Inadequate bone mass formation
This is the most important risk factor. If there is insufficient bone mass before it starts to decrease, the effects of osteoporosis will become apparent much earlier. Reasons for the inadequacy may involve any of the following risk factors.
Genetic factors can cause some people to form less bone than average. Osteoporosis is more prevalent among white and Asian women than African and Caribbean women.
Any condition that lowers estrogen levels (for instance, anorexia nervosa or exercise-induced amenorrhea) accelerates loss of bone mass. A lack of calcium or vitamin D through poor nutrition means that less bone is renewed and more calcium leaches out of bone into the blood to make up for the deficiency.
A sedentary lifestyle and lack of exercise can accelerate bone loss. Regular weight-bearing repetitive exercise promotes an increase in bone mass.
Slight women have less bone mass to start with, so the effects of loss of bone mass may become evident more quickly. They are more likely to be predisposed to fractures.
Tobacco increases the risk of osteoporosis. Smokers on average have menopausal symptoms up to two years earlier than non-smokers.
Excessive alcohol intake
Consistently consuming more than two drinks a day is associated with a higher risk of osteoporosis, because alcohol attacks the cells that form bone and inhibits the absorption of caffeine.
Consistently drinking more than three cups of caffeine-containing drinks a day, such as coffee, tea and cola, can increase the risk of developing osteoporosis. Adequate calcium intake can counteract this.
Long-term use of a number of drugs can cause osteoporosis. They include thyroid hormone, anticonvulsants, antacids that contain aluminum, methotrexate (used to treat cancer, immune disorders and arthritis), heparin (used to prevent blood clothing), cholestyramine (used to reduce levels of cholesterol in the blood) and some glucocorticoids, such as cortisone and prednisone, which are given to treat osteoarthritis, rheumatoid arthritis, asthma, allergic reaction, multiple sclerosis and chronic skin disorders.
Certain medical conditions
Bone loss may be caused by Cushing’s syndrome, in which the adrenal glands are overactive and produce excess glucocorticoids, and hyperparathyroidism, an over-activity of the parathyroid glands. The hormone from these glands controls blood calcium levels, and if there is not enough, it removes calcium from bone tissue. Thyroid disease and malabsorption (from digestive disorders may also effect bone mass.