Relation between dietary intake and nutritional status in cystic fibrosis

The relationship between energy intake and body-growth in children with cystic fibrosis

BACKGROUND & AIMS

Body-growth, expressed as weight- and height gain, is a strong predictor of morbidity and mortality in patients with cystic fibrosis (CF). Whether current historically based recommendations on a high-energy diet are sufficient for optimal growth is questionable. We therefore assessed the longitudinal relation between body-growth and routine energy intake in paediatric CF patients.

METHODS

Included were patients with CF, aged 2-10 years of whom we obtained 969 measurements of weight and height along with dietary records, and 786 coefficient of fat absorption measurements (CFA). We described body-growth, energy intake, macronutrient intake and the long-term effect of energy intake and coefficient of fat absorption on body-growth during the 8-year follow-up period.

RESULTS

Enrolled were 191 children with CF who had a compromised growth when compared to healthy children. The dietary intake was ≥110% estimated average requirement (EAR) in 47% of the measurements (457/969) and did not (fully) achieve the recommended high-energy level (110-200% EAR). Further, the intake expressed as EAR decreased with increasing age. Cross-sectionally, boys and girls with higher caloric intakes had higher weight-for-age (WFA). The caloric intake explained 18 and 6% of the variation. Further, boys with higher caloric intakes had also higher height-for-age-adjusted-for-target-height (HFA/TH) or BMI. The caloric intake explained 6 or 7% of the variation. Longitudinally, caloric intake was associated with both WFA in boys and girls, and with BMI in boys. Each 100 calories increased intake would result in a 0.01 (girls)-0.02 increase in z-score WFA and 0.03 increase in z-score BMI. We found no significant association between CFA and WFA, HFA/TH or BMI. The contribution of protein, fat and carbohydrates was not associated with WFA, nor with HFA/TH or BMI.

CONCLUSION

Even at this relatively early age, a compromised growth in children with CF was found when compared to healthy children. The energy intake was below 110% EAR in 47% of the measurements, and appeared to be insufficient to prevent suboptimal body-growth over the 8-years of follow-up.

Avaliação e recomendações nutricionais para crianças e adolescentes com fibrose cística

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

The effects of an intensive behavior and nutrition intervention compared to standard of care on weight outcomes in CF

Inadequate intake and suboptimal growth are common problems for patients with CF and a critical target for intervention. The purpose of this study was to compare the growth outcomes of children with CF who participated in a randomized clinical trial to improve energy intake and weight to children with CF receiving standard of care during the same time period. Our primary outcome was change in body mass index z-score (BMI z-score) over 2 years. An exploratory outcome was forced expiratory volume at 1-sec (FEV(1) ) over 2 years. Participants were children ages 4-12 with CF, who participated in a randomized clinical trial of behavior plus nutrition intervention versus nutrition education alone, and a matched Comparison Sample receiving standard of care drawn from the Cystic Fibrosis Foundation (CFF) Registry. Children in the Clinical Trial Group (N=67) participated in a 9-week, nutrition intervention and were followed at regular intervals (3, 6, 12, 18, and 24 months) for 2 years post-treatment to obtain anthropometric and pulmonary function data. For each child in the Comparison Sample (N=346), these measures were obtained from the CFF Registry at matching intervals for the 27-month period corresponding to the clinical trial. Over 27 months, children in the Clinical Trial Group (the combined sample of the behavior plus nutrition and the nutrition alone) demonstrated significantly less decline in BMI z-score, -0.05 (SD=0.68, CI= -0.23 to 0.13), as compared to children in the Comparison Sample, -0.21 (SD=0.67, CI= -0.31 to -0.11). No statistically significant differences were found for decline in FEV(1) between children in the Clinical Trial Group and the Comparison Sample. The key implication of these findings is that intensive behavioral and nutritional intervention is effective and needs to be adapted so that it can be broadly disseminated into clinical practice.

Randomized clinical trial of behavioral intervention and nutrition education to improve caloric intake and weight in children with cystic fibrosis

OBJECTIVE

To evaluate the efficacy of a behavioral plus nutrition education intervention, Be In CHARGE!, compared with that of a nutrition education intervention alone on caloric intake and weight gain in children with cystic fibrosis and pancreatic insufficiency.

DESIGN

Randomized controlled trial.

SETTING

Cystic fibrosis centers in the eastern, midwestern, and southern United States.

PARTICIPANTS

Seventy-nine children aged 4 to 12 years below the 40th percentile for weight for age were recruited. Sixty-seven completed the intervention and 59 completed a 24-month follow-up assessment.

INTERVENTION

Comparison of a behavioral plus nutrition education intervention with a nutrition education intervention alone.

MAIN OUTCOME MEASURES

Primary outcomes were changes from pretreatment to posttreatment in caloric intake and weight gain. Secondary outcomes were changes from pretreatment to posttreatment in percentage of the estimated energy requirement and body mass index z score. These outcomes were also examined 24 months posttreatment.

RESULTS

After treatment, the behavioral plus nutrition education intervention as compared with the nutrition education intervention alone had a statistically greater average increase on the primary and secondary outcomes of caloric intake (mean, 872 vs 489 cal/d, respectively), percentage of the estimated energy requirement (mean, 148% vs 127%, respectively), weight gain (mean, 1.47 vs 0.92 kg, respectively), and body mass index z score (0.38 vs 0.18, respectively). At the 24-month follow-up, children in both conditions maintained an estimated energy requirement of around 120% and did not significantly differ on any outcomes.

CONCLUSIONS

A behavioral plus nutrition education intervention was more effective than a nutrition education intervention alone at increasing dietary intake and weight over a 9-week period. However, across the 24-month follow-up, both treatments achieved similar outcomes. Trial Registration clinicaltrials.gov Identifier: NCT00006169.

Evidence-based practice recommendations for nutrition-related management of children and adults with cystic fibrosis and pancreatic insufficiency: results of a systematic review

The Cystic Fibrosis Foundation established a process of systematic review of evidence to inform the development of clinical care guidelines and encourage evidence-based practice. The Subcommittee on Growth and Nutrition reviewed the evidence in two areas: energy intake and dosing for pancreatic enzyme replacement therapy. Evidence-based recommendations are presented here. Also, an ad hoc working group conducted a review of the literature and performed new analyses using the Cystic Fibrosis Foundation Patient Registry to update the recommendations for growth and weight-status monitoring. These Registry data-based recommendations are presented.

Serum phospholipid fatty acid profile and dietary intake in an adult Mediterranean population with cystic fibrosis

The relative importance of the usual diet in serum phospholipids in subjects with cystic fibrosis (CF) has been poorly studied. To compare the fatty acid profile in serum phospholipids from adult CF subjects with that of healthy subjects, and determine the role of the normal diet in this profile, we studied thirty-seven adult CF subjects with stable pulmonary disease and thirty-seven healthy controls matched for age, sex and nutritional status. A dietary questionnaire was obtained, anthropometric data were recorded, and the fatty acid profile measured by GLC. Compared with the controls, the percentages of myristic, palmitoleic and stearic acids and total MUFA were significantly higher in the CF group, and DHA, linoleic acid, total PUFA and n−6 fatty acids were significantly lower in the CF group. The CF subjects with worse pulmonary function and with pancreatic insufficiency had significantly lower levels of linoleic and n−6 fatty acids. The total energy intake was significantly higher in the CF subjects, although the energy distribution in the CF subjects and the controls was not different for the carbohydrates, lipids and proteins. No differences were detected in fat intake for MUFA (51 (sd 4) v. 52 (sd 4) %) or saturated fatty acids (33·5 (sd 5) v. 31·2 (sd 3·8) %), but the PUFA were slightly lower in the CF subjects (15·4 (sd 4·5) v. 17·4 (sd 4·2) %; P=0·02). The usual dietary intake of fatty acids by adult CF subjects does not appear to explain the difference in the fatty acid profile compared with controls. This suggests an abnormal fatty acid metabolism in CF subjects.

Nutritional intake and status in children with cystic fibrosis: does age matter?

OBJECTIVES

To determine whether nutritional intake and status vary with age in children with cystic fibrosis (CF).

METHODS

Case-control study examining differences in nutritional parameters and intakes in 58 children with CF recruited from a regional centre (2000-2001) and 45 controls. Participants were divided into age groups of 5-8 years, 9-12 years and 13-16 years. Weight, height, body mass index and standard deviation scores were recorded. A 4-day food diary (51 CF, 31 controls) was calculated for macronutrients and micronutrients.

RESULTS

Energy intakes (%EAR) increased with age (112%, 115% and 116%, respectively) and were significantly higher in children with CF than controls. Lower weight and growth trends were observed in children ages 5 to 8 years (NS). Weight gain and growth was normal in children with CF ages 9 to 12 years but declined at 13 to 16 years (weight z score -0.85 vs 0.68 P = 0.003, height z score -0.54 vs 0.53 P = 0.002, body mass index z score -0.72 vs 0.41 P = 0.03). Lung function was the most significant predictor of nutritional status at 9 to 12 years (r2 = 0.37, P = 0.006) and 13 to 16 years (r2 = 0.31, P = 0.01), but was not significant in children ages 5 to 8 years.

CONCLUSION

Energy intakes increased with age in children with CF and exceeded that of healthy peers in all age groups. Weight gain and growth equaled that of healthy peers at 9 to 12 years but was suboptimal at 5 to 8 years and dramatically declines at 13 to 16 years. Energy intakes were unable to meet the clinical demands of children in these age groups. Both remain vulnerable and require greater nutritional targeting.

Energy balance and the accuracy of reported energy intake in preadolescent children with cystic fibrosis

BACKGROUND

Suboptimal growth and nutritional status are common among children with cystic fibrosis (CF) and pancreatic insufficiency (PI). A better understanding of energy balance is required to improve prevention and treatment of malnutrition.

OBJECTIVE

Our objective was to characterize energy balance and the reporting accuracy of dietary intake in children with CF by evaluating the relations between energy intake (EI), energy expenditure (EE), fecal energy loss, nutritional status, and growth.

DESIGN

The subjects were participants of a 24-mo prospective study of children 6-10 y of age with CF and PI. EE, EI, fecal energy loss, and anthropometric measures were obtained at baseline and at 24 mo.

RESULTS

The children (n = 69) had suboptimal growth at baseline (x +/- SD: weight-for-age z score, -0.53 +/- 1.19; adjusted height-for-age z score, -0.67 +/- 1.06; body mass index z score, -0.29 +/- 1.12), and these variables remained suboptimal at 24 mo. The median ratios of EI to EE at baseline and 24 mo were 1.15 and 1.18, respectively, which decreased to 1.09 and 1.10, respectively, when adjusted for fecal energy loss (EI(-FL):EE). At baseline, 7% of subjects were underreporters, 64% were accurate reporters, and 23% were overreporters of energy intake; the percentages were similar at 24 mo.

CONCLUSIONS

Although EI(-FL):EE ratios were higher than expected at both baseline and 24 mo, this cohort showed only age-appropriate weight gain. Self-reported dietary intake data at the individual level should be interpreted with caution, and weight gain velocity may serve as an objective measure of long-term energy balance.

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.

Exercise, stress, and inflammation in the growing child: from the bench to the playground

PURPOSE OF REVIEW

It is becoming increasingly clear that physical activity in children plays a critical role in growth and development, therapy for certain chronic diseases and disabilities, and in the pediatric origins of a variety of bone, metabolic, and cardiovascular diseases. New mechanistic insights have created the opportunity for a phase shift in understanding of the links between exercise and health in the context of the growing child.

RECENT FINDINGS

Exercise even in healthy children profoundly alters stress, immune, and inflammatory mediators including peripheral blood mononuclear cells and circulating pro- and anti-inflammatory cytokines (like interleukin-6). Moreover, exercise even in healthy adults stimulates the production of reactive oxygen species (ROS) and mediators that attenuate them. Oxidative stress, in turn, alters growth and stress mediators. Both ROS and stress/inflammatory factors interact with powerful growth mediators like growth hormone and insulinlike growth factor-I. These findings suggest specific ways in which the balance between pro- and anti-inflammatory, catabolic, and anabolic factors associated with exercise can influence health and growth in children.

SUMMARY

To address the current epidemic of physical inactivity and obesity in children and to optimize the therapeutic effects of exercise in children with disease and disability will require real changes in environments (eg, schools and playgrounds); innovative approaches to rehabilitation of children with chronic disease and disability; and enlightened training of child health professionals. Identifying novel exercise mechanisms involving stress, inflammation, and growth factors will help guide these efforts.

Fitness, acute exercise, and anabolic and catabolic mediators in cystic fibrosis

Exercise can stimulate catabolic inflammatory cytokines even in healthy children. For patients with cystic fibrosis (CF), this may be problematic because CF is characterized by increased inflammation and suppressed growth. We examined fitness and the response to brief exercise of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), insulinlike growth factor-I (IGF-I), and IGF binding protein-1 (IGFBP-1) in 14 subjects with CF (10.5 +/- 0.8 yr of age), 9 of whom were treated with ibuprofen, and 14 healthy control subjects (11.6 +/- 0.5 yr of age, NS). Subjects performed brief intermittent, constant work rate protocol (scaled to each individual's exercise capacity) with blood and urine sampling. Peak V O(2) was correlated with IGF-I (r = 0.68, p < 0.01) in control subjects but not in subjects with CF. In subjects with CF, baseline IL-6 was 79% greater (p < 0.05) and IGF-I was 47% lower than in control subjects (p < 0.05). Post hoc analysis revealed a progressive increase in the IL-6 response to exercise, with the lowest increase observed in control subjects (11.8 +/- 4.6 pg/L/kJ), higher increases in patients with CF treated with ibuprofen (23.4 +/- 7.7 pg/L/kJ), and highest in subjects with CF not receiving ibuprofen (29.2 +/- 7.5 pg/L/kJ). Qualitatively similar results were observed for TNF-alpha. Exercise also significantly increased IGFBP-1 in both control subjects and subjects with CF. Brief exercise can increase even chronically elevated inflammatory mediators in CF, and this response may be attenuated by ibuprofen.

Height and weight fail to detect early signs of malnutrition in children with cystic fibrosis

BACKGROUND

Many children with cystic fibrosis grow poorly and are malnourished. This study was undertaken to determine whether extensive anthropometry could detect early signs of malnutrition in prepubertal children with cystic fibrosis to prevent deficits in height and weight.

METHODS

Height, weight, six skin folds (triceps, subscapular, supraspinale, abdominal, front thigh, and medial calf) and five girths (arm relaxed, forearm, chest, thigh, and calf) were measured in a cross-sectional study of children aged 6 to 11 years with cystic fibrosis.

RESULTS

The children with cystic fibrosis were shorter and lighter for their age and gender than those in the reference groups. The mean weight and height z scores for the girls with cystic fibrosis were lower than those for the boys, significantly so for z weight ( P < 0.05). Although, the mean percent ideal body weight value of 98.6% suggested that the children with cystic fibrosis were adequately nourished, most of the measures of muscularity and adiposity of the children with cystic fibrosis were significantly lower than those of the reference group ( P < 0.05). The z scores of the anthropometric measures revealed that the deficit in muscularity of the children with cystic fibrosis was relatively much greater than the deficit in adiposity.

CONCLUSIONS

The percent ideal body weight index does not seem to be an adequate measure of nutritional status in children with cystic fibrosis. Anthropometric assessments should include skin-fold and circumference measurements of numerous sites on the upper and lower body, the trunk, and the limbs to detect deterioration in nutritional status early. Early detection of deficits in nutritional status may result in the adverse effects of malnutrition on height and weight, and possibly clinical status, being prevented.

Body image and dieting behavior in cystic fibrosis

OBJECTIVE

To examine the relationship between pulmonary function, nutritional status, body image, and eating attitudes in children with cystic fibrosis (CF) compared with healthy controls.

METHOD

Seventy-six children with CF (39 girls) and 153 healthy control children (82 girls) were recruited. All children were between 7 and 12 years of age. After being weighed and measured, participants undertook a structured 1-to-1 interview. Four measures were used to assess body image: body size (perception and satisfaction) were ascertained using the Children's Body Image Scale (CBIS), which uses photographs of children of various body mass index (BMI) representative of the range of BMI percentiles for children 7 to 12 years of age. Body size satisfaction was measured by the response to the questions, "Do you think your body is 1) much too thin, 2) too thin, 3) just right, 4) too fat, and 5) much too fat?" Body weight satisfaction was measured by the question, "Would you like your body to be 1) much thinner, 2) a little bit thinner, 3) stay the same, 4) a little bit fatter, and 5) much fatter?" Global self-esteem was measured using the children's version of the Rosenberg Self-Esteem Scale and Body Esteem Scale using a 24-item scale. Dieting behavior was measured by asking directly about previous weight control behaviors, use of the Dutch Eating Behavior-Restraint Scale (DEBQ-R), and, in children who acknowledged previous dieting behavior, the Children's Eating Attitude Test (ChEAT) was additionally administered. Results. Both girls and boys with CF had significantly reduced BMI percentiles compared with control children. Boys with CF did not have a significantly different BMI compared with girls with CF. There were significant positive correlations between forced expiratory volume in 1 second (FEV(1)) (% of predicted) and BMI percentile in girls (r =.35) and boys (r =.50) with CF. Body image perceptions in boys and girls with CF were examined in relation to the healthy control group using 2 (CF and control groups) by 2 (male and female) analysis of variance. The interaction effect was examined to explore the prediction that girls compared with boys with CF would have greater acceptance of their body shape and less desire to become larger. There were no differences between groups or sex in body esteem. On the CBIS body dissatisfaction score, children with CF were significantly more likely to perceive their ideal body size as a little larger than their current size while control children desired a smaller body size than their current size. CF children had a significantly lower mean score for body size satisfaction (an item assessing perception being too thin) and a significantly higher mean score on body weight satisfaction. There was a significant main effect of gender for only 1 measure, difference between the CBIS body dissatisfaction score, with girls being more likely to nominate a smaller ideal than their current figure. There were no significant interaction effects. Of children with CF and a low BMI (</=10th percentile), 25% of girls and 38% of boys thought they were too thin. Fewer girls (19%) than boys (38%) would have liked to be fatter. The CF group had significantly lower mean scores on the DEBQ-R scale compared with controls. Of the children with CF completing the ChEAT (n = 13), none obtained a score of clinical significance compared with 6 (4%) for controls. To examine predictors of BMI a multiple regression analysis was conducted separately for boys and girls with CF and control boys and girls in which the dependent variable was BMI and the independent variables were FEV(1) (% of predicted) (in CF children only), body esteem, self-esteem, and body dissatisfaction score. In the case of boys with CF, the regression equation was significant (Adjusted R(2) = 0.30). In the case of girls with CF, the regression equation was significant (Adjusted R(2) = 0.25) with body dissatisfaction making a significant independent contribution. For control boys the regression equation was significant (Adjusted R(2) = 0.18). Variables making a significant contribution to the equation were body esteem and body dissatisfaction. Finally, for control girls the regression equation was significant (Adjusted R(2) = 0.13). The only variable to make a significant contribution to the equation was body dissatisfaction.

DISCUSSION

Children with CF had very similar body esteem and general self-esteem as controls. A consideration of body image constructs does reveal group differences between perception and satisfaction with body size between groups. Children with CF were more likely to perceive their body size as larger than it actually was and have greater satisfaction with their current body size in contrast to control children. The girls and boys with CF with a higher BMI frequently selected a smaller body size as their ideal. (ABSTRACT TRUNCATED)

The validity of self-reported energy intake as determined using the doubly labelled water technique

In the 1980s the development of the doubly labelled water (DLW) technique made it possible to determine the validity of dietary assessment methods using external, independent markers of intake in free-living populations. Since then, the accuracy of self-reported energy intake (EI) has been questioned on a number of occasions as under-reporting has been found to be prevalent in many different populations. This paper is a review of investigations using the DLW technique in conjunction with self-reported EI measures in groups including adults, children and adolescents, obese persons, athletes, military personnel and trekking explorers. In studies where a person other than the subject is responsible for recording dietary intake, such as parents of young children, EI generally corresponds to DLW determined energy expenditure. However, in instances where the subjects themselves report their intake, EI is generally under-reported when compared with energy expenditure. It was originally believed that this phenomenon of under-reporting was linked to increased adiposity and body size, however, it is now apparent that other factors, such as dietary restraint and socio-economic status, are also involved. This paper therefore aims to present a more comprehensive picture of under-reporting by tying in the findings of many DLW studies with other studies focusing particularly on the characteristics and mechanisms for under-reporting. Awareness of these characteristics and mechanisms will enable researchers to obtain more accurate self-reports of EI using all dietary recording techniques.

Dietary recommendations to prevent and manage chronic pediatric health conditions: adherence, intervention, and future directions

This review provides a summary of the dietary aspects of pediatric health conditions. Within each condition, dietary recommendations are reviewed, and adherence rates, factors affecting adherence, and known interventions are reported. Findings indicate that knowledge is necessary but not sufficient for dietary change. Interventions specifically targeting diet appear more promising than interventions aimed at global treatment adherence. Behavioral interventions and group treatment modalities also appear promising. Recommendations for future research include a systematic assessment of barriers to dietary adherence across populations, integration of the research on normative development of eating behavior in childhood, and the application of this information to the design and implementation of future treatment.

What do children with cystic fibrosis and their parents know about nutrition and pancreatic enzymes?

OBJECTIVE

To describe the development and validation of questionnaires designed to assess nutrition and pancreatic enzyme replacement therapy knowledge and cystic fibrosis self-management skills, and the results obtained when the questionnaires were used.

DESIGN

A cross-sectional study using validated questionnaires to interview the respondents. The outcome measures were scores for knowledge, appropriate and inappropriate self-management, and Socioeconomic Index.

SUBJECTS

Forty-two children with cystic fibrosis aged 6 to 11 years and 55 caregivers of 2 to 11-year-old patients of the Princess Margaret Hospital Cystic Fibrosis Clinic, Perth, Australia.

STATISTICAL ANALYSES

Descriptive statistics and correlations between scores were used for statistical analyses. Associations between knowledge scores were examined using Pearson's correlation coefficient. Spearman's rank correlation was used to examine the associations between knowledge and self-management scores and socioeconomic index.

RESULTS

Children's and caregivers' mean knowledge scores were 63% and 85%, respectively. Mean appropriate and inappropriate self-management scores for children were 55% and 21%, respectively, and for the caregivers were 74% and 32%, respectively. There was a statistically significant (P < .05) positive association between caregivers' and children's knowledge (r = 0.32), and children's knowledge and appropriate self-management scores (r = 0.41); and a statistically significant negative association between caregivers' knowledge and inappropriate self-management scores (r = -0.35); and no statistically significant associations between Socioeconomic Index and children's and caregivers' knowledge and self-management scores.

APPLICATIONS

This study identified areas in which the nutrition knowledge of children with cystic fibrosis and their caregivers needs to be enhanced to increase the likelihood that optimum dietary and pancreatic enzyme therapy is achieved. The questionnaires that were developed for the study could be refined and used in the clinical setting to identify knowledge and self-management deficits. Alternatively, the questionnaires could become valuable research tools for assessing the type of intervention required and in planning and evaluating programs.

Cystic fibrosis: nutritional status and micronutrients

Recent studies have focused on the current dietary intake of cystic fibrosis patients, the impact of nutritional support on both the nutritional status and clinical outcome variables, and the effects on the nutritional status of antibiotic therapy and surgical treatment of meconium ileus. In addition to weight and height, skinfold measurements, bioelectrical impedance analysis and dual energy X-ray absorptiometry have been employed for the determination of nutritional status. A proton pump inhibitor has been used successfully along with pancreatic enzymes for the improvement of fat absorption. Attention has been paid to resting energy expenditure during pulmonary exacerbations, to vitamin K function in bone mineralization and to risk factors for low bone mineral density in cystic fibrosis. The relationships between glutathione and nutritional status have been studied, along with possible interactions with albumin, a potent antioxidant. Finally, a beneficial effect of docosahexaenoic acid on cystic fibrosis pathology has been suggested, but this requires further critical evaluation.

Psychosocial predictors of adherence to nutritional recommendations and growth outcomes in children with cystic fibrosis

This study aimed to elucidate the relationship between maternal psychosocial factors related to dietary adherence and growth outcomes in their children with cystic fibrosis (CF). Twenty-five children with CF and mild lung disease, aged 7-12 years, were weighed and measured and completed detailed food records. Mothers completed questionnaires that measured general nutritional knowledge, nutritional knowledge specific to CF, coping strategies, dieting behaviors, self-efficacy about the ability to provide the correct diet, and attitudes and beliefs about CF. Of the cohort, only 16% adhered to the dietary recommendations. Dietary adherence was positively correlated with weight. Maternal nutritional knowledge specific to CF significantly predicted children's dietary adherence score. There was a significant negative correlation between the child's weight and mothers who were dieting successfully. Other psychosocial factors assessed were not related to dietary adherence. Improving the mother's knowledge about nutritional needs in CF appears worthwhile and may have an impact on growth.

Physiological and psychosocial contributors to malnutrition in children with cystic fibrosis: review

Malnutrition was once thought to be an inevitable consequence of cystic fibrosis (CF). It is now considered preventable but still contributes considerable morbidity in children. Malnutrition is linked to poorer pulmonary function, reduced survival and quality of life. As the anticipated lifespan of children with CF continues to lengthen, the prevention of malnutrition attains greater importance. This review explores the complex organic and psychosocial factors implicated in the aetiology of malnutrition associated with CF.

Pancreatic enzyme replacement therapy in cystic fibrosis: Australian guidelines. Pediatric Gastroenterological Society and the Dietitians Association of Australia

Pancreatic enzyme replacement therapy (PERT) is a major factor associated with achieving optimum growth and nutritional status in cystic fibrosis (CF) patients with pancreatic insufficiency and consequent malabsorption. Currently in Australian CF clinics policies for the usage of PERT vary considerably. This paper highlights the current issues related to fat absorption and use of PERT in CF. It also provides evidence to support the recommendation of a PERT dose based on a standard ratio of lipase units per gram of dietary fat consumed for individual patients. A consistent approach to PERT doses will facilitate identification of patients whose PERT intake increases their risk of fibrosing colonopathy and for whom gastroenterological review is warranted. Recent reports indicate that PERT intake can be reduced with a secondary improvement in growth and nutrition status as a consequence of increased dietetic input. These Australian guidelines for the judicious use of PERT in CF should lead not only to a refinement in nutritional management of patients with CF but should also facilitate an improvement in compliance with therapy due to sophistication in patient education materials. The Australian guidelines for the use of PERT in CF if correctly applied, will also provide patients and their families with a better understanding of the relationship between PERT and nutritional status.

Cystic fibrosis: nutritional consequences and management

Malnutrition is an adverse prognostic factor in cystic fibrosis, influencing the course of pulmonary disease and correlating inversely with survival. A positive energy balance between energy intake and the combination of total energy expenditure, energy losses and growth-related energy cost is essential to maintain normal nutritional status. Before starting nutritional supplementation, it is important to rule out pathological conditions that may have a deleterious effect on nutritional status: persistent exocrine pancreatic insufficiency, chronic bacterial pulmonary colonization, impaired glucose tolerance, specific nutritional deficits and associated disorders leading to a decrease of energy intake. Several methods are available, ranging from boosted oral nutrition to behavioural intervention, oral supplementation, enteral nutrition and, rarely, parenteral nutrition. The use of elemental nutrients for either oral supplementation or enteral nutrition seems of no nutritional benefit and is more expensive than conventional polymeric nutrients. Provided that the goals of the nutritional supplementation are fulfilled, simpler is often better.