Osteoporosis is the commonest metabolic bone disease that affects humans. It particularly affects the elderly and is a cause for major morbidity, loss of independence and even death.
What is Osteoporosis?
Osteoporosis is a chronic progressive disease of multifactorial aetiology and is characterised by low bone mass and micro architectural deterioration of the bone tissue with increase in bone fragility usually becoming evident after a fracture. It is a serious health issue with devastating physical psychological and economic consequences.
How common is Osteoporosis?
Osteoporosis is quite common in the general community. 56% of the women and 18%of the men above the age of 50 Yrs have Osteoporosis.
How does osteoporosis happen?
The bones of the body are in a constant state of turnover. There is continuous bone resorption and build up. This process is referred to as remodelling. Osteoclasts that resorb bones are modified hematopoietic cells that can remove old bone within a matter of a few. Osteoblasts on the other hand are the cells that rebuild the bone and take a few months to produce new bone. Therefore weakening of the bone could happen quite quickly if the processes that increase Osteoclastic activity set in, as in the case of hormone withdrawal in menopausal women. Aging on the other hand causes osteoporosis by reducing Osteoblastic activity and bone building.
When does Osteoporosis happen?
Bone density reaches a peak around the 3rd decade of life after which it starts to reduce. Osteoporosis becomes evident usually after menopause in women and after the age of 50 in men. Osteoporosis begins much earlier, develops faster and is more severe in women.
Bone loss. Earlier and faster. Later and slower
Average bone loss at all sites. 3.4-4.8%. 0.2-3.6%
Fracture risk increased from age. 55 yr. 65 yrs
Mortality after fracture. 17-25%. 31-37%
What are the symptoms of Osteoporosis?
Osteoporosis is usually a silent disease and usually becomes evident only after a fracture. Pain the back or the hip after minor injury may signify the development of a fracture. 2/3rd of vertebral fractures are painless and they could occur aver very minor trauma. Loss of height or bending (stooped posture) in the elderly may be other symptoms of Osteoporosis.
When do you start screening for Osteoporosis?
It is recommended that screening is started above the age of 65 yrs for women or after menopause especially with risk factors. In men, it is recommended above the age of 70 yr or if aged between 50-65 yrs only if risk factors are present.
How is Osteoporosis diagnosed?
The gold standard test for the diagnosis of Osteoporosis is the DEXA scan (Dual Energy X-ray Absorbtiometry). The DEXA scan reports 2 scores. The T score compares the patients bone density to that of a normal person. The Z score compares the patients bone density to that of his peers (the Z score is usually used for Premenopausal women, men <50yrs of age and in children)
WHO classification of Osteoporosis by DEXA scan
0 and Above. Normal
-1to -2.5. Osteopenia
Less than -2.5. Osteoporosis
Less than -2.5 with fracture Severe Osteoporosis
For the Z score <2SD is below what is expected for age gender and ethnicity I.e., is abnormal.
What are the other useful tests that are required for Osteoporosis treatment?
The following tests are useful for the management of Osteoporosis:
Complete Blood counts
Liver function tests
Renal function tests and electrolytes
Thyroid function tests
25 hydroxy cholecalciferol assays
Serum Protein Electrophoresis
24 hr Urine calcium to creatinine ratio
Serum Testosterone and LH/FSH assays
What are the factor that accelerate Osteoporosis ? (risk factors)
There are many risk factors for osteoporosis. They can be broadly divided into the following categories. These risk factors would accelerate the development of Osteoporosis.
2. Calcium and Vit D deficiency and protein deficiency
3. Immobility and bed ridden state.
4. Hormonal – Estrogen deficiency (Late menarche, early menopause, surgical menopause)
Male hypogonadal state.
4. Substance abuse – Alcohol intake and smoking
5. Drugs – Anticonvulsants
6. Post surgery – bariatric surgery
7. Systemic diseases – Congestive Cardiac Failure
Cirrhosis of Liver
Connective tissue disease
How is osteoporosis managed?
The first step would be to interpret the DEXA scan.
The FRAX (WHO) score would have to calculated for those with Osteopenia. Treatment would be indicated if the 10yr probability of a Hip fracture was >/= 3% or the 10yr probability of any osteoporotic fracture was >/=20%.
All Patients would need to take in adequate Calcium and Vit D supplements and do adequate Muscle strengthening, weight bearing and antigravity exercises.
Patients with Osteoporosis or Osteopenia with a high FRAX score would need to be started on pharmacological therapies. While all medicines are approved for women, Bisphosphonates are preferred for men with Osteoporosis.
The American Association of Clinical Endocrinologists recommend the following choice of medicines:
1st line – Alendronate, Residronate, Zolendronic Acdid,(reduce both vertebral as well as non-vertebral fractures) and Denosumab (also for steroid induced osteoporosis)
2nd line- Ibandronate (has not been shown to reduce non-vertebral fractures)
3rd line – Raloxifene for women
4th line- Calcitonin
Others: Inj.Teriparetide is reserved for those with high risk for fracture who have failed Bisphosphonate therapy
To treat underlying Hyperparathyroidism and Hyperthyroidism.
Vertebroplasty and Kyphoplasty as indicated for severe pain from fracture vertebra.
How is Osteoporosis prevented?
Osteoporosis is inevitable with age. However it is believed that certain controllable factors could help in preventing or delaying the onset of osteoporosis. An active lifestyle with adequate outdoor exercise (especially in the Sun), doing antigravity resistance exercises, taking adequate calcium and Vitamin D, avoidance of sedentary lifestyle and Cigarette smoking and excessive alcohol use are all believed to prevent Osteoporosis. Early detection of bone demineralisation (Osteopenia) and initiation of pharmacologic treatment as well as lifestyle changes can prevent and delay the onset of Osteoporosis.