Osteoporosis

Osteoporosis is a systemic skeletal disease characterized by low bone density and resorption of bone tissue resulting in increased bone fragility. Osteoporosis can seriously affect the quality of life, including physical, social, and economic aspects. If left untreated, it can cause serious bone fractures that can be critical in old age. The risk of fractures is higher in elderly individuals with poor walking balance and vision.

WHO uses bone mineral density measurement (BMD) to define osteoporosis, according to which a T-score of less than or equal to -2.5 is considered osteoporosis.

Following are the causes of osteoporosis:

• Estrogen deficiency in post-menopausal women causes increased bone resorption and inadequate bone formation resulting in osteoporosis.
• Aging – with increasing age, bone resorption activity increases considerably, resulting in changes that can cause osteoporosis.
• Calcium deficiency – decreased calcium, vitamin D, and parathyroid hormone levels can cause bone resorption.
• Drugs such as glucocorticoids, chemotherapeutic drugs, hormonal therapies, antidepressants, and antivirals.
• Certain genetic conditions such as cystic fibrosis.
• Endocrine disorders include diabetes mellitus, Cushing syndrome, etc.
• Malabsorption due to vitamin-mineral deficiency, eating disorders, alcoholism, and chronic diseases.

There are two types of osteoporosis, primary and secondary:

• Primary – Osteoporosis is divided into juvenile and idiopathic types, including post-menopausal osteoporosis and age-associated or senile osteoporosis.
• Secondary – Osteoporosis occurs due to an underlying illness, vitamin and mineral deficiencies, and intake of certain drugs.

Osteoporosis can occur in all races and ethnicities; however, whites and Asians are at an increased risk. According to WHO, more than fifty percent of all hip fractures occur in Asia. Osteoporosis has a female to the male ratio of 4:1. Women of advanced age are more prone to non-traumatic hip fractures than men.
Following are the risk factors for osteoporosis:

• Advanced age
• Female gender
• Genetic factors with family history
• Early menopause
• Physical inactivity
• Calcium and vitamin D deficiency
• Smoking
• Drugs

Clinical features do not appear unless the disease progresses to cause fractures, and even these fractures could be painless such as the vertebral fractures in which the only findings are stooped posture and height loss. Common signs and symptoms after a bone fracture include:

• Acute localized pain (restricted to the involved area)
• Muscle spasms that increase with activity
• Chronic pain
• Decreased range of motion at joints, particularly at hip joints
• Involvement thoracic vertebrae can cause kyphosis, also known as hump
• Tenderness on palpation over the joints
• Gait abnormalities
• Balance difficulties

Complications of osteoporosis include:

• Vertebral compression fractures with slight activity such as lifting or bending.
• Complicated hip fractures with pulmonary thromboembolism, sepsis, and death.
• Chronic pain
• Deep vein thrombosis (DVT)
• Pressure ulcers

Laboratory investigations include the following:

• Complete blood count which may reveal anemia
• Serum chemistry levels
• Liver function test
• Thyroid-stimulating hormone levels (TSH)
• Vitamin D3 levels
• Serum protein electrophoresis for diseases like multiple myeloma that can cause osteoporosis
• Urine analysis for calcium and creatinine
• Testosterone levels in males as hypogonadism can cause osteoporosis
• Bone mineral density in women aged 65 years or older and men aged 70 years or older
• Bone scans using technetium 99 can detect hairline fractures missed on plain radiographs.
• Bone biopsy – typically, the hip bone is selected for biopsy to see cell changes associated with osteoporosis. The procedure is done under anesthesia.
• Imaging – plain radiographs/x-rays of bones that can show bone changes or otherwise painless fractures associated with osteoporosis

Differential diagnoses for osteoporosis include:

• Leukemia
• Lymphoma
• Fractures due to bone metastases from cancer
• Multiple Myeloma
• Scurvy
• Sickle Cell Disease
• Paget Disease
• Osteodystrophy

Pharmacologic intervention is recommended in all women with diagnosed osteoporosis who are at an increased risk of fractures and post-menopausal women. The drugs of choice in these groups are bisphosphonates and hormone therapies. Hormone therapies with estrogen and progesterone are done in postmenopausal women to replace these hormones as their loss is associated with increased resorption of bones.

Nonpharmacologic interventions are of prime importance to prevent fractures and other complications associated with osteoporosis. These include lifestyle modifications such as resistance training, exercise, weight loss, and dietary changes to improve vitamin D, calcium, and protein intake, promoting mineral deposition in bones and preventing resorption.

Surgical intervention is done in vertebral fractures, including vertebroplasty and kyphoplasty and hip replacement surgeries for hip fractures.
Pain management uses oral analgesics, calcitonin, hot packs, electrical nerve stimulation, narcotic analgesics for severe pain.

• For post-menopausal women, bisphosphonates are the first line of treatment.
• Hormone replacement therapies.
• Pain management with NSAIDs and other pain killers depending upon the severity of pain. These include diclofenac sodium and narcotics such as morphine for extremely painful cases.
• Combination therapy with vitamin D and calcium supplementation.

If diagnosed early with proper intervention and compliance with the treatment, the prognosis is usually good. Fractures due to osteoporosis are associated with considerable morbidity and can affect the quality of life. With increasing age (more than 90 years), osteoporosis-related fractures are associated with increased mortality.