Growth Deficiency in Cystic Fibrosis Is Observable at Birth and Predictive of Early Pulmonary Function

Developing a nutrition screening tool for children with cystic fibrosis ages 0 to 2 years: Children with cystic fibrosis nutrition screening tool

BACKGROUND

For children with cystic fibrosis (CF), achieving and maintaining optimal growth by the age of 2 years is critical for future health outcomes. A standardized nutrition screening is needed to identify growth problems, enable timely interventions, and improve nutritional outcomes for children (0 to 2 years) with CF. The purpose of this study was to develop a nutrition screening tool for children (0 to 2 years) with CF to identify nutrition risk at every clinical encounter.

METHODS

A retrospective cross-sectional study was used to develop a nutrition screening tool to determine if nutrition interventions needed to change (at-risk) or continue (not at-risk). Retrospective data for pertinent nutrition factors were collected for 99 children attending an accredited CF clinic. The nutrition factors were compared to a dietitian assessment. A stepwise discriminant analysis determined weight-for-age (WFA) and weight-for-length (WFL) z-scores were significant. Then anthropometric data and corresponding dietitian assessment results were collected for children with CF attending two other accredited CF clinics (n = 29, n = 30). Discriminant analysis was used to determine sensitivity and specificity of the nutrition factors and to create a nutrition screening tool equation.

RESULTS

The nutrition screening model that included WFA z-score, LFA z-score, WFL z-score, and weight change velocity adequacy determined nutrition risk the best. The sensitivity was 89.7 %, specificity 83.2 %, NPV 93.3 %, and PPV 75.4 % for this model.

CONCLUSION

The nutrition screening tool equation developed in this study standardizes the process to identify children (0 to 2 years) with CF at nutrition risk. Further validation is needed.

Academy of Nutrition and Dietetics: 2020 Cystic Fibrosis Evidence Analysis Center Evidence-Based Nutrition Practice Guideline

The Academy of Nutrition and Dietetics Evidence Analysis Center conducted a systematic review of the literature to develop an evidence-based practice guideline for primary nutrition issues in cystic fibrosis (CF). This guideline is designed to complement and build upon existing evidence-based CF nutrition guidelines. The objective of this guideline was to provide recommendations for registered dietitian nutritionists in the United States delivering medical nutrition therapy to individuals with CF and their families that fill gaps in current evidence-based guidelines on topics that are crucial in order to improve health and prevent disease progression. This guideline provides 28 nutrition recommendations to guide medical nutrition therapy, including nutrition screening, nutrition assessment, and dietary intake. For topics outside the scope of this guideline, practitioners are referred to external, evidence-based recommendations. The CF landscape is evolving rapidly with breakthroughs in cystic fibrosis transmembrane regulator modulators changing CF at a cellular level. Medical nutrition therapy for individuals with CF from infancy through advanced age requires novel and individualized approaches. The Academy Evidence Analysis Library CF guidelines provide a framework for expanding upon current knowledge to determine effective nutrition strategies for individuals with CF through long and healthy futures.

Cystic fibrosis-related diabetes and lung disease: an update

The development of cystic fibrosis-related diabetes (CFRD) often leads to poorer outcomes in patients with cystic fibrosis including increases in pulmonary exacerbations, poorer lung function and early mortality. This review highlights the many factors contributing to the clinical decline seen in patients diagnosed with CFRD, highlighting the important role of nutrition, the direct effect of hyperglycaemia on the lungs, the immunomodulatory effects of high glucose levels and the potential role of genetic modifiers in CFRD.

Growth failure and treatment in cystic fibrosis

Poor growth has long been a characteristic feature of cystic fibrosis (CF) and is significantly linked to lung function and overall health status. Improvements in pulmonary and nutrition care for patients with cystic fibrosis (CF) have resulted in better growth outcomes; however, height gains have not paralleled the improvements in weight in children with CF, and patients with more severe CF mutations remain significantly more affected. Many factors affect the growth hormone-IGF-1 axis and the growth plate of the long bones, including the chronic inflammatory state associated with CF. There are also increasing data on the direct effects of CFTR on bone and implications for CFTR modulators in attaining optimal growth. Treatments aimed at improving growth in CF are also reviewed here.

Alleviation of depression-like behavior in a cystic fibrosis mouse model by Hdac6 depletion

Cystic fibrosis (CF) patients experience heightened levels of anxiety and depression. Stress from dealing with chronic disease and rigorous treatment regimens certainly are primary contributors to these outcomes. We previously have demonstrated that microtubule alterations in CF are linked to a number of CF phenotypes including growth regulation and inflammatory responses to airway bacterial challenge. Deletion of histone deactelyase 6 (HDAC6), a cytosolic deacetylase that regulates tubulin acetylation, in CF mice restores growth and inflammatory phenotypes to wild type (WT) profiles. In this study, the hypothesis that Hdac6 depletion in CF mice would impact behaviors since Hda6 inhibition has been previously reported to have anti-depressive properties. Data demonstrate that CF mice exhibit reduced activity and reduced open arm time in an elevated plus maze test which can be consistent with anxiety-like behavior. CF mice also exhibit depression-like behaviors compared to WT mice in an age dependent manner. By eight weeks of age, CF mice exhibit significantly more immobile time in the tail-suspension test, however, Hdac6 depletion reverses the depressive phenotype. These data demonstrate that loss of CFTR function may predispose patients to experience depression and that this behavior is Hdac6 dependent.

Predictive effects of low birth weight and small for gestational age status on respiratory and nutritional outcomes in cystic fibrosis

INTRODUCTION

Prior literature shows that neonates with cystic fibrosis (CF) are more likely to be born low birth weight (LBW, <2500 grams) and/or small for gestational age (SGA, <10^th percentile for weight) than non-CF counterparts. There is limited literature exploring the predictive effects of birth parameters on long-term outcomes.

METHODS

The study population (CF Twin and Sibling Study) was recruited between 2000-2013 (n = 1677). Relationships between FEV₁ percent predicted at 6, 12, or 18 years or BMI z-score at 2, 6, 12, or 18 years, and predictor variables (LBW or SGA status) were assessed using adjusted linear regressions.

RESULTS

Mean birth weight was 3.3 ± 0.7 kg (Females: 3.2 ± 0.7kg; males: 3.4 ± 0.7kg) and mean gestational age was 38.4 ± 2.6 weeks, with 10.2% of participants classified as SGA. Predictors of LBW included female sex, pancreatic insufficiency, and prematurity. Predictors of SGA included female sex. After adjustment, LBW was associated with lower BMI at ages 2-12 years and SGA was associated with lower BMI at age 2 years. LBW was associated with lower FEV₁ percent predicted only at age 6 years. SGA was not associated with FEV₁.

CONCLUSIONS

We did not observe higher rates of LBW or SGA in full term infants compared to the general population. We observed associations particularly between LBW and BMI or FEV₁, but these associations decreased with age, suggesting that alternate factors contribute to outcomes over time. In lieu of the ability to target growth during gestation, efforts could be considered to optimize infant nutritional status, which may improve later life outcomes.

GH-IGF-1 Axis in Children with Cystic Fibrosis

OBJECTIVE

To verify whether growth hormone receptor (GHR) gene expression plays a role in growth of children with cystic fibrosis (CF), as a consequence of the chronic inflammatory condition and malnutrition.

DESIGN

We enrolled 49 prepubertal patients (24 males and 25 females) affected by CF in a stable clinical condition, 19 of whom had been diagnosed through newborn screening and 30 following presentation of symptoms. Patients had no significant comorbidity affecting growth or cystic fibrosis transmembrane conductance regulator (CFTR)-related diabetes requiring insulin therapy. Blood was collected during two follow-up visits to measure insulin-like growth factor (IGF-I), growth hormone-binding protein (GHBP), and GHR gene expression. Recruited as a control group were 52 healthy children, sex- and age-matched, were recruited as a control group.

METHODS

We compared body mass index (BMI), height, weight, IGF-I, GHBP, and GHR gene expression values (evaluated by Chemiluminescent Immunometric assay; ELISA and real-time PCR, respectively) in CF patients diagnosed through newborn screening (NBS) or by symptoms (late diagnosis [LD]) and in healthy controls.

RESULTS

BMI increased significantly in patients between the time of diagnosis and check-up (P<0.001), particularly in the LD group; median value was lower at diagnosis and significantly higher (P<0.001) at follow-up visits compared to controls. At initial evaluation, higher levels of IGF-I (not statistically significant) were found in both the NBS group and the LD group compared to the control group. At the second evaluation, significantly higher levels of IGF-I (P=0.003) were found in both the NBS and LD groups compared to controls; GHR mRNA expression had significantly increased (P=0.013) in LD patients compared with the first evaluation and was significantly higher in the NBS and LD groups than in controls. GHBP values had significantly increased (P=0.047) in the NBS group after one year of therapy compared to first visit levels and were significantly higher (P<0,0001) in the NBS and LD groups compared to controls.

CONCLUSION

In our LD patients during childhood, we observed good auxological values and a GH/IGF-I axis function within normal range for the factor evaluated. However, earlier diagnosis through NBS might further minimize and prevent growth retardation, by reducing the duration of symptoms before treatment.

Impact of cystic fibrosis on birthweight: a population based study of children in Denmark and Wales

BACKGROUND

Poor growth during infancy and childhood is a characteristic feature of cystic fibrosis (CF). However, the impact of CF on intrauterine growth is unclear. We studied the effect of CF on birth weight in Denmark and Wales, and assessed whether any associations are due to differences in gestational age at birth.

METHODS

We conducted national registry linkage studies in two countries, using data for 2.2 million singletons born in Denmark (between 1980 and 2010) and Wales (between 1998 and 2015). We used hospital inpatient and outpatient data to identify 852 children with CF. Using causal mediation methods, we estimated the direct and indirect (via gestational age) effect of CF on birth weight after adjustment for sex, parity and socioeconomic background. We tested the robustness of our results by adjusting for additional factors such as maternal smoking during pregnancy in subpopulations where these data were available.

RESULTS

Babies with CF were more likely to be born preterm and with low birth weight than babies with no CF (12.7% vs 5% and 9.4% vs 5.8% preterm; 11.9% vs 4.2% and 11% vs 5.4% low birth weight in Denmark and Wales, respectively). Using causal mediation methods, the total effect of CF on birth weight was estimated to be -178.8 g (95% CI -225.43 to -134.47 g) in the Danish population and -210.08 g (95% CI -281.97 to -141.5 g) in the Welsh population. About 40% of this effect of CF on birth weight was mediated through gestational age.

CONCLUSIONS

CF significantly impacts on intrauterine growth and leads to lower birth weight in babies with CF, which is only partially explained by shorter gestation.

Growth deficits in cystic fibrosis mice begin in utero prior to IGF-1 reduction

Growth deficits are common in cystic fibrosis (CF), but their cause is complex, with contributions from exocrine pancreatic insufficiency, pulmonary complications, gastrointestinal obstructions, and endocrine abnormalities. The CF mouse model displays similar growth impairment despite exocrine pancreatic function and in the absence of chronic pulmonary infection. The high incidence of intestinal obstruction in the CF mouse has been suggested to significantly contribute to the observed growth deficits. Previous studies by our group have shown that restoration of the cystic fibrosis transmembrane conductance regulator (CFTR) in the intestinal epithelium prevents intestinal obstruction but does not improve growth. In this study, we further investigate growth deficits in CF and gut-corrected CF mice by assessing insulin-like growth factor 1 (IGF-1). IGF-1 levels were significantly decreased in CF and gut-corrected CF adult mice compared to wildtype littermates and were highly correlated with weight. Interestingly, perinatal IGF-1 levels were not significantly different between CF and wildtype littermates, even though growth deficits in CF mice could be detected late in gestation. Since CFTR has been suggested to play a role in water and nutrient exchange in the placenta through its interaction with aquaporins, we analyzed placental aquaporin expression in late-gestation CF and control littermates. While significant differences were observed in Aquaporin 9 expression in CF placentas in late gestation, there was no evidence of placental fluid exchange differences between CF and control littermates. The results from this study indicate that decreased IGF-1 levels are highly correlated with growth in CF mice, independent of CF intestinal obstruction. However, the perinatal growth deficits that are observed in CF mice are not due to decreased IGF-1 levels or differences in placenta-mediated fluid exchange. Further investigation is necessary to understand the etiology of early growth deficits in CF, as growth has been shown to be a significant factor in disease outcomes.