Sharon Abdy, BSc (Hons), RN.
Osteoporosis Sister, Musculoskeletal Unit, Freeman Hospital, High Heaton, Newcastle upon TyneOsteoporosis is characterised by low bone mass and micro-architectural deterioration of bone tissue, leading to bone fragility and an increased risk of fracture. The condition affects one in three adult women and one in 12 men. Each year in the UK alone there are approximately 200 000 osteoporotic fractures, which are a major cause of pain, disability and death. Estimates suggest that the annual cost to the NHS is approximately £948 million, although this is likely to rise in the future (Torgerson et al, 2001).
Osteoporosis is characterised by low bone mass and micro-architectural deterioration of bone tissue, leading to bone fragility and an increased risk of fracture. The condition affects one in three adult women and one in 12 men. Each year in the UK alone there are approximately 200 000 osteoporotic fractures, which are a major cause of pain, disability and death. Estimates suggest that the annual cost to the NHS is approximately £948 million, although this is likely to rise in the future (Torgerson et al, 2001).
The main risk factors include early menopause, premenopausal amenorrhoea (of more than six months), prolonged use of oral corticosteroids, a previous fragility fracture and a family history of maternal hip fracture. Lifestyle factors may also influence bone density, for example diet, exercise, tobacco and alcohol consumption.
Unfortunately, osteoporosis may be well-established before a diagnosis is made, as the condition is asymptomatic in the absence of fractures. By selective case finding, individuals with risk factors for osteoporosis and/or fractures should be considered for bone-density assessment.
A variety of bone-mass measurement techniques exist, including dual-energy X-ray absorptiometry (DXA) and quantitative ultrasound. DXA can measure either site-specific bone mass or the whole skeleton. Total hip bone mineral density measured by DXA is predictive of both cervical and trochanteric fractures, which collectively cause the highest morbidity, mortality and cost of all osteoporotic fractures (RCS/BTS, 2000). Serial bone density measurements may also be useful in monitoring the efficacy of osteoporosis treatments.
The objectives of management are to preserve bone mass, prevent fractures, minimise symptoms and improve function and quality of life. A range of interventions can decrease bone turnover and/or improve bone mass and are licensed to prevent and treat osteoporosis. The Royal College of Physicians (2000) provides an analysis of the following pharmacological interventions.
Bisphosphonates - These are powerful antiresorptive agents licensed for the management of postmenopausal and glucocorticoid-induced osteoporosis. There are currently three preparations available, namely cyclical etidronate, alendronate and risedronate. They increase bone density in women with osteoporosis and decrease vertebral and/or hip fracture risk. The optimal duration of bisphosphonate therapy remains uncertain. Mild gastrointestinal side-effects have been commonly reported.
Hormone replacement therapy - A number of oral and transdermal HRT preparations are available for the prevention of postmenopausal osteoporosis. Oestrogenic side-effects of HRT can include breast tenderness, nausea and leg cramps while the progestogen may cause depression, loss of libido, bloating and fluid retention (Abdy, 1998). There may be a slight increased risk of breast carcinoma (in long-term users) and venous thrombo-embolism (during the first year of treatment). Risks and benefits should be discussed in detail.
Tibolone - This is a synthetic preparation with oestrogenic, progestogenic and androgenic properties. It is licensed for the prevention of postmenopausal bone loss. Side-effects are similar to those of HRT.
Raloxifene - A selective oestrogen-receptor modulator indicated for postmenopausal women to prevent and treat osteoporosis. Raloxifene activates bone and lipid metabolism, increases bone density at the hip and spine and decreases the risk of vertebral fractures. There is no increased risk of breast and endometrial carcinoma. The main side-effect of treatment is hot flushes.
Calcium and vitamin D - Although it is reasonable to use calcium and vitamin D supplementation in frail elderly individuals, there is currently little information regarding its benefits in people who have already experienced fractures. Supplementation may be useful for those who cannot or will not increase their dietary calcium intake.
The National Service Framework for Older People (NSF) has set out eight new national standards aimed at improving health and social care for the UK's growing elderly population (Sims, 2001). Standard 6 addresses falls, and osteoporosis is incorporated within this standard. It outlines measures to reduce the impact of falls by preventing osteoporosis and treating those at high risk. Although no specific funding has been identified, this is an ideal opportunity for primary-care organisations to use selective case finding and improve the care of individuals with osteoporosis. It is anticipated that, by 2005, there will be multidisciplinary falls services set up country-wide, all of which should have access to bone mineral densitometry.
OSTEOPOROSIS PREVENTION: LIFESTYLE MEASURES
Preventive strategies aimed at reducing the incidence of osteoporotic fractures should include measures that target not only high-risk individuals but also the population as a whole. Lifestyle factors that can influence bone density, include:
- Diet. A well-balanced diet rich in calcium and vitamin D is essential throughout the various life stages to maintain a healthy skeleton, particularly during the pre-pubertal growth spurt. The UK Dietary Reference Values for daily calcium intake in mg/day are shown in Table 1. Studies have suggested that providing elderly people with calcium and vitamin supplementation may reduce their risk of hip fracture (Chapuy et al, 1992).
- Exercise. Regular physical activity can decrease the risk of falls and subsequent fractures, strengthen bone and muscle groups, improve balance and posture and reduce pain. As a preventive strategy for osteoporosis, exercise is important from childhood as this is a critical time for bone-mass accrual. In adults, weight-bearing exercises such as jogging, skipping and aerobic activity can have a positive effect on the skeleton. Gentle exercise can also benefit elderly people by improving balance and reducing the risk of falls (Campbell et al,1997).
- Tobacco and alcohol consumption. High-risk individuals should be advised to stop smoking. Premature menopause is a major risk factor for osteoporosis and women who smoke are more likely to enter the menopause one to two years earlier than non-smokers due to a decrease in circulating oestrogens. Excessive smoking is also thought to affect bone formation and resorption although the exact mechanics of this are uncertain. Drinking excessive amounts of alcohol can affect calcium absorption and lead to decreased vitamin D levels. It also increases the risk of fracture because of the risk of falls while drinking excessively.
- Hip protectors. External hip protectors are aimed at decreasing the impact of falls in elderly people. Wearing specially designed underwear incorporating padded polypropylene shells has been shown to significantly reduce hip fracture risk by over 50% in frail elderly people (Lauritzen et al, 1993). However, achieving long-term adherence may be difficult as hip protectors are bulky and may be uncomfortable to wear.
National Osteoporosis Society (NOS), Camerton, Bath BA2 0PJ. Tel: 01761-471771. Website: www.nos.org.uk
Osteoporosis Advisors' Network, Contact: Jackie Parrington, Nurse Manager, National Osteoporosis Society
Camerton, Bath BA2 0PJ. Tel: 01761-471771; or by email at: email@example.com
Women's Health Concern, PO Box 2126, Marlow, Bucks SL7 2NB. Tel: 01628-890199.
Abdy, S.E. (1998)A strategy to prevent osteoporosis. Practice Nurse 16: 614-619.
Campbell, A.J., Robertson, M.C., Gardner, M.M. et al. (1997)A general practice programme of home-based exercise to prevent falls in elderly women. British Medical Journal 315: 1065-1069.
Chapuy, M.C., Arlot, M.E., Duboeuf, F. et al. (1992)Vitamin D and calcium to prevent hip fractures in elderly women. New England Journal of Medicine 327: 1637-1642.
Department of Health. (1994)Dietary Reference Values for Food, Energy and Nutrients in the UK (COMA report). London: The Stationery Office.
Lauritzen, J.B., Petersen, M.M., Lund, B. (1993)Effect of external hip protectors on hip fractures. Lancet 41: 11-13.
Royal College of Physicians, Bone and Tooth Society. (2000)Osteoporosis Clinical Guidelines for Prevention and Treatment (information booklet). Sudbury, Suffolk: Lavenham Press.
Sims, J. (2001)An Essential Summary of the National Service Framework for Older People (information booklet produced in association with the NHS Alliance, the National Association of Primary Care, National Osteoporosis Society and the Long Term Medical Conditions Alliance). Available from External Affairs Department, Merck Sharp & Dohme, tel: 01992-467272.
Torgerson, D.J., Iglesias, C.P., Reid, D.M. (2001)The economics of fracture prevention (chapter 9). In: The Effective Management of Osteoporosis (UK Key Advances in Clinical Practice Series). London: Aesculapius Medical Press.