Cystic fibrosis and fat malabsorption: Pathophysiology of the cystic fibrosis gastrointestinal tract and the impact of highly effective CFTR modulator therapy.

Cystic fibrosis (CF) is a progressive, genetic, multi-organ disease affecting the respiratory, digestive, endocrine, and reproductive systems. CF can affect any aspect of the gastrointestinal (GI) tract, including the esophagus, stomach, small intestine, colon, pancreas, liver, and gall bladder. GI pathophysiology associated with CF results from CF membrane conductance regulator (CFTR) dysfunction. The majority of people with CF (pwCF) experience exocrine pancreatic insufficiency resulting in malabsorption of nutrients and malnutrition. Additionally, other factors can cause or worsen fat malabsorption, including the potential for short gut syndrome with a history of meconium ileus, hepatobiliary diseases, and disrupted intraluminal factors, such as inadequate bile salts, abnormal pH, intestinal microbiome changes, and small intestinal bacterial overgrowth. Signs and symptoms associated with fat malabsorption, such as abdominal pain, bloating, malodorous flatus, gastroesophageal reflux, nausea, anorexia, steatorrhea, constipation, and distal intestinal obstruction syndrome, are seen in pwCF despite the use of pancreatic enzyme replacement therapy. Given the association of poor nutrition status with lung function decline and increased mortality, aggressive nutrition support is essential in CF care to optimize growth in children and to achieve and maintain a healthy body mass index in adults. The introduction of highly effective CFTR modulator therapy and other advances in CF care have profoundly changed the course of CF management. However, GI symptoms in some pwCF may persist. The use of current knowledge of the pathophysiology of the CF GI tract as well as appropriate, individualized management of GI symptoms continue to be integral components of care for pwCF.

Olfaction, body mass index, and quality of life with cystic fibrosis combination therapy.

BACKGROUND: Triple-combination therapy of elexacaftor-tezacaftor-ivacaftor (ETI) has been shown to reduce morbidity and mortality in people with cystic fibrosis (PwCF). Although patient body mass index (BMI) favorably increases with ETI treatment, factors contributing to this improvement are poorly characterized. Olfaction contributes to appetite stimulation and anticipation of eating, where higher rates of olfactory impairment (OI) in PwCF may contribute to malnutrition and BMI instability in this population. METHODS: The authors performed a prospective cohort study analyzing 41 CF patient responses to the Cystic Fibrosis Questionnaire-Revised (CFQR) and the 22-Item Sino-Nasal Outcome Test (SNOT-22) and used generalized estimating equations to understand the change in survey variables from being untreated (baseline) to undergoing 3 months of ETI therapy (follow-up). RESULTS: Patients reported significant improvement in their sense of smell at follow-up (p = 0.0036). Their improvements in sense of smell were not confounded by changes in rhinologic or extranasal rhinologic symptoms. Self-reported quality of life (QoL) improved after 3 months of ETI therapy (p = < 0.0001) as did BMI (p = < 0.0001), but improved sense of smell did not independently mediate these changes in QoL and BMI. CONCLUSION: Our results support the impression that ETI therapy improves CF-associated rhinologic symptoms and reverses OI, while contributing to improvement in rhinologic QoL. Sense of smell is not an independent mediator of improved QoL and BMI in this population, suggesting that other factors may have a stronger role in these realms. However, given the subjective improvement in sense of smell, additional evaluation of OI using psychophysical chemosensory assessment will clarify the connection between olfaction, BMI, and QoL in PwCF.

Updates in Nutrition Management of Cystic Fibrosis in the Highly Effective Modulator Era.

Attainment and maintenance of good nutrition has been an important aspect of management in cystic fibrosis (CF) for decades. In the era of highly effective modulator therapy for CF, the quality of the nutrients we recommend is increasingly important. Our therapy must support our patients' health for many years beyond what we previously thought. Preventing cardiovascular disease, reducing hyperlipidemia, and optimizing lean body mass for active, longer lives now join the long-standing goal of promoting lung function through nutrition. This chapter summarizes recent developments in nutrition in people with CF, with an eye to the evolution of our practice.

Nutrition in cystic fibrosis: From the past to the present and into the future.

Nutritional management is an integral part of multidisciplinary care for persons with cystic fibrosis. This review will look at how nutrition care has evolved over time. In addition, we will look at how some newer therapies impact nutrition care.

Influence of dietitian presence on outpatient cardiac rehabilitation nutrition services.

To describe variations in nutrition services offered in a nationally representative sample of out-patient cardiac rehabilitation programs by presence of a registered dietitian (RD), a survey was conducted of 250 randomly selected centers from 1,111 US outpatient cardiac rehabilitation centers in the 1998/1999 Cardiac Rehabilitation Directory of the American Association of Cardiovascular and Pulmonary Rehabilitation. A total of 190 of the 250 surveys (76%) were returned. Nutrition services offered by programs polled included distribution of nutrition pamphlets, one-on-one nutrition counseling, group nutrition classes, guest lectures on nutrition, and cooking demonstrations. Cardiac rehabilitation programs with an RD offered significantly more nutrition services on average (4.2+/-1.2) than programs without an RD (3.5+/-1.1, P=.01). Programs with RDs were more likely to offer one-on-one nutrition counseling than programs without them (98% and 80% respectively, P<.001), and they were also more likely to offer cooking demonstrations (43% and 17% respectively, P=.02). More, and a greater variety of, nutrition services are offered in cardiac rehabilitation programs that have an RD. Without an RD, exercise physiologists and registered nurses often provide some, but fewer and different, nutrition services.