Osteopenia and osteoporosis in cystic fibrosis
Osteopenia and osteoporosis are terms that mean bones are ‘thinner’ than they should be. A more scientific description is that the skeleton has a low bone mass, which means that the bones are more fragile and more likely to fracture.
Low bone mineral density (BMD)
BMD is a measure of bone mineralisation – the level of minerals contained in bone. The measurements are an indicator of the bone mass and therefore how strong the bones are.
How does cystic fibrosis cause low BMD?
CF-related low BMD can have many causes. These include:
- Severe of lung disease and low body weight
- Less effective uptake of vitamins, minerals and protein
- Steroid use
A lack of exercise
- Late onset of puberty
- The abnormal protein caused by the CF gene
People with CF are prone to developing bone disease (thin, brittle bones) due to nutrients in the diet being lost through stools because of the damaged pancreas, and other complaints related to the condition. For example, the side effects of steroids taken to control lung disease can cause bone disease. Thinning bones are a well-documented consequence of CF, with reduced bone mineral content found in people of all ages.
Low BMD is often found with increasing severity of the condition. Left untreated, low BMD can lead to osteoporosis. As a result of this, all adults require regular scans to monitor BMD.
Find out more about the causes of low BMD by downloading our factsheet.
What is a BMD measurement?
BMD measurements are scored according to how much they fall below or above the population average value. BMD results can be reported as Z- or T-scores; Z-scores are usually the most appropriate method in people with cystic fibrosis.
Find out more about ‘Z’ and ‘T’ scores by downloading our factsheet.
How can low BMD by prevented and treated?
People with CF should be screened for low BMD with regular scans and X-rays, but there are other ways that the complication can be prevented or treated. These include:
- Treating risk factors like low vitamin D or calcium levels
- Preventing the progression of lung disease
- Optimising nutrition through dietary intervention
- Increasing weight-bearing physical activity
- Developing an exercise programme
- Keeping glucocorticoid treatments to a minimum (only if this is recommended by your CF team)
- Treating and monitoring delayed puberty
- Preparing for female contraception with long-acting ‘depot’ and possibly other progesterone-only contraception preparations – this may reduce BMD, particularly in adolescents (although alternative contraceptive preparations may be suggested)
- Avoiding smoking and alcohol
Find out more about treatments for low BMD, including specific drug treatments, by downloading our factsheet.
Joint pain and arthritis in cystic fibrosis
Five-to-ten percent of people with cystic fibrosis will develop joint pain or joint disease (arthropathy) such as arthritis, with the risk increasing with age. The most common form of joint pain in CF is an arthritis that affects large joints, such as the knees, ankles, wrists, elbows and shoulders.
Arthritis in CF tends to come and go, with no symptoms between attacks. Joint pain can flare up during infections and periods of ill health.
Find out more about our joint pain Strategic Research Centre.