Supplemental parenteral nutrition in cystic fibrosis

Long term nutritional rehabilitation by gastrostomy in Israeli patients with cystic fibrosis: clinical outcome in advanced pulmonary disease

OBJECTIVES

Several studies have shown a linear correlation between nutritional status and pulmonary function in patients with cystic fibrosis. Our study aims were: 1) To evaluate the effect of nutritional supplementation via gastrostomy on nutritional, clinical, and pulmonary parameters, and 2) To identify predicting factors for success of long-term nutritional rehabilitation.

METHODS

Twenty-one Israeli patients, aged 8 months to 20 years, underwent gastrostomy insertion from 1992 to 2001. All patients were pancreatic insufficient, and all carried severe mutations (W1282X in 62% of the patients). Anthropometric and clinical data were obtained for each patient: 0-12 months before and 6-12 months and 18-24 months after gastrostomy placement. Standard deviation scores (SDS) for height, weight, and body mass index as well as percent of height-appropriate body weight were calculated.

RESULTS

The mean percent-of-predicted forced expiratory volume in 1 second (FEV1) decreased significantly during the first year of gastrostomy feeding (n = 16), from 44.2% +/- 13.9 to 41% +/- 13.3 (P = 0.05). However, during the second year of therapy (n = 10), a trend toward improvement was observed (from 39.4 +/- 12.1 to 41.4 +/- 16.1). Weight, and BMI z-scores as well as weight percent-of ideal body weight increased significantly. Height z-score for age decreased during the first year (from -1.9 +/- 1.3 to -2.1 +/- 1.4), However, a trend toward improvement was observed during the second year. A significant correlation was found between the change in weight z-score and height z-score during the first (r = 0.488, P = 0.016) and the second (r = 0.825, P < 0.001) years. There was no difference between compliers and noncompliers regarding height, weight, and BMI either before or after gastrostomy placement. A significant correlation between age at insertion of gastrostomy and improvement in height z-score (r = 0.52, P = 0.016) was observed. Cystic fibrosis related diabetes (n = 8) did not affect the response to supplemental feeding.

CONCLUSIONS

We observed a trend toward improvement of pulmonary disease during the second year, and a significant improvement in weight, height, and BMI z-scores. Compliance, diabetes, and young age prior to tube insertion did not predict success of nutritional rehabilitation.

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.

Cystic fibrosis-related diabetes

Diabetes mellitus (DM) has been recognized as a complication of cystic fibrosis (CF) for almost 50 years and commonly develops around 20 years of age. The prevalence increases with age and, with improved survival of those with CF, approaches 30% in certain centres. Its development appears to have a significant impact on pulmonary function and may increase mortality by up to six-fold. Subjects with CF are rarely ketosis-prone and phenotypically lie between Type 1 and Type 2 DM. Microvascular complications are recognized, although paucity of data does not permit a clear description of their natural history. An annual oral glucose tolerance test from the age of 10 years is recommended for screening, but logistical difficulties have led some groups to develop specific algorithms to aid diagnosis. Insulin sensitivity in CF is much debated and may depend upon the degree of glucose intolerance. Insulin resistance occurs in the presence of infection, corticosteroid usage and hyperglycaemia, whilst hepatic insulin resistance is considered an adaptation to CF. There is no universal consensus on the treatment of hyperglycaemia. With increased longevity of individuals with CF, greater numbers will develop diabetes and the diabetes physician is destined to play a greater role in the multidisciplinary CF team.

Nutrition and lung function in cystic fibrosis patients: review

Complex interactions between nutrition, skeletal and respiratory muscle function and energy expenditure in cystic fibrosis patients exist. Malnutrition significantly contributes to muscle weakness in patients with chronic obstructive pulmonary disease of the adult or in cystic fibrosis in childhood. Together with a measurable increase in resting energy expenditure the malnutrition, as a consequence of pancreatic insufficiency, leads to pulmonary deterioration. Whether pulmonary disease, pancreatic insufficiency, increased energy expenditure or insufficient intake of nutrition are the starters for the destructive circle or whether the basic defect is responsible for some of the components interacting with each other remains to be determined.

[Nutritional management of cystic fibrosis in children]

A major goal in the management of cystic fibrosis patients is to maintain a good nutritional status as it improves long-term survival. A link is clearly established between the degree of malnutrition and the severity of the disease. Clinical and biological follow-up, better knowledge of energy requirements, dietary counseling and nutritional intervention help to optimize the growth of these patients through childhood and adolescence.

The effects of enteral tube feeding and parenteral nutrition on appetite sensations and food intake in health and disease

Enteral tube feeding (ETF) and parenteral nutrition (PN) are unphysiological methods of feeding. They may not elicit the cephalic phase response because part or all of the gastrointestinal tract is bypassed, nutrients are typically given in liquid form by a continuous infusion over many hours and often overnight while patients sleep. Work conducted in animals, healthy subjects and patients suggests that nutrients delivered as ETF or PN are less effective in relieving appetite sensations than food intake. Distressing appetite sensations may even occur despite the provision by artificial nutrition of sufficient nutrients to meet requirements. The energy provided by ETF and PN is largely additional to oral food intake in humans eating ad libitum, although the extent to which this occurs may decrease with time. There is a need to establish ways (e.g. nutritional, pharmacological, psychological) to suppress appetite sensations and food intake when eating is contraindicated, and to enhance them when weaning from artificial nutrition is desirable.

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.

Interrelationship between circulating leptin concentrations, hunger, and energy intake in healthy subjects receiving tube feeding

BACKGROUND

Tube feeding is an unphysiological route of nutrient delivery, and yet there is a lack of controlled trials examining its effects on appetite, food intake, and factors involved in their control. This study aimed to investigate the relationship between diurnal tube feeding, hunger, food intake, and circulating concentrations of leptin (a putative satiety factor).

METHODS

Six healthy lean men received a continuous nasogastric infusion (9:00 AM to 9:00 PM) of colored water (2 days), liquid feeding (4.2 kJ/mL, energy provision 1 x the initial predicted basal metabolic rate; 3 days), and colored water (2 days). Measurements of hunger (visual analog scales), weighed food intake, and fasting circulating leptin concentrations were made while the subjects were allowed free access to isoenergetically dense food items.

RESULTS

Three days of diurnal nasogastric feeding (mean, 6.9 MJ/d) significantly increased total energy intake (to 19.4 MJ/d; p < .001; analysis of variance [ANOVA]), suppressing oral energy intake by only 17%, with no significant effect on mean daily hunger. Higher levels of energy intake led to a universal rise in circulating leptin concentrations (2.82 to 4.23 ng/mL; p < .004; ANOVA) that was not significantly related to subsequent breakfast energy intake, first rated hunger of the day, timing of morning food consumption, or subsequent mean daily oral energy intake or hunger.

CONCLUSIONS

This study suggests that 3 days of diurnal tube feeding (equivalent to basal metabolic rate) failed to suppress hunger and reduced food intake by only 17%. The rise in circulating leptin concentrations, associated with tube feeding and the increase in total energy intake, failed to predict subsequent hunger or oral energy intake.

Nutrition intervention for weight gain in cystic fibrosis: a meta analysis

OBJECTIVES

A meta analysis of the literature on treatment approaches to malnutrition in cystic fibrosis (CF) was conducted to evaluate the effectiveness of oral supplementation, enteral nutrition, parenteral nutrition, and behavioral intervention on weight gain before and after treatment.

STUDY DESIGN

Eighteen studies were reviewed: four behavioral, six supplement, five enteral nutrition, and three parenteral nutrition.

RESULTS

The weighted effect size for weight gain was large for each intervention: 1.51 behavioral, 1.62 oral, 1.78 enteral, and 2.20 parenteral intervention. All interventions produced a large effect for weight gain in patients with CF. A univariate analysis of variance indicated no significant difference among the four interventions, F(3, 17) = 0.87, p > 0.05. Effect size for calorie intake was also evaluated when data were available (N = 7 studies), yielding a sample size of three behavioral, two enteral, and two oral supplement studies. Analysis of variance indicated a significant effect for treatment, F(2,4) = 13.34, p < 0.05, with post hoc analysis indicating that the behavioral intervention had a greater effect size for calorie intake than oral supplement.

CONCLUSIONS

All interventions were effective in producing weight gain in patients with CF. Behavioral intervention appeared to be as effective in improving weight gain in patients with CF as more invasive medical procedures. These findings support continued research on nutrition intervention with patients with CF including controlled clinical trials of the interventions and long-term follow-up on the impact of nutrition on disease progression.

Behavioral intervention to improve calorie intake of children with cystic fibrosis: treatment versus wait list control

Changes in calorie intake and weight gain were evaluated in five children with cystic fibrosis (CF) who received behavioral intervention and four children with CF who served as wait list controls. The behavioral intervention was a 6-week group treatment that provided nutritional education plus management strategies aimed at mealtime behaviors that parents find most problematic. The control group was identified prospectively and was evaluated on all dependent measures at the same points in time pre- and posttreatment as the intervention group. Difference scores on calorie intake and weight gain from pre- to posttreatment were compared between groups using t tests for independent samples. The behavioral intervention group increased their calorie intake by 1,032 calories per day, while the control group's intake increased only 244 calories per day from pre- to posttreatment [t(6) = 2.826, p = 0.03]. The intervention group also gained significantly more weight (1.7 kg) than the control group (0 kg) over the 6 weeks of treatment [t(7) = 2.588, p = 0.03] and demonstrated catchup growth for weight, as indicated by improved weight Z scores (-1.18 to -0.738). The control group showed a decline in weight Z scores over this same time period (-1.715 to -1.76). One month posttreatment, the intervention was replicated with two of the four children from the control group. Improved calorie intake and weight gain pre- to posttreatment were again found in these children. At 3- and 6-month follow-up study of children receiving intervention, maintenance of calorie intake and weight gain was confirmed. No changes were found on pulmonary functioning, resting energy expenditure, or activity level pre- to posttreatment. This form of early intervention appears to be promising in improving nutritional status and needs to be investigated over a longer period of time to evaluate the effects of treatment gains on the disease process.

Protein-energy malnutrition in cystic fibrosis patients

Protein-energy malnutrition with associated specific nutrient deficiencies is an important feature of cystic fibrosis and has been recognized as a poor prognostic factor. Therefore, the nutritional status of cystic fibrosis patients has to be evaluated regularly by diet diaries, clinical evaluation, anthropometry and more sophisticated methods, such as bioelectrical impedance analysis. Nutritional management, including nutritional rehabilitation programmes, of cystic fibrosis patients is well established today. Consequently, protein-energy malnutrition is no longer acceptable in cystic fibrosis patients, except perhaps in end-stage disease when lung transplantation is not considered.

Increasing calorie consumption in children with cystic fibrosis: replication with 2-year follow-up

Three mildly malnourished children with cystic fibrosis and their parents participated in a behavioral group-treatment program that focused on promoting and maintaining increased calorie consumption. Treatment included nutritional education, gradually increasing calorie goals, contingency management, and relaxation training, and was evaluated in a multiple baseline design across four meals. Children's calorie intake increased across meals, and total calorie intake was 32% to 60% above baseline at posttreatment. Increased calorie consumption was maintained at the 96-week follow-up (2 years posttreatment). The children's growth rates in weight and height were greater during the 2 years following treatment than the year prior to treatment. Increases in pace of eating and calories consumed per minute were also observed 1 year posttreatment. These findings replicated and extended earlier research supporting the efficacy of behavioral intervention in the treatment of malnutrition in children with cystic fibrosis.