Nutrition and cystic fibrosis

Fecal dysbiosis in infants with cystic fibrosis is associated with early linear growth failure

Most infants with cystic fibrosis (CF) have pancreatic exocrine insufficiency that results in nutrient malabsorption and requires oral pancreatic enzyme replacement. Newborn screening for CF has enabled earlier diagnosis, nutritional intervention, and enzyme replacement for these infants, allowing most infants with CF to achieve their weight goals by 12 months of age¹. Nevertheless, most infants with CF continue to have poor linear growth during their first year of life¹. Although this early linear growth failure is associated with worse long-term respiratory function and survival^2,3, the determinants of stature in infants with CF have not been defined. Several characteristics of the CF gastrointestinal (GI) tract, including inflammation, maldigestion and malabsorption, could promote intestinal dysbiosis^4,5. As GI microbiome activities are known to affect endocrine functions^6,7, the intestinal microbiome of infants with CF might also impact growth. We identified an early, progressive fecal dysbiosis that distinguished infants with CF and low length from infants with CF and normal length. This dysbiosis included altered abundances of taxa that perform functions important for GI health, nutrient harvest, and growth hormone signaling, including decreased Bacteroidetes and increased Proteobacteria. Thus, the GI microbiota represent a potential therapeutic target to correct linear growth defects among infants with CF.

Immunonutrition in patients with cyctic fibrosis leads to drop of serum amyloid A and increase of oxidative stress

The aim of the present study is to evaluate of the impact of immunonutrition on parameters of oxidative stress and inflammation in patients with cystic fibrosis and malnutrition. In the 30 patients with cystic fibrosis and long-term enteral nutrition support for malnutrition the effect of standard and immunonutrion sipping on oxidative stress and inflammatory activity parameters was compared. Malonyldialdehyde (MDA) as parameter of oxidative stress and serum amyloid A (SAA), interleukin 1 and 6, hsCRP, IgM, IgA, IgG as parameters of inflammatory activity were examined. Immunonutrition decreased SAA to 17.6 mg/L comparing to 25.6 mg/L when standard nutrition was given (p = 0.014). MDA was 0.66 µM on standard and 0.96 µM on immunonutrition support (p<0.01). The significant negative correlation was recorded between MDA and SAA, hs-CRP, interleukin 6, IgA and IgG. In conclusion, the application of immunonutrition in patients with cystic fibrosis and malnutrition is associated with drop of SAA but with the rise of MDA.

Nutrition for Patients With Cystic Fibrosis

Cystic fibrosis (CF) is the most frequent, lethal genetic disorder among northern Europeans. The etiology of this autosomal recessive disease is known to be a defect in the cAMP activation of chloride (Cl-) channels in secretory cells in many organs of the body. Although this defect usually leads to severe lung disease, many of these patients also have nutritional deficiencies. Nutrition is one of the key components in the management of CF. Patients are at high risk for malnutrition, which may result in accelerated progression of the disease and increased morbidity. This review will discuss nutrition recommendations for calories, protein, vitamins and minerals, and enteral and parenteral nutrition support practices.

Diagnosis and treatment of endocrine comorbidities in patients with cystic fibrosis

PURPOSE OF REVIEW

The aim of this review is to provide an update on various relevant endocrine aspects of care in adolescents and adults with cystic fibrosis.

RECENT FINDINGS

As life expectancy in cystic fibrosis has continuously improved, endocrine complications have become more apparent. The common endocrine complications include cystic fibrosis related diabetes, cystic fibrosis related bone disease, vitamin D deficiency and poor growth and pubertal development. Thyroid and adrenal disorders have also been reported, although the prevalence appears to be less common.

SUMMARY

Endocrine diseases are an increasingly recognized complication that has a significant impact on the overall health of individuals with cystic fibrosis. This review summarizes the updated screening and management of endocrine diseases in the cystic fibrosis population.

Relationship Between Fat-Soluble Vitamin Supplementation and Blood Concentrations in Adolescent and Adult Patients With Cystic Fibrosis

Background: Pancreatic insufficiency is common in patients with cystic fibrosis (CF) and leads to malabsorption of fat-soluble vitamins. Multivitamins, including vitamins A, D, E, and K, are routinely prescribed to patients with CF to prevent vitamin deficiencies. Our objective was to examine the relationship between fat-soluble vitamin supplements and their impact on blood concentrations. Methods: This was a retrospective chart review of patients with CF who were treated at Emory Clinic and Emory University Hospital during 2008-2012. The amount of fat-soluble vitamin supplementation, serum markers of fat-soluble vitamin concentrations, CF transmembrane conductance regulator genotype, and other demographic information were recorded from electronic medical records. Mixed-effects models were used to investigate the trends over time of fat-soluble vitamin supplements and serum vitamin concentrations. Results: In total, 177 charts were eligible. Mean (SD) age was 26.1 (10.2) years. Ninety-two percent of patients had pancreatic insufficiency and 52% had the homozygous ΔF508 mutation. Recorded fat-soluble vitamin supplementation increased in the past 5 years (P < .001 for all). Serum 25-hydroxyvitamin D increased slightly (3% increase; P < .01); however, there were no changes in the blood concentrations of vitamins A, E, and K (P = .26-.96). Conclusions: Despite a near doubling of recorded fat-soluble vitamin supplementation over the past 5 years, there was no parallel increase in blood concentrations of these vitamins. Potential reasons include suboptimal dosages, low adherence, or ongoing issues with malabsorption.

Pathophysiology of cystic fibrosis and drugs used in associated digestive tract diseases

Cystic fibrosis (CF) causes chronic infections in the respiratory tract and alters the digestive tract. This paper reviews the most important aspects of drug treatment and changes in the digestive tract of patients with CF. This is a review of the literature, emphasizing the discoveries made within the last 15 years by analyzing scientific papers published in journals indexed in the Scientific Electronic Library Online, Sciences Information, United States National Library of Medicine and Medical Literature Analysis and Retrieval System Online databases, both in English and Portuguese, using the key words: cystic fibrosis, medication, therapeutic, absorption, digestion. Randomized, observational, experimental, and epidemiological clinical studies were selected, among others, with statistical significance of 5%. This review evaluates the changes found in the digestive tract of CF patients including pancreatic insufficiency, constipation and liver diseases. Changes in nutritional status are also described. Clinical treatment, nutritional supplementation and drug management were classified in this review as essential to the quality of life of CF patients, and became available through public policies for monitoring and treating CF. The information gathered on CF and a multi professional approach to the disease is essential in the treatment of these patients.

Avaliação e recomendações nutricionais para crianças e adolescentes com fibrose cística

OBJETIVO: Revisar e discutir evidências sobre a avaliação do estado nutricional e as recomendações para o tratamento nutricional de crianças e adolescentes com fibrose cística. FONTES DE DADOS: Bancos de dados MEDLINE (versão PubMed) e Latin American and Caribbean Center on Health Sciences Information (LILACS), entre 1984 a 2009. Aplicou-se a combinação dos seguintes descritores: fibrose cística, estado nutricional, criança e adolescente - em inglês e português. SÍNTESE DOS DADOS: A fibrose cística é uma doença genética, de evolução crônica, progressiva e fatal. Resulta do defeito na proteína reguladora transmembrana que regula a condução de cloro e, consequentemente, o fluxo de sódio e água através da membrana apical das células epiteliais. Pacientes fibrocísticos são vulneráveis à desnutrição, que resulta do desequilíbrio entre ingestão alimentar, gasto e perdas energéticas. Novos conhecimentos sobre a fisiopatologia da doença, adquiridos nas últimas décadas, resultaram em mudanças significativas nas atuais recomendações energéticas e principalmente de lipídeos. A importância da nutrição no bem-estar e sobrevida dos fibrocísticos está bem estabelecida, assim como a associação entre a desnutrição e a deterioração da função pulmonar. Existem múltiplos fatores inter-relacionados que afetam o estado nutricional, tais como, mutação genética, insuficiência pancreática, ressecção intestinal, perda de sais e ácidos biliares, refluxo gastroesofágico, inflamação e infecções pulmonares, diabetes e condições emocionais. CONCLUSÕES: O monitoramento nutricional e o aconselhamento dietético são elementos chave no manejo de crianças e adolescentes com fibrose cística com o intuito de controlar a sintomatologia e a progressão da doença, proporcionando melhor qualidade de vida.

Fibrose cística: uma abordagem clínica e nutricional

A fibrose cística é a doença genética letal mais comum em populações caucasianas e é caracterizada por infecções crônicas e recorrentes do pulmão, insuficiência pancreática e elevados níveis de cloro no suor. É uma doença de herança autossômica recessiva causada pela mutação no gene do Regulador da Condutância Transmembrana da Fibrose Cística, que induz o organismo a produzir secreções espessas e viscosas que obstruem os pulmões, o pâncreas e o ducto biliar. Muitos pacientes apresentam insuficiência pancreática, que leva a má-absorção de nutrientes especialmente de proteínas e lipídeos e a complicações gastrintestinais tais como prolapso retal, síndrome da obstrução intestinal, constipação e cirrose hepática. A fibrose cística normalmente é diagnosticada na infância, pelos programas de triagem neonatal ou pelo teste do suor. Devido aos vários sistemas envolvidos e à variabilidade e cronicidade da doença, uma abordagem multidisciplinar é essencial para auxiliar o paciente e sua família a compreenderem a doença e aderirem ao tratamento. A terapia atual da fibrose cística inclui a manutenção do estado nutricional, a remoção das secreções das vias aéreas com fisioterapia e mucolíticos, o uso de antibióticos para prevenção e tratamento de infecções, a prescrição de suplementos energéticos, dietas hiperlípidicas e hiperprotéicas, bem como a suplementação de minerais e vitaminas lipossolúveis. O objetivo deste trabalho foi realizar breve revisão de literatura sobre os aspectos clínicos e nutricionais da fibrose cística.

Growth outcomes and complications after radiologic gastrostomy in 120 children

BACKGROUND

Enteral feeding is ideal for children with low caloric intake. It can be provided through different methods, including nasogastric, nasojejunal, gastrostomy, or gastrojejunostomy tubes.

OBJECTIVE

To assess growth outcomes of pediatric patients following retrograde percutaneous gastrostomy (RPG) and compare complications with those following other gastrostomy methods.

MATERIALS AND METHODS

We retrospectively reviewed 120 random RPG patients from 2002 to 2003 (mean follow-up, 2.7 years). Patient weights and growth percentiles were recorded at insertion, and at 0-5 months, 6-12 months, and 18-24 months after insertion, and then compared using a Student's t-test. Complications and tube maintenance issues (TMIs) were recorded.

RESULTS

Gastrostomy tube insertion was successful in all 120 patients (59 boys, 61 girls; mean age 4.3 years). The most common underlying diagnosis was neurologic disease (29%, 35/120) and the main indication was inadequate caloric intake (24%, 29/120). Significant increases in growth percentile for the entire population were demonstrated between insertion and 0-5 months (18.7-25.3; P<0.001) and between insertion and 18-24 months (18.7-25.8; P<0.001). In boys and girls significant growth increases occurred between insertion and 0-5 months (boys P=0.004; girls P=0.01). There were 11 major postprocedural complications, 100 minor complications and 169 TMIs.

CONCLUSION

RPG provides long-term enteral nutrition in the pediatric population and increases growth significantly 6 and 24 months after insertion. Minor complications and TMIs are frequent.

Colonic energy salvage in chronic pancreatic exocrine insufficiency

BACKGROUND

Chronic pancreatic exocrine insufficiency results in maldigestion. As a result, increased amounts of undigested nutrients reach the colon, providing more substrate for bacterial fermentation to produce short-chain fatty acids, which could therefore provide additional energy supplement.

METHODS

This study aimed to assess carbohydrate malabsorption in patients with chronic pancreatic exocrine insufficiency after ingestion of a standard diet and to calculate energy salvaged by colonic bacterial metabolism. A 72-hour stool collection was done on 10 adult patients receiving a 3-day standard diet containing 100 g fat, 329 g carbohydrate, and 154 g protein, and short-chain fatty acids, fat, carbohydrate, and nitrogen excretion were assessed. A breath hydrogen test after ingestion of 200 g (dry weight) cooked maize meal (test meal) and 10 g oral inulin (standard), respectively, was subsequently done on the patients and 15 healthy adult controls.

RESULTS

Breath hydrogen production after ingestion of maize meal and inulin, respectively, and calculated carbohydrate malabsorption were significantly greater in patients (21.4% +/- 17%) than in controls (10.2 +/- 1.4%; p < .05). Patients malabsorbed 70.4 g/d (281.6 kcal) carbohydrate in the standard diet. Total carbohydrate loss in stool amounted to 8.1 g/d (2.4%), and 62.3 g/d (19%) was hence salvaged as short-chain fatty acids for energy provision. Colonic bacterial fermentation therefore converted 88.5% of malabsorbed carbohydrate to short-chain fatty acids, 92.8% of which was absorbed and 7.2% excreted. This suggests that 10.2% of energy expenditure/requirement in these patients is derived from salvage of malabsorbed carbohydrate.

CONCLUSIONS

Colonic bacterial metabolism is a significant source of energy salvage in patients with pancreatic enzyme deficiency.

Nutrient status of adults with cystic fibrosis

Nutrition is thought to influence disease status in patients with cystic fibrosis (CF). This cross-sectional study sought to evaluate nutrient intake and anthropometric data from 64 adult outpatients with cystic fibrosis. Nutrient intake from food and supplements was compared with the Dietary Reference Intakes for 16 nutrients and outcomes influenced by nutritional status. Attention was given to vitamin D and calcium given potential skeletal implications due to cystic fibrosis. Measurements included weight, height, body composition, pulmonary function, and serum metabolic parameters. Participants were interviewed about dietary intake, supplement use, pulmonary function, sunlight exposure, and pain. The participants' mean body mass index (+/-standard deviation) was 21.8+/-4.9 and pulmonary function tests were normal. Seventy-eight percent used pancreatic enzyme replacement for malabsorption. Vitamin D deficiency [25-hydroxyvitamin D (25OHD)<37.5 nmol/L] was common: 25 (39%) were deficient despite adequate vitamin D intake. Lipid profiles were normal in the majority, even though total and saturated fat consumption represented 33.0% and 16.8% of energy intake, respectively. Reported protein intake represented 16.9% of total energy intake (range 10%-25%). For several nutrients, including vitamin D and calcium, intake from food and supplements in many participants exceeded recommended Tolerable Upper Intake Levels. Among adults with cystic fibrosis, vitamin D deficiency was common despite reported adequate intake, and lipid profiles were normal despite a relatively high fat intake. Mean protein consumption was adequate, but the range of intake was concerning, as both inadequate or excessive intake may have deleterious skeletal effects. These findings call into question the applicability of established nutrient thresholds for patients with cystic fibrosis.

Vitamins A and E and pulmonary exacerbations in patients with cystic fibrosis

BACKGROUND

Increased levels of oxidative stress result in pulmonary damage contributing to the development of chronic lung disease in cystic fibrosis (CF). The aim of this study was to investigate the longitudinal effect of serum vitamin A and E levels on the incidence of pulmonary exacerbations in pancreatic insufficient (PI) and pancreatic sufficient (PS) patients with CF.

MATERIALS AND METHODS

Patient records were retrospectively examined over a 3-year period and serum vitamin A and E levels were retrieved. Subsequently, levels of vitamin A and E were prospectively measured over a 2-year period at the onset of intravenous antibiotic therapy for acute exacerbation and at the first recovery visit.

RESULTS

Retrospectively, 597 pulmonary exacerbations were identified in 102 patients, 74 PI and 28 PS, with a mean age of 11.1 +/- 6.4 years (range, 1.5-27 y). An increased number of exacerbations was directly correlated with lower vitamin A and E levels, even within the normal range. Prospectively, 62 exacerbations were analyzed (43 PI patients and 19 PS patients). At onset of exacerbation, vitamin A and E levels were reduced in the PI patients (P < 0.001; P < 0.001) and the PS patients (P < 0.005; P < 0.07).

CONCLUSIONS

Reduced serum levels of vitamin A and E even in the normal range are associated with an increased rate of pulmonary exacerbations in CF. Further studies are required to confirm the necessity of supplementation of vitamins A and E to PS patients.

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.

Normal adiponectin levels despite abnormal glucose tolerance (or diabetes) and inflammation in adult patients with cystic fibrosis

RATIONALE

Circulating adiponectin levels are negatively associated with glucose intolerance, inflammation and central adiposity. Since these conditions are common in cystic fibrosis (CF), we examined whether adiponectin values are altered in these patients.

AIM

To determine if CF patients have altered adiponectin levels and if these levels correlate with glucose tolerance categories (normal, impaired glucose tolerance (IGT) and cystic fibrosis-related diabetes (CFRD)), insulin resistance or inflammatory markers such as fibrinogen and C-reactive protein (CRP).

METHODS

Oral glucose tolerance tests (OGTTs) were performed and adiponectin levels were measured in 90 CF patients not known to be diabetic and 15 healthy controls matched for age, sex and body mass index (BMI). Inflammatory markers, serum albumin concentrations and the clinical status of CF patients (i.e. pulmonary function) were also examined.

RESULTS

CF pathology was characterized by a high prevalence (43.5%) of glucose tolerance abnormalities: 26.5% of IGT and 17.0% of newly diagnosed CFRD. CF patients also presented systemic inflammation as revealed by a significant increase of fibrinogen (P=0.029) in all patients and higher CRP levels in CFRD patients compared to the controls (P<0.05). On the other hand, CF and control subjects had similar albumin serum concentration. While CF patients and controls had similar serum adiponectin values, women had significantly higher hormone levels than men (P<0.001). Adiponectin levels did not correlate with glucose tolerance, inflammatory markers or insulin resistance. On the other hand, they correlated positively with both total and HDL-cholesterol (P<0.001).

CONCLUSION

CF patients did not show any alterations in adiponectin levels despite insulin resistance, glucose intolerance and sub clinical chronic inflammation. Thus, CF appears to be one of the rare conditions in which discordance between adiponectin values and insulin resistance or inflammation is evident.

Ghrelin and leptin levels in young adults with cystic fibrosis: relationship with body fat

BACKGROUND

Ghrelin and leptin are hormones implicated in energy balance coordination and body weight regulation. There are conflicting data regarding the levels and role of leptin while ghrelin has not been studied in CF. The aim of this study was to investigate fasting serum ghrelin and leptin levels in CF adolescents as compared to healthy controls and analyze their association with body fat.

METHODS

Fourteen CF adolescents having pancreatic insufficiency and twenty healthy adolescents were enrolled in the study. Diabetic patients were excluded. In all participants' height, weight, body mass index (BMI) and body fat % (BF %) were estimated. Ghrelin and leptin levels were determined after an overnight fast.

RESULTS

Weight, BMI and BF% were significantly lower in CF adolescents than those of controls. Fasting leptin levels in CF were significantly higher in CF patients (p=0.030), compared to controls and significantly lower in CF males as compared to CF females (p=0.01). Fasting ghrelin levels were significantly lower in CF males as compared to male controls (p<0.001) and comparable in females.

CONCLUSIONS

As the overall clinical outcome of CF patients is related to the nutritional status and body weight, the role of ghrelin and leptin in these patients needs to be elucidated.

Association of nutritional status and pulmonary function in children with cystic fibrosis

PURPOSE OF REVIEW

Multiple studies have shown that nutritional status is a strong predictor of morbidity and mortality in patients with cystic fibrosis (CF). Since CF is characterized by progressive lung disease, it could be argued that the underlying lung disease is what determines the nutritional failure seen in most patients. This review will summarize the data available from studies that have attempted to better define this relation and also present a review of the possible mechanisms involved taken from both observational and interventional studies.

RECENT FINDINGS

Longitudinal studies with sufficiently large follow-up times have demonstrated that young underweight patients have worst pulmonary function outcomes. More importantly, these studies concur in that the yearly change in growth parameters has a significant effect on the rate at which pulmonary function develops. Although the mechanisms behind this important association are yet unclear, there is some suggestion from interventional studies that the accrual of lean body mass is the factor that is involved in the preservation of lung function.

SUMMARY

Nutritional status strongly influences pulmonary health among CF patients. Therefore, aggressive nutritional support aiming at achieving normal growth patterns should lead to adequate development of lung function and maintenance of pulmonary health. However, more research is required with long-term longitudinal studies to better identify the most critical nutritional characteristics influencing this process as well as the most effective nutritional interventions.

Longitudinal changes in growth parameters are correlated with changes in pulmonary function in children with cystic fibrosis

OBJECTIVE

Nutritional status is associated with pulmonary health and survival in children with cystic fibrosis (CF). This study evaluated the weight gain pattern of children with CF in relation to the longitudinal trends of their pulmonary function. Our hypothesis was that children who experience continuous weight gain at a given rate will have better average forced expiratory volume in 1 second (FEV(1)) and change in FEV(1) than children who have weight gain patterns that deviate from this rate, even when total weight gain seems adequate.

METHODS

Prospectively collected data were examined in 319 children, aged 6 to 8, who were routinely followed at the Minnesota Cystic Fibrosis Center. One to 67 measurements of weight (kg), height (cm), and FEV(1) (mL) were taken per child during this 2-year period. The data were analyzed by repeated measure regression analysis and by growth pattern analysis.

RESULTS

At baseline, a 1-kg higher initial weight was associated with a 55-mL higher average FEV(1). During the follow-up period, a 1-kg gain in weight was associated with an increase in FEV(1) by 32 mL. Children who had a steady weight gain tended to experience greater increases in FEV(1) than children who experienced periodic losses in weight.

CONCLUSIONS

We established that children who weigh more and who gain weight at an appropriate and uninterrupted rate have a better FEV(1) trajectory. Aggressive nutritional support to maintain growth in these children may therefore improve FEV(1), which can be taken as a surrogate for better lung health, and may ultimately lead to better survival.

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.

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.

Therapy with macrolides in patients with cystic fibrosis

Cystic fibrosis affects 1/2500 individuals and is the most common lethal autosomal recessive disease in people of northern European descent. It is characterized by chronic infections with mucoid Pseudomonas aeruginosa and progressive deterioration of respiratory function. Much research has focused on the inflammatory component of the disease. Macrolide antibiotics are postulated to suppress inflammatory mediators and interfere with biofilm formation produced by P. aeruginosa. In vitro studies show promising results, and a limited number of human studies reported improvements in respiratory function with the drugs. Macrolide antibiotics are generally safe and well tolerated and may prove to be effective in patients with cystic fibrosis.

Changes in the exocrine pancreas secondary to altered small intestinal function in the CF mouse

The exocrine pancreas of the cystic fibrosis (CF) mouse (cftr(m1UNC)) is only mildly affected compared with the human disease, providing a useful model to study alterations in exocrine function. The CF mouse pancreas has approximately 50% of normal amylase levels and approximately 200% normal Muclin levels, the major sulfated glycoprotein of the pancreas. Protein biosynthetic rates and mRNA levels for amylase were not altered in CF compared with normal mice, and increases in Muclin biosynthesis and mRNA paralleled the increased protein content. Stimulated pancreatic amylase secretion in vitro and in vivo tended to be increased in CF mice but was not statistically significant compared with normal mice. We show for the first time that the CF mouse duodenum is abnormally acidic (normal intestinal pH = 6.47 +/- 0.05; CF intestinal pH = 6.15 +/- 0.07) and hypothesize that this may result in increased signaling to the exocrine pancreas. There were significant increases in CF intestinal mRNA levels for secretin (310% of normal, P < 0.001) and vasoactive intestinal peptide (148% of normal, P < 0.05). Furthermore, CF pancreatic cAMP levels were 147% of normal (P < 0.01). These data suggest that the CF pancreas may be chronically stimulated by cAMP-mediated signals, which in turn may exacerbate protein plugging in the acinar/ductal lumen, believed to be the primary cause of destruction of the pancreas in CF.

Antioxidant status in patients with cystic fibrosis

BACKGROUND

The aim of the study was to assess the antioxidant status in cystic fibrosis (CF) patients compared to healthy controls. In order to determine the influence of nutrition on the level of the antioxidants, nutrient intake was also monitored in both groups at the time of the antioxidant assessment.

SUBJECTS AND METHODS

The authors measured the serum malondialdehyde levels in children with CF, n = 21; 9 females and 12 males, mean age: 8.71 years (6-12 years) and compared these values to the levels found in age-matched healthy control subjects, n = 24; 13 females and 11 males, mean age: 8.33 years (6-12 years). In order to assess the antioxidant status, catalase and superoxide dismutase activities in washed erythrocytes, glutathione peroxidase activity of heparinized whole blood and serum ascorbic acid, alpha-tocopherol and retinol levels were measured. Total antioxidant status (TAS) was also tested. The patients with CF received vitamin supplementation in doses prescribed in international guidelines (alpha-tocopherol: <10 years 100 mg daily, >10 years 200 mg daily, retinol: 2.5 mg daily, ascorbic acid: 100-200 mg daily).

RESULTS

Plasma levels of malondialdehyde were significantly higher (p < 0.05), superoxide dismutase activities were significantly lower (p < 0.05) in patients with cystic fibrosis. There were no significant differences in catalase, glutathione peroxidase activities and TAS levels between CF patients and control group. Plasma ascorbic acid, alpha-tocopherol and retinol levels were within normal limits in both groups.

CONCLUSION

On the basis of the present results this regime failed to provide sufficient antioxidant protection. Therefore, the authors suggest that the daily dose of these antioxidants should be either increased or to administer in parenteral route to patients with severe form of the disease.

Improvement of nutrient absorption may enhance systemic oxidative stress in cystic fibrosis patients

BACKGROUND

The life expectancy of patients with cystic fibrosis (CF) is largely dependent on the pulmonary disease severity and progress. Malnutrition may be an important complicating factor in active and chronic lung disease.

AIMS

The focus of this study was to investigate several inflammatory markers in pancreatic-insufficient CF patients with different enzyme treatment regimens.

METHODS

CF patients with pancreatic insufficiency were examined at a time of symptomatic exacerbation of their lung disease. Group A (n = 11) regularly received microspheric enzymes. Group B (n = 8) were treated with enzymes during the hospitalization period only and demonstrated the presence of malnutrition. Inflammatory markers in the sputa (neutrophil elastase activity, interleukin-8 and tumour necrosis factor-alpha levels) and in the peripheral blood (plasma malondialdehyde (MDA), lymphocyte response to PHA, and the cell sensitivity to steroid suppression) have been investigated.

RESULTS

During acute lung exacerbation, group B demonstrated reduced levels of lymphocyte proliferation. This parameter was normalized after combined antibiotic and pancreatic enzyme therapy. Simultaneously, plasma MDA in group B markedly increased following treatment. For this group, a significant positive linear association between values of plasma MDA and lymphocyte proliferation has been observed. For group A, neither the same correlation nor changes in MDA levels and lymphocyte proliferation have been found.

CONCLUSIONS

Our data indicate that acute lung exacerbation in malnourished CF patients may be associated with alteration in T-lymphocyte activity. Adequate therapy normalizes lymphocyte function but results in systemic oxidative stress.

Challenges in the dietary treatment of cystic fibrosis related diabetes mellitus

Cystic fibrosis related diabetes mellitus is an increasingly recognized problem as survival in patients with cystic fibrosis improves. In a 5 year retrospective study of 627 children and adults attending Toronto cystic fibrosis clinics, we identified 57 (9%) patients with cystic fibrosis related diabetes mellitus; four (1.3%) of 301 children (<18 years) and 53 (16%) of 326 adults. The development of this complication of cystic fibrosis is associated with increased mortality, deteriorations in both respiratory and nutritional status, and the development of late microvascular, but not macrovascular, diabetic complications. Unfortunately, systematic review of the literature provides few well designed studies that provide sound evidence for clinical practice. Recommendations are therefore often based on anecdote, rather than physiological or outcomes research. Dietary therapy combines the principles of the dietary management of both cystic fibrosis and diabetes mellitus, but emphasizes the need for a high energy diet (> 100% of recommended daily intake) in patients with cystic fibrosis related diabetes mellitus. The importance of calories from fat is emphasized, with no restriction on total carbohydrate intake. Insulin intake mirrors carbohydrate intake. Routine dietary therapy is straightforward, but challenges occur due to both complications of cystic fibrosis and advancing disease. If a patient with cystic fibrosis related diabetes mellitus is malnourished, overnight enteral tube feeding is often used, with an adjusted insulin regimen. There is a great need for both physiological and outcomes research to provide sound scientific evidence for the dietary treatment of cystic fibrosis related diabetes mellitus.