Determining whether low bone mineral density is due to primary osteoporosis or secondary osteoporosis is a critical step in treating brittle bones. The terminology of "primary" versus "secondary" osteoporosis gets a little confusing, so here are five things every osteoporosis patient needs to know and five more pieces of important information for people who specific types of drugs.
1. Primary osteoporosis is loss of bone density not attributed to another disease process
A diagnosis of primary osteoporosis is identified as "type I" for age-related bone loss, "type II" when associated with menopause, or "idiopathic" in children, teens, and young adults.
2. Primary osteoporosis is associated with a variety of risk factors
- Primary osteoporosis is associated with low body mass. For most women, this would be weighing less than 60 kilos (132 pounds). For most men, low body mass would be recognized at about 70 kilos (154 pounds).
- Another risk factor for primary osteoporosis is any history of a broken bone after mild-to-moderate trauma. One unexpected bone break tends to be followed by another.
- Other risk factors include chronic kidney disease, acid reflux (especially if treated with medications that interfere with the absorption of calcium), tobacco use, excessive use of alcohol, bulimia, anorexia, or bad eating habits. Women who get their first period unusually late in life, or who have a history of irregular periods, or who have early menopause or estrogen deficiency are at greater risk for primary osteoporosis. Men who have erectile dysfunction (ED) or hypogonadism (underdevelopment of the sex organs) are at greater risk of brittle bones. These risk factors can be controlled or compensated for, reducing the risk of primary osteoporosis.
3. Secondary osteoporosis results from another disease or is a side effect of a drug
There are allergic, autoimmune, endocrine, genetic, and neurological diseases that cause loss of mineral content of bone. There are dozens of drugs that can cause loss of bone minerals.
4. Many common diseases can cause secondary osteoporosis
Among the diseases that can trigger secondary osteoporosis are ankylosing spondylitis, adrenal insufficiency, autoimmune diseases such as lupus and rheumatoid arthritis, biliary cirrhosis, cancer, celiac disease, Crohn's disease, Cushing's disease, cystic fibrosis, diabetes (both type 1 and type 2), hypothyroidism, hyperparathyroidism, hyperthyroidism, inflammatory bowel disease, lung diseases, multiple sclerosis, and Parkinson's disease.
5. Many medications can cause secondary osteoporosis
The most common culprit among prescription drugs in secondary osteoporosis is glucocorticoid treatment. Steroid drugs given for diseases such as asthma and rheumatoid arthritis trigger bone mineral loss in about 50 percent of cases. Taking as little as the equivalent of 2.5 mg of prednisone daily can lead to brittle bones. Another problem area is excessive thyroid hormone replacement. Getting a thyroid problem under control requires careful monitoring by the endocrinologist.
Less commonly, secondary osteoporosis results from use of:
- Depo-Provera (medroxyprogesterone acetate depot) for birth control
- Thiazolidinediones (Actos, Avandia) for type 2 diabetes
- Proton pump inhibitors for acid reflux disease
- Lithium therapy for bipolar disorder
- Long-term use of heparin
- Cancer chemotherapy drugs
- Excessive use of selective serotonin reuptake inhibitors (SSRIs) for depression and other psychological issues
- Anti-seizure drugs such as phenytoin (Depakote) and phenobarbital
This list is not exhaustive. There are still more drugs that can activate osteoporosis. It is important to be aware of the earliest signs of brittle bones if you take any of these drugs continuously. And there are five classes of drugs that require special attention.
6. Anyone at any age can develop osteoporosis while taking steroids
It only takes about six months for bone destructive processes to set in when taking glucocorticoids. Even a low-dose steroid can result in loss of bone. It's important to discuss bone health with the doctor who prescribes the medication. Bisphosphonates offset the damage this class of drugs does.
7. Thiazolidinediones (TZDs) are seldom a good idea for diabetics, but they are always bad for bones
A group of medications for type 2 diabetes known as TZDs (Actos, Avandia) causes stem cells intended for red blood cell production to become fat cells. These fat cells become ectopic, that is, they lodge in unexpected places in the body, such as bone. TZDs generate fat cells, and fat weakens bone.
8. Proton pump inhibitors (PPIs) such as Nexium and Prilosec cause bone loss
The "purple pill" Nexium (esomeprazole) and its competitor Prilosec, used for symptoms of gastroesophageal reflux disease (GERD) and heartburn, cause bone loss in two different ways. They interfere with the absorption of calcium from food, and they also interfere with the aborption of B vitamins. Deficiencies of B vitamins cause fatigue, weakness, and loss of balance, which puts anyone who has brittle bones at greater risk of falls and fractures. It's just not possible for the body to absorb certain nutrients without the action of stomach acid. And sometimes the answer to a problem with heartburn is not less stomach acid, but rather more. Judicious, medically supervised use of betaine supplements can help the stomach digest food more thoroughly so there is less pressure on the esophageal sphincter and less of a problem with acid coming up.
9. "Pee pills" stop loss of calcium into the urine, but increase the risk of falls
Thiazide diuretics are often prescribed to conserve the calcium in the bloodstream. The problem is that these pills increase the excretion of B vitamins, which increases the risk of falls. Bones may get stronger, but falls are more frequent.
10. People who take certain antiseizure medications are at high risk of fractures
Older medications for epilepsy such as Depakote and Depakene (valproic acid) interfere with calcium metabolism. They result in weaker bones. And if they are not properly regulated, the risk of falls is high.