Causes and Risk Factors for Osteoporosis
The more risk factors for osteoporosis that a person has, the greater the chance of fracture. Women with small body frames, a family history of osteoporosis, and early onset of menopause are at the highest risk.
Age & Osteoporosis
After age 65, osteoporosis damages both trabecular and cortical bone, making sites besides the hip, wrist, and vertebrae vulnerable to fracture. In the most severe cases, the disease also affects teeth and jawbones, resulting in periodontal disease and tooth loss.
Genetics & Osteoporosis
According to the National Institutes of Health, genetics may determine up to 80% of the risk for osteoporosis. Genetic risk factors include the following:
- EthnicityCaucasian and Asian
- Body SizeSmall frame, low body weight (less than 125 pounds), optimal bone density not reached
- Family historyMaternal history of osteoporosis, hip fracture, smoking, tallness, thinness
Hormones & Osteoporosis
Hormones regulate bone remodeling, which affects bone mass. After age 50, the rapid and severe decrease in estrogen production that occurs during and after menopause increases the risk for osteoporosis.
Modifiable Osteoporosis Risk Factors
Although optimal bone mass is determined mostly by genetics, other factors are involved. The amount of calcium, phosphorus, and vitamin D in the diet affects bone formation. Additionally, regular exercise, which increases bone mass, helps determine whether a person obtains optimal bone mass.
Several risk factors can be modified or eliminated by changing diet and habits:
- Cigarette smoking decreases estrogen production.
- Excessive alcohol use inhibits osteoblast activity and increases risk for falling.
- High caffeine intake increases loss of calcium in urine.
- Inactive, sedentary lifestyle eliminates physical activity that stimulates bone remodeling.
- Calcium and phosphorus deficiencies decrease formation of hydroxyapatite, the major mineral in bone.
- Lack of vitamin D reduces intestinal absorption of calcium and phosphorus.
Prolonged use of certain medications can induce or speed up the rate of osteoporosis, including:
- Antiseizure medications
- Gonadotropin releasing hormone (GnRH) analogs
- Thyroid hormone
Excessive amounts of antacids containing aluminum (e.g., Maalox, Mylanta) may increase the risk for osteoporosis in certain people.
Diseases caused by hormone imbalances (e.g., hyperthyroidism, hyperparathyroidism, Cushing's syndrome) may increase the risk for osteoporosis because they interfere with the regulation of the hormones that regulate remodeling. Gastrointestinal disorders (e.g., celiac disease, Crohn's disease) that affect absorption of calcium and vitamin D also increase the risk.
Early onset menopause brought on by the removal of the uterus (hysterectomy) and the complete removal of the ovaries (oophorectomy) is associated with osteoporosis.
Results of a study supported by the National Institutes of Health (NIH) and released in June 2012 indicate young men between the ages of 14 and 25 who are undergoing treatment for HIV infection may have an increased risk for low bone mass. Participants in the study had been diagnosed with HIV an average of two years earlier and, according to researchers, also had several other risk factors for osteoporosis, including smoking, alcohol use and low dietary intake of calcium and vitamin D.
More research is needed to determine how HIV treatment might affect bone density. People being treated for HIV should be monitored for bone loss, should exercise regularly and should get recommended amounts of calcium and vitamin D through diet and supplements.