Pathogenesis of malnutrition in cystic fibrosis, and its treatment

Characteristics of gastroesophageal reflux in adults with cystic fibrosis

BACKGROUND

Gastroesophageal reflux (GER) in adults with cystic fibrosis (CF) is poorly characterized. This study examines the frequency and predictors of GER symptoms and their relationship to lung function in adults with CF.

METHODS

Cross-sectional study of adults at the University of Minnesota CF Clinic using two validated self report surveys: The Mayo GER questionnaire and the GERD Symptom Assessment Scale (GSAS).

RESULTS

Of 274 invited patients, 201 (73%) completed the surveys and 173 performed spirometry at the same visit. Frequent symptoms (at least weekly) were reported by 24% of the patients and an additional 39% experienced occasional symptoms. Heartburn, acid regurgitation and dysphagia were the most common symptoms and 18% reported that GER symptoms worsened their respiratory condition. Females and patients reporting weight loss had more symptoms (mean GSAS symptom score 4.9 vs. 4.0, p=0.025 and 5.3 vs. 4.2, p=0.04) and more severe symptoms (mean GSAS distress score 5.6 vs. 3.8, p=0.005 and 6.8 vs. 4.0, p=0.01) compared to males and those who did not report weight loss. Patients on acid suppression (n=122, 61%) continued to report heartburn (n=80, 66%) and acid regurgitation (n=47, 23%). GER symptoms and severity of symptoms were not predictive of FEV(1) or FVC.

CONCLUSIONS

GER symptoms were present in a majority of patients. Females and patients with weight loss require special attention to their GER symptoms. Many patients on acid suppression continued to be report symptoms.

Inflammatory biomarker profile in children with cystic fibrosis: preliminary study

The aim of this preliminary study was to determine specific proteins, related to inflammation process and nutritional status as well as to total antioxidant capacity, in children suffering from cystic fibrosis (CF). The study was performed on 17 nonhospitalized children (12 boys and 5 girls) with CF aged 3 months to 10 years, who were assisted at the Nutrition Service from Pedro de Elizalde Hospital. Transferrin, transthyretin, ceruloplasmin (Cp), haptoglobin, C-reactive protein (CRP) and fibrinogen were measured by single radial immunodiffusion techniques. Total antioxidant capacity (TAC) was determined by a decolorization assay. Statistical analyses were performed by the Student's t test. Transferrin and transthyretin values were lower in CF patients in comparison with data obtained from healthy children (reference group, RG). The decreased transferrin concentration and the tendency towards low plasma transthyretin values suggested an abnormal nutritional status. However, higher Cp and haptoglobin levels were shown in patients than in RG. The fact that 23 and 50% of patients exceeded the desirable values for fibrinogen (<285·0 mg/dl) and CRP (<0·2 mg/dl), respectively, should be highlighted. The TAC (mM; Trolox equivalents) was shown to be lower in the CF group than in RG. The diminished TAC concomitant with an increased plasma Cp concentration would exacerbate the inflammatory status and could explain the depression of the immune system. These preliminary results could explain the need to include biochemical and functional parameters in the early nutritional status evaluation in CF patients in order to use appropriate nutritional and pharmacological therapies and consequently to improve their survival and quality of life.

CFTR depletion results in changes in fatty acid composition and promotes lipogenesis in intestinal Caco 2/15 cells

Background

Abnormal fatty acid composition (FA) in plasma and tissue lipids frequently occurs in homozygous and even in heterozygous carriers of cystic fibrosis transmembrane conductance regulator (CFTR) mutations. The mechanism(s) underlying these abnormalities remained, however, poorly understood despite the potentially CFTR contributing role.

Methodology/Principal Findings

The aim of the present study was to investigate the impact of CFTR depletion on FA uptake, composition and metabolism using the intestinal Caco-2/15 cell line. shRNA-mediated cftr gene silencing induced qualitative and quantitative modifications in FA composition in differentiated enterocytes as determined by gas-liquid chromatography. With the cftr gene disruption, there was a 1,5 fold increase in the total FA amount, largely attributable to monounsaturated and saturated FA compared to controls. The activity of delta-7 desaturase, estimated by the 16:1(n-7)/16:0, was significantly higher in knockdown cells and consistent with the striking elevation of the n-7 FA family. When incubated with [¹⁴C]-oleic acid, CFTR-depleted cells were capable of quick incorporation and export to the medium concomitantly with the high protein expression of L-FABP known to promote intracellular FA trafficking. Accordingly, lipoprotein vehicles (CM, VLDL, LDL and HDL), isolated from CFTR knockdown cells, exhibited higher levels of radiolabeled FA. Moreover, in the presence of [¹⁴C]-acetate, knockdown cells exhibited enhanced secretion of newly synthesized phospholipids, triglycerides, cholesteryl esters and free FA, thereby suggesting a stimulation of the lipogenic pathway. Conformably, gene expression of SREBP-1c, a key lipogenic transcription factor, was increased while protein expression of the phosphorylated and inactive form of acetylCoA carboxylase was reduced, confirming lipogenesis induction. Finally, CFTR-depleted cells exhibited lower gene expression of transcription factors (PPARα, LXRα, LXRβ and RXRα).

Conclusions/Significance

Collectively, our results indicate that CFTR depletion may disrupt FA homeostasis in intestinal cells through alterations in FA uptake and transport combined with stimulation of lipogenesis that occurs by an LXR/RXR-independent mechanism. These findings exclude a contributing role of CFTR in CF-associated fat malabsorption.

The behavioral phenotype of school-age children with shwachman diamond syndrome indicates neurocognitive dysfunction with loss of Shwachman-Bodian-Diamond syndrome gene function

OBJECTIVE

To investigate the cognitive, behavioral and adaptive functioning of children with Shwachman-Diamond syndrome (SDS).

STUDY DESIGN

Thirty-two children with SDS (6-17 years) were evaluated by use of standardized neuropsychological tests. Results were compared with normative data, unaffected siblings (n = 13), and age-and sex-matched children with cystic fibrosis (CF; n = 20).

RESULTS

Although intragroup variability in performance was evident, children with SDS displayed weaker overall intellectual reasoning, higher-order language skills, perceptual reasoning, visual-motor processing speed, visual motor- integration, visual executive problem-solving, attention, and aspects of academic achievement, as well as lower functional level of independence relative to the general population. Significant issues with behavior were also identified, including prior formal diagnoses and social problems. Lower abilities were found relative to sibling and CF control subjects and were not associated with secondary complications of SDS, age, or sex.

CONCLUSION

Neurocognitive deficits in subjects with SDS are largely independent of family environment and having a chronic illness and are likely the consequences of Shwachman-Bodian-Diamond syndrome gene dysfunction. There is a need for a broad-based approach to the assessment of cognitive function and appropriate remediation of individuals with SDS.

Association between nutritional status measurements and pulmonary function in children and adolescents with cystic fibrosis

OBJECTIVE

To evaluate the association between nutritional status measurements and pulmonary function in children and adolescents with cystic fibrosis.

METHODS

We evaluated the nutritional status of 48 children and adolescents (aged 6-18 years) with cystic fibrosis based on body mass index (BMI) and body composition measurements-mid-arm muscle circumference (MAMC) and triceps skinfold thickness (TST)-at a referral center in the city of Rio de Janeiro, Brazil. Pulmonary function was assessed by means of spirometry, using FEV1 to classify the severity of airway obstruction. We used Student's t-tests for comparisons between proportions and linear regression analysis for associations between continuous variables. The level of significance was set at p < 0.05.

RESULTS

The evaluation of nutritional status based on BMI identified a smaller number of malnourished patients than did that based on MAMC (14 vs. 25 patients, respectively). Most of the patients presented mild pulmonary disease. Mean FEV1 was 82.5% of predicted. Pulmonary function was found to correlate significantly with BMI, MAMC and TST (p = 0.001, p = 0.001 and p = 0.03, respectively). All subjects with moderate or severe pulmonary involvement were considered malnourished based on BMI and body composition parameters. Of the 25 patients considered malnourished based on body composition (MAMC), 19 were considered well-nourished based on their BMI.

CONCLUSIONS

In the present study, all nutritional status measurements correlated directly with the pulmonary function of children and adolescents with cystic fibrosis. However, body composition measurements allowed earlier detection of nutritional deficiencies.

Growth assessment of paediatric patients with CF comparing different auxologic indicators: A multicentre Italian study

OBJECTIVES

To evaluate growth in Italian patients with cystic fibrosis (CF).

PATIENTS AND METHODS

A multicentre cross-sectional study was carried out on patients with CF attending Italian reference centres. Anthropometric data were evaluated using the Centers for Disease Control and Prevention 2000 reference data. Nutritional failure was defined as height-for-age percentile (HAP) <5th (all patients); weight-for-length percentile (WLP) <10th (patients <2 years); body mass index percentile (BMIp) <15th (patients between 2 and 18 years). The risk of malnutrition (defined as HAP, WLP, and BMIp <25th) and the proportion of patients below the "BMIp goal" (BMIp > or =50th) were also evaluated. Nutritional status was evaluated in the whole population and in relation to age, sex, pancreatic insufficiency, meconium ileus, and lung function.

RESULTS

A total of 892 patients with CF (50.7% males, mean age 9.2 years, range 0.1-18 years) were enrolled. The proportion of children with HAP <5th, WLP<10th and BMIp<15th was 12.2%. 12.9%, 20.9%, respectively, and 54.4% did not fulfill the BMIp > or =50th goal. HAP <25th identified the highest proportion of children at risk of malnutrition, whereas BMIp <15th identified the highest proportion of children with nutritional failure. Whatever the criterion used to define malnutrition, the highest proportion of children with nutritional failure was found in adolescence (11-18 years). z scores for height, weight, and BMI were significantly associated with pancreatic status and lung function. Differences among centres for the auxologic parameters were not significant, except for BMIp.

CONCLUSIONS

Nutritional failure is present in a minority of Italian patients with CF, particularly during adolescence. Different auxologic indicators should be used for identifying children at risk for or with actual malnutrition.

Symposium 6: Young people, artificial nutrition and transitional care The nutritional challenges of the young adult with cystic fibrosis: transition

Cystic fibrosis (CF) is a complex multisystem disorder affecting mainly the gastrointestinal tract and respiratory system. Intestinal malabsorption occurs in approximately 90% of patients. In the past, malnutrition was an inevitable consequence of disease progression, leading to poor growth, impaired respiratory muscle function, decreased exercise tolerance and immunological impairment. A positive association between body weight and height and survival has been widely reported. The energy requirements of patients with CF vary widely and generally increase with age and disease severity. For many young adults requirements will be 120–150% of the age-related estimated average requirement. To meet these energy needs patients are encouraged to eat a high-fat high-energy diet with appropriate pancreatic enzyme supplements. Many patients are unable to achieve an adequate intake as a result of a variety of factors including chronic poor appetite, infection-related anorexia, gastro-oesophageal reflux and abdominal pain. Oral energy supplements and enteral tube feeding are widely used. Nutritional support has been shown to improve nutritional status and stabilise or slow the rate of decline in lung function. With such emphasis on nutritional intake and nutritional status throughout life, poor adherence to therapies and issues relating to body image are emerging. The median survival of patients with CF is increasing. CF is now considered a life-limiting disease of adulthood rather than a terminal childhood illness. With increased longevity new challenges are emerging that include the transition of young adults with CF to adult services, CF-related diabetes, disordered eating, osteoporosis, liver disease and transplantation.

Growth and long-term lung function in cystic fibrosis: a longitudinal study of patients diagnosed by neonatal screening

OBJECTIVE

So far there is no long-term analysis relating the achievement of growth milestones (such as prepubertal and pubertal take-off and peak velocity) to the course of respiratory function from childhood to adulthood in cystic fibrosis. This study was designed to evaluate linear growth and severity of lung disease, find a correlation between growth and disease severity throughout childhood.

PATIENTS

One hundred sixty-three patients from one center were selected according to: diagnosis by neonatal screening, complete follow-up available (four height measurements/year) until the age of 20, respiratory tests available from the age of 5-6 years until adulthood, lung transplantation, or death. Disease was classified as mild or severe according to FEV(1) (group 1 and group 2). A third group of patients (group 3) consisted of those who died or underwent lung transplantation before the age of 18.

METHODS

Individual growth profiles were fitted with a seven-constant nonlinear growth function. A multivariate linear model was fitted, with gender and severity of disease as covariates, and age, height, and height velocity at growth milestones as dependent variables. Data were compared with those of the normal Italian population.

RESULTS

Lung disease severity correlates with delayed prepubertal and pubertal growth milestones. Peak height velocities were significantly reduced in relation to the severity of the disease.

CONCLUSIONS

Patients with severe forms of cystic fibrosis exhibit reduced growth velocity values at an early age, before a clear decline in pulmonary function.

Intensive care management of the patient with cystic fibrosis

Cystic fibrosis was previously thought to be a disease of childhood. With a better understanding of this condition along with improvements in therapy, patients with cystic fibrosis are now living well into adulthood. The aim of this article is to familiarize the intensive care unit physician with cystic fibrosis care, to discuss complications associated with cystic fibrosis specifically related to the intensive care unit, and to detail the current recommendations for the clinical management of the patient with cystic fibrosis. With advancing disease, the most severely affected organs are the lungs. Obstruction, infection, and inflammation contribute to the decline of pulmonary function, ultimately leading to death. Some patients may be eligible for lung transplantation, but choosing wisely will affect posttransplant survival. Because other organs are affected by the genetic defect and associated treatments, serious complications related to the liver, pancreas, intestines, and kidneys must be considered by the intensivist faced with a patient with cystic fibrosis. As practitioners, the fact that not all patients will survive and help our patients and families gracefully through the end-of-life process should be accepted.

Liver disease in cystic fibrosis

PURPOSE OF REVIEW

This review highlights recent developments in liver disease associated with cystic fibrosis.

RECENT FINDINGS

The broad spectrum of hepatobiliary problems in cystic fibrosis includes specific alterations ascribable to the underlying defect as well as lesions of iatrogenic origin or that reflect the effects of a disease process occurring outside the liver. Focal biliary cirrhosis, resulting from biliary obstruction and progressive periportal fibrosis, is the most clinically relevant problem, because extension of the initially focal fibrogenic process may lead to multilobular biliary cirrhosis, portal hypertension and eventually liver failure. Cystic fibrosis associated liver disease is presently classified among genetic cholangiopathies and results from lack or dysfunction of the cystic fibrosis transmembrane regulator at the apical membrane of bile duct cells. Major advances have been achieved regarding characterization of natural history, risk factors, diagnostic modalities and treatment options.

SUMMARY

Liver disease is a relatively frequent and early complication of cystic fibrosis. The pathogenesis is apparently multifactorial, with contributions from environmental and genetic determinants. Its impact on quality of life and survival will increase in future years, and its early detection and treatment will become increasingly important issues. Ursodeoxycholic acid is the only treatment currently available, but novel therapeutic options are being evaluated.

Nutrition in pediatric lung disease

The respiratory system exists in an oxygenated milieu and is recurrently exposed to both endogenous and exogenous oxidants and irritants. A variety of dietary-dependent defenses have evolved to protect the lungs. These comprise vitamins, proteins, polyphenols, fatty acids and co-factors. This is a brief review of oxidant sources and the antioxidant system, as pertains to the respiratory system. The challenge to both clinicians and investigators is to understand how defenses are integrated and coordinated so that enhanced protection can be delivered.

Impact of nutrition on phenotype in CFTR-deficient mice

To elucidate the impact of nutrition in cystic fibrosis (CF), we compared the phenotypic traits of Cftr -/- mice fed either a lipid-enriched liquid diet (Peptamen) or a standard chow combined with polyethylenglycol osmotic laxative (PEG), two strategies commonly used to prevent intestinal obstruction in CF mice. Survival, growth, liver, and ventilatory status were determined in Cftr -/- and Cftr +/+ mice, followed-up until 120 d. Ventilation was recorded in conscious animals using whole-body plethysmography. We found that the survival rate was similar in Peptamen and PEG Cftr -/- mice. Cftr -/- mice had lower minute ventilation than Cftr +/+ mice, whatever the diet. Both Cftr -/- and Cftr +/+ mice fed Peptamen displayed preadult growth delay compared with PEG-treated animals. Despite subsequent growth catch-up, Cftr -/- mice remained smaller than Cftr +/+ mice, whatever the diet. All Peptamen fed Cftr -/- mice showed hepatomegaly and liver steatosis, which also occurred but to a lesser extent in Peptamen fed Cftr +/+ animals. Therefore, while both treatment strategies are similarly efficient to avoid high mortality at weaning, Peptamen induces preadult growth delay and liver steatosis. These effects of diet are important to consider in future animal studies and also prompt to evaluate high-energy diets in CF patients.

[Analysis of energy expenditure in adults with cystic fibrosis: comparison of indirect calorimetry and prediction equations]

OBJECTIVE

Undernutrition, which implies an imbalance between energy intake and energy requirements, is common in patients with cystic fibrosis. The aim of this study was to compare resting energy expenditure determined by indirect calorimetry with that obtained with commonly used predictive equations in adults with cystic fibrosis and to assess the influence of clinical variables on the values obtained.

PATIENTS AND METHODS

We studied 21 patients with clinically stable cystic fibrosis, obtaining data on anthropometric variables, hand grip dynamometry, electrical bioimpedance, and resting energy expenditure by indirect calorimetry. We used the intraclass correlation coefficient (ICC) and the Bland-Altman method to assess agreement between the values obtained for resting energy expenditure measured by indirect calorimetry and those obtained with the World Health Organization (WHO) and Harris-Benedict prediction equations.

RESULTS

The prediction equations underestimated resting energy expenditure in more than 90% of cases. The agreement between the value obtained by indirect calorimetry and that calculated with the prediction equations was poor (ICC for comparisons with the WHO and Harris-Benedict equations, 0.47 and 0.41, respectively). Bland-Altman analysis revealed a variable bias between the results of indirect calorimetry and those obtained with prediction equations, irrespective of the resting energy expenditure. The difference between the values measured by indirect calorimetry and those obtained with the WHO equation was significantly larger in patients homozygous for the DeltaF508 mutation and in those with exocrine pancreatic insufficiency.

CONCLUSIONS

The WHO and Harris-Benedict prediction equations underestimate resting energy expenditure in adults with cystic fibrosis. There is poor agreement between the values for resting energy expenditure determined by indirect calorimetry and those estimated with prediction equations. Underestimation was greater in patients with exocrine pancreatic insufficiency and patients who were homozygous for DeltaF508.

Nutrition and Lung Disease in Cystic Fibrosis

Among patients who have cystic fibrosis (CF), lung disease is a significant contributor to morbidity. From a clinical perspective, the link between malnutrition and lung dysfunction in CF is well established; however, the causal relationship remains unclear. Nutritional intervention for CF patients is predicated on the hypothesis that improved nutritional status improves pulmonary function. Which interventions will be of most value and have sustained gains is not completely clear from the available data. Taking into account that several factors condition the deficits that lead to malnutrition in CF, multidisciplinary interventions are likely to give the best results. More research is needed to better dissect the nutritional factors involved in lung disease and to identify effective and safe interventions through systematic controlled trials.

Update on enteral nutrition support for cystic fibrosis

Cystic fibrosis (CF) is an inherited disease affecting the respiratory, gastrointestinal, hepatobiliary, and reproductive systems. Nutrition status in persons with CF is often compromised due to increased energy needs, frequent infections, pancreatic insufficiency, lung disease, or CF-related diabetes. Maintaining good nutrition status has been associated with better pulmonary function, reduced hospitalizations, and increased longevity. Nutrition support as oral supplementation (used in >37% of the CF population) or tube feeding (used in >13% of the CF population) is often required for children and adults with CF. The purpose of this update is to describe current consensus and evidence for enteral nutrition support guidelines, reported complications of enteral feeding in the CF population, evidence of expected outcomes, and to discuss related areas requiring further research. A case report is provided to illustrate potential outcomes of aggressive enteral support.

Long term nutritional rehabilitation by gastrostomy in Israeli patients with cystic fibrosis: clinical outcome in advanced pulmonary disease

OBJECTIVES

Several studies have shown a linear correlation between nutritional status and pulmonary function in patients with cystic fibrosis. Our study aims were: 1) To evaluate the effect of nutritional supplementation via gastrostomy on nutritional, clinical, and pulmonary parameters, and 2) To identify predicting factors for success of long-term nutritional rehabilitation.

METHODS

Twenty-one Israeli patients, aged 8 months to 20 years, underwent gastrostomy insertion from 1992 to 2001. All patients were pancreatic insufficient, and all carried severe mutations (W1282X in 62% of the patients). Anthropometric and clinical data were obtained for each patient: 0-12 months before and 6-12 months and 18-24 months after gastrostomy placement. Standard deviation scores (SDS) for height, weight, and body mass index as well as percent of height-appropriate body weight were calculated.

RESULTS

The mean percent-of-predicted forced expiratory volume in 1 second (FEV1) decreased significantly during the first year of gastrostomy feeding (n = 16), from 44.2% +/- 13.9 to 41% +/- 13.3 (P = 0.05). However, during the second year of therapy (n = 10), a trend toward improvement was observed (from 39.4 +/- 12.1 to 41.4 +/- 16.1). Weight, and BMI z-scores as well as weight percent-of ideal body weight increased significantly. Height z-score for age decreased during the first year (from -1.9 +/- 1.3 to -2.1 +/- 1.4), However, a trend toward improvement was observed during the second year. A significant correlation was found between the change in weight z-score and height z-score during the first (r = 0.488, P = 0.016) and the second (r = 0.825, P < 0.001) years. There was no difference between compliers and noncompliers regarding height, weight, and BMI either before or after gastrostomy placement. A significant correlation between age at insertion of gastrostomy and improvement in height z-score (r = 0.52, P = 0.016) was observed. Cystic fibrosis related diabetes (n = 8) did not affect the response to supplemental feeding.

CONCLUSIONS

We observed a trend toward improvement of pulmonary disease during the second year, and a significant improvement in weight, height, and BMI z-scores. Compliance, diabetes, and young age prior to tube insertion did not predict success of nutritional rehabilitation.

Mouse as a model of growth retardation in cystic fibrosis

Cystic fibrosis (CF) is an autosomal recessive disease that results in lung failure and premature death. A long recognized symptom of CF is growth failure, which is clinically relevant because it correlates with the severity of lung disease. We describe growth retardation in a mouse model of CF and discuss its potential for modeling certain aspects of human growth retardation. Mice with a null mutation in Cftr (cystic fibrosis transmembrance conductance regulator) were compared with wild-type (WT) mice at 31, 45, and 84 d of age. CF mice were severely growth retarded in weight and length compared with wild-type controls. Serum insulin like growth factor I (Igf-1) was lower in CF mice by 31-55% (depending on age and sex) and it significantly correlated with the size of mice after controlling for gender, age, and Cftr genotype. There was a marginally significant deficiency of serum growth hormone (Gh) in CF females, but not males. Our findings were consistent with models of an energy deficit in rodents. We, therefore, assessed food intake and found no difference between CF and WT mice, suggesting that CF mice had a malabsorption-mediated energy deficit. We argue that CF mice are suited to study the effects of intestinal disease on growth as well as other proposed growth-modulating processes.

Adolescent development and energy expenditure in females with cystic fibrosis

BACKGROUND AND AIMS

Poor nutrition and growth status are common in people with cystic fibrosis (CF), and females often have a worse clinical course. Relationships between sexual maturity, nutrition, resting energy expenditure (REE), and pulmonary status in females with CF and pancreatic insufficiency (PI) were evaluated.

METHODS

Pre- and post-menarcheal females with CF and PI (8-29 yr) were compared to healthy females. Z-scores for growth and body composition, anthropometry and DEXA were assessed. REE was measured in all subjects and pulmonary function in CF.

RESULTS

Compared to healthy females (n=28, 14.6+/-4.1 yr), females with CF (n=16, 14.7+/-4.4 yr) had lower height Z (-0.1+/-0.9 versus -0.9+/-0.9, P=0.009) and muscle area Z (0.8+/-1.3 versus -0.4+/-1.2, P=0.007), and higher REE (100+/-10 versus 110+/-11% predicted, P=0.008). Difference in REE was more pronounced for post-menarcheal girls. REE adjusted for fat and fat-free mass was significantly higher with CF (+110 calories/day), and declined with menarcheal age in all subjects. FEV1 was positively associated with BMI Z score, and negatively associated with age at menarche.

CONCLUSIONS

Height and muscle stores were reduced and REE elevated in subjects with CF compared to healthy controls. Poorer growth and nutritional status and delayed menarche were associated with poorer pulmonary function in CF and were likely related to the cumulative effect of energy imbalance on growth and body composition.

Child behavior and parent management strategies at mealtimes in families with a school-age child with cystic fibrosis

Parent and child mealtime behaviors in school-age children with cystic fibrosis (CF; n = 28) and children without CF (n = 28) were examined during dinner meals by using multivariate analysis of variance. Parents of children with CF were found to differ from comparison parents in the frequency and rate of child management strategies. No differences were found in child behaviors. As the meal progressed, children displayed an increase in behaviors incompatible with eating, and parents increased behaviors to encourage eating. Slow eaters (> 20 min) with CF consumed more calories at the dinner meal than fast eaters (< 20 min) but did not achieve a higher daily caloric intake. Interventions targeting improvement of parent- child interactions during the mealtime are needed to achieve optimal dietary intake.

Failure of conventional strategies to improve nutritional status in malnourished adolescents and adults with cystic fibrosis

The use of oral dietary supplements was compared with dietary counseling in 13 malnourished patients (3 males, mean age 18.1 years) with cystic fibrosis. Energy intake and nutritional status were evaluated over 3 months. There was no significant change in energy intake or percent ideal body weight in either group.

Shwachman-Kulczycki score and resting energy expenditure in cystic fibrosis

BACKGROUND

Disease severity assessed by clinical scores in cystic fibrosis (CF) has been a topic of investigation for many years, although a correlation of clinical scores with resting energy expenditure (REE) has not been described yet. We aimed to assess disease severity as evaluated by the Shwachman-Kulczycki (SK) score and to correlate these findings with REE and forced expiratory volume in 1 s (FEV1).

METHODS

Twenty-eight patients performed respiratory function testing (FEV1), and assessment of REE with open circuit indirect calorimetry. The SK score was evaluated according to general activity, physical examination, nutrition and conventional chest X-ray findings.

RESULTS

Mean SK score was 75.3 +/- 15.7. Mean REE was 109.1% of predicted vs. 96.5% predicted in 16 healthy subjects (P = 0.002). There was a significant correlation between the SK score and REE (P = 0.001), the SK score and FEV1 (P < 0.001) and REE and FEV1 (P = 0.034).

CONCLUSIONS

The correlations between the SK score, REE and FEV1 demonstrate a close connection between disease severity, caloric requirement and lung damage. They confirm the clinical value of the SK score, which is easy to assess in a clinical setting.

Inflammation of the cystic fibrosis mouse small intestine

The CFTR null mouse [cystic fibrosis (CF) mouse] has a severe intestinal phenotype that serves as a model for CF-related growth deficiency, meconium ileus, and distal intestinal obstructive syndrome. DNA microarray analysis was used to investigate gene expression in the CF mouse small intestine. Sixty-one genes exhibited a statistically significant twofold or greater increase in expression, and 98 genes were downregulated twofold or greater. Of the upregulated genes, most were associated with inflammation and included markers for cells of the innate immune system (mast cells and neutrophils) and for acute-phase genes (serum amyloid A and complement factors). The downregulated genes include 10 cytochrome P-450 genes; several are involved in lipid metabolism, and several are involved in various transport processes. Confirmation by quantitative RT-PCR showed gene expression was significantly increased for mast cell protease 2 (27-fold), hematopoietic cell transcript 1 (17-fold), serum amyloid A3 (2.9-fold), suppressor of cytokine signaling 3 (2.0-fold), leucine-rich alpha(2)-glycoprotein (21-fold), resistin-like molecule-beta (49-fold), and Muclin (2.5-fold) and was significantly decreased for cytochrome P-450 4a10 (28-fold) and cubilin (114-fold). Immune cell infiltration was confirmed histologically by staining for mast cells and neutrophils. These data demonstrate that the CF intestine exhibits an inflammatory state with upregulation of components of the innate immune system.

Factors affecting clinical outcome in gastrostomy-fed children with cystic fibrosis

In order to assess the effects of gastrostomy feeding on nutritional status, respiratory function, and survival in children with cystic fibrosis (CF), we studied all patients undergoing gastrostomy between 1989-1997 at the Royal Children's Hospital, Melbourne. Clinical information was collected from medical records, including serial measurements of weight-for-age standard deviation scores (WAZ) and forced expired volume in 1 sec (FEV1) (percent predicted). Measurements were compared for 2 years before and 2 years after gastrostomy placement. Data on gastroesophageal reflux (GER), adherence to the gastrostomy feeding program, and sputum culture were also assessed. Of 37 children (22 male; mean age, 11.6 +/- 4.8 years; range, 3-20), 11 died during the study period (7 female, 4 male). Female patients were more likely to die within 2 years of gastrostomy placement (OR = 3.9; 95% CI, 0.72-23.2; P = 0.07). Mortality was significantly associated with a WAZ score < -2 (OR = 10.7; 95% CI, 1.07-466.6; P = 0.02) and predicted FEV1 < 50% (OR = 10.8; 95% CI, 1.07-512.9; P = 0.02) at time of gastrostomy. Patients with clinical evidence of GER (n = 11) had significantly lower weight gain after gastrostomy (delta WAZ, -0.32 +/- 0.26 vs. 0.03 +/- 0.39; P = 0.03). In conclusion, the presence of advanced lung disease, GER, and female gender were factors associated with a poor clinical outcome after gastrostomy placement.

Cystic fibrosis-related diabetes

Diabetes mellitus (DM) has been recognized as a complication of cystic fibrosis (CF) for almost 50 years and commonly develops around 20 years of age. The prevalence increases with age and, with improved survival of those with CF, approaches 30% in certain centres. Its development appears to have a significant impact on pulmonary function and may increase mortality by up to six-fold. Subjects with CF are rarely ketosis-prone and phenotypically lie between Type 1 and Type 2 DM. Microvascular complications are recognized, although paucity of data does not permit a clear description of their natural history. An annual oral glucose tolerance test from the age of 10 years is recommended for screening, but logistical difficulties have led some groups to develop specific algorithms to aid diagnosis. Insulin sensitivity in CF is much debated and may depend upon the degree of glucose intolerance. Insulin resistance occurs in the presence of infection, corticosteroid usage and hyperglycaemia, whilst hepatic insulin resistance is considered an adaptation to CF. There is no universal consensus on the treatment of hyperglycaemia. With increased longevity of individuals with CF, greater numbers will develop diabetes and the diabetes physician is destined to play a greater role in the multidisciplinary CF team.

Transition of care between paediatric and adult gastroenterology. Cystic fibrosis

Advancement in treatment has resulted in a dramatic increase in life expectancy of patients with cystic fibrosis (CF) to well beyond 30 years of age in most centres. What was once a fatal genetic disease in childhood now sees over a third of its CF populations in adult clinics. The improved survival is multifactorial, but most attribute the reasons to more aggressive nutritional care along with better management of the gastrointestinal and pulmonary systems. Many of the nutritional and GI issues of paediatric patients remain similar when they become adults, except that there is the added psychosocial stress associated with this transition. This chapter aims to highlight the gastrointestinal and nutritional issues manifesting at the different stages of life from infancy to adulthood, and the recommended management.

Chest physiotherapy in infants with cystic fibrosis: to tip or not? A five-year study

There is controversy about the need for postural drainage physiotherapy in asymptomatic infants with cystic fibrosis (CF). We aimed to compare the effectiveness of standard postural drainage chest physiotherapy (SPT) with a modified physiotherapy regimen without head-down tilt (MPT) in young infants with CF. Twenty newly diagnosed infants with CF (mean age, 2.1 months; range, 1-4) were randomized to SPT or MPT. Parents kept a detailed symptom and treatment diary for the following 12 months. Serial chest radiographs, taken at diagnosis, 12 months, 2(1/2) years, and 5 years after diagnosis, were assessed using the Brasfield score. Pulmonary function tests were compared between groups after 5 years. Of the 20 infants, 16 (80%) completed the review at 12 months, and 14 (70%) at 2(1/2) and 5 years. Patients receiving SPT had more days with upper respiratory tract symptoms than those on MPT (70 +/- 32.8 vs. 37 +/- 24.9 days; P = 0.04) and required longer courses of antibiotics (23 +/- 28.5 vs. 14 +/- 11.2 days; P = 0.05). Chest x-ray scores were similar at diagnosis but were worse at 2(1/2) years for those receiving SPT (P = 0.03). Forced vital capacity and forced expired volume in 1 sec (FEV(1)) at 5-6 years was lower for SPT than for MPT (P < 0.05). In conclusion, MPT was associated with fewer respiratory complications than SPT in infants with CF.

Resting energy expenditure and lung disease in cystic fibrosis

Optimal nutritional support is considered to be an integral part in the management of cystic fibrosis (CF). Several factors contribute to increased resting energy expenditure (REE), which itself can lead to energy imbalance and thus contribute to deterioration of the nutritional status. We aimed to assess the impact of lung parenchyma damage on REE and correlated these findings with forced expiratory volume in 1 s (FEV(1)). Twenty patients performed respiratory function testing (FEV(1)), pulmonary high-resolution computed tomography (HRCT) and assessment of REE with open circuit indirect calorimetry. HRCT was scored by using a modified Bhalla method. Mean HRCT score was 8.4 and mean REE value was 108.4% predicted vs. 96.5% predicted of 16 healthy subjects (P<0.01). There was a significant correlation between HRCT score and REE (P<0.01), HRCT score and FEV(1) (P<0.001) and REE and FEV(1) (P<0.05). The correlations demonstrate a close correlation between lung damage and elevated REE in people with CF. Prevention of negative energy balance is an important part in follow-up of patients with CF. Any increase in REE should raise suspicion of progress in lung impairment.

Effect of an organized lipid matrix on lipid absorption and clinical outcomes in patients with cystic fibrosis

OBJECTIVES

To compare the absorption of a lysophosphatidylcholine, monoglyceride, and fatty acid matrix (organized lipid matrix, OLM) with that of a triacylglycerol (TG)-based fat meal in patients with cystic fibrosis (CF).

STUDY DESIGN

Five adolescents with CF and 3 control patients were given fat meals supplemented with retinyl palmitate of either OLM or TG at a 2-week interval. In a clinical trial, 73 patients with CF were randomly assigned to nutritional supplements containing either OLM or TG for a 1-year double-blind trial followed by a 6-month observation period.

RESULTS

The peak increases and areas under the curve for TG and retinyl palmitate after the fat meal were 10-fold higher after OLM than after the TG fat load and did not differ from values obtained in control patients. OLM led to better clinical outcomes in terms of energy intake from the diet, weight-for-age Z score, essential fatty acid status, vitamin E, and retinol binding protein. Height-for-age Z score and FEV(1) only reached statistical significance at the end of the 6-month observation period.

CONCLUSIONS

These results suggest that OLM is a readily absorbable source of fat and energy in CF and is an effective nutritional supplement.

Relationship between nutritional status and lung function in cystic fibrosis: cross sectional and longitudinal analyses from the German CF quality assurance (CFQA) project

BACKGROUND

The German cystic fibrosis (CF) quality assurance (CFQA) project is a patient registry for CF which was founded in 1995. Relevant clinical and laboratory data, respiratory function test results, complications, and CF treatments are entered into the database once a year for each patient. Using the database, a study was undertaken to elucidate the relationship between nutrition and lung function in a large patient cohort by cross sectional and longitudinal analysis.

METHODS

A cohort of 3298 patients above 2 years of age was analysed. Patients were grouped according to the presence or absence of malnutrition (wasting and/or stunting). Cross sectional and longitudinal analyses over 2 and 3 years including mixed model analyses were performed.

RESULTS

The prevalence of abnormal weight for height (<90% predicted) increased with age from 19% in children aged <6 years to 38% in adults with CF. Patients with malnutrition had significantly lower mean values of vital capacity, arterial oxygen tension (PO(2)), and forced expiratory volume in 1 second (FEV(1)) and higher serum IgG (p<0.05). Pseudomonas aeruginosa infection was also associated with decreased pulmonary function. Malnourished adolescents aged 12-18 years experienced a serious decline in FEV(1) of about 20% predicted, whereas mean FEV(1) values remained stable at above 80% predicted in adolescents of normal weight. Longitudinal follow up showed that malnourished patients of all ages and those with P aeruginosa infection had significantly worse lung function than their normally nourished counterparts and a greater yearly loss of FEV(1) % predicted. During 1 year of observation adolescents who experienced a >5% predicted decrease in weight for height had a concomitant mean loss of FEV(1) of 16.5% predicted during that year, whereas patients who gained relative weight had a parallel increase in FEV(1) of 2.1% predicted.

CONCLUSIONS

These data emphasise the close relationship between nutrition, lung function, and clinical course in CF. Normal body weight and absence of P aeruginosa infection was associated with better preservation of lung function.