Arthritis-India

An Old Lady

Osteoporosis

Osteoporosis is one of the costliest diseases of aging. Osteoporosis implies diminution of quality and mineral density of bone. Bones become fragile and susceptible to fractures on minor trauma. The problem of osteoporosis is underestimated and grossly neglected in India. It is estimated that 36 million Indians would be osteoporotic by year 2013. It appears that osteoporotic fractures occur10-20 year earlier in Indian population as compared to West. Most fragility fractures are managed by orthopedic surgeons. Unfortunately, many of them do not subject these patients to osteoporosis tests.

FeaturesOsteoporosis is rightly known as 'hidden enemy' in our body as it does not cause any symptoms (akin to many cases of blood pressure, diabetes and raised cholesterol). The problem is recognized only after a fracture following trivial trauma. A low trauma or stress fracture is defined as one that occurs after a fall from a height equivalent to height of the patient. Three common sites of osteoporotic fractures are - wrist, vertebra (spine) and thigh bone (femur). All fractures are costly and cause significant disability as well as loss of work days. Hip fractures are most dangerous as 15-20% of these cases die within one year due to one or the other causes and around 50% cannot walk without support. Vertebral fractures are usually painless but lead to spinal deformity (dowager's or widow's hump) and loss of height. They can cause pain that radiates to flanks. Each vertebral fracture reduces respiratory capacity by about 9%.

Types

Postmenopausal - This occurs in females within 15-20 years of menopause but may precede by 2-3 years. Lack of female hormones leads to loss of bone due to increased osteoclast action and subsequent calcium resorption.
Senile - This is due to age related decrease in osteoblastic activity and inability of the body to produce active Vitamin D.

Secondary osteoporosis is due to an identifiable cause.

Some of the causes are as follows:

Thyroid and parathyroid hyperfunction, Type 1 diabetes, Hypogonadism
Diseases causing chronic diarrhea
Inflammatory diseases: rheumatoid arthritis, ankylosing spondylitis, etc
Chronic kidney disease
Drugs such as glucocorticoids, anticoagulants, anticonvulsants and anticancer drugs
Others

Though rare, children can also develop primary as well as secondary osteoporosis.

Risk Factors
World Health Organization has derived an assessment tool based on various risks for a 10-year probability of fracture in patients of osteoporosis

These and other risk factors for development of osteoporosis are summarized below:

Personal risks	- Female sex - Low body weight/body mass index - Early menopause - Family history of osteoporosis/fracture - Surgical removal of uterus and/or ovaries
Lifestyle Risks	- Smoking (More than 20 cigarettes/day) - Alcohol (90 ml or more hard liquor/day) - Caffeine excess (More than 2 servings/day) - Lack of exposure to sunlight - Low Calcium and Vitamin D intake - * Physical Inactivity (Up to 5% bone loss/month)
Drugs and Diseases	- See Secondary Osteoporosis

* Prolonged bedrest in situations such as pregnancy, fractures, chronic diseases and others is deleterious to bone health.

Investigations
Standard X-ray is highly insensitive for diagnosis of osteoporosis as bone loss is apparent only after 30-50% decrease in bone mass. Measurement of bone density is an accepted method of diagnosis though it does not indicate the cause of osteoporosis. Ultrasound and Computed Tomography (CT) are not yet accepted to derive true bone density values. Dual Energy X-ray Absorptiometry (DEXA) is the only method endorsed by WHO at present. DEXA compares bone density of a patient with that of a standard individual. No Indian standards are available as yet. All women above 65 years age and those with risk factors need to be screened for bone mineral density (BMD) by DEXA. FRAX requires estimation of BMD at femoral neck only. Blood and urine examination for biochemical markers of bone turnover are not routinely used in clinical practice.

Treatment
Exercise and adequate proteins, calcium and vitamin D are essential. Smoking and alcohol consumption must be stopped. No therapy can fully restore lost bone mass. It is therefore necessary to achieve higher peak bone mass at 25-30 years of age. This needs regular exercise and proper nutrition (including adequate calcium and vitamin D) during childhood and young age.

One would not get a fracture if there is no trauma. Prevention of falls is an important aspect of osteoporosis therapy. This needs proper ground surface with adequate illumination, use of hand rails, correction of vision and proper treatment of medical diseases that cause giddiness and imbalance.
Bisphosphonates are the drugs commonly prescribed for treatment of osteoporosis. Oral bisphosphonates can be administered once a week or month. These tablets must be consumed on empty stomach with 200 ml of water. One should not lie down or bend forwards and avoid food for 30 minutes after ingestion of the tablet. Intravenous bisphosphonates are administered once in 3 or 12 months. Intravenous bisphosphonates as well as certain other drugs (raloxifene, teriparatide, and newly introduced denosumab) can be used in special circumstances on medical advice.