Energy metabolism in infants with cystic fibrosis

Malnutrition in Children With Chronic Disease

Malnutrition occurs when nutrient intake does not meet the needs for normal body functions and as a consequence leads to alterations of growth and development in children. Chronic illness puts children at risk for developing malnutrition. Because of children's rapid periods of growth and development, early diagnosis, prevention, and management of malnutrition are paramount. The reasons for malnutrition in children with chronic disease are multifactorial and are related to the underlying disease and non-illness-associated factors. This review addresses the causes, evaluation, and management of malnutrition in pediatric congenital heart disease, chronic kidney disease, liver disease, and cystic fibrosis.

The Relation Between Malnutrition and the Exocrine Pancreas: A Systematic Review

OBJECTIVE

The relation between malnutrition and exocrine pancreatic insufficiency (EPI) has been described previously, but it is unclear if malnutrition leads to EPI or vice versa. We systematically synthesized current evidence evaluating the association between malnutrition and EPI in children.

METHODS

Pubmed, Embase, and Cochrane databases were searched from inception until February 2017. We included cohort or case-controlled studies in children reporting on prevalence or incidence of EPI and malnutrition. Data generation was performed independently by 2 authors. Quality was assessed by using quality assessment tools from the National Heart, Lung, and Blood Institute.

RESULTS

Nineteen studies were divided into 2 groups: 10 studies showing EPI leading to malnutrition, and 9 studies showing malnutrition leading to EPI. Because of heterogeneity in design, definitions, and outcome measures, pooling of results was impossible. Quality was good in 4 of 19 studies. Pancreatic insufficiency was linked to decreased nutritional status in 8 of 10 articles, although this link was not specified properly in most articles. In malnourished children, improvement was seen in pancreatic function in 7 of 9 articles after nutritional rehabilitation. The link between the 2 was not further specified. Heterogeneity exists with respect to definitions, outcome measures, and study design.

CONCLUSIONS

There is sufficient evidence for an association between EPI and malnutrition. We could not confirm whether there is a correlation or causality between EPI or malnutrition. It was therefore not possible to draw firm conclusions from this systematic review on underlying pathophysiological mechanisms between EPI and malnutrition. More observational clinical trials are crucially needed.

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.

Nutrional status and dietary factors in cystic fibrosis patients with delta F508 mutation

Objective To examine the association between nutritional status and dietary factors in children and adolescents with cystic fibrosis that are carriers of delta F508 mutation. Methods Cross-sectional study of cystic fibrosis children and adolescents. Nutritional status (body mass index percentile) and dietary intake (3-day diet records presented as a percentage of estimated energy requirement) were assessed. Results Thirty six patients (median of 8.6; interquartile range 6.8-12.5 years; 50% male). The Poisson regression analysis showed that the carriers for delta F508 mutation had 60% lower prevalence ratio of body mass index ≥25° (PR=0.4; 95%IC=0.2-0.8) and 90% lower prevalence ratio (PR=0.1; confidence interval 95%IC=0.02-0.3) of ≥150% of estimated energy requirement when compared with non-delta F508 mutation carriers. The model was adjusted for lung function, estimated energy requirement, and body mass index. Conclusion Carriers for delta F508 mutation showed lower body mass index percentile and lower daily caloric consumption when compared with patients without this mutation.

Serum metabolomics indicate altered cellular energy metabolism in children with cystic fibrosis

BACKGROUND

Cystic fibrosis (CF) is a multi-system disease affecting multiple organs and cells besides the respiratory system. Metabolomic profiling allows simultaneous detection of biochemicals originating from cells, organs, or exogenous origin that may be valuable for monitoring of disease severity or in diagnosis.

AIM

We hypothesized that metabolomics using serum from children would differentiate CF from non-CF lung disease subjects and would provide insight into metabolism in CF.

METHODS

Serum collected from children with CF (n = 31) and 31 age and gender matched children with other lung diseases was used for metabolomic profiling by gas- and liquid-chromatography. Relative concentration of metabolites was compared between the groups using partial least square discriminant analyses (PLS-DA) and linear modeling.

RESULTS

A clear separation of the two groups was seen in PLS-DA. Linear model found that among the 459 detected metabolites 92 differed between CF and non-CF. These included known biochemicals in lipid metabolism, oxidants, and markers consistent with abnormalities in bile acid processing. Bacterial metabolites were identified and differed between the groups indicating intestinal dysbiosis in CF. As a novel finding several pathways were markedly different in CF, which jointly point towards decreased activity in the β-oxidation of fatty acids. These pathways include low ketone bodies, low medium chain carnitines, elevated di-carboxylic acids and decreased 2-hydroxybutyrate from amino acid metabolism in CF compared to non-CF.

CONCLUSION

Serum metabolomics discriminated CF from non-CF and show altered cellular energy metabolism in CF potentially reflecting mitochondrial dysfunction. Future studies are indicated to examine their relation to the underlying CF defect and their use as biomarkers for disease severity or for cystic fibrosis transmembrane regulator (CFTR) function in an era of CFTR modifying drugs.

Nutrition management of pediatric patients who have cystic fibrosis

Since the identification of cystic fibrosis (CF) in the 1940s, nutrition care of patients who have CF has been a challenge. Through optimal caloric intake and careful management of malabsorption, patients are expected to meet genetic potential for growth. Yet factors beyond malabsorption, including nutrient activity at the cellular level, may influence growth and health. This article reviews nutrition topics frequently discussed in relationship to CF and presents intriguing new information describing nutrients currently being studied for their impact on overall health of patients who have CF.

Longitudinal analysis of resting energy expenditure in patients with cystic fibrosis

OBJECTIVE

To assess whether elevated resting energy expenditure (REE) in female patients with cystic fibrosis (CF) persists longitudinally during late childhood and puberty.

STUDY DESIGN

REE and body composition were measured 3 times in 2 years in 86 children with CF. Pubertal status, bacterial colonization, liver disease, pancreatic and pulmonary function, and genotype were determined, and linear mixed model analyses were used to determine predictors and changes in REE longitudinally.

RESULTS

REE did not change with time allowing for fat free mass, pancreatic insufficiency (PI), or severe mutations. Pulmonary function and liver disease were not significant predictors of REE. Percentage predicted REE compared with control data was higher (P = .002) in female patients with CF (109.5%) and lower in male patients with CF (104%) and persisted with time. In post-menarchal female patients with CF, REE adjusted for fat free mass was 366 kJ/d lower than in pre-menarchal female patients, but still 112% predicted.

CONCLUSIONS

This longitudinal study demonstrates that REE is elevated in patients with CF with PI and severe mutations. The elevation of percentage predicted REE was greater in female patients than male patients and persisted for 2 years, and during pubertal maturation, independent of pulmonary and liver disease. These results highlight the need for a high-energy diet throughout childhood and adolescence, particularly in female patients with PI.

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.

Cystic fibrosis: nutritional consequences and management

Life expectancy for patients with Cystic Fibrosis (CF) has steadily improved during the last three decades, and death in childhood is now uncommon. Nutrition is a critical component of the management of CF, and nutritional status is directly associated with both pulmonary status and survival. Expert dietetic care is necessary, and attention must be given to ensuring an adequate energy intake in the face of demands which may be increased by inadequately controlled malabsorption, chronic broncho-pulmonary colonisation by bacteria and fungi, exacerbations of acute lung infection, impaired lung function, and the need for rehabilitation, repair and growth. Pancreatic enzyme replacement therapy (PERT) is needed by up to 90% of CF patients in Northern Europe, where the 'severe' mutation deltaF508 predominates, but a smaller proportion in Mediterranean countries and elsewhere, because pancreatic insufficiency is one of few features of CF which correlate with genotype. Complications of CF including liver disease and CF-related diabetes pose further challenges. In addition, deficiency of specific nutrients including fat soluble vitamins (particularly A, E and K) essential fatty acids and occasionally minerals occur for a variety of reasons. Osteopenia is common and poorly understood. Liver disease increases the likelihood of vitamin D deficiency. Glucose intolerance and diabetes affect at least 25% of CF adults, and the diabetes differs from both types 1 and 2 diabetes mellitus, but it inversely correlates with prognosis. Management consists of anticipating problems and addressing them vigorously as soon as they appear. Supplements of vitamins are routinely given. Energy supplements can be oral, enteral or, rarely, parenteral. All supplements, including PERT, are adjusted to individual needs.

Vitamin A and E deficiency and lung disease in infants with cystic fibrosis

OBJECTIVES

Vitamin A and E deficiency is common in cystic fibrosis (CF). These vitamins have immunomodulating properties and we determined whether decreased serum vitamin A and E levels in young infants are associated with early CF lung disease and lower airway inflammation.

METHODS

A post-hoc analysis was undertaken on previous data collected prospectively in 39 newly diagnosed infants identified by a newborn CF screening programme. Assessment of CF genotype, nutrition, pancreatic status, serum retinol and alpha-tocopherol levels was performed at diagnosis. Pulmonary status was determined clinically, by Brasfield chest radiographic scores and analysis of bacterial counts and inflammatory indices in bronchial lavage (BL) fluid. These assessments were repeated 12 months later.

RESULTS

At diagnosis, 20 out of 39 (51%) CF infants had low serum retinol (mean (SD) 0.7 (0.3) micromol/L) and 9/38 (24%) had low alpha-tocopherol (mean (SD) 13.4 (8.4) micromol/L) levels. Dietary energy intake was related to serum retinol concentrations at diagnosis (r(2) = 0.27; P = 0.001). At 1 year, serum retinol and alpha-tocopherol levels had normalized following vitamin A and E supplementation. Respiratory symptoms, radiographic scores and BL inflammatory indices systematically deteriorated during infancy, reaching significance for free neutrophil elastase activity (9 out of 29 vs 21 out of 33; P = 0.01) and IL-8 levels (79 vs 416; P = 0.046) in BL fluid. No association was seen between serum vitamin levels at diagnosis and airway inflammatory indices at either diagnosis or 12 months later.

CONCLUSION

We found in this CF birth cohort no evidence to implicate vitamin A or E deficiency in the development of lung disease or airway inflammation during infancy.

[Technical aspects and relevance of energy expenditure and physical activity assessment in clinical research for cystic fibrosis patients]

Cystic fibrosis (CF) is characterized by deteriorating lung function and mal-digestion, which result in growth failure and/or under-nutrition. Several factors, alone or combined, contribute to malnutrition in CF: poor energy intake, elevation of energy loss as a result of malabsorption, increasing resting energy expenditure due to genetic mutation and/or pulmonary exacerbation. Several techniques have been used to assess energy expenditure and physical activity in order to better understand mechanisms of malnutrition in CF and follow therapeutic interventions. Indirect calorimetry (IC) studies have shown that resting energy expenditure (REE) was 10-22% higher than predictive values. This increase could be attributed to chronic inflammation as a result of Pseudomonas aeruginosa (PA) infection. Indeed, intravenous antibiotic therapy decreases REE. Doubly labelled water technique and heart rate monitoring calibrated against IC techniques shows that total energy expenditure (TEE) was not different than in healthy children. Physical activity level assessed by the ratio TEE-REE is also not different between CF of healthy children. Recently, new accelerometry technics, easier to use and less invasive have been successfully used in order to assess physical activity level in CF. Precise and ambulatory assessment of energy expenditure and physical activity permit to check and adapt dietary allowances in CF. These techniques could be simultaneously used and be helpful to assess efficacy of intervention studies.

Energy balance in cystic fibrosis when stable and during a respiratory exacerbation

BACKGROUND AND AIMS

Undernutrition is common in young adult patients with cystic fibrosis (CF) and implies an imbalance between energy intake and total energy expenditure (TEE). The aim of this study was to measure energy intake and TEE expenditure in a group of patients when they were clinically stable at home and during an exacerbation of respiratory symptoms when they were in hospital receiving intravenous antibiotics.

METHODS

Eleven patients aged between 15 and 40 years with moderate respiratory disease, mean FEV(1) 51.4% predicted took part. An exacerbation was defined as>15% decrease in FEV(1), an increase in sputum production and a decision to treat in hospital with intravenous antibiotics. Resting energy expenditure (REE) was measured using indirect calorimetry and energy intake by 3 day food diaries. TEE expenditure was measured using 24 h heart rate and doubly isotopically labelled water.

RESULTS

REE was higher at the beginning of an exacerbation than the end, P<0.05. There was no significant difference in TEE during the stable period compared to the exacerbation 10.53(2.39)MJ/day compared to 8.77(1.59)MJ/day using doubly isotopically labelled water. There was no difference in energy intake during the exacerbation compared to the stable period, 11.19(2.31)MJ/day compared to 11.77(2.30)MJ/day.

CONCLUSIONS

There was no difference in TEE and energy intake when patients were unwell in hospital compared to when they were stable at home despite an increase in REE.

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.

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.

Measurement of resting energy expenditure in infants

OBJECTIVE

The method for measurement of basal metabolic rate (BMR) using indirect calorimetry in adults is well established but is impractical in infants.

METHODS

In this prospective study energy expenditure was measured using indirect calorimetry in 14 infants when sleeping and when lying quietly awake.

RESULTS

Sleeping metabolic rate (SMR) was lower than energy expenditure (EE) measured in the same infants in a quiet resting state (mean difference [SD]: 297 [162] kJ/d; P < 0.005; 55 [33.4] kJ/kg per day; P < 0.005). The correlation within individuals suggests that these differences are related to the level of arousal. Awake EE, but not SMR, was significantly greater than estimated BMR using the FAO/WHO/UNU predictive equation.

CONCLUSIONS

In infants, the level of arousal during measurement of EE can significantly impact on the interpretation of EE results. A standardized method for the measurement of EE in infants using indirect calorimetry is proposed.

Energy expenditure, nutrition status, and body composition in children with cystic fibrosis

OBJECTIVE

Undernutrition is a frequent complication in patients with cystic fibrosis (CF). Elevated energy requirements have been found to be 4% to 33% higher than in controls in some studies. Whether or not this is caused by a primary defect or energy metabolism is still a matter of controversy. To this end, we assessed energy expenditure, nutrition status, and body composition of clinically stable CF outpatients.

METHODS

Fifteen clinically stable CF patients, ages 2 to 15 y, were paired with 15 healthy control children. Measurements consisted of anthropometry and body composition. Plasma tocopherol, retinol, and hair zinc content were measured. Resting energy expenditure was determined by indirect calorimetry. Physical activity and dietary intake were recorded by recall methods.

RESULTS

Two children were nutritionally at risk according to the weight/height index, eight were normal, three were overweight, and two were obese. Body composition was similar in both groups. Zinc, tocopherol, and retinol levels were low in three, two, and three patients, respectively. Resting energy expenditures were 4.7 MJ/d (1127 +/- 220 kcal/d) in CF children and 4.63 MJ/d (1108 +/- 191 kcal/d) in control children (P = not significant). Physical activity level was sedentary in 86.6% of CF patients; the rest had a light physical activity pattern. Energy intake represented 141% of the estimated daily energy expenditure.

CONCLUSIONS

Non-oxygen-dependent CF children, without acute respiratory infection, had resting energy expenditures comparable to those of matched controls. Total energy expenditure was similar to or slightly lower than that in healthy children. Dietary recommendations for CF patients need to be reassessed.

Newborn screening for cystic fibrosis

Early diagnosis of cystic fibrosis (CF) provides an opportunity to improve disease control and prevent early complications. Of patients with CF in the United States, 10% are identified early through newborn screening (including infants born in Colorado, Massachusetts, New Jersey, New York, Wisconsin, Wyoming, and parts of California, Connecticut, Pennsylvania, and Montana). Successful screening programs in these states have stimulated other states to consider adding CF screening to their newborn programs. Additionally, new technology permits expanded screening for numerous genetic conditions. Genetic screening, such as that used most frequently for CF, creates new challenges for the clinician, including atypical disease presentations and carrier detection. In this review, we examine the many advances in CF newborn screening and early care that were reported during the last few years.