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Osteoporosis

Osteoporosis is a very serious disease with potentially devastating consequences for the genuine sufferer. But it might not be the bone breaking ailment many claim it to be. The information in patient brochures, advertising and the media can be misleading and tends to exaggerate the impact that osteoporosis can have on a post-menopausal women's lifestyle. It fails to mention that fragility fractures are rare in healthy women, that the majority of the postmenopausal women who do have vertebral compression 'fractures' are unaware of the fact and have no symptoms; and that most hip fractures occur only in the very elderly (in New Zealand the average age is 83 years) and are linked to many factors that can results in falls - such as poor eyesight, hazardous home environments, lack of alertness, medications including corticosteroids and tranquillisers, general frailty and immobility.
Twenty years ago most people had never heard of osteoporosis, and doctors reported that they saw few patients with the condition. Because of increasing elderly populations world-wide we are now warned of an epidemic and many postmenopausal women have been convinced that they need to take action to prevent the onset of the crippling disease.
New Zealanders are warned that 56 percent of postmenopausal women will fracture as a result of osteoporosis. But a careful examination of the evidence reveals that almost every aspect of osteoporosis is hotly debated and there are widely diverging statistics.
In 1994 osteoporosis was re-defined by the World Health Organisation as a measure of low bone mineral density. Previously defined as a condition of fragile bones following a low impact fracture, the new definition coincided with the availability of bone densitometry - technology that could measure the mineral content of bone.
Bone mineral content relates to the quantity not the quality of bone. It reveals nothing about the strength, micro-architecture, turnover, size or shape of bone - all factors which contribute to fragility. Many women with low bone density never have a fracture, while others with high bone density might have a fracture if they fell.
Extensive reviews of the evidence by Health Technology Assessment Agencies of the US, Canada, Sweden, Australia and the UK all conclude that bone density testing does not accurately identify individuals who will go on to fracture. An article in the British Medical Journal of October 6, 2001, concludes: 'The ability of bone densitometry to predict fracture is overstated, and the data on which claims are based are over-interpreted'.[i]
Despite this, low bone density is now commonly diagnosed as osteoporosis. Everybody loses bone density as they age, but because the current standard measures an older person's bone density against that of a healthy young woman aged 20-35, more than half the postmenopausal population of Western women can now find themselves diagnosed with the disease. Accordingly, treatments that can slow down normal age-related bone density loss are prescribed to vast numbers of 'at risk' women.

Risk Factors
Low bone density is just one of many osteoporosis risk factors. Other factors include: a history of low-trauma fracture after the age of 40; a family history of osteoporosis; smoking more than 20 cigarettes a day, a body weight of less than 60kg; Celiac disease, Crohn's disease;  eating disorders; hyperthyroidism; hyperparathyroidism, low blood levels of Vitamin D and calcium; and high urinary calcium loss.
Certain drugs are associated with bone loss and increased risk of fracture. The list is extensive and includes corticosteroids (prednisone etc), excess thyroid hormone, alcohol, medroxyprogesterone acetate (Depo Provera), luteinizing hormone-releasing hormone agonists, anti-seizure medications, cyclosporine A, aluminium, lithium, and exchange resins.

Current Treatment Options

Bisphosphonates

The bisphosphonate Fosamax (or Alendronate) is subsidised in New Zealand for individuals who have low bone density and have had previous low impact fracture indicating bone fragility. However, bisphosphonates remain a controversial treatment. Their mechanics are still not understood and the majority of people who take them do not stand to benefit.  Unlike most drugs, once taken they stay in the body.
Bisphosphonates do not offer significant fracture benefit.  Ninety high risk women with low bone density and a history of a previous vertebral fracture would have to be treated with Fosamax for three years in order to prevent a single hip fracture in one of them. The remaining 89 would receive no benefit[ii] Similarly, around 22 women with low bone density and previous vertebral fracture would need to be treated for three years in order to prevent one of them having a vertebral fracture identifiable by x-ray.[iii]
Side-effects include chronic and acute joint bone and muscle pain, sudden serious fractures of the femur, osteonecrosis (bone death) of the jaw, inflammatory eye disease, and cancer of the esophagus.
Other types of bisphosphonates are Etidronate, Risedronate, Pamidronate and Ibandronate

SERMS

SERMS (selective estrogen receptor modulators) such as Raloxifene (or Evista) can prevent bone loss and may reduce the incidence of vertebral fractures. They can increase menopausal symptoms of hot flushing by 50 percent and increase the risk for deep vein thrombosis and pulmonary embolism.

Calcitonin

Calcitonin has been used for the prevention of fractures and several studies provide evidence that it is a weak anti-resorptive agent with some anti-fracture efficacy. It also has a role in the management of severe pain due to vertebral crush fractures, apparently as a result of pain relief analgesic qualities which are separate from its effects on bone.[iv]

Parathyroid hormone

Parathyroid hormone (PTH) or Forteo, is a relatively new treatment that stimulates bone formation and appears to significantly reduce fractures. It is not currently approved for use in New Zealand. In the USA, Forteo comes with a 'black box' warning as animal studies showed an association with bone cancer. It is not yet known if humans treated with Forteo have a higher risk of bone cancer.

Calcitriol

Calcitriol is a derivative of vitamin D - necessary and important for the proper absorption and use of calcium in the body.  Calcitriol is used along with oral calcium to prevent bone loss. There is preliminary evidence that calcitriol treatment may reduce vertebral fractures.
Hormone Replacement Therapy

Although results from the Womens Health Initiative trial in 2002 showed that there were fewer fractures with HRT users, the increased risks for breast cancer, heart attack and stroke from HRT use mean that it is no longer recommended for the prevention of osteoporosis.

Recommendations:

  • Educate yourself about bone health. Understand that low bone density (osteopenia) or osteoporosis when diagnosed as bone density alone, is not sufficient reason to embark on a treatment regime. There are many other risk factors for osteoporosis such as previous fragility fracture, smoking, corticosteroid use and so on which need to be considered when a diagnosis is made. You can be tested for secondary causes of osteoporosis by your doctor.
  • Make sure your diet covers the diverse nutritional needs of bone including calcium, magnesium, vitamin K, boron, manganese, zinc, copper, silicon and others nutrients is ideal. Fresh vegetables, fruits, nuts and seeds are good sources of these foods. Limit heavy protein and salt intake, reduce alcohol, don't smoke, and for essential vitamin D, get sunlight on your skin at safe times of the day. Note: too much supplemental calcium may be harmful and there is inadequate evidence that dairy foods protect against fracture.
  • Exercise often! The force of muscles pulling against bone stimulates bone remodelling and formation. Higher impact activities like running, jumping and jogging are very effective, but regular aerobic exercise such as walking is also beneficial. Weight bearing exercises, resistance training, and flexibility and balancing exercises like Pilates, Tai Chi and yoga are also important. Research has demonstrated that we can benefit from exercise at any age - even centenarians will experience an increase in strength, stamina and muscle mass. Exercise programs have been found to reduce the frequency of falls in high risk older people.
  • Don't rush into taking drugs that may influence bone density but at present have little known benefit in terms of reducing fractures.

 

Gill Sanson, updated July 2009

www.gilliansanson.com

Further reading: The Myth of Osteoporosis by Gillian Sanson

(MCD Century Publications 2003)


[i] BMJ Vol 323 October 6 2001
[ii] Therapeutics Letter, issue 20, July - August 1997 http://www.interchg.ubc.ca/jauca/pages/letter20.htm#alendronate
[iii] Cummings SR, et al. Effect of Alendronate on risk of fracture in women with low bone density but without vertebral fractures. JAMA 1998;280 (24):1077-2082
[iv] Postmenopausal osteoporosis: optimum time to start therapy unclear. Drugs & Ther Perspect. 1997 10(7):8-12

Resources

  • Osteoporosis- from 'Feeling Fabulous at 40, 50 and Beyond' S.Coney 1996
  • WHIS factsheet - Osteoporosis - are you at risk? - now online

The Burden of Osteoporosis?

November 2007 Women's Health Update

A staggering 84,354 New Zealanders are predicted to break bones this year as a result of osteoporosis; that's one osteoporosis related fracture every six minutes and a hip fracture every two hours. By 2020 the annual osteoporosis-related fracture rates are predicted to exceed 115,000. So cautions the Fonterra funded 'Burden of Osteoporosis in New Zealand Report' commissioned by Osteoporosis New Zealand. Gill Sanson takes a look at the assumptions behind the report and suggests that we ought not be intimidated by the spectre of crumbling bones and debilitating fractures. A mountain of osteoporotic fractures is not likely should we choose not to heed the exhortations to drink more milk, scoff calcium supplements, have our bones scanned or swallow powerful drugs....Read More (pdf)

Cola weakens bone for women

December 2006 Women's Health Watch

The intake of cola, but not other carbonated soft drinks is associated with low bone mineral density in women but not in men. This study of 1125 men and 1413 women in the Framingham population based study measured BMD (bone mineral density) of participants and compared it with their semi-qualitative food-frequency questionnaires. After adjusting for confounding factors such as smoking status, caffeine consumption and physical activity the study found significant negative associations for women.
This study builds on earlier studies on cola consumption and adolescent girls with similar findings. It is hypothesised that the phosphoric acid in cola has a deleterious effect. Other studies supposed that cola consumption displaced milk consumption but this Framingham study finds otherwise. The major difference between cola and other carbonated beverages is phosphoric acid, caffeine and cola extract. After controlling for overall caffeine consumption this study still showed a negative association between cola and BMD. It is not clear why women would be more sensitive to the effects of cola than men. Women have smaller bones and are at higher risk for osteoporosis so they may be more affected by nutritional imbalance.

Reference
Tucker, K.L et al (2006) Colas but not other carbonated beverages, are associated with low bone mineral density in older women. American Journal of Clinical Nutrition 84:936-42.

Calcium supplements don't prevent hip fractures

June 2006 Women's Health Watch

The Women's Health Initiative (WHI), who ran the large US study that uncovered the risks of HRT has recently found that calcium and vitamin D supplements do not prevent broken bones or colorectal cancer and increase the incidence of kidney stones in middle-age and elderly women... Read More

More on Depo-Provera and Bone density

November 2005 Women's Health Update

A contribution from Dr Christine Roke, the National Medical Advisor from the Family Planning Association. The Family Planning Association has been aware of the link between Depo Provera and lowered bone density for more than a decade since some of our clients were involved in research on the issue at Auckland Medical School. Unfortunately not enough teenagers wished to participate in the observational study at the time so we were left with no clear answers for this age group. However the Auckland work and overseas studies indicated that bone loss plateaus after a few years on Depo Provera and that bone loss was reversible on stopping Depo Provera use. Read More (pdf)

Depo-provera, bone density & young women

July 2005 Women's Health Update

Back in November 2004 the FDA issued its strongest possible warning about the substantial loss of bone mineral density that research shows follows long term use (two or more years) of the drug. As a result of a new study published in September 2002 the drug manufacturer Pfizer wrote to health professionals advising that the contraceptive injection should be used for no longer than two years and only when other birth control methods are inadequate. Read More (pdf)

Fosamax - free for all?

July 2005 Women's Health Update

New Zealand appears to be the only country in the world exercising restraint in the prescribing of the osteoporosis prevention drug Fosamax - the new 'gold standard' treatment for the condition and one of a class of drugs called bisphosphonates. Pharmac's restrictions have reflected careful consideration of the evidence for the drugs effectiveness and safety, but things may be about to change. Merck Pharmaceutical's Medical Director indicated on National Radio recently that the restrictions on their drug are about to be lifted. Gillian Sanson reports....Read More (pdf)

Prolonged Depo-Provera use compromises bone density

October 2004 Women's Health Update

The USA Food & Drug Administration (FDA) has issued a 'Black Box'warning about long-term use of the long-acting, injectable contraceptive drug, Depo-Provera - stating recent research suggests prolonged use of the drug may result in the loss of bone density. The warning goes on to state that the loss of bone density is greater the longer the drug is administered, and it may not be completely reversible after discontinuation of the drug. Therefore women should only use Depo-Provera Contraceptive Injection as a long-term birth control method (ie longer than two years) if other birth control methods are inadequate... Read More

Exercise most effective at preventing falls

September 2002 Women's Health Watch

A Melbourne study of more than 1,000 older people living at home has found that a weekly exercise programme was the most effective of three interventions at preventing falls.
The research, by the Accident Research Centre at Monash University, compared group-based exercise with home hazard management and vision improvement in a randomised controlled trial of over 70-year-olds in good health.
The reduction in falls among participants assigned to the exercise intervention seemed to be associated with improved balance. Neither home hazard management nor treatment of poor vision significantly effected falls.
However, exercise combined with home hazard management and improved vision produced the strongest effect, an estimated 14% reduction in falls. Seven people needed to be treated with the three interventions combined to prevent one fall a year.
Ref: BMJ 2002; 325:128

Hip fractures lower than predicted

September 2002 Women's Health Watch

The number of hip fractures in New Zealand from 1988 to 1999 was fewer than predicted in a major 1990 study, but researchers do not understand the reasons.
In 1990 it was predicted that hip fractures would increase from 2,000 in 1987 to 4,000 in 2011. However, a Wellington School of Medicine team found that 1999 figures were 20% less than this prediction as the hip fracture rate between 1989 and 1998 dropped significantly for all women over 65.
The research group speculated that four factors could have contributed to this

  • Osteoporosis prevention measures such as diets rich in calcium and vitamin D, and increased weight bearing exercise
  • Strategies to prevent falls and fractures in older people, including risk assessments of their homes and installation of hand rails, lighting, arm rests and other measures
  • A higher use of HRT, bisphosphonates or selective oestrogen receptor agonists
  • Population changes, including a 2.4% increase in the 65+ age group and a 4.6% decrease in the 85+ age group on that predicted in 1990.

Ref: NZMJ 2001;114:154-56

Bone density screening raises questions

September 2000 Women's Health Watch

Doctors and the public should understand the limitations of the newer peripheral densitometry devices, used to help diagnose osteoporosis. These devices measure bone density at sites like the heel, whereas the major problems caused by osteoporosis are the hip and spine. An editorial in the British Medical Journal says the limitations of measuring bone density at peripheral sites mean there is the potential for misdiagnosis.
One of the main problems is that bone mineral density is not the same throughout the skeleton, raising the risk of misdiagnosis, especially in women under the age of 65 years. More than one site should be measured in younger women to avoid this risk of misclassification.
The article raises concerns about increasing use of the World Health Organisation definition of osteoporosis, which it says was arrived at for research purposes only. Increasingly the WHO definition has been used for the diagnosis of osteoporosis. It says while optimal methods for defining osteoporosis and predicting fracture risks are debated, it is imperative users understand the limitations of the techniques. Portable peripheral densitometry devices should be used in conjunction with other risk factors such as previous fractures and falls.
Ref: BMJ 2000; 321: 396-98

RALOXIFENE (a.k.a. Evista) What we know - and don't know

June 2000 Women's Health Watch

New hormonal drugs called SERMs or Selective Estrogen Receptor Modulators are being hailed as the latest women's health wonder drugs for mid-life women. Unlike hormone replacement therapy, it's claimed they'll prevent osteoporosis without stimulating oestrogen dependent cancers. This article by Sari Tudiver, PHD, and Janine O'Leary Cobb, MSc, examines the evidence. It was first printed in the US journal A Friend Indeed ... Read More

Osteoporosis - the good news

January 2000 Women's Health Watch

Ian Reid, Professor of Medicine at the University of Auckland, gives an update on this common bone condition.

Osteoporosis is a major health issue for New Zealand's ageing population. The number of hip fractures in New Zealand women increased from 300 to about 2,500 per annum in the last 50 years. According to a large study recently carried out in Australia at least 56% of postmenopausal women and 29% of men now have a fracture of some sort... Read More

Hormones and hip fracture: benefits only for current users

June 1998 Women's Health Watch

A recent Swedish case-control study showed that women currently using hormone replacement therapy reduced their risk of hip fracture, but that within five years of ceasing therapy, women had lost most of the benefit... Read More

How good are bone scans at predicting fractures?

January 1997 Women's Health Watch

Bone density measurements have been promoted as a way of identifying individuals at high risk of fracture and taking preventive measures.

Swedish researchers conducted a meta-analysis of cohort studies published between 1985 and 1994 which took a baseline measurement of bone density then followed up the women for subsequent fractures. Eleven studies covering 90,000 person years of observation with over 2000 fractures were covered.

The researchers found that bone density measurements can predict risk of fracture but cannot identify individual people who will have a fracture. They compared the use of BMD measurements to predict fractures with the use of blood pressure to predict stroke and serum cholesterol concentration to predict coronary heart disease.

The authors concluded that they could not recommend a bone screening programme. There was wide overlap in the bone densities of people who had a fracture and those who did not. They also noted that there is little information about whether people would comply would comply with a bone screening programme, or comply with a bone screening programme, or comply with treatment, and little information about the effectiveness of treatments, particularly any that show a reduction in fractures.
Ref: BMJ 1996; 312: 1254-59

Resources

Osteoporosis- from 'Feeling Fabulous at 40, 50 and Beyond' S.Coney 1996 Read Here

WHIS factsheet - Osteoporosis - are you at risk? - Read here

 

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