4 June 2001
Siblings of osteoporosis sufferers have a high risk of developing the debilitating bone disease themselves, new research has found.
Brothers and sisters of patients with osteoporosis are six times more likely to suffer from low bone density than the general population, says leading medical research charity Action Research.
Lead researcher, Dr Emma Duncan says: ‘This is the first time the sibling connection has been calculated, and has important implications for the screening of relatives.’
The team of researchers, based at Oxford’s Radcliffe Infirmary and Nuffield Orthopaedic Centre, has also shed new light on likely causes of the common and costly illness - which coincidentally is currently the focus of National Osteoporosis Month.
In the largest candidate gene study to-date of the many genes likely to determine the disorder, the project has narrowed down several key culprits. The Action Researchers have also discovered osteoporosis is likely to manifest itself differently in males and in females.
Osteoporosis affects about one in three women and one in 12 men, and costs the NHS an estimated £900m each year. The condition causes bones to become weak and brittle, and many sufferers are only aware of the problem after they have experienced a fracture of the wrist, hip or spine.
Dr Duncan, who, during the project was a Research Fellow in the Department of Endocrinology and Metabolism, at Oxford’s Nuffield Orthopaedic Centre, says: ‘Hip fractures are the most serious clinical outcome of osteoporosis because they account for most of the mortality, morbidity and costs of the disease.’
In fact, hip fracture rates are expected to quadruple worldwide from an estimated 1.66 million hip fractures in 1990 to 6.26 million by 2050, she adds.
Dr Duncan, now a Specialist Registrar with the Oxford Radcliffe NHS Trust, undertook her detective work in conjunction with Professor John Wass and Professor Andrew Carr, both of the Nuffield Orthopaedic Centre.
The team aimed to assess the genes that determine bone mineral density -and thus osteoporosis - in both men and women.
They screened and extracted DNA samples from several generations of more than 170 families from Oxfordshire, and 28 genes assessed for their role. Eight genes overall showed evidence of linkage to bone density, with the strongest connection with the receptor for Parathyroid Hormone (PTHR1).
This important hormone plays a crucial role in calcium balance, along with Vitamin D, and affects bones and kidneys in particular.
Although it’s already been suggested that osteoporosis is a disease with substantial genetic contribution, most genetic studies have looked at women only, or included very few men.
Dr Duncan’s team - which studied 45 male and 102 female sufferers and their relatives - found that although there are some common genes determining bone mineral density (BMD) at the hip and spine, the ways in which individuals inherit these may differ. Furthermore, there may be genes with unique effects in both males and females, she adds.
Dr Duncan, who says further research now needs to be done, says: ‘We’ve been really pleased with the results, especially as it’s the first time PTHR1 has been examined with respect to osteoporosis.
‘The findings emphasise the need for screening and early preventative measures for both men and women, for example ensuring adequate calcium intake (particularly for adolescent girls) and weight-bearing exercise. It’s also important in terms of helping prevent fractures in sufferers.’
Osteoporosis sufferer and champion British cyclist, Chris Boardman, welcomes the study. The father-of-four, who was diagnosed with the brittle bone disease in 1998, says: ‘My own case illustrates that although osteoporosis is widely considered a female condition, it’s a growing problem among men.
‘Action Research is playing a crucial role in the battle against the condition, and this latest study could have important implications for the screening of family members.’
Action Research, which is fast approaching its 50th anniversary, has awarded 21 grants specifically looking at osteoporosis over the last nine years - a commitment of more than £1 million.
The charity has funded this latest project as part of its overall commitment to overcoming disease and disability, and its Touching Lives Campaign aims to raise £2m for vital medical research. Visit the website at www.action.org.uk
For further media information, please contact Nicole Duckworth in the Action Research press office on 01403 327403 Fax: 01403 210541, or email firstname.lastname@example.org
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*Families were identified through the osteoporosis clinics at the Nuffield Orthopaedic Centre, and a volunteer study of women in Oxfordshire that was currently taking place at the Radcliffe Infirmary.
*Cutting down on smoking and alcohol, boosting calcium levels, and weight bearing exercise will help improve bone density and prevent fractures.
*Women should also consider Hormone Replacement Therapy (HRT) at the time of menopause, as low oestrogen levels contribute to low BMD.
*National Osteoporosis Month takes place throughout June and has been organised by the National Osteoporosis Society.
Notes for Editors: The national medical research charity, Action Research, is dedicated to preventing and treating disease and disability by funding vital medical research.
Founded in 1952 by Duncan Guthrie, Action Research is one of the UK’s leading medical research charities. We support research into a wide range of conditions, benefiting all age groups. We are currently funding over 160 projects throughout the UK; a total commitment in excess of £14 million.
As a charity which has been at the forefront of medical research for nearly 50 years, our support has been crucial in the development of life-saving polio and rubella vaccines, the artificial hip operation, the use of ultrasound scans in pregnancy and the use of folic acid to prevent spina bifida.
Current grants include support for research into meningitis, back pain, osteoporosis, pregnancy complications, incontinence and epilepsy.