diabetes mellitus, acromegaly.

Other causes: pregnancy, early surgical menopause (removal of ovaries), exercise-induced amenorrhea, anorexia, bulimia malabsorption, cystic fibrosis, bone marrow diseases including myeloma, mastocytosis, and thalassemia, renal insufficiency, depression, spinal cord injury, systemic lupus hepatic disease, hypercalciuria, and rheumatoid arthritis.

Treating secondary osteoporosis is more complicated than treating primary osteoporosis because you also have to consider the treatment for the underlying disease. If you have secondary osteoporosis, be sure to find a doctor who knows a lot about your primary disease as well as osteoporosis.

Why We Get Osteoporosis

Osteoporosis, which literally means "porous bones," is a degenerative disease. It is not necessarily a "normal part of aging," and it is not limited to postmenopausal women. What happens is that when our body stops getting the calcium that it needs (which does tend to happen more as we get older) it steals the needed calcium from our bones. Over a period of time, when our bones have lost more calcium than they can replace, osteopenia (thinning of the bones) develops. If not treated, this turns into full-blown osteoporosis. One way to look at this is that the process that leads to osteoporosis (calcium being leeched from bones) is actually the long-term negative result of a short-term coping mechanism. The secret to preventing osteoporosis is to give your body all the calcium (and vitamin D and exercise) it needs, so that it doesn't have to start this calcium-stealing process in the first place.

Your body cannot survive without adequate levels of calcium, magnesium, phosphorous, and sodium. When the levels of these minerals and nutrients get too low in your blood, your bones (where these substances are normally stored) give them up to restore a healthy balance of them in your bloodstream. When your blood mineral levels are restored to normal, your body can go on functioning in a healthy way. Think of your bones as your favorite charity. Bones are givers. The most charitable of all our bones are those that have a high trabecular content, like the jaw, pelvis, wrist, and spine. Sometimes the first sign of systemic bone loss is receding gums. The wrist and vertebrae also tend to fracture before the hip, because they are composed largely of trabecular bone, while the hip has a thin outer layer of cortical bone.

Contributing factors that make the development of osteoporosis more likely include lifelong patterns of inadequate nutrition, smoking, alcohol abuse, minimal exercise, depression, some medications, irregular periods, some surgeries, and exposure to toxins in the environment. Let's take a look at some of the recent statistics on osteoporosis in the U.S. and worldwide.

In the United States

In the United States, the highest percentages of osteoporosis occur in California, Florida, New York, Pennsylvania, and Texas. It is not surprising that these states also rank high in the proportion of older residents.

Here are some more interesting statistics about the lifetime fracture risks for Americans: After the age of fifty, Caucasian women have a 40% chance of fracturing their wrist, hip, or spine in their lifetime, specifically:

18% chance of hip fracture
16% chance of spine (vertebral) fracture
16% chance of wrist fracture

This is equal to the combined risk of developing breast, uterine, and ovarian cancer in the remaining years of their lives.
(Source: Melton, Chrischilles, Cooper, Lane, and Riggs, 1992)

After the age of fifty, Caucasian men have a 13% risk of osteporatic bone fracture, specifically:

6% chance of hip fracture
4% chance of spine fracture
3% chance of wrist fracture
(Source: Melton et al., 1992)

For African-Americans, data is currently only available for the hip. The lifetime risk factor is:

5.6% for women
2.8% for men
(Source: Cummings, Black and Rubin, 1989)

These statistics are still being refined and will be discussed in more detail in the next chapter.

What Are the Costs Associated with These Osteoporatic Fractures in the U.S.?

• $38 million per day
• $13.8 billion per year
• 62% inpatient care
• 28% nursing home care
• 10% outpatient care

Hip fractures account for about 63% of these costs and fractures at other sites for the remaining 37%.
(Source: Ray, Chan, and Thamer, 1997)

Worldwide Statistics

It is interesting to see some of the worldwide statistics for the incidence of hip fractures related to osteoporosis:

As the world population ages, the risk of a worldwide osteoporosis epidemic grows. People are living longer now, and the fastest-growing segment of the population is the oldest of the old, those people eighty-five and up. By the year 2050, the incidence of hip fracture will increase fourfold, from 1.66 million fractures in 1990 to 6.26 million fractures in 2050. The most significant increase is expected in Asia. Today, Asia accounts for 30% of all hip fractures. By 2050, Asia is expected to account for 50% of all hip fractures.

What Does This Have To Do With Me?

There is simply no question that we are facing a worldwide osteoporosis epidemic in the near future, and it is likely to affect you or someone you care about. Part of the reason that this is such a tragedy is that osteoporosis is frequently preventable and always treatable. My goal is to help you better understand this crippling disease. Right now, you can start taking the three simple steps to prevent this killer disease:

1. Eat right - to get adequate calcium and vitamin D into your diet.
2. Exercise - to keep your bone density at its maximum.
3. Get a BMD test if you are in any of the high-risk groups for developing osteoporosis.

Prevention requires some concentrated effort on your part, but the payoff is enormous. Think of it. You can probably add years of healthy, active, pain-free living to your already increased life expectancy by making a few simple changes in your lifestyle. Even if you already have osteoporosis, there is so much you can do to treat it, and the prognosis is better now than it ever has been before. You can do it. You can live a healthier, happier, longer life. It is never too late to learn. It is never too late to begin.

Copyright © 2005 Dr. Leon Root

About the Author

Dr. Leon Root is an orthopedic surgeon at the Hospital for Special Surgery in New York, where he also serves as the Director of Rehabilitation Medicine and Director of the Back School Program. A Professor of Clinical Orthopedics at the Weill College of Medicine, Cornell University and a frequent guest on national media, he lives in New York City.