Plasma zinc and growth status in preadolescent children with cystic fibrosis

The Role of Zinc in Developed Countries in Pediatric Patients: A 360-Degree View

Zinc is an important trace element for growth and health at pediatric ages. Zinc is fundamental in inflammatory pathways, oxidative balance, and immune function. Zinc exhibits anti-inflammatory properties by modulating Nuclear Factor-kappa (NF-κB) activity and reducing histamine release from basophils, leukocytes, and mast cells. Furthermore, its antioxidant activity protects against oxidative damage and chronic diseases. Finally, zinc improves the ability to trigger effective immune responses against pathogens by contributing to the maturation of lymphocytes, the production of cytokines, and the regulation of apoptosis. Given these properties, zinc can be considered an adjunctive therapy in treating and preventing respiratory, nephrological, and gastrointestinal diseases, both acute and chronic. This review aims to deepen the role and metabolism of zinc, focusing on the role of supplementation in developed countries in pediatric diseases.

Nutritional Care in Children with Cystic Fibrosis

Patients with cystic fibrosis (CF) are prone to malnutrition and growth failure, mostly due to malabsorption caused by the derangement in the chloride transport across epithelial surfaces. Thus, optimal nutritional care and support should be an integral part of the management of the disease, with the aim of ameliorating clinical outcomes and life expectancy. In this report, we analyzed the nutrition support across the different ages, in patients with CF, with a focus on the relationships with growth, nutritional status, disease outcomes and the use of the CF transmembrane conductance regulator (CFTR) modulators. The nutrition support goal in CF care should begin as early as possible after diagnosis and include the achievement of an optimal nutritional status to support the growth stages and puberty development in children, that will further support the maintenance of an optimal nutritional status in adult life. The cornerstone of nutrition in patients with CF is a high calorie, high-fat diet, in conjunction with a better control of malabsorption due to pancreatic enzyme replacement therapy, and attention to the adequate supplementation of fat-soluble vitamins. When the oral caloric intake is not enough for reaching the anthropometric nutritional goals, supplemental enteral feeding should be initiated to improve growth and the nutritional status. In the last decade, the therapeutic possibilities towards CF have grown in a consistent way. The positive effects of CFTR modulators on nutritional status mainly consist in the improvement in weight gain and BMI, both in children and adults, and in an amelioration in terms of the pulmonary function and reduction of exacerbations. Several challenges need to be overcome with the development of new drugs, to transform CF from a fatal disease to a treatable chronic disease with specialized multidisciplinary care.

Update on the management of vitamins and minerals in cystic fibrosis

Advancements in respiratory and nutrition management have significantly improved the survival of patients with cystic fibrosis (CF). With the availability of several nutrition interventions such as oral/enteral nutrition supplements, enteric‐coated pancreatic enzymes, and water‐miscible CF‐specific vitamin supplements, frank vitamin deficiencies—with the exception of vitamin D—are rarely encountered in current clinical practice. Whereas they were previously considered as micronutrients, our current understanding of fat‐soluble vitamins and minerals as antioxidants, immunomodulators, and disease biomarkers has been evolving. The impact of highly effective modulators on the micronutrient status of patients with CF remains elusive. This narrative review focuses on the updates on the management of fat‐soluble vitamins and other micronutrients in CF in the current era and identifies the gaps in our knowledge.

Zinc status and growth in infants and young children with cystic fibrosis

BACKGROUND

Zinc deficiency is associated with poor growth in children without cystic fibrosis (CF), but its impact on growth in children with CF is unknown.

OBJECTIVE

To determine the prevalence of low serum Zn (sZn) and its relationship with growth in the first 3 years of life in children with CF.

METHODS

We utilized data from infants with CF who were enrolled in a longitudinal study of nutrition and lung health and had sZn measured as part of clinical care. Cross-sectional correlations between sZn levels and growth z scores were assessed by Pearson's correlation coefficient. To identify factors associated with sZn status and its association to longitudinal growth patterns, multiple regression analysis with repeated measures were performed using generalized estimating equations.

RESULTS

A total of 106 sZn measurements from 53 infants were identified. Seventeen infants (32%) had intermittent Zn insufficiency, defined as at least one sZn <70 mcg/dl in their first 3 years of life. There were no significant cross-sectional associations between sZn and growth z scores. However, analysis of longitudinal growth patterns revealed that weight- and length-for-age z scores in children with intermittent Zn insufficiency were lower during early infancy and their weight-for-length z scores at age 3 years were also lower compared to those who were always Zn sufficient.

CONCLUSION

Low sZn occurs in one-third of children with CF in the first 3 years of life. Cross-sectional and longitudinal analyses revealed discrepant associations between sZn and growth. Therefore, prospective studies are needed to understand the role of Zn in growth in CF.

Zinc Nutritional Status in Patients with Cystic Fibrosis

BACKGROUND

Zinc is an essential nutrient for all forms of life and its deficiency affects the normal growth and development of human beings.

OBJECTIVE

The main aim was to investigate zinc nutritional status by serum zinc concentration (SZC) and dietary zinc intake and their association in cystic fibrosis (CF) patients.

METHODS

A cross-sectional study was conducted in CF patients. Anthropometric measurements and respiratory and pancreatic tests were conducted. Hypozincemia was determined by SZC while using atomic absorption spectrophotometry and dietary zinc deficiency by prospective 72-h dietary surveys.

RESULTS

Mean SZC (87.2 ± 16.7 μg/dL) and dietary zinc intake (97 ± 26.9% Dietary Reference Intake) were normal. Three of 17 patients with CF (17.6%) had hypozincemia and four (23.5%) had a dietary zinc deficiency. No patient with dietary zinc deficiency had hypozincemia. A positive and significant association was observed between SZC and Z-score of BMI-for-age (p = 0.048) and weight-for-height (p = 0.012) and between dietary zinc intake and energy intake (EI, p = 0.036) and Z-score of weight-for-high (p = 0.029).

CONCLUSION

SZC was associated with the nutritional status, expressed as BMI (Body Mass Index) and weight-for-height Z score, and dietary zinc intake with EI and weight-for-height Z-score. No patient with hypozincemia had dietary zinc deficiency. This situation should alert us to a marginal zinc deficiency and it may explain why there were no overlapping cases between the two groups. We suggest that probably 41% of the cases in this study would be at elevated risk of zinc deficiency and a zinc supplementation may be considered.

ESPEN-ESPGHAN-ECFS guidelines on nutrition care for infants, children, and adults with cystic fibrosis

BACKGROUND

Malnutrition is both a frequent feature and a comorbidity of cystic fibrosis (CF), with nutritional status strongly associated with pulmonary function and survival. Nutritional management is therefore standard of care in CF patients. ESPEN, ESPGHAN and ECFS recommended guidelines to cover nutritional management of patients with CF.

METHODS

The guidelines were developed by an international multidisciplinary working group in accordance with officially accepted standards. The GRADE system was used for determining grades of evidence and strength of recommendation. Statements were discussed, submitted to Delphi rounds, reviewed by ESPGHAN and ECFS and accepted in an online survey among ESPEN members.

RESULTS

The Working Group recommends that initiation of nutritional management should begin as early as possible after diagnosis, with subsequent regular follow up and patient/family education. Exclusive breast feeding is recommended but if not possible a regular formula is to be used. Energy intake should be adapted to achieve normal weight and height for age. When indicated, pancreatic enzyme and fat soluble vitamin treatment should be introduced early and monitored regularly. Pancreatic sufficient patients should have an annual assessment including fecal pancreatic elastase measurement. Sodium supplementation is recommended and a urinary sodium:creatinine ratio should be measured, corresponding to the fractional excretion of sodium. If iron deficiency is suspected, the underlying inflammation should be addressed. Glucose tolerance testing should be introduced at 10 years of age. Bone mineral density examination should be performed from age 8-10 years. Oral nutritional supplements followed by polymeric enteral tube feeding are recommended when growth or nutritional status is impaired. Zinc supplementation may be considered according to the clinical situation. Further studies are required before essential fatty acids, anti-osteoporotic agents, growth hormone, appetite stimulants and probiotics can be recommended.

CONCLUSION

Nutritional care and support should be an integral part of management of CF. Obtaining a normal growth pattern in children and maintaining an adequate nutritional status in adults are major goals of multidisciplinary cystic fibrosis centers.

Clinical, anthropometric and laboratory nutritional markers of pancreatic exocrine insufficiency: Prevalence and diagnostic use

Pancreatic exocrine insufficiency (PEI) frequently occurs secondary to exocrine pancreatic disease (e.g. chronic pancreatitis, cystic fibrosis, cancer) or pancreatic/gastrointestinal surgery, resulting in the maldigestion of nutrients and consequently malnutrition. Pancreatic enzyme replacement therapy (PERT) is the cornerstone of PEI management. Despite its clinical relevance, the diagnosis of PEI in clinical practice is challenging, as the current gold standard test is cumbersome, and alternatives have limited availability or accuracy. There is a need for accurate and easily applicable diagnostic modalities. We review the prevalence of clinical symptoms and changes in anthropometric measurements and laboratory nutritional markers indicative of malnutrition in patients with PEI, and the relevance of these findings in diagnosing PEI and monitoring PERT efficacy. Based on limited available evidence, assessment of clinical symptoms, body weight, body mass index and other anthropometric parameters are not sensitive methods for PEI diagnosis, owing to high variability and multiple confounding factors, but appear useful in monitoring PERT efficacy. Limited evidence precludes strong recommendations but suggests that serum levels of vitamin E, magnesium, and plasma proteins, notably retinol binding protein, albumin, and prealbumin, may have diagnostic utility in PEI. Studies show that assessment of changes in these and other nutritional parameters is helpful in monitoring PERT efficacy. Further research is needed to confirm the diagnostic accuracy of these parameters for PEI. Until such data are available, a nutritional evaluation including circulating vitamin E, magnesium, retinol binding protein, albumin, and prealbumin may be used to evaluate the probability of PEI in clinical practice when reliable pancreatic function tests are not available.

Serum zinc concentration in cystic fibrosis patients with CFTR I1234V mutation associated with pancreatic sufficiency

OBJECTIVE

To determine serum zinc (Zn) level among cystic fibrosis (CF) patients with homozygous CFTR I1234V mutation associated with pancreatic sufficiency (PS).

METHODS

A cross-sectional study was conducted including both pediatric and adult CF patients. Data on age, weight, height, body mass index (BMI), BMI Z-score, FEV1, and chronic Pseudomonas aeruginosa infection were collected. Serum Zn, albumin, and total proteins were measured and analyzed.

RESULTS

Forty-five CF patients with homozygous CFTR I1234V mutation belonging to a large Arab kindred tribe and eight CF patients with other mutations associated with pancreatic insufficiency (PI). Patient's age ranged from 2 to 49 years with a mean age of 15.1 ± 9.1 years and mean plasma Zn of 0.78 ± 0.15 mcg/mL. Seven (13.2%) patients with CFTR I1234V and PS had low Zn levels (<0.6 mcg/mL). Mean age among Zn deficient group was significantly older. The mean FEV1 in the deficient group was found to be insignificant low. Persistent P. aeruginosa colonization was more prevalent in Zn deficient group. BMI Z-scosre of CF patients were positively correlated with Zn levels. Forty-five healthy subjects belonging to the same Arab tribe were selected in order to assess their Zn levels and their mean plasma Zn of 0.84 ± 0.11 mcg/mL (range 0.65-1.1 mcg/mL) with mean age 20.4 ± 10.1 years (range 6-40 years).

CONCLUSION

These findings suggest that Zn deficiency can occur in CF patients with PS. The association of Zn levels and the frequency of P. aeruginosa isolated in CF patients need further investigation.

Plasma zinc in adults with cystic fibrosis: correlations with clinical outcomes

BACKGROUND

Zinc status has been previously documented in cystic fibrosis (CF) infants, children and adolescents. However, despite the increasing life expectancy observed in CF populations, data regarding zinc status of CF adults are surprisingly lacking. The objectives of this study were to (1) characterize zinc status and (2) explore associations between zinc status and clinical outcomes of CF adult patients.

METHODS

A retrospective chart review was performed for patients who had their plasma zinc measured between 2009 and 2012. Data included demographics, clinical characteristics, biochemical parameters and co-morbid conditions.

RESULTS

A total of 304 CF patients were included in the study. These patients displayed a good nutritional status (mean BMI±SD: 22.7±3.5) and moderate lung disease (mean FEV1±SD: 66.3±22.2). Low plasma zinc concentration (<9.2μmol/L) was found in 68 out of 304 CF patients (22.4%). Compared to patients with normal zinc, those with low zinc had significantly lower forced vital capacity and forced expiratory volume in one second. 72% of CF adults with low zinc suffered from bone disease (vs 49% with normal zinc, p=0.037) and 79% had impaired glycemic status (vs 58%, p=0.016). Accordingly, negative correlations were found between plasma zinc and glucose (r=-0.139, p=0.0001), HbA1c (r=-0.237, p=0.0001) and fructosamine (r=-0.134, p=0.034). In multiple linear regression, albumin and glycemic status were significant predictors of plasma zinc.

CONCLUSION

Our data indicated that nearly one quarter of CF adults with good nutritional status and moderate lung disease had low plasma zinc concentration and that low zinc status was associated with worse clinical outcomes.

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.

Effect of zinc supplementation on respiratory tract infections in children with cystic fibrosis

Zinc (Zn) has significant anti-oxidant and anti-inflammatory activity. Zn deficiency can occur in subsets of patients with cystic fibrosis (CF) especially those with malabsorption and impaired growth. Although supplemental Zn has significantly reduced infections in various disorders, its efficacy has not been thoroughly investigated in CF. We performed a double blind placebo controlled pilot study to investigate the effect of daily 30 mg elemental Zn for 1 year on the rate of respiratory tract infections (RTIs), use of antibiotics and plasma cytokines in 26 children with CF (ages 7-18 years). Plasma Zn, Cu, inflammatory cytokines and ex vivo generation of IL-2 were measured at baseline and at the end of the study. The number of days of oral antibiotics was lower in Zn treated patients compared to placebo (P = 0.05). However, compared to placebo, the effect of Zn was greater in patients who exhibited low plasma Zn at baseline (P = 0.02) than those who had plasma Zn levels identical to normal subjects (P = 0.55). Zn supplementation was marginally effective in reducing percentage increase in plasma IL-6 and IL-8 while increasing the percentage change in ex vivo generation of IL-2 in isolated mononuclear cell. In conclusion, oral intake of 30 mg/day of Zn reduced the number of days of oral antibiotics used to treat RTIs in children with CF. A higher daily Zn dose may be needed to decrease RTIs and modify immune responses.