Consensus report on nutrition for pediatric patients with cystic fibrosis

Evaluation of body mass index percentiles for assessment of malnutrition in children with cystic fibrosis

OBJECTIVE

To compare the performance of recently released body mass index percentiles (BMIp) with standard anthropometric indexes, including height-for-age percentile (HAP), weight-for-age percentile (WAP) and percent ideal body weight (%IBW), as measures for nutritional failure in children with cystic fibrosis (CF).

DESIGN

Cross-sectional analysis of growth and lung function data from 4577 children with CF reported to the German CF quality assurance (CFQA) project from 1995 to 2004.

RESULTS

Frequency distribution of HAP (mean+/-s.d.: male 30.0+/-27.5; female 31.3+/-27.4) and WAP (male 28.9+/-27.0; female 29.6+/-26.7) were skewed, with significant numbers of patients below the fifth percentiles of a healthy reference population. However, because deficits occurred in both measures simultaneously, mean %IBW (male 97.0+/-12.1; female 98.1+/-12.3) assumed subjects weight close to the nominal weight-for-height at all ages. In contrast, mean BMIp was markedly reduced (male 35.7+/-27.9; female 35.6+/-27.2) and steadily declined with age. Ideal weight-for-age was significantly lower when predicted by %IBW compared with BMIp method, particularly in subjects with shorter-than-average stature. Consequently, less CF children were identified with nutritional failure according to %IBW method (male 20.5%; female 22.7%) compared with BMIp method (male 30.4%; female 28.7%). The clinical relevance of these findings was confirmed by stronger correlation of BMIp with impaired %forced expiratory volume/s, a marker for disease progression in CF.

CONCLUSION

BMIp predicts nutritional failure more sensitively and accurately than conventional anthropometric indexes, at least in children with CF. Screening of CF patients by BMIp could provide an early warning sign and allow for timely therapeutic intervention.

Insulin-like growth factor-1, leptin, body composition, and clinical status interactions in children with cystic fibrosis

BACKGROUND/AIMS

Children with cystic fibrosis (CF) are of increased risk of reduced fat body mass (FBM) and lean body mass (LBM). Serum concentrations of insulin-like growth factor-1 (IGF-1)and leptin could be markers of LBM and/or FBM depletion. To evaluate the relationships between disease activity, body composition, IGF-1 and leptin concentrations in CF children.

METHODS

A cross-sectional study with 26 CF children aged 5.0-15.5 years and 33 healthy controls, mean age 9.4 years. Body composition was evaluated by dual-energy X-ray absorptiometry. Fasting blood samples were analyzed for leptin, IGF-1 and IGFBP-3.

RESULTS

FBM standard deviation score (SDS; CF boys -0.02 +/- 0.88 vs. 0.78 +/- 0.65, p < 0.01; CF girls -0.37 +/- 1.15 vs. 0.70 +/- 0.97, p < 0.05), leptin concentration (CF boys 2.07 +/- 0.79 vs. 3.07 +/- 1.28 ng/ml, p < 0.05; CF girls 2.71 +/- 0.86 vs. 5.00 +/- 2.95 ng/ml, p < 0.05) and IGF-1SDS (CF boys -1.43 +/- 1.50 vs. -0.32 +/- 0.88, p < 0.05; CF girls -0.66 +/- 1.66 vs. 0.64 +/- 0.57, p < 0.01) were lower in CF children compared to controls. Shwachman score was the strongest predictor of lean body mass (R = 0.63). Leptin levels explain 60% of the variability in FBM.

CONCLUSION

Serum concentrations of IGF-1 and leptin are decreased in children with CF and are associated with clinical conditions and body composition.

Evaluation of formulas for calculating total energy requirements of preadolescent children with cystic fibrosis

BACKGROUND

To support age-appropriate growth and to prevent and treat malnutrition in children with cystic fibrosis (CF), energy requirements for those children are often set above the requirements for healthy children. Care providers use one of several empirically derived formulas to calculate energy requirements, yet the validity of these formulas has seldom been tested.

OBJECTIVE

We evaluated 6 proposed formulas for calculating energy requirements in children with CF against a total energy requirement for children with CF (TER-CF) derived from measured total energy expenditure, fecal fat energy loss, and the theoretic energy required for age-appropriate tissue accretion.

DESIGN

Subjects were children aged 6-8 y who had CF and pancreatic insufficiency. Calculated TERs from each formula were evaluated against TER-CF by using summary statistics, regression analysis, and residual plots.

RESULTS

Subjects (n = 53) had suboptimal nutrition and growth status and mild-to-moderate lung disease. The formula that most closely (within 2%) approximated TER-CF was the estimated energy requirement (EER) formula at the active level (EERact). Regression analysis of TER-CF onto calculated TER from each formula yielded the best indexes of model fit for the EERact formula; residual plots of the EERact formula were tightly and normally distributed around zero.

CONCLUSIONS

The EERact formula should be used to establish TER-CF in children in this age group who have mild-to-moderate CF. Changes in weight, height, and other indicators of nutritional status must be monitored to modify TER-CF as needed to support individual patient care goals.

Antioxidants in cystic fibrosis. Conclusions from the CF antioxidant workshop, Bethesda, Maryland, November 11-12, 2003

Although great strides are being made in the care of individuals with cystic fibrosis (CF), this condition remains the most common fatal hereditary disease in North America. Numerous links exist between progression of CF lung disease and oxidative stress. The defect in CF is the loss of function of the transmembrane conductance regulator (CFTR) protein; recent evidence that CFTR expression and function are modulated by oxidative stress suggests that the loss may result in a poor adaptive response to oxidants. Pancreatic insufficiency in CF also increases susceptibility to deficiencies in lipophilic antioxidants. Finally the airway infection and inflammatory processes in the CF lung are potential sources of oxidants that can affect normal airway physiology and contribute to the mechanisms causing characteristic changes associated with bronchiectasis and loss of lung function. These multiple abnormalities in the oxidant/antioxidant balance raise several possibilities for therapeutic interventions that must be carefully assessed.

Growth hormone treatment improves growth and clinical status in prepubertal children with cystic fibrosis: results of a multicenter randomized controlled trial

CONTEXT

This multicenter, randomized, controlled, crossover trial of prepubertal children with cystic fibrosis (CF) tests the hypotheses that recombinant human GH (rhGH) treatment 1) improves height, weight, lean mass, and bone content irrespective of baseline measures; 2) improves clinical status and quality of life; and 3) has continued effect after cessation after 1 yr of treatment.

METHODS

Sixty-one prepubertal subjects (<or=25th percentile for height and weight) were randomized into two groups: daily rhGH treatment or no treatment groups for 1 yr. In yr 2, treatments were crossed over. Outcome measures included serial standardized height and weight, number of hospitalizations and antibiotic courses, random blood glucose levels, lean mass, bone mineral content, pulmonary function, nutritional intake, and CF quality of life questionnaires.

RESULTS

Groups were similar at baseline and prepubertal during the entire study. After 1 yr, GH showed significantly greater gain in height, weight, lean mass, and bone mineral content. Gain in height was similar regardless of baseline. There were fewer hospitalizations in the rhGH-treated group and improvement in CF quality of life questionnaires measures of weight and body image. There was no difference in pulmonary function between groups. Results were similar in those treated with rhGH the second year. After cessation of rhGH treatment, there was sustained effect for increased height and weight velocity, as well as accrual of bone mineral.

CONCLUSION

rhGH therapy improves height and weight, decreases the number of hospitalizations, and improves quality of life in prepubertal children with CF. These effects are sustained after rhGH is discontinued.

Unresponsive or non-compliant steatorrhea in cystic fibrosis?

In 105 pancreatic insufficient CF patients (steatorrhea and low fecal elastase-1 concentrations), the effectiveness of pancreatic enzyme therapy (PET) has been assessed (fecal fat losses and coefficient of fat reabsorption). Eight unresponsive subjects were checked for PET compliance with fecal chymotrypsin assay. Three patients were documented to be non-compliant. Unresponsive patients should undergo evaluation for PET compliance.

Potential utility of plasma fatty acid analysis in the diagnosis of cystic fibrosis

BACKGROUND

An altered distribution of fatty acids in cells and tissues is found in patients with cystic fibrosis (CF). In this study, we assessed the potential role of plasma fatty acid analysis in the diagnosis of CF.

METHODS

In this 2-part study, we first used gas chromatography-mass spectrometry to analyze fatty acids in plasma from 13 CF patients and 11 controls without CF. We then used the fatty acid distribution data to identify the fatty acids or multiple fatty acid calculations most effective in identifying CF patients. Part 2 of the study was a blinded analysis of 10 CF patients and 9 controls to directly test the effectiveness of the diagnostic parameters for CF identified from the plasma fatty acid analysis.

RESULTS

In the nonblinded trial, the multiplication product of (18:2 n-6) x (22:6 n-3) (each as percentage of total plasma fatty acid) was the most effective indicator for distinguishing patients with CF from controls (P = 0.0003). In part 2 (the blinded trial), this multiplication product was also the most effective indicator for distinguishing CF patients from controls (P = 0.0008).

CONCLUSIONS

The product of (18:2 n-6) x (22:6 n-3) is effective for distinguishing CF patients from persons without CF. This diagnostic marker may have value as an alternative to the sweat chloride test in selected patients being evaluated for CF.

Acetate correction for postabsorption metabolism does not improve the [13C]mixed triacylglycerol breath test

OBJECTIVE

The [C]mixed triacylglycerol (MTG) breath test is a noninvasive measure of fat digestion. After absorption and oxidation, C appears in breath CO2. Recovery is no more than 50% in healthy subjects because of sequestration of acetate in intermediary metabolism. The aims of this study were to investigate interindividual variation and postabsorptive metabolism of MTG using oral [1-C]acetate and to examine the use of correction factors to account for the "missing" label.

PATIENTS AND METHODS

[C]mixed triacylglycerol and [1-C]acetate breath tests were performed on 8 healthy adults, 9 healthy children and 3 children with cystic fibrosis. Breath was sampled for 6 hours on each occasion. The enrichment of CO2 in breath was measured by isotope ratio mass spectrometry. Cumulative percentage dose recovered CO2 during the MTG test was corrected for label absorbed, but not completely oxidized using the cumulative percentage dose recovered during the acetate test.

RESULTS

Mean recovery of C during the [C]MTG test with an acetate correction was close to 100% in healthy subjects: 103.1% (SD, 11.6%) in adults and 98.9% (SD, 30.3%) in children, but the wide variance indicated that some of the assumptions governing the use of acetate corrections with oral tracers may not be valid.

CONCLUSION

The need to perform 2 tests, variation in physical activity between tests and differences in intermediary metabolism preclude the use of acetate correction factors when using [C]MTG to assess intraluminal fat digestion, especially in children.

Meal patterns, dietary fat intake and pancreatic enzyme use in preadolescent children with cystic fibrosis

OBJECTIVES

To describe the usual pattern of intake and adherence to cystic fibrosis (CF) food and pancreatic enzyme replacement therapy (PERT) recommendations in preadolescent children with CF and pancreatic insufficiency (PI).

METHODS

Children, 8 to 11 years old, with CF and PI were assessed for PERT adherence ratio (number taken/number prescribed per day) and energy and fat intake for 7 days (weighed food records), adherence to PERT and dietary recommendations, pulmonary function, growth status and stool fat malabsorption. Using the PERT adherence ratio, children were divided into good (> or =80%), moderate (60% to 79%) and poor (<60%) adherence groups.

RESULTS

Of the 75 children (age, 9.3 +/- 1.0 years; forced expiratory volume in 1 s, 95 +/- 14% predicted), 61% consumed less than 120% of energy intake, and 72% consumed less than 40% of calories as fat recommended for CF. Using the PERT adherence ratio (mean +/- SD, 75 +/- 14%), 29%, 61% and 9% of children had good, moderate and poor adherence, respectively. Better adherence to PERT was significantly associated with missing fewer snacks, higher energy intake, greater fat content of snacks and poorer growth status. About 85% of the children were in the 500 to 4000 lipase unit (LU) of PERT (LU/g fat per day) and 500 to 2500 LU/kg per body weight per meal guidelines, whereas only 58% to 68% were within the guidelines for snacks. Eleven percent of children always took PERT at an inappropriate time after meals.

CONCLUSIONS

Most preadolescent children with CF and PI did not meet dietary recommendations. Future educational and behavioral interventions focused on increasing PERT adherence with snacks, fat content of meals and snacks, appropriate timing of enzymes and adjustment of PERT and meal fat content are suggested.

Liver involvement in cystic fibrosis

The hepatobiliary manifestations of cystic fibrosis (CF) encompass a broad clinical spectrum, from mild steatosis, associated with poor nutrition, to multilobular cirrhosis and the complications of portal hypertension. The factor(s) responsible for the development and progression of liver disease in a subset of patients with CF are unknown. Liver disease can be silent and progressive, manifesting only with complications associated with cirrhosis and portal hypertension. Clinical evaluation for detecting and monitoring the progression of liver disease includes the following: physical examination of the liver, biochemical tests of liver function and injury, and radiological imaging with abdominal ultrasonography. Careful monitoring should take place in all patients with CF, as currently, there are no sensitive and/or specific historical or biochemical markers to predict who is at risk for the development of liver disease. Current treatment options for CF-associated liver disease are very limited. The bile acid ursodeoxycholic acid may improve biochemical parameters of liver disease, but its long-term efficacy in preventing the progression of liver disease in CF is unproven. Treatment therefore rests on optimizing nutritional status; correcting fat-soluble vitamin, essential fatty acid, and other mineral deficiencies; and treating complications of end-stage liver disease, such as pruritus, ascites, and portal hypertension.

Classification of nutritional status in cystic fibrosis

PURPOSE OF REVIEW

Nutritional status impacts on the progression of cystic fibrosis. Current guidelines recommend the use of anthropometric indicators to classify nutritional status and identify malnutrition. However, the current nutrition-classification systems are problematic. I summarize these problems and review recent progress in the development of evidence-based anthropometric criteria for classifying nutritional status in cystic fibrosis patients.

RECENT FINDINGS

Percentage of ideal body weight as a malnutrition index is flawed. In children with cystic fibrosis, this index underestimates the severity of underweight in short patients and overestimates it in tall patients. In adults with cystic fibrosis, percentage of ideal body weight based on the Metropolitan Life Insurance reference weights for medium/large frames overestimates the severity of underweight. Body-mass-index percentile for children and body mass index for adults as underweight indices have been proven to be valid. Strong associations between body mass index and lung function are also observed, but cutoff values to maintain a desirable level of lung function can vary.

SUMMARY

Body mass index should replace the use of percentage of ideal body weight for classifying underweight in cystic fibrosis patients. More research is needed to identify appropriate indicators to classify short stature in children with cystic fibrosis.

Dietary and circulating polyunsaturated fatty acids in cystic fibrosis: are they related to clinical outcomes?

OBJECTIVE

To assess the relationship between dietary intakes, plasma phospholipid (PL) fatty acid profile and clinical parameters in children with cystic fibrosis (CF) in comparison to healthy controls.

PATIENTS AND METHODS

A cross-sectional survey including 37 patients with CF (ages 8.0 +/- 2.9 yrs) and a reference group of 68 healthy children (ages 8.0 +/- 0.7 yrs) was carried out by means of a food-frequency questionnaire. At enrollment, all subjects underwent blood sampling for plasma PL fatty acids (FA). In CF patients, pulmonary function tests (forced expiratory volume in 1 second and forced vital capacity), anthropometric measurements and the Shwachman score were also determined.

RESULTS

In CF patients, mean z score for weight and height (-0.35 +/- 1.16 and -0.28 +/- 0.99) were lower than controls (0.83 +/- 1.73 and 0.55 +/- 1.11, respectively). Patients with CF showed higher energy intakes (110 +/- 43 kcal/d) compared with controls (75 +/- 22 kcal/d; P < 0.0001), with higher intake of total (saturated and monounsaturated) fats and lower intake of polyunsaturated FA (3.9 +/- 1.0% of total macronutrient intake vs 4.3 +/- 1.2%, P = 0.05). In CF patients, plasma and PL levels of linoleic and docosahexaenoic acids were lower, whereas those of arachidonic acid were similar compared with controls. The Shwachman score showed significant positive associations with plasma PL levels of arachidonic acid and total n-6 long-chain FA (r = 0.32, P = 0.05, and r = 0.35, P = 0.03, respectively).

CONCLUSIONS

The data give suggestions that fat intake and CF-associated biomechanisms are bound in a vicious circle, concurring to create the clinical and biochemical picture of CF. The quantity and quality of fat supplementation in CF need careful attention to balance the fat supply with polyunsaturated FA.

Case study: providing evidence-based behavioral and nutrition treatment to a toddler with cystic fibrosis and multiple food allergies via telehealth

Barriers to successful outcome for cystic fibrosis (CF) therapies can include distance from a CF care center, co-morbid conditions that require individualized alterations to the prescribed treatment, and patient-provider interactions, among others. We present the case of a 21-month-old female with CF for whom modifications of an efficacious behavioral and nutrition treatment were made due to food allergies and distance from the CF care center. She was classified as at-risk nutritionally. Following treatment a significant increase in energy intake (calories) was observed in addition to her meeting weight and height growth rates for a child of this age and gender who is growing normally at the 50th percentile.

Growth and health in children with moderate-to-severe cerebral palsy

BACKGROUND

Children with cerebral palsy frequently grow poorly. The purpose of this study was to describe observed growth patterns and their relationship to health and social participation in a representative sample of children with moderate-severe cerebral palsy.

METHODS

In a 6-site, multicentered, region-based cross-sectional study, multiple sources were used to identify children with moderate or severe cerebral palsy. There were 273 children enrolled, 58% male, 71% white, with Gross Motor Function Classification System levels III (22%), IV (25%), or V (53%). Anthropometric measures included: weight, knee height, upper arm length, midupper arm muscle area, triceps skinfold, and subscapular skinfold. Intraobserver and interobserver reliability was established. Health care use (days in bed, days in hospital, and visits to doctor or emergency department) and social participation (days missed of school or of usual activities for child and family) over the preceding 4 weeks were measured by questionnaire. Growth curves were developed and z scores calculated for each of the 6 measures. Cluster analysis methodology was then used to create 3 distinct groups of subjects based on average z scores across the 6 measures chosen to provide an overview of growth.

RESULTS

Gender-specific growth curves with 10th, 25th, 50th, 75th, and 90th percentiles for each of the 6 measurements were created. Cluster analyses identified 3 clusters of subjects based on their average z scores for these measures. The subjects with the best growth had fewest days of health care use and fewest days of social participation missed, and the subjects with the worst growth had the most days of health care use and most days of participation missed.

CONCLUSIONS

Growth patterns in children with cerebral palsy were associated with their overall health and social participation. The role of these cerebral palsy-specific growth curves in clinical decision-making will require further study.

An enteric-coated high-buffered pancrelipase reduces steatorrhea in patients with cystic fibrosis: a prospective, randomized study

OBJECTIVE

Enteric-coated (EC) high-buffered (2.5 mEq [2.5 mmol] bicarbonate per capsule) pancrelipase microsphere enzymes were compared to EC-nonbuffered pancreatic enzymes for efficacy in reducing steatorrhea in patients with cystic fibrosis.

DESIGN

Prospective, randomized, controlled trial using a crossover design with each subject as his/her own control.

SUBJECTS/SETTING

Eighteen subjects with cystic fibrosis, who had pancreatic insufficiency and required large enzyme doses, were studied over two consecutive 7-day treatment periods.

INTERVENTION

Each 7-day period consisted of 3 days at home followed by 4 days in a general clinical research center for careful control of diets, enzyme lipase doses (given at approximately 50% of the subject's usual lipase dose), and carmine red-labeled stool collections for 72-hour fecal fat balance studies.

MAIN OUTCOME MEASURE

Fecal fat excretion.

STATISTICAL ANALYSES PERFORMED

Differences in fat excretion, when each subject received EC-high-buffered pancrelipase vs EC-nonbuffered enzymes, were compared using linear modeling.

RESULTS

Mean fat excretion decreased significantly in each subject during periods when given EC-high-buffered pancrelipase compared with periods when given EC-nonbuffered enzymes (fat excretion 18.2% vs 24.9% or fat absorption 81.8% vs 75.1%, respectively; P=0.01). Thirteen of 18 subjects (72%) excreted less fat when receiving EC-high-buffered pancrelipase whereas 10 (56%) decreased fat excretion by more than 5%, and five subjects did not respond.

CONCLUSIONS

EC-high-buffered pancrelipase decreased fat excretion, symbolizing improved fat absorption, when compared with EC-nonbuffered pancreatic enzymes given at equivalent, reduced (approximately 50% of usual) lipase doses in nourished subjects with cystic fibrosis and mild pulmonary disease.

Evidence of choline depletion and reduced betaine and dimethylglycine with increased homocysteine in plasma of children with cystic fibrosis

Cystic fibrosis (CF) is associated with many clinical complications including steatosis for which the relation to defective CF transmembrane conductance regulator protein is unclear. Choline deficiency results in hepatic steatosis. Choline is the precursor of betaine, which donates methyl groups for remethylation of homocysteine to methionine and dimethylglycine. Previously, we have shown phospholipid malabsorption and increased plasma homocysteine in children with CF. In these studies we used normal phase HPLC with tandem mass spectrometry to determine plasma choline, betaine, and dimethylglycine in children with CF (n = 34) and healthy control children without CF (n = 15). Plasma choline, betaine, and dimethylglycine were significantly lower in children with CF (means +/- SEM, 6.48 +/- 0.35, 23.8 +/- 1.49, 1.49 +/- 0.13 mumol/L, respectively) than in children without CF (8.98 +/- 0.46, 37.3 +/- 1.84, 3.01 +/- 0.17 mumol/L, respectively). Plasma choline (r = 0.373, P = 0.007) and betaine (r = 0.399, P = 0.005) were positively related to methionine, and choline was inversely related to homocysteine (r = -0.316, P = 0.03). Choline, betaine, and dimethylglycine were all significantly and positively related to the plasma S-adenosylmethionine:S-adenosylhomocysteine (SAM:SAH) ratio (r = 0.294, r = 0.377, r = 0.442, respectively; P < 0.05). The plasma choline:betaine and betaine:dimethylglycine ratios did not differ between the children with CF and the control children, suggesting no increase in betaine synthesis, or betaine-dependent remethylation of homocysteine. These studies suggest that choline depletion may contribute to increased homocysteine in children with CF. Choline depletion and altered thiol metabolism may contribute to the clinical complications associated with CF.

Plasma zinc and growth status in preadolescent children with cystic fibrosis

OBJECTIVE

To investigate plasma zinc status in relation to dietary and supplemental zinc intake, growth and pulmonary status in preadolescent children with cystic fibrosis (CF) and pancreatic insufficiency (PI).

METHODS

Fasting plasma zinc was assessed in children (age, 8-11 years) with CF and PI. Food (7-day weighed records) and supplemental zinc intake, serum alkaline phosphatase and albumin, pulmonary function (spirometry), coefficient of fat absorption (%COA, 72-hour fecal fat) and growth status [height adjusted for genetic potential (AHAZ), weight (WAZ) and BMI Z scores (BMIZ)] were assessed.

RESULTS

For the 62 children (32 males), mean plasma zinc (+/-SD) was 16.8 +/- 3.1 micromol/L (110 +/- 20 ug/dL). Sixty-five percent of the subjects had levels above the study reference range of 9.2 to 15.3 micromol/L (60-100 ug/dL); no subjects had low zinc levels. Median (range) total daily zinc intake was 279% (83-988%) recommended dietary allowance, growth status was suboptimal (mean +/- SD: AHAZ, -0.8 +/- 1.0; WAZ, -0.5 +/- 1.2; BMIZ, -0.2 +/- 1.1), and forced expiratory volume at 1 second (FEV1) was 92 +/- 13% predicted. Plasma zinc was not correlated with growth, pulmonary or alkaline phosphatase status. Plasma zinc was correlated with serum albumin (r = 0.25, P < 0.05) and was inversely correlated with coefficient of fat absorption (as %; r = -0.30, P = 0.02).

CONCLUSIONS

Under current patterns of care in CF Centers, total zinc intake and plasma zinc status were adequate. These findings suggest that zinc was not a limiting micronutrient for preadolescent children with CF and PI and mild-to-moderate lung disease, and not likely contributing to their suboptimal growth status.

Elevated vitamin A intake and serum retinol in preadolescent children with cystic fibrosis

BACKGROUND

Persons with cystic fibrosis (CF) and pancreatic insufficiency (PI) are at risk of vitamin A deficiency because of steatorrhea, despite pancreatic enzyme replacement. Long-standing vitamin A supplementation may increase the risk of vitamin A toxicity.

OBJECTIVE

The aim was to describe the vitamin A intake and serum retinol concentrations of preadolescent children with CF, PI, and mild-to-moderate pulmonary disease, who were cared for under current practice recommendations.

DESIGN

This cross-sectional study evaluated children aged 8.0-11.9 y with CF and PI from 13 US CF centers. Dietary and supplemental vitamin A intakes were compared with the Dietary Reference Intakes (DRIs) for healthy children, CF recommendations, and data from the National Health and Nutrition Examination Survey (NHANES), 1999-2000. Serum retinol concentrations were compared with NHANES data.

RESULTS

The 73 subjects with CF had a dietary vitamin A intake of 816 +/- 336 microg retinol activity equivalents (165 +/- 69% of the recommended dietary allowance), which was similar to the NHANES value. The supplement intake provided 2234 +/- 1574 microg retinol activity equivalents/d and exceeded recommendations in 21% of the subjects with CF. Total preformed retinol intake exceeded the DRI tolerable upper intake level in 78% of the subjects with CF. The serum retinol concentration was 52 +/- 13 microg/dL (range: 26-98 microg/dL), which was significantly higher than the NHANES value (37 +/- 10 microg/dL; range: 17-63 microg/dL; P < 0.001).

CONCLUSION

Although supplementation helps to prevent vitamin A deficiency in children with CF and PI, their high vitamin A intakes and serum retinol concentrations suggest that usual care may result in excessive vitamin A intake and possible toxicity that would increase the risk of CF-associated liver and bone complications.

Cystic fibrosis mutations with widely variable phenotype: the D1152H example

D1152H is a type IV cystic fibrosis transmembrane regulator (CFTR) mutation associated with abnormal chloride gating. Although comprising 5-6% of mutations on genetic screening, clinical reports of cystic fibrosis (CF) are rare, suggesting that the disease is mild, atypical, or even absent. We describe our experience, which contrasts with this assumption, in a retrospective case series encompassing 91 CF patients (74 Jewish) aged 8 months to 56 years, from 2000-2005. Nine patients of varied Jewish ethnic origins were homozygous (2 patients) or compound heterozygous for D1152H with 11 of 182 potential alleles (6%). Five were diagnosed at age 33-49 years. Of 4 infants, 1 was diagnosed by prenatal screening, 1 had a prenatal dilated bowel, and 1 had pulmonary symptoms. Sweat chloride was 28-120 meq/l. Three adults had chronic mucoid Pseudomonas aeruginosa in sputum, and a forced expired volume in 1 sec (FEV1) of 20-55%. One was on bilevel positive airway pressure (BIPAP) ventilation. The infants had pulmonary symptoms that responded well to therapy. All 9 patients had good nutrition, 6 were pancreatic-sufficient, and 3 adults had subclinical pancreatic insufficiency. Three adults had recurrent pancreatitis. None had a bowel obstruction. Two of 3 adult males were fertile. Although asymptomatic at times, the D1152H mutation is associated with a broad clinical spectrum. This information is crucial for genetic counseling. Lung disease may be evident from infancy, and is severe in some adults, although all have outlived the median life expectancy of CF. Hopefully, with early diagnosis and therapy, prognosis can be good. A multicenter study of this mutation is warranted.

Temporal associations among energy intake, plasma linoleic acid, and growth improvement in response to treatment initiation after diagnosis of cystic fibrosis

OBJECTIVE

It is unclear why some patients with cystic fibrosis (CF) succeed ("responders") in recovering from malnutrition and growth faltering after treatment initiation whereas others fail to do so ("nonresponders"). We conducted a study to test the hypothesis that sustained high energy intake (increased EN) and normal plasma essential fatty acid status are critical determinants of treatment responsiveness within 2 years after diagnosis of CF.

METHODS

A total of 71 CF children who had pancreatic insufficiency but not meconium ileus and were enrolled in the Wisconsin CF Neonatal Screening Project were studied. Responders were defined by having achieved adequate weight gain, as indicated by a recovery of weight z score (Wtz) comparable to Wtz at birth (WtzBR) within 2 years of diagnosis. Increased EN and sustained normal plasma linoleic acid level (increased pLA) were defined by achieving energy intake > or =120% of estimated requirement for > or =75% of the time and maintaining plasma LA > or =26% of total fatty acids for > or =75% of the time, respectively.

RESULTS

Thirty-two (68%) screened patients and 13 (54%) patients whose CF was diagnosed conventionally recovered WtzBR within 2 years of diagnosis. Screened patients responded at significantly younger ages (mean/median: 6.3/4.3 months) than patients whose CF was diagnosed conventionally (mean/median: 15.8/11.8 months). Proportionately fewer screened patients (33%) achieved increased EN compared with patients whose CF was diagnosed conventionally (73%). However, more screened patients responded to increased EN and recovered WtzBR (91%) than patients whose CF was diagnosed conventionally (56%), although this difference was of borderline significance. Compared with having neither increased EN nor increased pLA, the likelihood of being a responder was greatest with combined increased EN and increased pLA, followed by increased EN only. The positive associations between increased EN and increased pLA to treatment responsiveness remained significant after adjustment for neonatal screening status, baseline height and weight status, and indices of pulmonary disease severity.

CONCLUSION

Increased EN and increased pLA are critical in promoting adequate weight gain in children with newly diagnosed CF.

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.

Randomized clinical trial of behavioral and nutrition treatment to improve energy intake and growth in toddlers and preschoolers with cystic fibrosis

OBJECTIVE

To conduct a randomized clinical trial comparing a behavioral and nutrition intervention (BEH) with a usual care control condition (CTL) for children (ages 18 months to 4 years) with cystic fibrosis (CF) and pancreatic insufficiency. This trial was designed to (1) evaluate a randomized comparison of BEH with CTL over 8 weeks, (2) provide a replication of the impact of BEH by inviting the CTL group to receive BEH after 8 weeks, and (3) examine the maintenance of BEH at 3- and 12-month follow-up.

METHODS

Of 14 eligible children, 10 were randomly assigned and initiated treatment (71% recruitment rate). Four participants were randomly assigned to BEH, and 6 were assigned to CTL (5 of whom chose to crossover to BEH). BEH included nutrition counseling to increase energy intake (via types of foods and addables/spreadables) and child behavioral management training to teach parents differential attention and contingency management skills. CTL was consistent with the 2002 CF Foundation Consensus Conference Guidelines for nutritional care.

RESULTS

BEH led to greater increases in energy intake pre- to posttreatment than CTL as measured by calories per day (842 kcal/day vs -131 kcal/day change). On receiving BEH, the change in energy intake was replicated with the CTL group (892 kcal/day change). At 3- and 12-month follow-up, energy intake was maintained (672 kcal/day increase from baseline and 750 kcal/day increase from baseline, respectively). Children in this study met or exceeded normal weight and height velocities from pretreatment to the 3-month follow-up (mean weight: 1.4 kg/6 months; mean height: 5.1 cm/6 months) and from posttreatment to the 12-month follow-up (mean weight: 2.5 kg/12 months; mean height: 8.3 cm/12 months).

CONCLUSIONS

Toddlers and preschoolers who have CF and received BEH were able to meet the energy intake recommendations for this disease and maintain these gains up to 12 months after treatment. In addition, these children demonstrated weight and height velocities from pretreatment to 12-month follow-up, consistent with the goal of normal growth. BEH is a promising, evidence-based, early nutritional intervention for children with CF. An upcoming multisite clinical trial will test BEH versus an attention control condition using a larger sample (N = 100), providing additional evidence about the efficacy of this treatment for energy intake and growth in young children with CF.

Pancreatic exocrine function in patients with cystic fibrosis

Pancreatic insufficiency in cystic fibrosis (CF) is associated with more severe disease and requires replacement therapy. Outcome measures such as growth and number of stools, frequency of abdominal pain, and flatulence have often been used to identify pancreatic-insufficient patients and to adjust the dose of replacement enzymes. Unfortunately, some patients with CF are misclassified, and approximately 9% do not receive therapy appropriate for their pancreatic exocrine functional status. Growth, number of stools, frequency of abdominal pain, and flatulence cannot be used to adjust enzyme doses.

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.

Long-term trial of cyproheptadine as an appetite stimulant in cystic fibrosis

Appetite stimulants have been used to help overcome decreased appetite and malnutrition in children and adults with various chronic illnesses, including cystic fibrosis (CF). Stimulants have included megestrol acetate (MA), cyproheptadine hydrochloride (CH), cannabinoids, hydrazine sulfate, anabolic hormones, and growth hormone. Many of these, including MA, have substantial side effects and may not be suitable for prolonged use. We previously studied the effects of CH on weight gain in a short-term (12 week) trial in CF with good results compared to placebo. Side effects were few, and weight gain was significant. In this study, we sought to determine the effects of CH over a longer term in order to assess its suitability for prolonged use. Sixteen CF children and adults enrolled in the original short-term study subsequently entered this study, and 12 completed the 9-month trial. All patients receiving placebo in the original short-term study received CH 4 mg up to four times a day in the long-term study continuation, and those receiving CH in the short-term study continued on the drug. No pill counts were done, and patients were queried at quarterly visits as to their CH use. Anthropometrics and spirometry were also done quarterly, and antibiotic use was quantified. Subjects who had changed from placebo (CH2 group) gained weight significantly over 3-6 months, and those continuing on CH (CH1 group) generally maintained previously gained weight over the duration of the study. Select spirometric measures improved in both groups but not significantly, and side effects were mild. CH appears to be an effective appetite stimulant in CF, and generally maintains its effect over time with an acceptable side-effect profile.

Mealtime behaviors in families of infants and toddlers with cystic fibrosis

BACKGROUND

Parents of infants and toddlers with cystic fibrosis (CF) report problematic mealtime behaviors. Controlled studies that examine parent and child mealtime behaviors in infants and toddlers with CF using objective, observational procedures are needed to augment parent report findings and identify targets for effective interventions. We examined four hypotheses: 1) Parents of young children with CF would engage in more mealtime management behaviors to encourage eating than parents of control children. 2) Infants and toddlers with CF would engage in more problematic mealtime behaviors than control children. 3) Infants and toddlers with CF and their parents would demonstrate a greater frequency of behaviors incompatible with eating in the second half of the meal compared to the first half. 4) During slow meals, infants and toddlers would display a higher rate of mealtime behavior problems than during fast meals.

METHODS

Thirty-four infants and toddlers with CF (M age = 18.3 +/- 7.9 months) and a matched community sample of same age peers participated. Videotaped mealtimes were coded using the Dyadic Interaction Nomenclature for Eating (DINE).

RESULTS

Parents of children with CF gave a higher rate and frequency of commands to eat than controls. All children displayed similar rates and frequencies of mealtime behaviors incompatible with eating. As the meal progressed, all children, regardless of illness status, displayed a greater frequency of behaviors incompatible with eating.

CONCLUSION

Direct observation of mealtime behaviors indicates that parents of infants and toddlers with CF engage in more mealtime management behaviors than parents of controls and that young children exhibit more behaviors incompatible with eating as the meal progresses. These findings highlight modifiable targets for behavioral and nutrition interventions that can be specifically designed for families of infants and toddlers with CF.

Survey of professionals' expectations of developmental task achievement of cystic fibrosis self-care in children

We surveyed 174 professionals with at least 6 months of experience working with children and adolescents with cystic fibrosis (CF), to obtain estimates of ages at which 50% of children with CF may be able to perform each of 44 self-care behaviors related to the treatment of CF. Respondents were 63 physicians, 36 nurses, 24 dietitians, 18 respiratory therapists, 17 nurse practitioners, 10 social workers, and 4 psychologists, who had a mean of 11.4 years (SD = 7.5) of experience working with pediatric patients with CF. Mean age estimates for self-care behaviors ranged from 5.5-13.9 years. For each item, responses varied among respondents, as reflected by a mean standard deviation of 2.75 years for all behaviors. Analyses of concordance suggested a high level of agreement among respondents for the order of mastery of specific skills related to diet and enzymes use only. To date, there are no empirically defined age estimates for when children with CF may be able to perform specific self-care behaviors involved in the management of CF. This survey is the first step in generating age estimates for self-care independence in CF. Future research should conduct an objective assessment of children's CF knowledge and skill in performing these behaviors, and compare these findings to the age estimates offered in this study.

Examining clinical trial results with single-subject analysis: an example involving behavioral and nutrition treatment for young children with cystic fibrosis

OBJECTIVE

To examine the process of change in a clinical trial of behavioral and nutrition treatment for children age 18-48 months with cystic fibrosis (CF) using single-subject analysis.

METHODS

The 5-week treatment included nutrition counseling and child behavioral management training for parents and was designed to increase energy intake measured by diet diaries 600-800 calories per day.

RESULTS

Energy intake changed at each meal, only when treatment was introduced (week 1: snacks, 420 to 691; week 2: breakfast, 325 to 443; week 4: lunch, 350 to 443; and week 5: dinner, 373 to 460 calories per day). Total daily intake increased in a systematic fashion that exceeded the criterion set each week during treatment.

CONCLUSIONS

Toddlers and preschoolers with CF meet energy intake recommendations as a result of behavioral intervention. Single-subject research designs are important methodologies for advancing clinical investigation in pediatric psychology.

Growth hormone improves bone mineral content in children with cystic fibrosis

AIM

Osteoporosis and osteopenia have been reported as common complications of cystic fibrosis (CF); however, little is known about accrual of bone mineral in CF. The goal of our study was to measure bone mineral content (BMC) in non-acutely-ill, but poorly growing children with CF, and to determine the relationship between height, lean body mass and BMC. Our second aim was to evaluate the effect of one year of treatment with human recombinant growth hormone (GH) on total body BMC.

METHODS

We measured total-body BMC using dual energy X-ray absorptiometry in 32 poorly growing (height < or =10th percentile for age) prepubertal Caucasian children (ages 7 years 6 months-12 years 9 months, 17 M and 15, F) with CF. BMC and lean tissue mass (LTM) were measured at baseline, at 6 months and one year. One half of the children were randomly assigned to receive treatment with GH (GHTX). Results were compared to reference data maintained for healthy children matched for age and ethnicity. Sex steroid and IGF-I levels were also measured.

RESULTS

Children with CF exhibited lower total body BMC and LTM than age-, ethnicity- and gender-matched controls. This was still apparent when the data were matched for height and bone age. BMC correlated with height, LTM, and IGF-I levels. Although at baseline the groups were similar, the GHTX group demonstrated significantly greater increase in height, weight, LTM and BMC than the NonTX group. These differences remained despite correction for increase in height

CONCLUSION

Our study is the first to evaluate BMC in children with CF and suggests that poor accumulation of bone mineral is a problem. We have further demonstrated that GH treatment improves accumulation of bone mineral.

A retrospective study of growth hormone use in adolescents with cystic fibrosis

OBJECTIVES

Studies of growth hormone (GH) effectiveness in prepubertal children with cystic fibrosis (CF) have been published previously. We present a retrospective study of GH treatment in adolescents with CF.

STUDY DESIGN

We performed a retrospective evaluation of data from 25 pubertal adolescents (ages 13 years 4 months to 16 years 11 months, Tanner stage III or IV). Thirteen (4 F) were followed for 1 year, then received 1 year of treatment with GH (GHTX). We compared the results with a 'control' group of 12 (4 F) whose growth was followed for 1 year (NonTX) but who were not treated with GH at the time of this review. Anthropometric data included: height, weight, lean tissue mass (LTM) and bone mineral content (BMC). Pulmonary function, number of hospitalizations, glycosylated haemoglobin (HbA1c), random blood glucose levels, IGF-I, oestradiol and testosterone levels are also reported.

RESULTS

There was no difference between the groups at baseline. After 1 year, GHTX had significantly greater height and weight velocity, height and weight Z-scores, body mass index (BMI), LTM and BMC. Absolute pulmonary function was better and hospitalizations were fewer in the GHTX. No subject developed glucose intolerance or had any other side-effects.

CONCLUSION

These results suggest that GH use in pubertal adolescents with CF safely improves height, body weight, bone mineralization and clinical status.

Vitamin K status among children with cystic fibrosis and its relationship to bone mineral density and bone turnover

OBJECTIVE

The aim of this study was to assess vitamin K status in an unselected population of children with cystic fibrosis (CF) and to investigate any vitamin K effect on bone turnover and bone mineral status.

METHODS

Children > or =5 years of age who were attending the CF unit were invited to enter the study. Fasting blood samples were analyzed for levels of vitamin K1 and prothrombin produced in vitamin K absence; total, undercarboxylated, and carboxylated osteocalcin (OC); and bone-specific alkaline phosphatase and procollagen I carboxy-terminal propeptide (bone formation markers). Levels of N-telopeptide and free pyridinoline and deoxypyridinoline (bone breakdown products) were measured in urine samples. Bone mineral density and bone mineral content were measured at the lumbar spine and for the total body with a GE Lunar Prodigy densitometer. Statistical analyses were performed with Minitab version 9.1.

RESULTS

One hundred six children entered the study. Sixty-five of 93 children (70%) from whom blood samples were obtained showed suboptimal vitamin K status, on the basis of low serum vitamin K1 levels, increased prothrombin produced in vitamin K absence levels, or both abnormalities. Vitamin K1 levels showed a significant negative correlation with undercarboxylated OC levels but showed no significant correlation with any marker of bone turnover or measurement of bone mineral status. Undercarboxylated OC levels were correlated significantly with bone turnover markers, which themselves showed a significant negative correlation with measurements of bone mineral density and content. There were no significant correlations between carboxylated or undercarboxylated OC levels and bone density measurements.

CONCLUSIONS

Vitamin K1 deficiency is common among children with CF, and routine supplements should be considered. Through its role in the carboxylation of OC, vitamin K deficiency may be associated with an uncoupling of the balance between bone resorption and bone formation. A cause-effect relationship between vitamin K deficiency and low bone mass has not been proved.

Combining unprotected pancreatic enzymes with pH-sensitive enteric-coated microspheres does not improve nutrient digestion in patients with cystic fibrosis

OBJECTIVES

To assess the efficacy of combining unprotected powder enzymes and oral enteric-coated microsphere (ECM) and to ECM alone in treating nutrient maldigestion in patients with cystic fibrosis.

STUDY DESIGN

Patients were randomly assigned into 2 consecutive, 2-week phases; ECM alone, and ECM plus unprotected powder enzymes. Fecal fat, energy, and nitrogen output were compared with intake at the end of each phase. Two-tailed, paired t tests were performed to compare outcomes.

RESULTS

The mean age of the 14 patients (3 girls) was 5.7 +/- 3.2 years (range, 1.9 to 13.4 years). There was no significant difference in percent malabsorption of fat (15.6% vs 18.2%), energy (13.3% vs 13.4%), or nitrogen (11.8% vs 11.3%) between phases.

CONCLUSIONS

The addition of powder enzymes to ECM did not improve nutrient maldigestion compared with ECM alone.

Weight and energy: parents' and children's perspectives on managing cystic fibrosis diet

AIMS

To explore the meanings that parents and children attach to food and eating, and how these influence their approaches to dietary management of cystic fibrosis (CF).

METHODS

Ethnographic design using in-depth interviews with 32 children with CF (aged 6-14 years) and their parents, and participant observations during visits to CF clinics with a sub-group of 21 children. Data were analysed using the constant comparative method and theoretical sampling was used to further explore and develop emergent themes.

RESULTS

Dietary management was found to be a demanding task for children and their parents, and priorities differed between them. A priority of feeding for parents was to protect their children's long term physical health and survival by keeping their weight up. A challenge for parents was to ensure their children's cooperation with eating. A priority for children in being healthy was to have energy for physical activities and so energy rather than weight was of immediate relevance to their daily lives. These differences between parents and children gave rise to tensions and conflicts in their interactions with one another in managing diet.

CONCLUSIONS

Healthcare professionals should take account of the meanings that children and their parents attach to food and eating that can influence their decisions about implementing CF dietary recommendations. The role of children in making food choices has implications for acknowledging them as active participants in their dietary care and for adopting child centred approaches to dietary advice for CF.

Growth hormone treatment enhances nutrition and growth in children with cystic fibrosis receiving enteral nutrition

OBJECTIVES

Impaired longitudinal growth and poor weight gain are common and important problems in children with cystic fibrosis. This study evaluates the hypothesis that adjunctive growth hormone (GH) therapy augments the growth response to nutritional supplementation.

STUDY DESIGN

We recruited 18 prepubertal children who received enteral nutritional supplementation for at least 2 years before enrollment. Nine were randomly assigned to receive no GH for 1 year, followed by 1 year of GH. Nine were randomly assigned to receive 1 year of GH followed by a second year of GH. Measurements included height, weight, pulmonary function, lean tissue mass, bone mineral content, hospitalizations, outpatient antibiotic use, and caloric intake.

RESULTS

Growth hormone resulted in significant improvement in height, weight, bone mineral content, lean tissue mass, and number of hospitalizations. Pulmonary function was similar at baseline. Absolute forced vital capacity and forced expiratory volume in 1 minute significantly increased in GH treatment, but there was no significant change in percent predicted pulmonary function. Caloric intake was similar in both groups during both years.

CONCLUSIONS

These results suggest that GH is a useful for enhancing growth in children with cystic fibrosis receiving enteral nutritional supplementation.

Short-term protein intake and stimulation of protein synthesis in stunted children with cystic fibrosis

BACKGROUND

Stunted children with cystic fibrosis (CF) have less net protein anabolism than do children without CF, and the result is retarded growth in the CF patients. It is not known whether protein intake above that recommended by the Cystic Fibrosis Foundation would further stimulate whole-body protein synthesis.

OBJECTIVE

We studied the effects of 3 amounts of protein intake on whole-body protein synthesis and breakdown by using isotopic infusion of [1-(13)C]valine and [(15)N(2)]urea in children with stable CF who required tube feeding.

DESIGN

In 8 pediatric CF patients, we administered 3 randomly allocated isocaloric diets with normal (NP), intermediate (IP), and high (HP) amounts of protein (1.5, 3, and 5 g . kg(-1) . d(-1), respectively) by continuous drip feeding during a 4-d period at 6-wk intervals. Each patient acted as his or her own control. On the fourth day of feeding, whole-body protein synthesis and breakdown were measured.

RESULTS

Protein synthesis was significantly higher in the HP group (x +/- SEM: 1.78 +/- 0.07 micromol . kg(-1) . min(-1)) than in the IP (1.57 +/- 0.08 micromol . kg(-1) . min(-1); P=0.001) and NP (1.37 +/- 0.07 micromol . kg(-1) . min(-1); P < 0.001) groups. There were no significant differences in protein breakdown. Net retention of nitrogen was significantly higher in the HP group (12.93 +/- 1.42 micromol . kg(-1) . min(-1)) than in the IP (7.61 +/- 1.40 micromol . kg(-1) . min(-1); P=0.01) and HP (2.48 +/- 0.20 micromol . kg(-1) . min(-1); P < 0.001) groups.

CONCLUSION

In stunted children with CF requiring tube feeding, the highest stimulation of whole-body protein synthesis was achieved with a short-term dietary protein intake of 5 g . kg(-1) . d(-1).

A comparison of food group variety between toddlers with and without cystic fibrosis

OBJECTIVES

To compare the food group variety and nutritional adequacy of the diet between toddlers with cystic fibrosis (CF) and age-matched controls. Subjects A clinical sample of 22 toddlers with CF (mean age=21.3 +/- 7.2 months) matched to a community sample of 22 healthy peers.

MAIN OUTCOME MEASURES

The variety index for toddlers (VIT) and the mean adequacy ratio (MAR).

RESULTS

Fruit group scores were highest for children with CF (0.95 +/- 0.13; possible range 0.00-1.00), and dairy group scores were highest for controls (0.90 +/- 0.18). All children earned the lowest scores for vegetables (CF: 0.15 +/- 0.12; controls: 0.26 +/- 0.22). No significant differences were found when comparing VIT and MAR scores by sample (P >0.05). A moderate positive relationship was found between total VIT scores and MAR scores for all children (r=0.38, P <0.05). Toddlers with CF did not achieve the 120-150% of Recommended Dietary Allowance (RDA) for energy.

CONCLUSIONS

Toddlers with CF are consuming diets that are varied and nutritionally adequate for a healthy child. To optimize nutritional status and growth, current recommendations for toddlers with CF to eat a well-balanced diet and to exceed daily RDA for energy requirements remain key dietary issues.

Nutritional status is an important predictor of diaphragm strength in young patients with cystic fibrosis

BACKGROUND

The effect of nutritional status and lung disease progression on diaphragm strength in young patients with cystic fibrosis remains unclear.

OBJECTIVE

The aim of this study was to investigate the effect of nutritional status and airway obstruction on diaphragm strength.

DESIGN

Twitch transdiaphragmatic pressure (Tw Pdi) obtained by bilateral anterior magnetic phrenic nerve stimulation, body mass index (BMI) z score, fat mass, fat-free mass (FFM), arm muscle circumference (AMC), forced expiratory volume in 1 s (FEV(1)), and functional residual capacity (FRC) were measured in 20 patients aged 15.1 +/- 2.8 y (x +/- SD). Values were expressed as a percentage of predicted values.

RESULTS

Mean (+/-SD) Tw Pdi was 24.3 +/- 5.5 cm H(2)O. Univariate regression analysis showed positive correlations between Tw Pdi and nutrition scores (BMI z score: r = 0.63, P = 0.003; FFM: r = 0.47, P = 0.04; AMC: r = 0.45, P = 0.04), airway obstruction (FEV(1): r = 0.68, P = 0.001), and arterial oxygen partial pressure (r = 0.68, P = 0.001). Negative correlations were observed between Tw Pdi and dynamic hyperinflation (FRC: r = -0.65, P = 0.005) and arterial carbon dioxide pressure (r = -0.50, P = 0.03). Furthermore, stepwise regression analysis showed that Tw Pdi correlated with BMI z score (r = 0.75, P = 0.0002) and FEV(1) (r = 0.69, P = 0.001).

CONCLUSIONS

Diaphragm strength is relatively well preserved in young patients with cystic fibrosis. However, the strength of the diaphragm decreases with the progression of malnutrition and airway obstruction.

Comparison of the use of body mass index percentiles and percentage of ideal body weight to screen for malnutrition in children with cystic fibrosis

BACKGROUND

The Cystic Fibrosis Foundation (CFF) recommends using the percentage of ideal body weight (%IBW(CFF)) and body mass index percentiles (BMIp) to assess weight-for-height status and to screen for malnutrition.

OBJECTIVE

The objective was to examine the agreement and discrepancy between the use of %IBW(CFF) and BMIp for screening malnutrition.

DESIGN

Data from 13 021 children reported to the 2000 CFF Patient Registry were analyzed.

RESULTS

In children of average stature (ie, height-for-age between the 25th and 75th percentiles) and aged <10 y, %IBW(CFF) corresponded closely to BMIp, and the prevalence of underweight estimated by %IBW(CFF) < 90% was similar to that by BMIp < 15th percentile. However, in children with short stature (ie, height-for-age < 25th percentile), %IBW(CFF) reflected significantly better weight-for-height status than did the BMIp, whereas the opposite trend was observed in children with tall stature (ie, height-for-age > 75th percentile). Such discrepancies averaged 8-12 percentage points when BMIp was reexpressed to the same unit and scale as %IBW(CFF). Consequently, the prevalence of underweight estimated by %IBW(CFF) < 90% was significantly lower (7.3%) than that estimated by BMIp < 15th percentile (25.7%) in children with short stature, whereas the opposite trend was found in children with tall stature (47.7% and 14.4%, respectively). Additional analyses showed that BMIp was more sensitive to, and had stronger associations with, the percentage of predicted forced expiratory volume in 1 s.

CONCLUSION

Compared with BMIp, %IBW(CFF) underestimated the severity of malnutrition in children with short stature and overestimated the severity of malnutrition in children with tall stature.

Family functioning in young children with cystic fibrosis: observations of interactions at mealtime

This study examined family functioning at mealtime, a context relevant to the management of cystic fibrosis (CF). Thirty-three families of children with CF and a control sample of 33 families of children without a chronic illness were assessed. Family functioning was rated during a videotaped dinner using the McMaster Mealtime Interaction Coding System (MICS), and mealtime behavioral problems were assessed using the Behavioral Pediatrics Feeding Assessment Scale (BPFAS). Ratings for families of children with CF were lower than for control families on overall functioning and five of six MICS dimensions (Communication, Interpersonal Involvement, Behavior Control, Affect Management, Roles). In families of children with CF, better family functioning was related to less frequently occurring mealtime behavioral problems (BPFAS); however, family functioning was not related to the child's weight status or the child's caloric intake. Data support that nutritional intervention may be maximized if dietary adherence is promoted in the context of positive parent-child and family interactions.

Cyproheptadine is an effective appetite stimulant in cystic fibrosis

Chronic pulmonary infection and intestinal malabsorption often lead to malnutrition in children and adults with cystic fibrosis (CF). Appetite stimulants, along with provision of adequate calories, may aid in overcoming nutritional deficits, allowing a better prognosis. We undertook a trial of cyproheptadine hydrochloride (CH) to determine its effectiveness as an appetite stimulant in 18 adults and children with CF. This was a 12-week, randomized, double-blind, controlled trial of CH vs. placebo. Eighteen subjects with documented CF (sweat or genetics positive), minimum age of 5 years, and ideal body weight for height <100% were entered, and 16 completed the study. Subjects were seen at baseline and every 4 weeks. Measures included baseline demographics, Shwachman score, anthropometrics (weight, height, body mass index, skin folds, and body composition by bioelectric impedance analysis), spirometry, caloric intake, days of oral (PO) and intravenous (IV) antibiotics, and a symptom and satisfaction survey. Subjects in the CH group showed significant increases in weight (mean 3.45 kg vs. 1.1 kg in the placebo group), height, BMI percentiles, ideal body weight/height, weight for age z-scores, and fat and fat-free mass. There were no changes or differences in PO or IV antibiotic use or spirometric changes. No significant side effects except transient mild sedation occurred in the CH group. Patient acceptance was good. In conclusion, CH appears to be an effective appetite stimulant with minimal side effects in children and adults with CF.

Assessment of phospholipid malabsorption by quantification of fecal phospholipid

OBJECTIVES

The standard methods for quantifying fat absorption involve extraction of fat from fecal samples with heptane, ether and ethanol. These solvents do not quantitatively recover phospholipids. Malabsorption of dietary and biliary phosphatidylcholine could potentially result in choline deficiency. Therefore, the authors developed a method extracting and quantifying fecal phospholipids.

METHODS

Fecal samples were collected for 72 hours from 18 children with cystic fibrosis and 10 control children. Fat was extracted first with hexane/diethyl ether/ethanol and then with chloroform/methanol. Total fat was quantitated gravimetrically. Phospholipids in extracted fat were separated and quantified using high-performance liquid chromatography with evaporative light-scattering detection (HPLC-ELSD). Phospholipid quantification was validated with a phosphomolybdate colorimetric assay.

RESULTS

The combination of solvent systems used in this study significantly improved total fat (p < 0.05) and phospholipid (p < 0.001) extraction compared with either hexane/diethyl ether/ethanol or chloroform/methanol alone. Fecal phospholipid measured by HPLC-ELSD was significantly correlated with lipid-soluble phosphorous using the phosphomolybdate assay (r = 0.75, p < 0.001). This method also allows quantification of fecal phosphatidylcholine and lysophosphatidylcholine.

CONCLUSIONS

Hexane/diethyl ether/ethanol followed by chloroform/methanol extraction of fecal samples and quantification of phospholipids using HPLC-ELSD is a new method for investigating phospholipid malabsorption.