The majority of osteoporotic individuals are asymptomatic because bone loss without fracture is a painless process. The first symptom of osteoporosis may be a fracture or collapsed vertebrae. Otherwise, the disease causes no symptoms and is therefore often called a “silent disease”. A collapsed vertebra may cause severe back pain, loss of height, or spinal deformities such as stooped posture. Loss of bone can result in microfractures that do not result in change in the shape of the bones. An ache or pain however can be associated with this change in bone structure.
Bone is living tissue that is constructed like a building. Buildings have an internal framework, girders, that are surrounded by cement to form rooms. The equivalent in bone for girders is collagen and for cement is calcium and phosphorus. Bone is constantly being remodeled; osteoclast cells that excavate and resorb, and osteoblasts form new bone. This process supplies a constant source of calcium that supports essential bodily function. When younger, the balance is in favor of osteoblasts that make bone. As we age, the balance shifts to the osteoclasts that hasten bone loss. As calcium is lost from bone, the architecture is altered with cross struts supporting weight being lost. The result is weakened bone with increased fracture risk.1,2,3
Causes of Osteoporosis
Though osteoporosis tends to affect older individuals, it may be caused during childhood and adolescence—if bones don’t grow adequately early in life, optimal peak bone mass is never reached. Less than optimal bone mass increases risk for osteoporosis later in life.
Hormonal changes later in life also contribute to bone loss. This is especially true for women, who experience a decrease in estrogen production when menopause occurs. Estrogen may be decreased by natural menopause, surgical removal of the ovaries, or chemotherapy and radiation treatments for cancer. Men also experience a decline in sex hormone (testosterone) levels that can contribute to bone loss, but the decline is not as pronounced as it is in women.1,2,3
Some health conditions, as well as the medications used to treat them, can cause bone loss as a side effect.
Medications That Can Cause Bone Loss
- Corticosteroids Women who have arthritis or asthma may lose bone mass as a result of avoiding weight-bearing exercise because it’s painful or can trigger an attack. Also, medications often used to treat these conditions—corticosteroids such as prednisone (Deltasone® and Orasone®) and dexamethasone (Decadron® and Hexadrol®)—cause bone loss by inhibiting new bone formation and interfering with the body’s absorption of calcium. According to the American College of Rheumatology, anyone who takes corticosteroids (also called glucocorticoids) for more than three months is at risk of osteoporosis.4 Conditions such as lupus and inflammatory bowel disease may be treated with long-term corticosteroids, as well.
- Proton pump inhibitors (e.g., Aciphex,® Nexium,® and Prilosec®), used to treat gastrointestinal reflux, and selective serotonin reuptake inhibitors (e.g., Prozac,® Paxil,® and Zoloft®), used to treat depression—may increase the risk of hip fracture, especially when they are taken for a long time.5
6 Further research is needed on the fracture risks posed by these commonly prescribed medications.
- Anti seizure medications
- Hyperparathyroidism increase the risk of secondary osteoporosis.
- Kidney disease
- Crohn;s disease
- Anorexia nervosa
Risk Factors for Osteoporosis
There are risk factors that increase and individual’s likelihood of developing osteoporosis. Some of the risk factors cannot be changed however others can be modified to reduce risk.
Risk factors that cannot be changed
- Gender—Women are at greater risk than men.
- Age—Risk increases with age, as bones become thinner and weaker.
- Body size—People (women, in particular) with small, thin bones are at greater risk.
- Ethnicity—White women and Asian women are at highest risk. Risk is lower but significant in African-American and Hispanic women.
- Family history—A family history of fractures (specifically, in one’s parents) may increase risk.
Risk factors that can be changed with medical treatment and lifestyle measures
- Sex hormones—Estrogen deficiency resulting from abnormal absence of menstrual periods and menopause (natural or due to surgical removal of ovaries or medical treatments) can contribute to osteoporosis in women; Low testosterone levels can increase a man’s risk.
- Anorexia nervosa—This eating disorder (irrational fear of weight gain) increases risk.
- Calcium and vitamin D intake—A diet low in these nutrients increases risk.
- Medication use—Certain medications increase risk (anti-inflammatory drugs known as glucocorticoids and anticonvulsants, or antiseizure medications, for example).
- Lifestyle—People with an inactive lifestyle or those on extended bed rest may have weaker bones.
- Cigarette smoking—Smoking, which harms the heart and lungs, is also bad for bone health.
- Alcohol intake—Excessive consumption of alcohol can increase bone loss and risk for fractures.
Men and Osteoporosis
Osteoporosis is less common in men than women. Men have more bone than women to start. Bone loss starts later in life. Bone loss does occur in men as testosterone levels decrease. The ability to absorb calcium is decreased with age. The risk for fractures also increases with the tendency to fall more often. In men, hormone ablation therapy for prostate cancer can result in an increased risk. By age 75, 25% of men are osteoporotic.
Next: Diagnosing Osteoporosis
4 [2Glucocorticoid-induced Osteoporosis. American College of Rheumatology Web site. Available at http://www.rheumatology.org/public/factsheets/gi_osteopor_new.asp?aud=pat.
5 Yang Y-X, Lewis JD, Epstein S, Metz DC. Long-term proton pump inhibitor therapy and risk of hip fracture. Journal of the American Medical Association. 2006;296(24):2947-53.
6 Richards JB, Papaioannou A, Adachi JD, et al. Effect of selective serotonin reuptake inhibitors on the risk of fracture. Archives of Internal Medicine. 2007;167(2):188-94.