A variety of diseases or conditions can increase bone loss and/or fall risk. Some of the more common examples are discussed below.
Rheumatoid Arthritis and Other Rheumatological Conditions
An inflammatory disease of the joints, rheumatoid arthritis is often treated with glucocorticoids, usually prednisone. Pain and loss of joint function can lead to inactivity, which can further contribute to bone loss. Research suggests that osteoclast (a bone removing cell) activity and bone resorption is increased at the affected sites. In addition to rheumatoid arthritis, ankylosing spondylitis has been associated with bone loss. Several other rheumatological conditions may affect the joints, resulting in poor balance and increased risk of falls, including lupus, psoriatic arthritis and severe osteoarthritis of the hip or knee.
Malabsorption can result from bowel diseases such as Crohn’s disease, ulcerative colitis and celiac disease, and other conditions that affect the bowel such as weight loss surgery. These conditions reduce the absorption of nutrients from the intestine including dietary calcium and vitamin D. The result is lower levels of calcium and vitamin D, which can increase bone loss and falls risk, leading to fractures.
Sex Hormone Deficiency (Hypogonadism)
In women this generally results in the early stoppage of menstrual periods (amenorrhea). Common causes include premature menopause (before the age of 45), eating disorders such as anorexia nervosa, exercise-induced amenorrhea (typically seen in high performance athletes and dancers), pituitary disease, chemotherapy and chronic illness. Some of these conditions can be treated with hormone therapy.
In men low levels of testosterone can be caused by a number of conditions including liver disease, pituitary disease, chemotherapy, chronic illness and ageing. Some of these conditions can be treated with testosterone.
The parathyroid glands produce parathyroid hormone, which controls blood calcium levels. In primary hyperparathyroidism a tumour (generally benign) in one or more of these glands causes the production of more parathyroid hormone than is needed. This causes an increase in bone turnover, which results in excess calcium release from bone and a rise in the level of calcium in the blood. As a result, the risk of osteoporosis and fractures also increases.
Chronic Kidney Disease
Many patients with chronic kidney disease are treated with glucocorticoids such as prednisone, which puts them at risk for developing osteoporosis. In addition, chronic kidney disease may cause several different metabolic bone diseases (called renal osteodystrophy) that are associated with reduced bone formation, hyperparathyroidism, and vitamin D deficiency. In renal osteodystrophy bone quality is poor, and this increases the risk of fracture.
Chronic Liver Disease
Chronic liver disease is associated with reduced bone formation, vitamin D deficiency and low sex hormones, all of which may result in bone loss. In addition, some forms of liver disease may be treated with glucocorticoids such as prednisone, which may cause even greater bone loss. Up to 50% of patients with chronic liver disease develop osteoporosis.
There is evidence to suggest that both men and women with type 1 diabetes are at higher risk for low bone density and for osteoporotic fractures. Poorly controlled type I and type II diabetes are often associated with hypoglycemic episodes (low blood sugar) and/or neuropathy (poor sensation) in the feet. Both of these complications of diabetes can increase the risk of falls and fractures.
Chronic Obstructive Pulmonary Disease (COPD)
COPD is a type of chronic lung disease that usually results after prolonged smoking but can also occur due to other causes. COPD can consist of chronic bronchitis or emphysema or both, and is often associated with a chronic cough, phlegm production, shortness of breath on exertion or at rest (depending on the severity) and frequent chest infections. There is a strong association between COPD and low bone mass or osteoporosis, usually from a combination of factors such as smoking history, low body weight, poor nutrition and treatment with oral glucocorticoids.
Normal thyroid hormone levels maintain good bone health. Too much thyroid hormone interferes with the body’s ability to absorb calcium into the bones and increases bone turnover, which can cause bone loss over time.
Many neurological disorders are associated with an increased risk of fractures (broken bones) because they increase fall risk, bone loss or both. For example:
1. Conditions or injuries resulting in immobility are associated with bone loss. This includes stroke, multiple sclerosis and spinal cord injury.
2. Conditions or injuries that result in poor balance, or problems with gait or movement, are associated with an increased risk of falls and fractures. These include cerebral palsy, multiple sclerosis, Parkinson’s disease, spinal cord injury, stroke, confusion (due to dementia or delirium), dizziness and vertigo, and lower limb muscle weakness.
3. Neuropathy (numbness or reduced sensation) of the feet or legs can also lead to poor balance. This includes diabetic neuropathy, sciatica and other types of neuropathy.