Nutritional management of people living with cystic fibrosis throughout life and disease continuum: Changing times, new challenges.

Cystic fibrosis (CF) is a genetic disease caused by mutations in the gene encoding for the ion channel cystic fibrosis transmembrane conductance regulator (CFTR). The management of CF disease has evolved in recent decades from treating downstream disease manifestations affecting the airways, the lungs and the gastrointestinal system to addressing the CFTR gene defect. The advent of CFTR modulators, which correct the functionality of the defective CFTR, contributes to reshaping the landscape of CF demographics, prognosis and therapies, including nutritional management. A spectrum of clinical manifestations is emerging within the same patient population where undernutrition and nutritional deficiencies coexist with excessive weight gain and metabolic derangements. Such contrasting presentations challenge current practices, require adjustments to traditional approaches, and involve more individualised interventions. This narrative review examines the current state of knowledge on the nutritional management of people living with cystic fibrosis from early life to adulthood in the era of CFTR modulation.

Glycated Hemoglobin as a First-line Screening Test for Cystic Fibrosis‒Related Diabetes and Impaired Glucose Tolerance in Children With Cystic Fibrosis: A Validation Study.

OBJECTIVES: Our aims in this study were to document the screening rate for cystic fibrosis‒related diabetes (CFRD) in children followed at a cystic fibrosis (CF) clinic in Canada and to evaluate the accuracy of various glycated hemoglobin (A1C) cutoffs to screen for CFRD and impaired glucose tolerance (IGT) in a pediatric CF population. METHODS: The CFRD screening rate was calculated over a follow-up period of up to 8 years among children who attended the CF clinic between 1993 and 2018. Test performance of A1C at various thresholds ranging from 5.5% to 6.2% was compared with the oral glucose tolerance test (OGTT) as the reference method. Children with CF aged ≥10 years with an OGTT performed within 120 days of A1C measurement were included in the analysis. RESULTS: The overall CFRD screening rate was 53.0%. A total of 256 children were included for the A1C performance analysis, of whom 8.6% had an OGTT-confirmed CFRD diagnosis. An A1C threshold of 5.8% demonstrated an optimal balance between sensitivity (90.9%) and specificity (60.7%) for CFRD screening, leading to a potential reduction of 56.3% of the annual required OGTTs. A1C demonstrated poor accuracy for identifying children with IGT. CONCLUSIONS: An A1C threshold ≥5.8% allows for identification of children requiring further CFRD investigations, which may reduce the clinical burden of children with CF without compromising the ability of early CFRD diagnosis.

Abnormal glucose tolerance in a pediatric cystic fibrosis cohort: Trends in clinical outcomes and associated factors in the preceding years.

BACKGROUND AND AIMS: Deterioration of anthropometric and lung function parameters was shown to precede the onset of cystic fibrosis-related diabetes (CFRD) in adults. In children, studies have been conducted in small cohorts with relatively short observation period. Study objectives were to document the longitudinal trends of anthropometric, pulmonary, nutritional and metabolic parameters from cystic fibrosis (CF) diagnosis to the ascertainment of abnormal glucose tolerance and identify parameters associated with the incidence of such abnormalities in a pediatric CF cohort. METHODS AND RESULTS: Retrospective cohort study of 281 children with CF. Longitudinal trends of anthropometric, lung function, nutritional and metabolic data were generated from CF diagnosis to the ascertainment of abnormal glucose tolerance defined as the presence of either impaired glucose tolerance (IGT), unconfirmed CFRD or CFRD. Cox models and Kaplan-Meier curves were used to identify factors associated with developing abnormal glucose tolerance. Forty-five percent of cohort had normal glucose tolerance (NGT), 27% IGT, 10% unconfirmed CFRD and 18% CFRD. Children who developed CFRD displayed lower height z-scores from a very early age. Conversely, HbA1c levels began to rise closer to CFRD ascertainment. Height z-scores (HR: 0.45; CI 95% [0.29-0.69]) and HbA1c (HR: 2.43; CI 95% [1.86-3.18]) in years preceding ascertainment were associated with the risk of developing CFRD. CONCLUSION: Children who developed CFRD display distinctive trends for height z-scores from a very early age, whereas HbA1c appears as a marker of established glucose metabolism derangements.

Association between fat-soluble nutrient status and auditory and visual related potentials in newly diagnosed non-screened infants with cystic fibrosis: A case-control study.

Nutritional deficiencies often precede the diagnosis of cystic fibrosis (CF) in infants, and occur at a stage where the rapidly developing brain is more vulnerable to insult. We aim to compare fat-soluble nutrient status of newly diagnosed non-screened infants with CF to that of healthy infants, and explore the association with neurodevelopment evaluated by electroencephalography (EEG). Our results show that CF infants had lower levels of all fat-soluble vitamins and docosahexaenoic acid (DHA) compared to controls. The auditory evoked potential responses were higher in CF compared to controls whereas the visual components did not differ between groups. DHA levels were correlated with auditory evoked potential responses. Although resting state frequency power was similar between groups, we observed a negative correlation between DHA levels and low frequencies. This study emphasizes the need for long-term neurodevelopmental follow-up of CF infants and pursuing intervention strategies in the future.

Prophylaxis against respiratory syncytial virus in young children with cystic fibrosis.

INTRODUCTION: In cystic fibrosis (CF) patients, respiratory syncytial virus (RSV) infection is associated with significant morbidity. Although passive prophylaxis with palivizumab lowers hospitalization rate for RSV infection in populations at risk of severe infection, its use is not recommended in infants with CF disease. OBJECTIVE: To determine the effect of palivizumab prophylaxis on hospitalization for acute respiratory illness in young children with CF during the first RSV season following the diagnosis of CF. METHODS: In this retrospective study, medical records of patients diagnosed with CF between the years 1997 and 2005 inclusively and on whom the diagnosis was made before 18 months of age were reviewed. Collected data included age at diagnosis, palivizumab prophylaxis, occurrence of hospitalization for acute respiratory tract illness during the RSV season and identification of RSV infection. RESULTS: A diagnosis of CF was made in 76 young children and data collected from 75 children. Of those, 40 did not receive RSV prophylaxis while 35 received palivizumab injection monthly during the RSV season. Among non-recipient children, 7 out of 40 were hospitalized for acute respiratory illness during the RSV season. Of these seven patients, RSV detection was positive in nasopharyngeal secretions in three patients, negative in one patient and not requested in the others. Among palivizumab recipients, 3 out of 35 children were hospitalized for acute respiratory illness (P > 0.05 compared to non-recipients group). In these three palivizumab recipients, RSV detection was negative in nasopharyngeal secretions. Palivizumab recipients experienced fewer hospital days per patient for acute respiratory illness (mean +/- SD: 0.8 +/- 3.07 days) as compared to non-recipients (mean +/- SD: 1.73 +/- 4.27 days) but this difference did not reach statistical significance. CONCLUSION: CF infants may benefit from RSV immunoprophylaxis with palivizumab.