Osteoporosis :: Metabolic Bone Disease
The term osteoporosis means porous bones. Osteoporosis is a metabolic disorder characterized by progressive loss of bone mass making the bones increasingly weak and prone to fractures. In the initial stages it is undetected till the development of a fracture. Fractures of the hip, spine, leg, arm and wrist are more common in these patients, usually secondary to a fall. With the progression of the disease, the patient may experience low back and neck pain due to a fracture of the spinal vertebrae. In severe cases, osteoporosis may lead to a vertebral compression fracture resulting in a loss in overall height (around 6 inches) and a stooped back which is also known as dowager’s hump.
Causes and risk factors
The exact cause of osteoporosis is not clear. The major risk factors associated with an increase in the incidence of osteoporosis include
Age and gender
After the age of 35 years, the body gradually loses bone mass. Hence the greater the age, the higher the risk of osteoporosis. Moreover women are four times more prone to osteoporosis when compared to men. Thus older women over 50 are at a high risk for osteoporosis.
Family history and ethnicity
Caucasians, Hispanics and Asians are at an increased risk to develop osteoporosis. This risk is further increased by a small, thin body frame and a family history of fractures. Hence heredity plays an important role in the development of osteoporosis.
Endocrine disorders such as hyperparathyroidism and thyroid problems increase the risk of osteoporosis by adversely affecting the process of bone formation.
Hormone replacement therapy for prostate cancer or breast cancer, long term corticosteroid therapy (more than 3 months) and some anti-epileptic drugs increase the risk for osteoporosis.
Nutrition and lifestyle
A sedentary lifestyle, smoking, excessive alcohol intake and poor nutrition with a calcium deficient diet make an individual highly prone to develop osteoporosis.
These may lead to a deficiency of essential nutrients required for healthy bone and thereby increase the risk for osteoporosis.
Rheumatoid arthritis is an auto immune disease associated with bone loss at the affected joints. This increases the risk for joint fractures.
The diagnosis of osteoporosis includes medical and family history, physical examination and radiological examination (X-ray). If these examinations detect a low bone mass, additional lab tests may be ordered to rule out other conditions associated with bone loss. A bone scan using Dual Energy X-ray Absorbtiometry (DEXA) may be performed to measure bone density or bone strength. It is a safe and simple test with a high accuracy and sensitivity which can detect osteopenia, a condition with weak bones, suggesting an early sub-clinical stage of osteoporosis. The results of DEXA are represented in terms of T-score, which is a comparison of the individual’s bone mineral density to that of a young Caucasian female.
- T score of +1 to -1 indicates normal bone density
- T score of -1 to -2.5 indicates low bone density (osteopenia)
- T score of less than -2.5 indicates osteoporosis
Treatment of osteoporosis aims at strengthening the existing bones and stopping the disease progression. Medication such as calcium and vitamin D supplements, estrogen for post menopausal women and testosterone for men, parathyroid hormone shots and bisphosphonates can be prescribed to patients. Pain medication and non-steroidal anti-inflammatory drugs (NSAIDs) may be prescribed for the resolution of pain. Back braces may also be recommended to support the back and minimize movement to reduce mechanical pain.
Simple lifestyle changes such as a healthy, well balanced diet rich in protein, calcium and vitamin D, regular exercises such as walking and jogging, along with abstinence from smoking and alcohol improve overall bone health and prevent the development of osteoporosis. In patients with osteoporosis these lifestyle changes may delay the progression of the disease.
Metabolic Bone Disease
Metabolic bone disease or MBD refers to a large spectrum of bone disorders, usually caused by mineral abnormalities such as calcium, phosphorus, magnesium or vitamin D. The most common metabolic bone diseases include osteoporosis, osteomalacia, rickets, renal osteodystrophy and osteitis deformans (Paget’s disease of bone).
Metabolic bone disease can be caused by a number of factors including vitamin D deficiency, hereditary hypophosphatemia, and hyperparathyroidism (over-activation of the parathyroid gland).
The most common form of metabolic bone disorder is osteoporosis. Osteoporosis is a bone disease characterized by a decrease in bone mass and density resulting in brittle, fragile bones that are more susceptible to fractures. The condition most commonly affects elderly women. Osteoporosis related fractures are more common at the hips, wrists, or vertebral bodies of the spine. Osteoporosis is called a "silent disease," because a majority of patients are unaware of their condition until they develop a bone fracture.
Metabolic bone disease in children can result in linear growth reduction, bone deformities, non-traumatic fractures, and impairment of motor development and function.
The diagnosis of MBD is usually made based upon a careful history, physical examination, radiographic (X-rays) examinations, appropriate lab tests, and bone biopsy if indicated.
Treatment for MBD depends on the underlying cause. Early detection and treatment of risk factors is essential to maintain the skeletal health of an individual. A balanced diet with adequate amounts of vitamin D and calcium and an adequate amount of physical activity are needed for normal bone metabolism. Your doctor may prescribe osteoporosis medications to help slow the rate of bone loss, and in some cases, to replace the lost bone structure.