Osteoporosis

Osteoporosis is the most common systemic metabolic skeletal disease characterised by a loss of bone mass. It stems from a deterioration of the microarchitecture of the bone tissue over time resulting in fragility and increased risk of fracture (NHS, 2022).

Background 

Osteoporosis currently presents as a major public health condition. It can occur in any age group, gender, and race. However it is most common in the female, older Caucasian population. Amongst the population of people over 50 years of age, 1 in 3 women and 1 in 5 men will sustain an osteoporosis related fracture (Cooper et al, 2019). Throughout life, the size and density of the skeleton changes dramatically; the peak bone mass is achieved in both sexes by the mid-twenties. In men, there is a steady decline into the later years of life however in women there is a plateau phase and a sharp decline after menopause (Lu et al, 2016).  

Bone turnover 

To understand how a deterioration in the microarchitecture of bone tissues results in weak and fragile bones, understanding anatomy and physiology of bone turnover is necessary. Bone itself is formed of two types of

The most common presentation of osteoporosis is a fragility fracture (British Geriatrics Society, 2007). Someone who has experienced a minor trauma such as falling from standing height sustaining a fracture to their bones can be defined as having a fragility fracture. The most common sites of fracture are wrist, spine and hip although any bone can be affected. 

The risk factors can be broken down into modifiable and non-modifiable as well as common chronic conditions that are associated with osteoporosis (Pouresmaeili et al, 2018): 

Non-modifiable risk factors include:

• female 
• elderly 
• post-menopausal and early menopause 
• previous fragility fractures 
• family history 

Modifiable risk factors include: 

• underweight 
• poor nutrition 
• high alcohol intake 
• Smoking 
• medications such as:
  • androgen deprivation therapy- treatment for some prostate cancers 
  • aromatase inhibitors - treatment for breast cancer 
  • glucocorticoids - used in autoimmune disorders such as multiple sclerosis, rheumatoid arthritis, inflammatory bowel disease
  • selective serotonin reuptake inhibitors - used in depression.  
  • thiazolidinediones - used in diabetes 

Common chronic conditions that can lead to osteoporosis:

• Chronic kidney disease 
  • 4 times more likely to sustain a fragility fracture if the patient is on dialysis 
• Diabetes 
• Dementia 
• Chronic disease in childhood 
  • Many chronic conditions in childhood such as inflammatory bowel disease, juvenile idiopathic arthritis and malignancy can result in a low peak bone mass 

The first step in identifying patients with osteoporosis is identifying those at risk. According to the National Institute for Health and Care Excellence (NICE), fracture risk assessment should occur in : 

• All women aged > 65 years
• All men aged > 65 years
• Women < 65 years and men < 75 years with the presence of other risk factors including: 
  • previous fragility fracture 
  • recurrent falls 
  • systemic steroids 
  • low body mass index (18.5kg/m²) 
  • high alcohol intake 
  • smoking 
  • family history of hip fractures 
  • other risk factors for developing osteoarthritis as previously mentioned (Lorentzon & Cummings, 2015; NICE, 2017)

Fracture risk assessment is completed using one of two scoring systems. These estimate as a percentage the predicted risk of major osteoporotic fractures over a 10-year timeline. The use of either FRAX or QFracture are advised (NICE, 2017). When a score is generated, clinicians define high risk, intermediate risk and low risk groups. Depending on

Fragility fracture risk scores: 

• Those at high risk of fragility fracture  
  • Bone sparing drug treatments can be offered if osteoporosis is confirmed on DEXA scan
  • Modifiable risk factors should be addressed if T-score is >-2.5 with reassessment to take place usually within 2 years
• Those with intermediate risk of fragility fracture 
  • If the score is close to the treatment threshold and there is a chance that the score has been underestimated, then DEXA scan can be considered
  • Reassessment should be undertaken at regular intervals 
• Those with low risk of fragility fracture 
  • No drug treatments are advised in this group however reassessment is recommended within 5 years with lifestyle advice (NICE, 2021). 

Medications used in osteoporosis 

Bone-sparing medications called bisphosphonates (Alendronate and Risedronate) work by inhibiting osteoclastic resorption of bone. They are prescribed if there are no contraindications to (Maraka annd Kennel, 2015):  

• Postmenopausal women and men > 50 years who have a DEXA

Lifestyle advice 

• Exercise - 
  • Regular walks in the open air not only increases muscle strength but also increases exposure to UVB which increases natural Vitamin D production
  • Strength training such as weight resistance training has been shown to reduce bone loss and even help build new bone
• Diet - 
  • Increasing calcium intake in products such as dairy, green leafy vegetables, baked goods made with fortified flour 
• Smoking cessation 
• Alcohol consumption within recommended limits (Brecher et al, 2002; NICE, 2021).

References

Brecher LS, Pomerantz SC, Snyder BA et al. Osteoporosis prevention project: a model multidisciplinary educational intervention. J Am Osteopath Assoc. 2002;102(6):327-35.

British Geriatrics Society. Care of patients with fragility fracture (Blue Book). 2007. https://www.bgs.org.uk/resources/care-of-patients-with-fragility-fracture-blue-book (accessed 20 December 2022)

Cooper C, Ferrari F, Hughes DB et al. IOF Compendium of Osteoporosis. International Osteoporosis Foundation. 2019. https://www.osteoporosis.foundation/sites/iofbonehealth/files/2020-01/IOF-Compendium-of-Osteoporosis-web-V02.pdf (accessed 20 December 2022)

Lorentzon M, Cummings SR. Osteoporosis: the evolution of a diagnosis. J Intern Med. 2015;277(6):650-61. https://doi.org/10.1111/joim.12369

Lu J, Shin Y, Yen MS, Sun SS. Peak bone mass and patterns of change in total bone mineral density and bone mineral contents from childhood into young adulthood. J Clin Densitom. 2016;19(2):180-91. https://doi.org/10.1016/j.jocd.2014.08.001

Maraka S, Kennel KA. Bisphosphonates for the prevention and treatment of osteoporosis. BMJ. 2015; 351:h3783. https://doi.org/10.1136/BMJ.H3783

National Institute for Health and Care Excellence. Osteoporosis - prevention of fragility fractures: How common is it. 2021. https://cks.nice.org.uk/topics/osteoporosis-prevention-of-fragility-fractures/background-information/prevalence/ (accessed 20 December 2022)

National Institute