There is a biological inevitability about loss of bone mass as we age. However, there are lifestyle choices women can make to slow that loss and reduce the risk of fractures, writes Steve Titmarsh…

The World Health Organization’s definition of osteoporosis describes the condition as ‘a disease characterised by low bone mass and microarchitectural deterioration of bone tissue, leading to enhanced bone fragility and a consequent increase in fracture risk’.¹

An individual is said to have osteoporosis if they have a bone mineral density (BMD) T-score of ≤-2.5. Bone mineral density is not the only risk factor for fractures though. Indeed, most people who have a fragility fracture have a femoral neck BMD T-score greater than -2.5.

Around half of adult women and a fifth of adult men will have a fragility fracture in their lifetime, typically of the wrist, hip or spine. A fragility fracture is one sustained from a fall from standing height or less (vertebral fractures can happen spontaneously).²

Hospital treatment is needed in almost all cases of hip fracture: it is fatal in 1 in 5 cases and half of those who fracture their hip are permanently disabled, with only 1 in 3 making a full recovery.³

Fragility fractures cost the NHS £5.4 billion in 2019 – 2.4 per cent of health care spending.²

Numark’s lead information pharmacist Naresh Rallmil says women approaching the menopause are at high risk of developing osteoporosis because of hormone changes that occur within the body during the menopause transition.

“The reduced oestrogen levels that take place cause a reduction in bone mineral density, making the bones weaker and more likely to be prone to osteoporosis,” Naresh says. 

“Osteoporosis is not easily identified, with many patients only noticing their symptoms once they have had a fall and fractured one of their bones. Earlier indicators of osteoporosis include a stooped posture and a reduction of height – a symptom which is caused by broken bones within the spine.

“To help prevent broken bones and a damaged spine, patients at risk of developing osteoporosis should be advised by their local community pharmacy teams to take preventative measures to maintain healthy bones. Pharmacy teams should advise patients to undertake regular exercise to keep bones as strong as possible, as well as eating a healthy balanced diet that features food rich in calcium and vitamin D.

“Taking a vitamin D supplement daily to maintain calcium levels, can also be a useful tool to combat osteoporosis.”

Pre-disposing factors

Bone is in a continual process of being formed by osteoblasts and resorbed by osteoclasts, with a balance between both processes. A fall in oestrogen levels after the menopause means that women lose bone more quickly than men, as oestrogen protects against bone loss.⁴

In most cases the cause of osteoporosis cannot be identified.⁶ Low vitamin D levels and ,insufficient calcium intake can lead to reduced BMD;⁶ and there are a number of risk factors including:²

• Low body mass index (<18.5kg/m²)⁵
• History of previous fracture
• Parental history of hip fracture
• Smoking
• Oral glucocorticoid therapy
• Alcohol intake of 3 or more units a day
• Diabetes type 1 and 2
• Drugs, including antidepressants, antiparkinsonian drugs, antipsychotic drugs, anxiolytic drugs, benzodiazepines, sedatives, H2 receptor antagonists and proton pump inhibitors. 

So-called secondary osteoporosis can be caused by:

• endocrine disorders (eg hypogonadism in men or women, including untreated premature menopause; hyperthyroidism; hyperparathyroidism; hyperprolactinaemia; Cushing's disease; and diabetes)
• gastrointestinal disorders (eg coeliac disease; inflammatory bowel disease; chronic liver disease; chronic pancreatitis; other causes of malabsorption)
• rheumatological disease (eg rheumatoid arthritis; other inflammatory arthropathies)
• haematological disorders (eg multiple myeloma; haemoglobinopathies; systemic mastocytosis)
• respiratory disease (eg cystic fibrosis; chronic obstructive pulmonary disease)
• metabolic disease (such as homocystinuria)
• chronic renal disease
• immobility (due, for example, to neurological injury or disease).³

How is risk assessed?

The risk of a fragility fracture can be assessed using tools such as FRAX (Fracture Risk Assessment tool) which calculates the 10-year probability of a fracture.⁷ QFracture is the second tool recommended by the National Institute for Health and Care Excellence (NICE) and again is an online calculator.^3,8

Bone mineral density of measured using a dual-energy X-ray absorptiometry, also known as a DEXA scan, of the femoral neck. Fracture risk approximately doubles for each standard deviation (SD) decrease in BMD.²

Osteoporosis occurs without symptoms until a person has a fracture. Pain is the main symptom of a fracture, although two-thirds of vertebral compression fractures are asymptomatic.⁶.

Treatment

People at low risk of fracture can be advised to exercise regularly, eat a balanced diet, not drink alcohol to excess and stop smoking if they do so.⁵

Postmenopausal women at high risk of fracture and a T-score of -2.5 or lower should be offered treatment with a bisphosphonate. Vitamin D and calcium supplementation may also be needed. Postmenopausal women aged 60 years or younger could be offered hormone replacement therapy to relieve menopausal symptoms and reduce the risk of fractures.^2,5

For those who cannot tolerate bisphosphonates or for whom they are contraindicated, specialist treatment with zoledronic acid, strontium ranelate, raloxifene, denosumab, and teriparatide is an option.²

National Osteoporosis Guideline Group recommends treating with bisphosphonates for five years initially, at which point fracture risk should be reassessed. Treatment should continue for at least 10 years in women:

• aged ≥70 years at the time the bisphosphonate is started
• with a previous history of a hip or vertebral fracture(s)
• treated with oral glucocorticoids ≥7.5mg prednisolone/day or equivalent
• who experience one or more fragility fractures during the first five years of treatment (if treatment is not changed).²

Before prescribing bisphosphonates people should be made aware of the side-effects, including rare but important side-effect such as atypical femoral fractures, which affect 3.2–50 cases/100,000 person-years of exposure, and osteonecrosis of the jaw, which has an incidence of 10–100/100,000 person-years of exposure.² 

Those at intermediate risk of fracture should be offered drug treatment if their T-score is -2.5 or lower.⁵ 

A Lancet meta analysis of vitamin D supplementation found it to be ineffective or to have no effect on total fracture, hip fracture or falls. The authors said: “Our findings suggest that vitamin D supplementation does not prevent fractures or falls, or have clinically meaningful effects on bone mineral density. There were no differences between the effects of higher and lower doses of vitamin D. There is little justification to use vitamin D supplements to maintain or improve musculoskeletal health.”⁹

Nevertheless, the Royal Osteoporosis Society recently launched updated practical clinical guidelines on vitamin D supplementation, commenting that the meta analysis does not change its advice.¹⁰

Practical advice

Practical advice on maintaining good bone health should include sticking to a healthy balanced diet. One that includes at least 700mg of calcium daily is a cornerstone of maintaining bone health.² Online calculators such as https://webapps.igmm.ed.ac.uk/world/research/rheumatological/calcium-calculator can help people work out if there is enough calcium in their diet.

People at risk of vitamin D deficiency (particularly those who are housebound or living in care homes) or who are already deficient, should be prescribed vitamin D supplements of at least 800IU/day. 

Stopping smoking and moderate alcohol consumption (≤2 units a day) are important, as is regular weight-bearing and muscle strengthening exercise.²

Further resources and information about bone health and other aspects of osteoporosis can be found on the Royal Osteoporosis Society’s website – https://theros.org.uk.

References

1. World Health Organization (WHO). Assessment of fracture risk and its application to screening for postmenopausal osteoporosis (https://apps.who.int/iris/bitstream/handle/10665/39142/WHO_TRS_843.pdf;jsessionid=206CF125861C022F5493085D034D7D2C?sequence=1; accessed 2 June 2022)
2. National Osteoporosis Guideline Group (NOGG). Clinical Guideline for the prevention and treatment of osteoporosis. London: NOGG, 2021.
3. Clinical Knowledge Summaries. Osteoporosis – prevention of fragility fractures (https://cks.nice.org.uk/topics/osteoporosis-prevention-of-fragility-fractures; accessed 3 June 2022).
4. Osteoporosis (https://patient.info/bones-joints-muscles/osteoporosis-leaflet; accessed 6 June 2022).
5. National Institute for Health and Care Excellence. Osteoporosis: assessing the risk of fragility fracture. Clinical guideline [CG146] (www.nice.org.uk/guidance/cg146/chapter/1-Guidance; accessed 2 June 2022).
6. MSD Manual. Osteoporosis (www.msdmanuals.com/en-gb/professional/musculoskeletal-and-connective-tissue-disorders/osteoporosis/osteoporosis; accessed 3 June 2022).
7. Clinical Knowledge Summaries. Osteoporosis – prevention of fragility fractures (https://cks.nice.org.uk/topics/osteoporosis-prevention-of-fragility-fractures; accessed 3 June 2022).
8. www.sheffield.ac.uk/FRAX
9. https://qfracture.org/index.php
10. Bolland M, Grey, A, Avenell A. Effects of vitamin D supplementation on musculoskeletal health: a systematic review, meta-analysis, and trial sequential analysis. Lancet Endocrinology 2018;6(11):847–58.
11. https://nos.org.uk/news/2018/october/05/new-study-does-not-change-current-advice-on-vitamin-d-supplementation-say-osteoporosis-experts