osteoporosis

osteoporosis
Name	Osteoporosis
Caption	Comparison of healthy and osteoporotic bone microarchitecture.
Field	Endocrinology, Rheumatology
Symptoms	Increased risk of fractures, often asymptomatic until fracture occurs
Complications	Hip fracture, Vertebral fracture, Chronic pain
Onset	Typically older adults
Duration	Chronic
Risks	Menopause, Corticosteroid use, Hyperthyroidism, Rheumatoid arthritis
Diagnosis	Dual-energy X-ray absorptiometry
Prevention	Calcium intake, Vitamin D, weight-bearing exercise
Treatment	Bisphosphonates, Denosumab, Teriparatide
Frequency	Common, especially in postmenopausal women
Deaths	Increased mortality post-fracture

osteoporosis. Osteoporosis is a systemic skeletal disorder characterized by compromised bone strength, predisposing individuals to an increased risk of fracture. It is often called a "silent disease" because bone loss occurs without symptoms until a fracture happens. The condition involves both a reduction in bone mineral density and deterioration of the microarchitecture of bone tissue.

Overview

The fundamental pathology involves an imbalance between bone resorption by osteoclasts and bone formation by osteoblasts, leading to a net loss of bone mass. This process weakens the structural integrity of the skeleton, making bones fragile. The World Health Organization defines osteoporosis operationally based on measurements from Dual-energy X-ray absorptiometry. The most common sites for osteoporotic fractures are the vertebrae, hip, and distal radius, with hip fractures carrying significant morbidity and mortality. The National Osteoporosis Foundation and the International Osteoporosis Foundation are key organizations dedicated to awareness and research.

Causes and risk factors

Primary osteoporosis is most frequently related to menopause and aging, while secondary osteoporosis results from specific medical conditions or medications. Key non-modifiable risk factors include advanced age, female sex, Caucasian or Asian ancestry, and a family history of fracture. Modifiable risks encompass low body mass index, smoking, excessive alcohol consumption, and physical inactivity. Endocrine disorders such as hyperparathyroidism, Cushing's syndrome, and diabetes mellitus can contribute, as can gastrointestinal diseases like celiac disease and inflammatory bowel disease. Long-term use of glucocorticoids, certain anticonvulsants, and aromatase inhibitors is strongly associated with bone loss. Nutritional deficiencies in calcium and vitamin D are also major contributors.

Diagnosis

Clinical diagnosis typically relies on Dual-energy X-ray absorptiometry scanning of the hip and lumbar spine, with results reported as a T-score compared to young adult reference data from the NHANES study. According to WHO criteria, a T-score of -2.5 or below defines osteoporosis. Other imaging tools include quantitative computed tomography and peripheral DXA. Laboratory tests, such as measurements of serum calcium, 25-hydroxyvitamin D, and thyroid-stimulating hormone, help identify secondary causes. Biochemical markers of bone turnover, like serum C-telopeptide and bone-specific alkaline phosphatase, can assess the rate of bone loss but are not used for definitive diagnosis. The FRAX tool, developed by the University of Sheffield, calculates a patient's 10-year probability of major osteoporotic fracture.

Prevention and management

Lifestyle interventions form the cornerstone of prevention. Adequate intake of calcium, primarily from dietary sources like dairy products, and sufficient vitamin D, from sunlight exposure or supplementation, are essential. Regular weight-bearing exercises, such as walking or strength training, and balance training to prevent falls are strongly recommended. Avoidance of tobacco and limitation of alcohol are important. Public health initiatives by organizations like the Centers for Disease Control and Prevention promote fall prevention strategies in the elderly, including home safety assessments. For individuals at high risk, early assessment with Dual-energy X-ray absorptiometry is advised.

Treatment

First-line pharmacological therapy usually consists of oral bisphosphonates such as alendronate or risedronate. Intravenous options include zoledronic acid. For patients intolerant of bisphosphonates or at very high risk, denosumab, a monoclonal antibody targeting RANK ligand, is an effective alternative. Teriparatide, a recombinant form of parathyroid hormone, is an anabolic agent used for severe cases. Newer agents include romosozumab, which inhibits sclerostin. Hormone replacement therapy is sometimes considered for postmenopausal women, balancing benefits with risks like breast cancer. All drug therapies should be coupled with adequate calcium and vitamin D supplementation. Treatment decisions are often guided by guidelines from the American Association of Clinical Endocrinologists.

Epidemiology

Osteoporosis is a major global public health problem, affecting hundreds of millions of people worldwide. It is most prevalent among postmenopausal women, with estimates suggesting that over one-third of women over 50 will experience an osteoporotic fracture. In the United States, the condition causes more than 2 million fractures annually, with direct medical costs estimated in the tens of billions of dollars. The incidence is rising in many regions due to aging populations, particularly in Europe and Asia. Significant geographic and ethnic variations exist; for instance, rates of hip fracture are highest in Scandinavia and lowest in Africa. The economic and social burden is substantial, often leading to loss of independence, chronic pain, and increased mortality, particularly following a hip fracture.

Category:Musculoskeletal disorders Category:Geriatrics Category:Women's health