It is especially important that cystic fibrosis patients with an end-stage lung disease not limit their consumption of healthy food, even if they have diabetes, the researchers argued.
People with chronic lung diseases are at risk of developing pulmonary cachexia, a condition of muscle wasting and weakness caused by a chronic disease such as CF. Pulmonary cachexia is the final result of malnutrition in patients with end-stage lung disease.
In addition to speeding up the course of the disease, poor nutrition complicates medical care and increases the risks of poor outcomes for patients having a lung transplant.
Proper nutrition can improve patients’ functioning, ability to exercise, and quality of life, the researchers wrote.
But maintaining nutrition is difficult for CF patients, who are unable to absorb fats and other nutrients because of pancreatic enzyme insufficiency. Liver disease and diabetes can also complicate CF. These factors mean patients commonly expend an abnormally high amount of energy.
Stress and failing to stick with treatment may worsen malnutrition in CF, the researchers added.
All of these elements combined make it necessary for doctors to closely monitor CF patients’ nutrient intake and energy, they maintained.
Many patients should be taking supplements formulated for their condition that contain the fat-soluble vitamins A, D, E, and K and nutrients such as calcium, sodium, iron, and zinc, the researchers said.
Doctors should also ensure that pancreatic enzyme replacement therapy is adequate, by monitoring symptoms of malabsorption. These symptoms are most easily recognized by gut problems such as bloating or abnormal stool.
Since many patients are used to the symptoms, they may not react when they worsen, researchers said. This means doctors should encourage patients to talk about their toilet habits and stool to detect subtle changes, the team said.
In addition, doctors need to keep an eye on patients’ levels of salt, calcium, iron, zinc, and selenium, the researchers said.
While doctors should tell all CF patients about the importance of good nutrition, and possibly prescribe supplements, some of their patients will still end up needing to be fed through a tube inserted in a hole in their stomach, the team said.
The review mentioned other approaches to improving CF patients’ nutrition besides not limiting food intake.
A number of small-sample-size studies have examined whether growth hormone supplements could help CF patients. Although the studies reported improvements in patients’ height, weight, and lean tissue mass from the hormones, they were too small to generate any strong conclusions.
The same could be said of a series of small studies exploring lactobacillus probiotics as a nutritional aid for CF patients. These probiotics are known to reduce gut inflammation, and two studies showed they lowered the rates of CF patients’ lung exacerbations and hospitalizations. But again, the studies were small, and hence, the results uncertain.
Appetite stimulants are also commonly used in CF, and small studies show short-term improvements in weight, body fat, lean body mass, and lung function. These findings, too, need to be validated in larger studies, the Oklahoma researchers said.
“Management of pulmonary cachexia, regardless of etiology, should be part of a patient’s with end-stage lung disease overall care plan,” the team wrote. “This includes oral nutrition supplementation and often with a pulmonary rehabilitation program for maximal benefit. Nutrition support as seen does not change overall pulmonary function, but can improve function capacity and morbidity for patients and may decrease or slow overall mortality.”