Energy balance during acute respiratory exacerbations in children with cystic fibrosis

Nutrition management of pediatric patients who have cystic fibrosis

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

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Nutrition in patients with cystic fibrosis: a European Consensus

This document is the result of an European Consensus conference which took place in Artimino, Tuscany, Italy, in March 2001 involving 33 experts on nutrition in patients with cystic fibrosis, organised by the European Cystic Fibrosis Society, and sponsored by Axcan-Scandipharm, Baxter, Dr Falk Pharma, Fresenius, Nutricia, SHS International, Solvay Pharmaceuticals (major sponsor). The purpose of the conference was to develop a consensus document on nutrition in patients with cystic fibrosis based on current evidence.

Relation between physical activity and energy expenditure in a representative sample of young children

BACKGROUND

Strategies for the prevention and treatment of childhood obesity require a better understanding of the relation between the pattern of free-living physical activity and total energy expenditure (TEE).

OBJECTIVE

We assessed the relations between TEE and physical activity level (PAL) during engagement in different intensities of physical activity.

DESIGN

We used a cross-sectional study of 104 children (median age: 5.4 y) in Scotland. TEE was measured with use of doubly labeled water (DLW), and resting energy expenditure was predicted to determine PAL. Time spent sedentary and in light-intensity activity and in moderate- and vigorous-intensity physical activity (MVPA) was assessed by accelerometry concurrent with DLW measurements. Correlation and regression were used to assess the relations between measures of sedentary behavior, intensities of activity, and PAL as the dependent variable.

RESULTS

Time spent sedentary was negatively correlated with PAL (r = -0.33, P < 0.01), and time spent in light-intensity activity was positively correlated with PAL (r = 0.31, P < 0.01). In multiple regression analyses, both time spent sedentary and in light-intensity activities were significantly associated with PAL. Time spent in MVPA was not associated with PAL; engagement in MVPA was limited in this sample (median: 3% of waking hours; range: 0-14%). PAL was significantly higher in boys than in girls.

CONCLUSION

In this sample and setting, PAL was not influenced by engagement in MVPA but was influenced by time spent sedentary and in light-intensity activities. This study suggests that in young children, MVPA could make only a minor contribution to free-living TEE and PAL.

Understanding chronic malnutrition in childhood and old age: role of energy balance research

Undernutrition is commonly associated with chronic disease in children and the elderly. Overnutrition is also, but less commonly, associated with chronic illness. In most diseases malnutrition arises because energy intake does not match energy output. Traditionally, the focus of research has been on abnormalities in energy expenditure, in the belief that these factors were the main determinants of energy imbalance. Recent studies using the doubly-labelled-water method to measure total energy expenditure, combined with more complex study design, have suggested an alternative conclusion. In many chronic diseases patient behaviour, and particularly energy intake, is responsible for energy imbalance and malnutrition. Energy balance studies have therefore provided a useful foundation for the design of strategies aimed at preventing or managing chronic malnutrition. However, modifying patient behaviour is an ambitious undertaking which may not be within the scope of existing clinical nutrition services. A number of non-traditional models of managing chronic malnutrition in children and the elderly are promising. Increasing recognition of the value of systematic review will also provide improved strategies for prevention and management of chronic malnutrition.

Energy intake by multiple pass 24 h recall and total energy expenditure: a comparison in a representative sample of 3-4-year-olds

The accuracy of the multiple pass 24 h recall for assessment of habitual energy intake in pre-school children is unclear. The primary aim of this study was to assess its accuracy by comparison with measurement of total energy expenditure by doubly-labelled water in a representative sample of forty-one 3-4-year-olds. The recall method was well tolerated by subjects and was administered quickly and easily. However, it produced estimates of energy intake which significantly exceeded measures of total energy expenditure from doubly-labelled water, mean paired difference 660 kJ/d (P<0.01). Agreement between the two methods was poor at the individual level: limits of agreement 660+/-3018 kJ/d. Error and imprecision in both methods contribute to individual differences, but the present study suggests that the multiple pass 24 h recall does not provide accurate estimates of dietary energy intake in individual children.

Total energy expenditure in children with obstructive sleep apnoea syndrome

Childhood obstructive sleep apnoea syndrome (OSAS) acts as a check on growth and nutritional status. An increase in sleeping energy expenditure has been proposed as a possible mechanism, but to date, no studies have determined whether energy requirements (total energy expenditure; TEE) are raised in OSAS. The aim of this study was to test the hypothesis that OSAS is associated with increased TEE. Eleven children (mean+/-SD 5.8+/-2.2 yrs of age) with OSAS confirmed by nocturnal polysomnography were each matched with a pair of healthy controls (n=22) of the same age and sex. TEE was measured using the doubly-labelled water method in all subjects. In 10/11 patients TEE was also measured after adenotonsillectomy and changes in TEE assessed. There was no significant difference in TEE between patients (mean+/-SD 325+/-44 kJ x kg(-1) x day(-1)) and controls (339+/-48 kJ x kg(-1) x day(-1)), nor between patients and age- and sex-specific literature data on TEE, using the doubly-labelled water method. Differences in TEE within patients, before versus after surgery, were minor and not statistically significant. This study does not support the hypothesis that obstructive sleep apnoea syndrome in childhood is associated with increased energy requirements, and suggests that alternative explanations for the effect of this syndrome on growth and energy balance should be sought.

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.

The adjuvant effect of particles-importance of genetic background and pre-sensitisation

BACKGROUND

We have previously reported that simple and well-characterised particles, such as polystyrene particles (PSP), have an IgE adjuvant effect in mice. The purpose of this study was to explore the importance of genetic background concerning the adjuvant effect of PSP in different strains of mice.

METHODS

Inbred NIH/Ola, BALB/c and C3H/HeJ mice were given two intraperitoneal injections with either PSP plus OVA or OVA alone, and then an intraperitoneal challenge with OVA alone. NIH/Ola mice were also pre-sensitised to develop a weak or strong IgE response to OVA, and then given an intraperitoneal challenge with PSP plus OVA or OVA alone. Serum levels of total and allergen-specific IgE and IgG2a were measured.

RESULTS

PSP had a specific IgE and IgG2a adjuvant effect in NIH/Ola mice but not in C3H/HeJ and BALB/c mice. Weakly pre-sensitised NIH/Ola mice showed the same response pattern as the naive NIH/Ola mice. In contrast, strongly pre-sensitised mice showed an antibody response pattern similar to that of high-responder BALB/c mice.

CONCLUSIONS

Our results indicate that the allergen responder status, either genetic or induced, is of importance for the adjuvant effect from particles. The IgE and IgG2a adjuvant effect may depend on the genetically determined susceptibility of an individual to be influenced by exposure to the adjuvant. Therefore, the allergy-enhancing effect from particle pollution may differ between individuals.

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.