What is Osteoporosis?
Osteoporosis is a bone disorder characterized by fragile bones which ultimately increases the risk of fracture with minimal or no inury. Although post-menopausal women usually suffer from osteoporosis, the disease can also affect males above 75 years of age and any person who uses certain drugs like steroids for long periods of time.
The early stage of osteoporosis usually does not produce any symptom other than low back pain. Fracture with minimal or no trauma is usually the most common presenting feature of osteoporosis. Hip bone, wrist and vertebral bones forming the spine are the most common sites of fractures due to osteoporosis.
Apart from increased risk of fracture and disability, untreated osteoporosis may lead to shortening of height and a hunched posture. Osteoporosis can be effectively managed with dietary changes, exercise and drugs like bisphosphonates, calcium, vitamin D and selective estrogen receptor modulators.
Symptoms of Osteoporosis
Usually osteoporosis in the initial stages do not produce any specific symptoms other than bone pain and non-specific lower back pain. With progression of the disease, the symptoms that may be seen include :
- Increased chance of fracture with trivial injury or no trauma: The hip and spine are the most common sites of fracture. Apart from the pain, surgery is often required especially in management of hip fracture. Surgery increases the risk of pulmonary embolism and venous thromoebolism due to blockage of pulmonary artery and usually leg veins by a moving blood clot, thus increasing the mortality rate.
- Vertebral fracture presents with sudden increase in severity of low back pain along with shooting pain due to compression of the nerves leaving the vertebral column. This type of compression fracture may also present with shortening of height, forward bending and characteristic hump known as “Dowager’s hump”. Sometimes in severe cases nerve compression may occur leading to shooting pain, weakness in the lower limbs.
- Decreasing height.
- Loss of body weight.
Causes of Weak Bones
All the bones of the human body are constantly undergoing alternate phases of bone formation and resorption together known as remodeling. Bone consists of mineralized and non-mineralized components. Calcium is the main component of the mineralized part responsible for compressive strength whereas non-mineralized collagenous part imparts tensile strength to the bone.
There two types of cells in the bone known as osteoblasts and osteoclasts are responsible for remodeling. Osteoblasts are responsible for bone formation and osteoclasts are responsible for bone resorption. The function of theses two cells are intricately dependent upon each other. Osteoblasts require months to form bone whereas osteoclasts require weeks for bone resorption.
Any imbalance in the activity of osteoblasts and osteoclasts will lead to osteoporosis. During periods of rapid remodeling, like in the postmenopausal phase, the chance of fractures is high as bone is poorly mineralized. In the early years of life bone mineral density (BMD) is highest and with aging it decreases thereby making people susceptible to osteoporosis and bone fracture.
- Females especially postmenopausal women.
- Older age groups, both men and women.
- Family history of osteoporosis.
- Lack of exercise or a sedentary lifestyle.
- Cigarette smoking and alcoholism.
- Intake of certain drugs like steroids, anticonvulsants and anticancer drugs (chemotherapy).
- Low calcium levels.
- Fall in estrogen level as is seen in postmenopausal women.
- Overactivity of the thyroid and parathyroid glands.
Treatment aims at restoring bone mass density and limiting or even stopping the loss of bone mass. The treatment options include :
- Dietary supplementation of calcium and vitamin D.
- Bisphosphonate like alendronate and risedronate.
- Selective estrogen receptor modulator like raloxifene.
- Adequate exercise especially weight bearing activities.