Cystic Fibrosis: The Importance of Bone Health
Anyone living with cystic fibrosis knows that the lungs, GI tract, pancreas, and other organs are damaged by the caustic mucus it produces.
However, some might be unaware that the absorption of food nutrients, including calcium, is severely hampered by the disease’s damage to the small intestines. The small intestines become unable to pass nutrients, vitamins, and minerals through their walls and into the bloodstream. This can create a life-threatening condition referred to as malabsorption syndrome. Malabsorption leads to weight loss and/or difficulty in regaining or maintaining a healthy weight. Malabsorption can readily cause malnutrition, which causes bone-thinning.
Although people with CF need to take oral enzyme replacements with each meal, malabsorption is still compromised for certain vitamins and minerals. Among these are calcium, which is needed to build strong bone mass, and vitamin D. For the calcium to be used by the body, it needs vitamin D to stimulate the action. This becomes an issue for those with CF.
Vitamin D deficiency is common in CF
We learn from the International Journal of Endocrinology that: “Hypovitaminosis D (a low Vitamin D blood level) is almost universal in CF patients, likely due to a combination of inadequate absorption, impaired metabolism, and lack of sun exposure”.
You may already be aware of this good news: Nutrition and exercise are keys for those with CF to control their bone health (CFF). Oh, and a little sunshine each day to help the body create its own supply of Vitamin D. We will learn further in this article about the specifics of these approaches for bone health.
Did you know that due to the malabsorption issues, those with CF have a high incidence of osteopenia (the forerunner to osteoporosis) and osteoporosis itself? These conditions refer to bones that are thin, brittle and prone to fracture. With osteoporosis, there is an actual loss of bone mass. Kyphosis (a spine deformity) and worsening pulmonary status are also connected to low Vitamin D levels for those with CF (PubMed).
Did you know that tobacco, alcohol, and caffeine can thin your bones as well? To learn more about these bone issues, please continue reading.
Delayed puberty
Relative to CF, during the teen years, most of the body’s bone formation occurs. However, many with CF are already behind the game. A frequent hallmark of CF is delayed puberty; thus, CF interferes with normal bone formation during these years.
CFF promotes the reminder that “nutrition, lung disease, and bone health are related.” Those with CF are challenged by all three. In the general population, bones also weaken with age. Now that those with CF are living longer, an unhealthy skeletal system has become very common for these folks.
As you’ll read below, CF is a very “complicated” condition, affecting many organs and body systems. To meet the individual’s physical and social/emotional needs, treatment requires a professional and “holistic team approach.” All disciplines on the team work in concert with the person and his/her physician, to create a personalized treatment plan.
If you are a person with CF, you probably also know that diet and exercise can even reverse bone thinning. But, did you know that cystic fibrosis-related diabetes (CFRD) is also a factor in the body’s inability to use required vitamins and minerals for proper bone formation and maintenance? (CFF).
Cystic fibrosis and diabetes
As noted above, the healthy pancreas is assigned the role of producing and releasing enzymes needed to digest food. It also does the same for insulin, meant to break down dietary sugars. With CF, the pancreas is damaged from the tissue-irritating and duct-clogging mucus. Cellular damage interferes with the production of insulin. This places those with CF at high risk for developing CFRD. The resultant fluctuation of blood sugar levels places an additional strain on an already over-burdened body dealing with CF.
CFF informs us that CFRD is quite common in those with CF, and is also a forerunner to bone loss. One’s response to insulin is lowered during illness, when taking cortisone (prescribed for lung exacerbations), or if pregnant. We also learn that those with CF can contract either type of diabetes mellitus (DM); Type I, requiring life-saving insulin along with a diabetic diet, and Type II, calling for dietary changes and probable oral medication as well.
Unfortunately, for those with cystic fibrosis, DM can also lead to weight loss and problems with proper lung functioning. To monitor for the presence of DM in those with cystic fibrosis, the CFF care guidelines call for annual DM testing of those with CF aged 10 and older.
The importance of a dietitian and physical therapist in CF care
When addressing the individual needs of a particular person with CF, two of the very important members of his/her care team are the Dietician and the Physical Therapist. Together, in collaboration with the physician and the individual with CF, these medical professionals will address the person’s bone issues, to include prevention and reversal of bone disease.
To fight against issues of malabsorption, the team’s dietician, in concert with the physician, works with the person to maintain healthy nutrition. As a preventive measure against malnutrition, CF dieticians concur with the 3000 calories per day plan, to give an “extra window” of available nutrition to persons with CF. Caloric intake, combined with the correct ratio of digestive enzymes, is crucial for preventing malnutrition and bone loss; this will be computed and become a part of the care plan, as well. (The dietician can also help the person draft a “game plan” for ensuring adequate dietary intake on those days when they don’t feel well and just aren’t hungry.)
Additionally, to promote the proper absorption of vitamins and minerals, the dietician generally recommends a diet high in fat to help prevent/reverse bone disease. (Vitamin D is a fat-soluble vitamin.) If a person with CF is also diagnosed with CFDR, the dietician must also address that nutritional need.
Anyone with CF could also challenged by other conditions that adversely affect bone health: lung infections, meds such as steroids (used to treat CF flare ups), and organ transplants (lung transplants are becoming more common as patients with CF are living longer).
For further information on CF and bone thinning as presented, refer to the cited CFF site on Bone Health.
Diet and physical activity’s prominent impact
Now, for the nitty gritty on the good news: “A high-calorie, nutrient-dense diet, and exercise, leads to healthy, strong bones for people with cystic fibrosis. Good nutrition also means taking vitamin and mineral supplements and sometimes medication”, per CFF, which promotes “walking, jogging and lifting weights.” If the person is taking oral Vitamin D, blood levels of that vitamin must be frequently monitored.
The NIH further exclaims that “Bones and muscles both become stronger when muscles push and tug against bones during physical activity. And emedicinehealth tells us that “Exercise also helps the body absorb calcium”. The physical- therapist will work with the individual to create a personalized exercise plan just for them.
The CFF also informs us that, in order to carefully watch for the presence of bone disease in those with CF, a person’s height and weight will be monitored. Also, yearly blood calcium levels are recommended. Additionally, the CFF recommends that all persons with CF have a DEXA scan by age 18 to screen for osteoporosis. This x-ray test is also to be repeated every 1 to 5 years. If the CF person is prone to, or has osteoporosis, the DEXA scan is to be done more often.
And so, take a breath and be thankful: Your treatment care team has your back.
References
https://www.emedicinehealth.com/osteoporosis_and_calcium/page7_em.htm
https://www.nichd.nih.gov/health/topics/bonehealth/conditioninfo/Pages/activity.aspx
https://www.emedicinehealth.com/osteoporosis_and_calcium/page7_em.htm
https://www.hindawi.com/journals/ije/2010/218691/
https://www.ncbi.nlm.nih.gov/pubmed/6723186