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Epidemiology of osteoporosis

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Osteoporosis represents a major public health problem through its association with fragility fractures. All osteoporotic fractures increase patient morbidity; however, fractures of the hip and vertebrae are also linked with significant mortality. The public health burden of osteoporotic fracture is likely to rise in future generations, due in part to an increase in life expectancy. Understanding the epidemiology of this disease is therefore essential in trying to develop strategies to help reduce this load. This chapter will review the epidemiology of osteoporosis, including the relationship between low bone mass and fracture. It will review the epidemiology of fractures, concentrating on the sites where the majority of age-related fractures occur. Finally it will discuss new developments in the assessment of fracture risk.

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Definition of osteoporosis

The definition of osteoporosis has been difficult. A definition based solely on bone mineral density (BMD) does not encompass all the risk factors for fracture, whereas a fracture-based definition will not enable identification of an at-risk population An expert panel convened by the World Health Organization (WHO)5 in 1994 tried to resolve this issue, resulting in the current most widely used definition that encompasses both BMD and previous fracture; osteoporosis is defined as BMD

Prevalence and incidence of osteoporosis

It has been estimated that 10 million Americans >50 years old have osteoporosis, and that a further 34 million are at risk of the disease.4 There are an estimated 1.5 million fragility fractures each year. While most American women under the age of 50 have normal BMD, 27% are osteopenic and 70% are osteoporotic at the hip, lumbar spine or forearm by the age of 80 years.4

Epidemiological studies from North America have estimated the remaining lifetime risk of common fragility fractures to be

Health impact of osteoporotic fracture

All osteoporotic fractures are associated with significant morbidity, but both hip and vertebral fractures are also associated with excess mortality. In the year 2000 there were an estimated 9 million new osteoporotic fractures, of which 1.6 million were at the hip, 1.7 million at the forearm and 1.4 million were clinical vertebral fractures.10

It has been estimated that there are around 740,000 deaths per year associated with hip fracture.11 Osteoporotic fractures account for 0.83% of the

Bone mineral density and fracture

There have been several prospective and cross-sectional epidemiological studies showing that there is an inverse relationship between bone mass and fracture. The risk of osteoporotic fracture increases continuously as BMD declines with a 1.5- to 3-fold increase in risk of fracture for each standard deviation fall in BMD.22 In the Rotterdam Study, a prospective population-based cohort study of 7806 men and women aged 55 years or older, the age-adjusted hazard ratio per standard deviation

Falls and fracture

It is worthy of note that only 1% of falls lead to a hip fracture. This is due mainly to the orientation of the fall, which has been found to be the most important predictor of hip fracture after a fall. Most hip fractures result from individuals falling sideways, failing to break their fall with an outstretched hand, and directly impacting on their greater trochanter.24

Fractures occur due to an interaction between bone fragility, largely determined by bone mass, and trauma (usually due to a

Fracture epidemiology

Fracture incidence in the community is bimodal, with a peak in the young and elderly. In young people, fractures are usually associated with substantial trauma, occur in the long bones, and are seen more frequently in males than females. In this group the question of bone strength rarely arises, although recent data suggest that this may not be entirely irrelevant as a risk factor.29 Osteoporotic fractures characteristically occur in those areas of the skeleton with high amounts of trabecular

Economic cost

In 1997, a conservative estimate of the worldwide direct and indirect annual costs of hip fracture was US $131.5 billion. More recently, the annual cost of all osteoporotic fractures has been estimated at $20 billion in the USA and $30 billion in the European Union. In the UK alone, the annual cost to the health-care system from osteoporotic fracture has been estimated at 1.7 billion pounds. Hip fractures account for over a third of the total figure, and reflect the cost of inpatient medical

Future projections

Osteoporotic fractures represent a significant public health burden which is set to rise in future generations. Life expectancy is increasing around the globe, and the number of elderly individuals is rising within every geographic region. The world population is expected to rise from the current 323 million individuals aged ≥65 years to 1555 million by the year 2050. These demographic changes alone can be expected to increase the number of hip fractures occurring among people aged ≥35 years

Assessment of fracture risk

Currently osteoporosis is defined in terms of BMD. The clinical development of pharmacological agents has focused on the selection of patients on the basis of low BMD for inclusion into trials of efficacy. Thus guidance on whom to treat has emphasized the assessment of BMD. Using T-scores has many benefits, as it is simple and widely used, has a good correlation with fracture risk, and can detect some high-risk patients.5 However, shortcomings include lack of standardization regarding which

Summary

Osteoporosis is a disease that has a huge effect on public health. The impact of osteoporotic fracture is far-reaching not only for the individuals themselves, but for the health service, economy, and population as a whole. Osteoporotic fractures are expected to rise in future generations. Recently several of the risk factors for this disease have been elucidated, and models are currently being developed to allow a more accurate assessment of fracture risk in patients to enable appropriate

References (69)

  • C. Cooper

    Epidemiology of osteoporosis

    Osteoporosis International

    (1999)
  • World Health Organization

    Assessment of fracture risk and its application to screening for postmenopausal osteoporosis. WHO technical report series

    (1994)
  • J.A. Kanis et al.

    Ten year probabilities of osteoporotic fractures according to BMD and diagnostic thresholds

    Osteoporosis International

    (2001)
  • D. Grady et al.

    Hormone therapy to prevent disease and prolong life in postmenopausal women

    Annals of Internal Medicine

    (1992)
  • C. Cooper et al.

    Epidemiology of childhood fractures in Britain: a study using the General Practice Research Database

    Journal of Bone and Mineral Research

    (2004)
  • O. Johnell et al.

    An estimate of the worldwide prevalence and disability associated with osteoporotic fractures

    Osteoporosis International

    (2006)
  • O. Johnell et al.

    An estimate of the worldwide prevalence, mortality and disability associated with hip fracture

    Osteoporosis International

    (2004)
  • C. Cooper et al.

    Population-based study of survival after osteoporotic fractures

    American Journal of Epidemiology

    (1993)
  • Office of Technology Assessment, Congress of the United States

    Hip fracture outcomes in people aged fifty and over: Mortality, Service Use, Expenditures, and Long-Term Functional Impairment

    (1993)
  • D.M. Kado et al.

    Vertebral fractures and mortality in older women: a prospective study

    Archives Internal Medicine

    (1999)
  • E.A. Crischilles et al.

    A model of lifetime osteoporosis impact

    Archives Internal Medicine

    (1991)
  • J.A. Kanis et al.

    The risk and burden of vertebral fractures in Sweden

    Osteoporosis International

    (2004)
  • C. Baudoin et al.

    Clinical outcomes and mortality after hip fracture: A 2-year follow-up study

    Bone

    (1996)
  • G. Poor et al.

    Predictors of hip fractures in elderly men

    Journal of Bone and Mineral Research

    (1995)
  • O. Johnell et al.

    Risk factors for hip fracture in European Women: The MEDOS Study

    Journal of Bone and Mineral Research

    (1995)
  • T.W. O'Neill et al.

    Back pain, disability, and radiographic vertebral fracture in European women: a prospective study

    Osteoporosis International

    (2004)
  • D. Marshall et al.

    meta-analysis of how well measures of bone mineral density predict occurence of osteoporotic fractures

    BMJ

    (1996)
  • S.C. Shuit et al.

    Fracture incidence and association with bone mineral density in elderly men and women: the Rotterdam study

    Bone

    (2004)
  • J. Parkkari et al.

    Majority of hip fractures occur as a result of a fall and impact on the greater trochanter of the femur: a prospective controlled hip fracture study with 206 consecutive patients

    Calcified Tissue International

    (1999)
  • S.J. Winner et al.

    Perimenopausal risk of falling and incidence of distal forearm fracture

    BMJ

    (1989)
  • R.G. Cumming

    Epidemiology of medication-related falls and fractures in the elderly

    Drugs Aging

    (1998)
  • P. Schwab et al.

    Nonpharmacological approaches to improve bone health and reduce osteoporosis

    Current Opinion in Rheumatology

    (2008)
  • A. Goulding et al.

    More broken bones: A 4year double cohort study of young girls with and without distal forearm fractures

    Journal of Bone and Mineral Research

    (2000)
  • C. Cooper et al.

    Hip fractures in the elderly: a world-wide projection

    Osteoporosis International

    (1992)
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