Osteoporosis is the commonest bone disease worldwide. As it is a silent disease, the first sign is usually a low trauma fracture, or loss of height. Osteoporosis usually does not cause pain unless the person has had a fracture, which in many cases could have been prevented.
The high morbidity, mortality and social costs of osteoporosis have been well-documented. Osteoporosis is usually a complication of many medical conditions or their treatment; including endocrine, gastrointestinal, neurological disorders and drug induced osteoporosis. Lifestyle choices, especially in childhood, can have detrimental affects on bone health. These occur in both men and women and children.
Research shows that the majority of people who fracture have moderate to marked osteopenia, which is the precursor to osteoporosis. Those at risk must be scanned as soon as possible and all patients with a low trauma fracture should have a DEXA (dual energy X-ray absorptiometry) scan.
It is now known that healthy bone requires a balance between RANK Ligand and osteoprogerin (OPG). Osteoporosis is the result of the negative balance between bone formation and bone resorption, i.e. more bone is lost than formed. Some 60 per cent of bone is laid down during an adolescent’s growth spurt and the rate of bone turnover is determined by hormonal and local factors. Bones require normal levels of sex hormones, adequate caloric intake, particularly protein, calcium and vitamin D and regular weight bearing exercise.
The most common cause of osteopenia or osteoporosis in females is oestrogen deficiency. Post menopausal women may have low bone mass and bone mineral density (BMD) due to low oestrogen levels. Those postmenopausal women who have a low body mass and/or a history of eating disorders are more at risk.
Multiple factors contribute to low bone mass and osteoporotic fractures.
Many medical conditions, or their medications, can increase the risk of osteoporotic fractures. All causes should be found and addressed.
A family history of osteoporosis is a very strong risk factor, as 60 per cent of a person’s bone is genetic, particularly if it includes a history of hip fracture/s. Senior citizens are more at risk, as they are more likely to have low oestrogen and testosterone levels, low vitamin D levels, poor nutrition, take less exercise and have other medical conditions or be on a medication that can increase bone loss.
The rate of hip fracture among residents of nursing homes is between three and 11 times that of age-matched community-dwellers.
Gluten intolerance is very common and is associated with low levels of vitamin D particularly if people avoid any sun exposure. A history of irritable bowel, bloating, constipation or loose stools associated with eating bread, pasta, drinking beer, wheat or gluten products or a family history of coeliac disease should be investigated.
If low levels of vitamin D persist for a period of time it may cause secondary hyperparathyroidism resulting in increased bone loss and prevents absorption of medication.
Compliance
Compliance is one of the main problems in treating patients with osteoporosis, particularly if they have not previously fractured. The results of the DEXA scan should be explained fully, and also the consequences of not taking medication as well as the importance of implementing lifestyle changes.
The various treatment options should be explained to the patient as well as the importance of taking the medication correctly. The individuals’ lifestyle should also be taken into consideration in order to best select an appropriate treatment.
In most cases the patient will not feel any different; this is why it is essential to explain to the patient, to help improve compliance. A person’s treatment should be based on the patient’s risk of fracture or re-fracture; medical history; age; and DEXA results of spine and hips.
Treatments
A range of medications are now available to treat or prevent osteopenia or osteoporosis.
A new approach to osteoporosis treatment has recently become available in Ireland. Acting on the RANK Ligand pathway, the monoclonal antibody, denosumab, is given via twice yearly subcutaneous injection.
While patients receiving this medication must have normal levels of vitamin D, it is particularly suitable for people who have absorption problems. It also negates many of the compliance issues associated with osteoporosis treatment.
Other options include:
• Bisphosphonates are given once weekly (alendronate or risedronate) or monthly (ibandronate) and must be taken with water generally 30 or 60 minutes before breakfast. The patient must stay upright, and caution must be exercised if the patient has oesophageal problems. IV infusions can be given once a year (zoledronic acid) or IV every three months (ibandronate).
• HRT is an option for people who have had an early menopause before 45, particularly if they are very thin or have menopausal symptoms or for menopausal symptoms and if they have no contraindications.
• Strontium ranelate has a dual action, both preventing bone loss and building bone. It is given as a daily sachet with water, usually at bedtime or during the night. No calcium containing food can be taken two hours either side.
Anabolic agents are PTH34 (teriparatide) or PTH84 (parathyroid hormone), which are given as daily subcutaneous injection for a maximum of two years, must take calcium and vitamin D and weight bearing exercise. Stop any other osteoporotic medication. Monitor by blood tests and DXA. To maintain the increase in BMD, in most cases patient needs to go on an osteoporotic medication at the end of the course of PTH.
The critical thing to remember is that osteoporosis can be diagnosed, prevented and treated.
Professor Emeritus Moira O’Brien,
Euromedic, Dundrum, Dublin 14
For copies of the Osteoporosis Guidelines please contact the Irish Osteoporosis Society on 1890 252 751 or log on to www.irishosteoporosis.ie
