Nutrient status of adults with cystic fibrosis

Dietary intake and quality among adults with cystic fibrosis: A systematic review

AIMS

This systematic review aims to describe the dietary quality, dietary intake and related behaviours of adults diagnosed with cystic fibrosis.

METHODS

A comprehensive literature search was conducted in four databases (Medline, CINAHL, EMBASE, CENTRAL); studies were included if they addressed dietary intake, diet quality or eating behaviours among adults (≥15 years) living with cystic fibrosis and were published from January 2000 to November 2022. The Mixed Methods Appraisal Tool was used to assess the risk of bias and quality of included studies. Findings were synthesised narratively.

RESULTS

Nineteen observational studies (n = 2236) were included and considered high to moderate quality. Most (13/19) studies reported that individuals with cystic fibrosis were consuming high-energy diets; where studies reported energy intake as a proportion of requirements met, energy intake was high, even when using individualised or cystic fibrosis-specific referents. In addition, fat intakes as a proportion of energy appeared high (29%-39% of total energy), particularly as current guidelines recommend macronutrient profile similar to the general population (<30% of total energy). There was considerable variation in the reporting of fatty acid profiles and other nutrients. Five studies reported on concerns regarding diet and eating in this population.

CONCLUSION

Findings from the current review suggest dietary intakes of adults with cystic fibrosis appear to be less than optimal and concerns about diet, weight and food may be emerging in this population. Future research utilising consistent measures of dietary assessment and reporting, reporting of medical therapies, and exploring potential concerns about diet and eating is warranted.

ESPEN-ESPGHAN-ECFS guideline on nutrition care for cystic fibrosis

BACKGROUND

Nutritional status is paramount in Cystic Fibrosis (CF) and is directly correlated with morbidity and mortality. The first ESPEN-ESPGHAN-ECFS guidelines on nutrition care for infants, children, and adults with CF were published in 2016. An update to these guidelines is presented.

METHODS

The study was developed by an international multidisciplinary working group in accordance with officially accepted standards. Literature since 2016 was reviewed, PICO questions were discussed and the GRADE system was utilized. Statements were discussed and submitted for on-line voting by the Working Group and by all ESPEN members.

RESULTS

The Working Group updated the nutritional guidelines including assessment and management at all ages. Supplementation of vitamins and pancreatic enzymes remains largely the same. There are expanded chapters on pregnancy, CF-related liver disease, and CF-related diabetes, bone disease, nutritional and mineral supplements, and probiotics. There are new chapters on nutrition with highly effective modulator therapies and nutrition after organ transplantation.

Vitamin D deficiency in patients with cystic fibrosis: a systematic review and meta-analysis

AIM

Vitamin D is a prominent modulator of immunity and respiratory function. It plays a vital role in respiratory diseases such as cystic fibrosis (CF). S. However, there is a dearth of information on patients with CF. The purpose of the meta-analysis is to highlight the importance of following the existing guidelines regarding maintenance of Vitamin D serum levels in patients with CF.

METHODS

The systematic search was conducted without utilizing any time or language limitations in original database from the beginning until March 2022. The meta-analysis was performed using a random-effects model. Heterogeneity was determined by I2 statistics and Cochrane Q test.

RESULTS

Pooled analysis using the random-effects model of the 8 case-control studies with 13 effect sizes revealed that the serum 25-OH-vitamin D in participants with cystic fibrosis was significantly lower than controls in pediatrics and adolescences (WMD: - 3.41 ng/ml, 95% CI - 5.02, - 1.80, p =  < 0.001) and adults (WMD: - 2.60 ng/ml, 95% CI - 4.32, - 0.89, p = 0.003). Based on data from 12 studies (21 effect sizes) with a total of 1622 participants, the prevalence of vitamin D levels of 20-30 ng/ml in CF patients was 36% among pediatrics/adolescents and 63% among adults. In addition, 27% of pediatric/adolescent CF patients and 35% of adult CF patients had vitamin D levels of below 20 ng/ml.

CONCLUSIONS

As a result, according to the existing guidelines, our results proved the need to pay attention to the level of vitamin D in these patients.

What do people with cystic fibrosis eat? Diet quality, macronutrient and micronutrient intakes (compared to recommended guidelines) in adults with cystic fibrosis-A systematic review

BACKGROUND

Treatment advancements have improved life expectancy and nutritional status of people with cystic fibrosis (CF). Alongside reductions in malnutrition, incidences of overweight, obesity and risk factors for diet-related chronic diseases have increased in recent years. This study aimed to synthesise the available literature on diet quality, macronutrient and micronutrient intakes compared to the recommended guidelines in adults with CF, an essential step in deducing the optimal dietary pattern and intakes for CF adults.

METHODS

A systematic search of five electronic databases from inception until April 2023 was conducted using keywords related to CF, diet quality and nutrient intakes.

RESULTS

Twenty-one studies were included comprising 18 cross-sectional, one cohort and two case control studies, reporting data from 724 adults with CF. Energy and / or macronutrient intake data was reported across 17 cohorts, eight studies provided micronutrients data, and diet quality was determined for four CF cohorts by using a diet quality score, and / or categorising food intake into servings per day for food groups and comparing findings to national dietary guidelines. Although energy intake recommendations were met, and most micronutrient requirements were achieved through supplementation, total energy intake from fat was above recommendations and diet quality was poor.

CONCLUSION

This is the first systematic review comprehensively evaluating literature on dietary intakes of adults with CF. Energy-dense, nutrient-poor foods contribute to intakes which pose risk in developing diet-related chronic diseases. Revision of dietary guidelines and practice change in CF nutritional therapy is warranted to optimise nutrition and health outcomes.

Lipidomic alterations in human saliva from cystic fibrosis patients

Cystic fibrosis is a hereditary metabolic disorder characterized by impaired traffic of chloride ions and water through membranes of the respiratory and gastrointestinal, that causes inadequate hydration of airway surfaces, dehydrated mucous secretions and a high-sodium chloride sweat. Although the classical presentation of the condition is well known, a better characterization of metabolic alterations related is need. In particular, the metabolic composition alterations of biological fluids may be influence by the disease state and could be captured as putative signature to set targeted therapeutic strategies. A targeted comprehensive mass spectrometry-based platform was employed to dissect the lipid content of saliva samples form CF patients, in order to investigate alterations in the lipid metabolic homeostasis related to the pathology, chronic obstructive pulmonary disease, Pseudomonas Aeruginosa infection, pancreatic insufficiency, liver disfunction and diabetes-related complications.

Academy of Nutrition and Dietetics: 2020 Cystic Fibrosis Evidence Analysis Center Evidence-Based Nutrition Practice Guideline

The Academy of Nutrition and Dietetics Evidence Analysis Center conducted a systematic review of the literature to develop an evidence-based practice guideline for primary nutrition issues in cystic fibrosis (CF). This guideline is designed to complement and build upon existing evidence-based CF nutrition guidelines. The objective of this guideline was to provide recommendations for registered dietitian nutritionists in the United States delivering medical nutrition therapy to individuals with CF and their families that fill gaps in current evidence-based guidelines on topics that are crucial in order to improve health and prevent disease progression. This guideline provides 28 nutrition recommendations to guide medical nutrition therapy, including nutrition screening, nutrition assessment, and dietary intake. For topics outside the scope of this guideline, practitioners are referred to external, evidence-based recommendations. The CF landscape is evolving rapidly with breakthroughs in cystic fibrosis transmembrane regulator modulators changing CF at a cellular level. Medical nutrition therapy for individuals with CF from infancy through advanced age requires novel and individualized approaches. The Academy Evidence Analysis Library CF guidelines provide a framework for expanding upon current knowledge to determine effective nutrition strategies for individuals with CF through long and healthy futures.

Adherence to Dietary Recommendations, Nutrient Intake Adequacy and Diet Quality among Pediatric Cystic Fibrosis Patients: Results from the GreeCF Study

Nutrition is an important component of cystic fibrosis (CF) therapy, with a high-fat diet being the cornerstone of treatment. However, adherence to the dietary recommendations for CF appears suboptimal and burdensome for most children and adolescents with CF, leading to malnutrition, inadequate growth, compromised lung function and increased risk for respiratory infections. A cross-sectional approach was deployed to examine the degree of adherence to the nutrition recommendations and diet quality among children with CF. A total of 76 children were recruited from Aghia Sophia’s Children Hospital, in Athens, Greece. In their majority, participants attained their ideal body weight, met the recommendations for energy and fat intake, exceeding the goal for saturated fatty acids consumption. Carbohydrate and fiber intake were suboptimal and most participants exhibited low or mediocre adherence to the Mediterranean diet prototype. It appears that despite the optimal adherence to the energy and fat recommendations, there is still room for improvement concerning diet quality and fiber intake.

Dietary Macronutrient Distribution and Nutrition Outcomes in Persons with Cystic Fibrosis: An Evidence Analysis Center Systematic Review

Cystic fibrosis (CF) increases risk for undernutrition and malabsorption. Individuals with CF traditionally have been counseled to consume a high-fat diet. However, a new era of CF care has increased lifespan and decreased symptoms in many individuals with CF, necessitating a re-examination of the high-fat CF legacy diet. A literature search was conducted of Medline (Ovid), Embase, and CINAHL (EBSCO) databases to identify articles published from January 2002 to May 2018 in the English language examining the relationships between dietary macronutrient distribution and nutrition outcomes in individuals with CF. Articles were screened, risk of bias was assessed, data were synthesized narratively, and each outcome was graded for certainty of evidence. The databases search retrieved 2,519 articles, and 7 cross-sectional articles were included in the final narrative analysis. Three studies examined pediatric participants and 4 examined adults. None of the included studies reported on outcomes of mortality or quality of life. Very low certainty evidence described no apparent relationship between dietary macronutrient distribution and lung function, anthropometric measures, or lipid profile in individuals with CF. The current systematic review demonstrates wide ranges in the dietary macronutrient intakes of individuals with CF with little to no demonstrable relationship between macronutrient distribution and nutrition-related outcomes. No evidence is presented to substantiate an outcomes-related benefit to a higher fat-diet except in the context of achieving higher energy intakes in a lesser volume of food.

Enteral tube feeding for cystic fibrosis

BACKGROUND

Enteral tube feeding is routinely used in many cystic fibrosis centres when oral dietary and supplement intake has failed to achieve an adequate nutritional status. The use of this method of feeding is assessed on an individual basis taking into consideration the patients age and clinical status. This is a final update of a previously published review.

OBJECTIVES

To examine the evidence that in people with cystic fibrosis, supplemental enteral tube feeding improves nutritional status, respiratory function, and quality of life without significant adverse effects.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. We also contacted the companies that market enteral feeds and reviewed their databases.Date of the most recent search of the Group's Cystic Fibrosis Trials Register: 10 July 2019.Date of the most recent hand search of PubMed: 26 October 2018.

SELECTION CRITERIA

All randomised controlled trials comparing supplemental enteral tube feeding for one month or longer with no specific intervention in people with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

The searches identified 44 trials; however, none were eligible for inclusion in this review.

MAIN RESULTS

There are no trials included in this review.

AUTHORS' CONCLUSIONS

Supplemental enteral tube feeding is widely used throughout the world to improve nutritional status in people with cystic fibrosis. The methods mostly used, nasogastric or gastrostomy feeding, are expensive and may have a negative effect on self-esteem and body image. Reported use of enteral tube feeding suggests that it results in nutritional and respiratory improvement; but, efficacy has not been fully assessed by randomised controlled trials. It is acknowledged, however, that performing a randomised controlled trial would be difficult due to the ethics of withholding an intervention in a group of people whose nutritional status necessitates it.

Bone involvement in young adults with cystic fibrosis awaiting lung transplantation for end-stage respiratory failure

Patients with cystic fibrosis awaiting lung transplantation for end-stage respiratory failure have high prevalence of reduced bone mineral density and fragility fracture. Suboptimal 25-hydroxyvitamin D levels could significantly contribute to the development of cystic fibrosis-related bone disease.

INTRODUCTION

The assessment of the prevalence of cystic fibrosis-related bone disease (CFBD) and its associated risk factors in young adults with cystic fibrosis (CF) awaiting lung transplantation for end-stage respiratory failure.

METHODS

Clinical characteristics, bone mineral density (BMD), the parameters of calcium metabolism, including vitamin D (25OHVitD) levels, and the presence of fragility fractures were evaluated in 42 CF patients (24 females, age 34.0 ± 8.4 years) consecutively referred as lung transplant candidates.

RESULTS

Mean 25OHVitD levels (54.9 ± 26.2 nmol/L) were below the reference range and hypovitaminosis D (25OHVitD < 75 nmol/L) was found in 34 patients (81%) and daily calcium intakes (median 550 mg/day) were lower than recommended. A BMD below the expected range for age (Z-score of - 2.0 or lower) and at least one prevalent fragility fracture were found in 22 patients (52.4%) and 18 patients (45.2%), respectively. The coexistence of low BMD and the presence of fracture was observed in 13 patients (31.0%). In these patients, the prevalence of nephrolithiasis was higher than in the remaining ones (p = 0.046). The presence of kidney stones was associated with a worse bone status and with severe vitamin D deficiency. In the whole sample, femoral BMD Z-scores were directly correlated with albumin-adjusted calcium (p < 0.05) and 25OHVitD levels (p < 0.01).

CONCLUSIONS

Despite the improvement of CF care, CFBD is still highly prevalent in young adults awaiting lung transplantation for end-stage CF. Suboptimal 25OHVitD levels could significantly contribute to the development of CFBD. The presence of nephrolithiasis could be an additional warning about the need for a careful evaluation of bone health in CF patients.

Exocrine pancreatic insufficiency is common in people living with HIV on effective antiretroviral therapy

OBJECTIVES

The primary aim of this prospective study was to determine the prevalence of exocrine pancreatic insufficiency (EPI) in people living with HIV (PLHIV) on suppressive antiretroviral therapy (ART).

METHODS

PLHIV ≥18 years of age and on ART for >6 months and with HIV RNA <50 copies/mL plasma were included. Faecal elastase-1 measurement was performed on a single stool sample, serum markers of malnutrition were collected, and participants answered a short questionnaire about gastrointestinal symptoms. Participants with EPI and symptoms were offered pancreatic enzyme replacement therapy (PERT), and the result of this therapy was also evaluated.

RESULTS

Of 100 participants, 32% had EPI (faecal elastase-1 < 200 μg/g) and 20% severe EPI (faecal elastase-1 < 100 μg/g). We did not find any correlation between self-reported symptoms and degree of EPI. Twelve out of the 32 participants with EPI accepted to start PERT. Nine out of 12 (75%) reported improvement or became asymptomatic within 14 days.

CONCLUSION

EPI is common in PLHIV on effective ART. We could, however, not find a correlation between gastrointestinal symptoms and the presence of EPI. Assessment of pancreatic exocrine function could be considered in PLHIV particularly in those with gastrointestinal discomfort, since there is a possible gain in treating them with relief of symptoms and improved quality of life. The effects of PERT in PLHIV on effective ART need further study.

Expression stability of 13 housekeeping genes during carbon starvation of Pseudomonas aeruginosa

Quantitative real-time polymerase chain reaction (qRT-PCR) is a reliable technique for quantifying mRNA levels when normalised by a stable reference gene/s. Many putative reference genes are known to be affected by physiological stresses, such as nutrient limitation and hence may not be suitable for normalisation. In this study of Pseudomonas aeruginosa, the expression of 13 commonly used reference genes, rpoS, proC, recA, rpsL, rho, oprL, anr, tipA, nadB, fabD, ampC, algD and gyrA, were analysed for changes in expression under carbon starvation and nutrient replete conditions. The results showed that rpoS was the only stably expressed housekeeping gene during carbon starvation. In contrast, other commonly used housekeeping genes were shown to vary by as much as 10-100 fold under starvation conditions. This study has identified a suitable reference gene for qRT-PCR in P. aeruginosa during carbon starvation. The results presented here highlight the need to validate housekeeping genes under the chosen experimental conditions.

Vitamin D deficiency in patients with intestinal malabsorption syndromes--think in and outside the gut

There is a very high prevalence of vitamin D deficiency, which is defined by a serum level of 25-hydroxyvitamin D [25(OH)D] of lower than 20 ng/mL, in all populations of the world. Unfortunately, the prevalence of vitamin D deficiency in patients with intestinal malabsorption syndromes, including cystic fibrosis (CF), celiac disease (CD), short bowel syndrome and inflammatory bowel disease (IBD), is higher than that in the general population, indicating the presence of disease-specific causative factors. In this review, we aimed to present clinical findings to highlight the roles of insufficient exposure to sunlight and inflammation in the development of vitamin D deficiency in patients with intestinal malabsorption syndromes. Furthermore, we aimed to present experimental evidence that supported a role of vitamin D deficiency in the pathogenesis of IBD. Finally, we reviewed clinical intervention strategies aiming to normalize vitamin D status in and even to improve the conditions of patients and to discuss certain issues that needed to be addressed in future research.

Clinical, anthropometric and laboratory nutritional markers of pancreatic exocrine insufficiency: Prevalence and diagnostic use

Pancreatic exocrine insufficiency (PEI) frequently occurs secondary to exocrine pancreatic disease (e.g. chronic pancreatitis, cystic fibrosis, cancer) or pancreatic/gastrointestinal surgery, resulting in the maldigestion of nutrients and consequently malnutrition. Pancreatic enzyme replacement therapy (PERT) is the cornerstone of PEI management. Despite its clinical relevance, the diagnosis of PEI in clinical practice is challenging, as the current gold standard test is cumbersome, and alternatives have limited availability or accuracy. There is a need for accurate and easily applicable diagnostic modalities. We review the prevalence of clinical symptoms and changes in anthropometric measurements and laboratory nutritional markers indicative of malnutrition in patients with PEI, and the relevance of these findings in diagnosing PEI and monitoring PERT efficacy. Based on limited available evidence, assessment of clinical symptoms, body weight, body mass index and other anthropometric parameters are not sensitive methods for PEI diagnosis, owing to high variability and multiple confounding factors, but appear useful in monitoring PERT efficacy. Limited evidence precludes strong recommendations but suggests that serum levels of vitamin E, magnesium, and plasma proteins, notably retinol binding protein, albumin, and prealbumin, may have diagnostic utility in PEI. Studies show that assessment of changes in these and other nutritional parameters is helpful in monitoring PERT efficacy. Further research is needed to confirm the diagnostic accuracy of these parameters for PEI. Until such data are available, a nutritional evaluation including circulating vitamin E, magnesium, retinol binding protein, albumin, and prealbumin may be used to evaluate the probability of PEI in clinical practice when reliable pancreatic function tests are not available.

Dietary intake and nutritional status of micronutrients in adults with cystic fibrosis in relation to current recommendations

An increased prevalence of cystic fibrosis (CF) related complications such as impaired bone health and diabetes has accompanied increased survival of patients with CF. This review was conducted to determine the extent to which adults with CF are meeting current nutrition recommendations for micronutrients in association with CF-related complications management. Although dietary intake and nutritional status in CF has improved significantly in recent decades, micronutrient status seems to have diverged. While vitamin A and E intakes appear adequate, frequent vitamin D and K deficiency/insufficiency and compromised bone health in CF, occurs despite supplementation. Although deficiency of water-soluble vitamins and minerals is uncommon, ongoing surveillance will enhance overall health outcomes, particularly in cases of CF-related liver disease and deteriorated lung function and bone health. Salt and fluid status in CF may also need attention due to diminished thirst sensation and voluntary rehydration. Further investigation in micronutrient status optimisation in CF will inform the development of more effective and targeted nutrition therapies to enable integration of more refined recommendations for micronutrient intakes in CF based on individual needs and disease progression.

Enteral tube feeding for cystic fibrosis

BACKGROUND

Enteral tube feeding is routinely used in many cystic fibrosis centres when oral dietary and supplement intake has failed to achieve an adequate nutritional status. The use of this method of feeding is assessed on an individual basis taking into consideration the patients age and clinical status.

OBJECTIVES

To examine the evidence that in people with cystic fibrosis, supplemental enteral tube feeding improves nutritional status, respiratory function, and quality of life without significant adverse effects.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. We also contacted the companies that market enteral feeds and reviewed their databases.Date of the most recent search of the Group's Cystic Fibrosis Trials Register: 13 February 2015.Date of the most recent hand search of PubMed and conference abstract books: 13 February 2015.

SELECTION CRITERIA

All randomised controlled trials comparing supplemental enteral tube feeding for one month or longer with no specific intervention in people with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

The searches identified 38 trials; however, none were eligible for inclusion in this review.

MAIN RESULTS

There are no trials included in this review.

AUTHORS' CONCLUSIONS

Supplemental enteral tube feeding is widely used throughout the world to improve nutritional status in people with cystic fibrosis. The methods mostly used, nasogastric or gastrostomy feeding, are expensive and may have a negative effect on self-esteem and body image. Reported use of enteral tube feeding suggests that it results in nutritional and respiratory improvement; but, efficacy has not been fully assessed by randomised controlled trials. It is acknowledged, however, that performing a randomised controlled trial would be difficult due to the ethics of withholding an intervention in a group of patients whose nutritional status necessitates it.

Inflammation, oxidative stress, and cardiovascular disease risk factors in adults with cystic fibrosis

Cystic fibrosis (CF) represents one of a number of localized lung and non-lung diseases with an intense chronic inflammatory component associated with evidence of systemic oxidative stress. Many of these chronic inflammatory diseases are accompanied by an array of atherosclerotic processes and cardiovascular disease (CVD), another condition strongly related to inflammation and oxidative stress. As a consequence of a dramatic increase in long-lived patients with CF in recent decades, the specter of CVD must be considered in these patients who are now reaching middle age and beyond. Buttressed by recent data documenting that CF patients exhibit evidence of endothelial dysfunction, a recognized precursor of atherosclerosis and CVD, the spectrum of risk factors for CVD in CF is reviewed here. Epidemiological data further characterizing the presence and extent of atherogenic processes in CF patients would seem important to obtain. Such studies should further inform and offer mechanistic insights into how other chronic inflammatory diseases potentiate the processes leading to CVDs.

Increased risk of colorectal neoplasia in adult patients with cystic fibrosis: a matched case-control study

OBJECTIVE

As the lifespan of patients with cystic fibrosis (CF) increases, concerns regarding the occurrence of bowel cancer have arisen. However, previous cohort studies have yielded contradictory results as to the risk of colorectal cancer (CRC) in the CF population. The aim of this study was to determine whether CF is associated with an increased risk of colorectal neoplasia.

METHODS

We performed a matched case-control study at a statewide CF center. Cases were adult CF patients undergoing colonoscopy in a 5-year period from 2007 to 2012. Controls were matched in a 2:1 ratio for age, gender, and colonoscopy indication.

RESULTS

A total of 50 patients with CF who underwent colonoscopy were identified. Among CF patients, there were 5 (10%) cases with CRC, 1 (2%) with ileal adenocarcinoma, 13 (26%) with adenomas, and 16(32%) with advanced adenomas. In contrast, there was 1 (1%) case with CRC, 11 (11%) with adenomas, and 6 (6%) with advanced adenomas identified among controls. Compared to controls, CF was associated with a 10-fold increased risk of CRC (odds ratio [OR] = 10.0, 95% confidence interval [CI]: 1.2-85.6; p = 0.03), threefold increased risk of adenomas (OR = 3.34, 95%CI: 1.23-9.08; p = 0.018], and sevenfold increased risk of advanced adenomas (OR = 6.95, 95% CI: 2.30-21.01; p = 0.001). Moreover, the quality of bowel preparation was significantly worse in CF patients with a fourfold (p = 0.01) increased likelihood of a poor preparation.

CONCLUSIONS

Our data suggest that CF patients are at significantly increased risk of CRC compared to age, sex, and colonoscopy-indication matched controls. Consideration should be given to the introduction of a CRC surveillance program in the CF population.

The clinical significance of the gut microbiota in cystic fibrosis and the potential for dietary therapies

Cystic fibrosis (CF) is characterised by many comorbidities related to aberrant mucosa and chronic inflammation in the respiratory and digestive systems. The intestinal mucosa serves as the primary interface between the gut microbiota and endocrine, neural and immune systems. There is emerging evidence that aberrant intestinal mucosa in CF may associate with an altered gut microbiota. Compared to healthy subjects, the overall bacterial abundance and species richness seems to be reduced in CF, accompanied by a trend in suppression of Firmicutes and Bacteroidetes spp. and an augmentation of potentially pathogenic species. There is also some concordance of gut and respiratory microbiotas in CF infants over time. The clinical significance of these observations awaits investigation. The gut microbiota have some potential in CF management by affecting inflammatory and immune responses, and influencing aberrant mucosa. As an important modifiable factor, diet therapies such as probiotics and prebiotics have shown initial promise in improving CF related conditions associated with chronic inflammation. More studies are needed to confirm this, as well as the efficacy of other dietary strategies such as modulating dietary fat and indigestible carbohydrate. Similarly, dietary modification of gut microbiota to optimise nutritional status in CF may be feasible, although more CF-specific studies are warranted.

Hypovitaminosis D in patients with cystic fibrosis: a cross-section study in South Brazil

INTRODUCTION

Cystic fibrosis (CF) patients have a susceptibility to vitamin D deficiency because of nutrient malabsorption.

OBJECTIVES

To evaluate the prevalence of hypovitaminosis D in CF patients and the factors associated with serum 25-hydroxyvitamin D levels.

METHODS

We evaluated the prevalence of vitamin D deficiency defined as 25-hydroxyvitamin D <30 ng/mL, as suggested recently by the Cystic Fibrosis Foundation, and factors associated with its serum levels. Patients with confirmed CF were included. Nutritional status and hospital admissions were evaluated. Serum C-reactive protein, calcium, phosphate, magnesium, albumin, 25-hydroxyvitamin D and parathyroid hormone levels were measured. Lung function was evaluated by spirometry, and clinical and chest radiographic scores were assessed. Statistical significance level was set at P < 0.05.

RESULTS

Fifty-nine patients were included. Prevalence of hypovitaminosis D was 61%. Patients with pancreatic insufficiency had a trend to have higher vitamin D levels. Sixteen patients had severe lung disease with percentage of forced expiratory volume in 1 s predicted below 40%. After multivariate analysis, body mass index and hospitalization in the last month remained significantly associated with serum vitamin D levels.

CONCLUSIONS

Vitamin D insufficiency is still a problem in CF patients, even in those receiving supplementation.

Enteral tube feeding for cystic fibrosis

BACKGROUND

Enteral tube feeding is routinely used in many cystic fibrosis centres when oral dietary and supplement intake has failed to achieve an adequate nutritional status. The use of this method of feeding is assessed on an individual basis taking into consideration the patients age and clinical status.

OBJECTIVES

To examine the evidence that in people with cystic fibrosis, supplemental enteral tube feeding improves nutritional status, respiratory function, and quality of life without significant adverse effects.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. We also contacted the companies that market enteral feeds and reviewed their databases.Date of the most recent search of the Group's Cystic Fibrosis Trials Register: 03 September 2012.Date of the most recent hand search of PubMed and conference abstract books: 15 June 2012.

SELECTION CRITERIA

All randomised controlled trials comparing supplemental enteral tube feeding for one month or longer with no specific intervention in people with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Thirty-one trials were identified by the searches; however, none were eligible for inclusion in this review.

MAIN RESULTS

There are no trials included in this review.

AUTHORS' CONCLUSIONS

Supplemental enteral tube feeding is widely used throughout the world to improve nutritional status in people with cystic fibrosis. The methods mostly used, nasogastric or gastrostomy feeding, are expensive and may have a negative effect on self-esteem and body image. Reported use of enteral tube feeding suggests that it results in nutritional and respiratory improvement; but, efficacy has not been fully assessed by randomised controlled trials. It is acknowledged, however, that performing a randomised controlled trial would be difficult due to the ethics of withholding an intervention in a group of patients whose nutritional status necessitates it.

Vitamin D bioavailability in cystic fibrosis: a cause for concern?

Despite the inclusion of extra vitamin D in their regimen of fat-soluble vitamin supplementation, cystic fibrosis patients remain chronically depleted of vitamin D. The persistence of suboptimal vitamin D status is often blamed on the maldigestion and malabsorption of fat. However, the mitigated success of recent clinical trials with high-dose vitamin D supplementation suggests that vitamin D bioavailability might be impaired in these patients. Given the growing understanding of the importance of this vitamin in the regulation of multiple biological functions beyond skeletal health, the present review analyzes the current literature by addressing each step of vitamin D metabolism and action in the context of this life-limiting pathology. In addition, it highlights the importance of vitamin D in relation to organs and or conditions affected by cystic fibrosis.

Dietary intake and nutritional status in a Scandinavian adult cystic fibrosis-population compared with recommendations

BACKGROUND

Malnutrition is a well-known complication in cystic fibrosis (CF). There is good evidence that maintaining a normal body-weight correlates well with improved survival in CF. Energy intake in excess of 120% of the estimated average requirement (EAR) has been advised since 1980s.

OBJECTIVES

To investigate the nutritional intake and status in the adult Scandinavian CF-population.

SUBJECTS/METHODS

A cross-sectional multi-centre study was used to investigate the nutritional status of 456 adult CF-patients (2003 2006). Height and weight were measured and body mass index (BMI) and z-scores were calculated. Pulmonary function was examined by dynamic spirometry. A 7-day pre-coded food record (FR) obtained energy and nutrient intake data in 180 patients.

RESULTS

The mean energy intake was 114 (SD 30.0)% of EAR and thus significantly lower than the target of 120% EAR (p< 0.001) for patients with pancreatic insufficiency (PI) (n=136). Mean BMI was 22.0 (SD 2.9), the prevalence of BMI <18 was 13% and the prevalence of BMI ≥25 was 15% (n=136). Mean BMI was 20.8 (SD 2.4) in PI-patients with FEV(1) <70% and 23.2% (SD 3.0), in PI-patients with FEV(1) ≥70%, mean difference 2.4, (95% CI: 1.5, 3.3) (p<0.001), but there was no difference in energy intake. BMI ≥18.5 and a reported energy intake <120% were revealed in 54% of the PI-patients.

CONCLUSIONS

The energy intake did not reach the recommended 120% EAR, but the prevalence of underweight was lower than reported in other studies. The recommendation may exceed the requirement for a number of CF-patients. The nutritional status must still be closely monitored and nutritional advice and intervention should be individualised and adjusted to actual needs.

Vitamin d deficiency in cystic fibrosis

Cystic Fibrosis is the most common inherited genetic respiratory disorder in the Western World. Hypovitaminosis D is almost universal in CF patients, likely due to a combination of inadequate absorption, impaired metabolism, and lack of sun exposure. Inadequate levels are associated with the high prevalence of bone disease or osteoporosis in CF patients, which is associated with increased morbidity including fractures, kyphosis, and worsening pulmonary status. Treatment goals include regular monitoring 25 hydroxyvitamin D (25OHD) levels with aggressive treatment for those with levels <75 nmol/L (<30 ng/mL). More research is needed to determine optimal supplementation goals and strategies.

Role of vitamin D in adults requiring nutrition support

The major and most well-known function of vitamin D is to maintain calcium and phosphorus homeostasis and promote bone mineralization. However, recent evidence suggests that vitamin D may be important for a variety of nonskeletal outcomes. The review synthesizes the available evidence for the role of vitamin D in skeletal health as well as its novel roles in medical conditions such as muscle function, falls, immunity, glucose homeostasis, and cardiovascular diseases. The article reviews methods for assessing vitamin D status and suggests strategies to restore vitamin D status in patients requiring enteral or parenteral nutrition who are at particularly high risk of hypovitaminosis D. Screening for hypovitaminosis D with plasma total 25-hydroxyvitamin D should be a routine part of the care of the patient requiring enteral or parenteral nutrition. Restoration of optimal vitamin D status with high-dose supplemental vitamin D is required in most cases, whereas exposure to sunlight or an ultraviolet B radiation-emitting device is most effective in patients with severe malabsorption or those requiring long-term parenteral therapy. Given the emerging role of vitamin D for a variety of acute and chronic conditions, the optimal vitamin D status in acutely ill patients as well as in patients requiring long-term nutrition therapy warrants further investigation.