Effects of elexacaftor / tezacaftor / ivacaftor triple combination therapy on glycaemic control and body composition in patients with cystic fibrosis-related diabetes.

Cystic fibrosis transmembrane conductance regulator (CFTR) modulators are a group of new drugs for the treatment of cystic fibrosis (CF) and elexacaftor + tezacaftor + ivacaftor (ETI) triple combination therapy has been approved as first choice therapy in the treatment of patients with at least 1 copy of F508del variation. Data on the effects of CFTR modulators on glucose metabolism are limited to small studies with conflicting results. We conducted a prospective observational study on 24 CF patients with CF-related diabetes requiring insulin therapy, with the aim to evaluate the effectiveness of ETI on glucose metabolism, glucose variability and body composition. After six months of treatment, HbA1c and coefficient of variation, measured through flash or continuous glucose monitoring, significantly decreased (median changes: -0.5, P = 0.029 and -6.3, P = 0.008, respectively), despite unchanged insulin requirements. Over the treatment period, percent of fat mass increased by a median value of 3% (p = 0.029).

Effects of prolonged proton pump inhibitor treatment on nutritional status and respiratory infection risk in cystic fibrosis: A matched cohort study.

BACKGROUND: Evidence on the effectiveness of proton pump inhibitors (PPI) as adjuvant therapy to improve maldigestion in people with cystic fibrosis (pwCF) is limited and there is increasing concern on possible side effects. METHODS: We conducted a matched cohort study based on paediatric and adult pwCF who received PPI for ≥3 months. Treated patients were matched to a group of patients who never received PPI using a nearest neighbour propensity score matching based on sex, year of birth, CFTR genotype and pancreatic insufficiency. RESULTS: The study included 160 pwCF: 80 treated and 80 untreated patients. Over a median follow-up of 2 years, no significant differences in changes in BMI z-score were detected between groups (adjusted mean difference: 0.06, 95% CI: -0.17-0.30). At baseline 25% (n = 20) of the treated patients and 22.5% (n = 18) of the untreated patients had a positive culture for P. aeruginosa (Pa). At follow-up percentages of Pa positive cultures increased to 47.5% (n = 38) in the treated group and to 26.3% (n = 21) in the untreated group (adjusted mean difference: 23.1%, 95% CI: 10.8-35.3). CONCLUSIONS: Prolonged PPI therapy should be used cautiously in pwCF since it may increase the risk of respiratory infection by Pa. In addition, such treatment does not seem to improve nutritional status.

Change in Nutrient and Dietary Intake in European Children with Cystic Fibrosis after a 6-Month Intervention with a Self-Management mHealth Tool.

Cystic Fibrosis (CF) is a life-long genetic disease, causing increased energy needs and a healthy diet with a specific nutrient distribution. Nutritional status is an indicator of disease prognosis and survival. This study aimed at assessing the effectiveness of a self-management mobile app in supporting patients with CF to achieve the dietary goals set by the CF nutrition guidelines. A clinical trial was conducted in pancreatic insufficient children with CF, followed in six European CF centres, where the self-management app developed within the MyCyFAPP project was used for six months. To assess secondary outcomes, three-day food records were compiled in the app at baseline and after 3 and 6 months of use. Eighty-four subjects (mean 7.8 years old) were enrolled. Compared to baseline, macronutrient distribution better approximated the guidelines, with protein and lipid increasing by 1.0 and 2.1% of the total energy intake, respectively, by the end of the study. Consequently, carbohydrate intake of the total energy intake decreased significantly (-2.9%), along with simple carbohydrate intake (-2.4%). Regarding food groups, a decrease in ultra-processed foods was documented, with a concomitant increase in meat and dairy. The use of a self-management mobile app to self-monitor dietary intake could become a useful tool to achieve adherence to guideline recommendations, if validated during a longer period of time or against a control group.

Night Blindness in Cystic Fibrosis: The Key Role of Vitamin A in the Digestive System.

Vitamin A is a fundamental micronutrient that regulates various cellular patterns. Vitamin A deficiency (VAT) is a worldwide problem and the primary cause of nocturnal blindness especially in low income countries. Cystic fibrosis (CF) is a known risk factor of VAD because of liposoluble vitamin malabsorption due to pancreatic insufficiency. We describe a case of a 9-year-old girl who experienced recurrent episodes of nocturnal blindness due to profound VAD. This little girl is paradigmatic for the explanation of the key role of the gut-liver axis in vitamin A metabolism. She presents with meconium ileus at birth, requiring intestinal resection that led to a transient intestinal failure with parenteral nutrition need. In addition, she suffered from cholestatic liver disease due to CF and intestinal failure-associated liver disease. The interaction of pancreatic function, intestinal absorption and liver storage is fundamental for the correct metabolism of vitamin A.

Age- and Sex-Dependent Distribution of OGTT-Related Variables in a Population of Cystic Fibrosis Patients.

CONTEXT: Cystic fibrosis (CF) causes an exceptionally high prevalence of diabetes that increases with age, especially in females. The glucose tolerance defect is progressive, but a cystic fibrosis transmembrane conductance regulator-dependent insulin secretory defect cannot be excluded. The age and sex dependence of the secretory defect is unclear. OBJECTIVE: The objective of the study was to analyze the age and sex dependency of insulin secretory and sensitivity parameters in CF. DESIGN: This was a cross-sectional analysis in an observational ongoing cohort (mean follow-up duration 7.5 y). SETTING: The study was conducted at the CF Center of Milan. PATIENTS: The study included 187 patients aged 8-30 years. INTERVENTION: Interventions included 3-hour oral glucose tolerance tests (n = 478) with 30-minute insulin and c-peptide sampling. MAIN OUTCOME MEASURES: Model-derived insulin secretory and sensitivity parameters were measured. RESULTS: Age was associated with a progressive decrement in insulinemia (at 30 min) and a subsequent increment in glycemia (at 60-90 min), returning at or below baseline (at 180 min). These changes are explained by a progressive reduction in ß-cell sensitivity to glucose and a progressive increment in insulin clearance. Fasting and postprandial insulin sensitivity do not seem to be involved. Compared with males, females display higher glucose, insulin, and c-peptide responses with greater insulin secretion, ß-cell sensitivity to glucose, insulin clearance, and equal insulin sensitivity. CONCLUSIONS: A defect in ß-cell sensitivity to glucose progressively develops with age, but it is not sex specific and does not explain the worse glucose tolerance reported in females. In contrast, insulin clearance increases with age, especially in females, contributing to the deterioration in glucose tolerance. The effects of age and sex should be considered when evaluating oral glucose tolerance test results in CF patients.

A polymorphism in the 5' UTR of the DEFB1 gene is associated with the lung phenotype in F508del homozygous Italian cystic fibrosis patients.

BACKGROUND: The identification of cystic fibrosis (CF) patients who are at greater risk of lung damage could be clinically valuable. Thus, we attempted to replicate previous findings and verify the possible association between three single nucleotide polymorphisms (SNPs c.-52G>A, c.-44C>G and c.-20G>A) in the 5' untranslated region (5' UTR) of the ß defensin 1 (DEFB1) gene and the CF pulmonary phenotype. METHODS: Genomic DNA from 92 Italian CF patients enrolled in different regional CF centres was extracted from peripheral blood and genotyped for DEFB1 SNPs using TaqMan(®) allele specific probes. In order to avoid genetic confounding causes that can account for CF phenotype variability, all patients were homozygous for the F508del CFTR mutation, and were then classified on the basis of clinical and functional data as mild lung phenotype (Mp, n=50) or severe lung phenotype patients (Sp, n=42). RESULTS: For the c.-20G>A SNP, the frequency of the A allele, as well as the AA genotype, were significantly more frequent in Mp than in Sp patients, and thus this was associated with a protective effect against severe pulmonary disease (OR=0.48 and 0.28, respectively). The effect of the c.-20G>A A allele is consistent with a recessive model, and the protective effect against Sp is exerted only when it is present in homozygosis. For the other two SNPs, no differences were observed as allelic and genotypic frequency in the two subgroups of CF patients. CONCLUSIONS: Our results, although necessary to be confirmed in larger and multiethnic populations, reinforce DEFB1 as a candidate modifier gene of the CF pulmonary phenotype.

Molecular characterization and structural implications of 25 new ABCB4 mutations in progressive familial intrahepatic cholestasis type 3 (PFIC3).

Progressive familial intrahepatic cholestasis type 3 (PFIC3) is an autosomal-recessive disorder due to mutations in the ATP-binding cassette, subfamily B, member 4 gene (ABCB4). ABCB4 is the liver-specific membrane transporter of phosphatidylcholine, a major and exclusive component of mammalian bile. The disease is characterized by early onset of cholestasis with high serum gamma-glutamyltranspeptidase activity, which progresses into cirrhosis and liver failure before adulthood. Presently, about 20 distinct ABCB4 mutations associated to PFIC3 have been described. We report the molecular characterization of 68 PFIC3 index cases enrolled in a multicenter study, which represents the largest cohort of PFIC3 patients screened for ABCB4 mutations to date. We observed 31 mutated ABCB4 alleles in 18 index cases with 29 distinct mutations, 25 of which are novel. Despite the lack of structural information on the ABCB4 protein, the elucidation of the three-dimensional structure of bacterial homolog allows the three-dimensional model of ABCB4 to be built by homology modeling and the position of the mutated amino-acids in the protein tertiary structure to be located. In a significant fraction of the cases reported in this study, the mutation should result in substantial impairment of ABCB4 floppase activity. The results of this study provide evidence of the broad allelic heterogeneity of the disease, with causative mutations spread along 14 of the 27 coding exons, but with higher prevalence on exon 17 that, as recently shown for the closely related paralogous ABCB1 gene, could contain an evolutionary marker for mammalian ABCB4 genes in the seventh transmembrane segment.

Benefits of breastfeeding in cystic fibrosis: a single-centre follow-up survey.

AIM: To study the effect of breastfeeding (BF) on growth, lung function and number of infections during the first 3 years of life in children with cystic fibrosis (CF). MATERIAL AND METHODS: One hundred forty-six CF patients, 5-18 years old, were recruited at their annual care visit. Information about infant feeding, psychosocial and socioeconomic conditions and smoking exposure was obtained by interviews. Anthropometric parameters at 1 year of age and the number of infections and hospitalisations during the first 3 years of life were obtained from clinical charts. Anthropometrics and pulmonary function parameters were obtained at enrollment. RESULTS: In CF patients, particularly those with pancreatic insufficiency, the prevalence of BF was lower than the general Italian population. After multivariate analysis patients with prolonged BF showed higher values of CED expiratory volume in 1 sec (FEV-1) (p = 0.001) and a lower number of infections during the first 3 years of life (p = 0.098). CONCLUSION: Prolonged BF is beneficial in children with CF and may protect them against decline of pulmonary function. Particular attention should be paid to promote BF in infants with CF.

Dietary and circulating polyunsaturated fatty acids in cystic fibrosis: are they related to clinical outcomes?

OBJECTIVE: To assess the relationship between dietary intakes, plasma phospholipid (PL) fatty acid profile and clinical parameters in children with cystic fibrosis (CF) in comparison to healthy controls. PATIENTS AND METHODS: A cross-sectional survey including 37 patients with CF (ages 8.0 +/- 2.9 yrs) and a reference group of 68 healthy children (ages 8.0 +/- 0.7 yrs) was carried out by means of a food-frequency questionnaire. At enrollment, all subjects underwent blood sampling for plasma PL fatty acids (FA). In CF patients, pulmonary function tests (forced expiratory volume in 1 second and forced vital capacity), anthropometric measurements and the Shwachman score were also determined. RESULTS: In CF patients, mean z score for weight and height (-0.35 +/- 1.16 and -0.28 +/- 0.99) were lower than controls (0.83 +/- 1.73 and 0.55 +/- 1.11, respectively). Patients with CF showed higher energy intakes (110 +/- 43 kcal/d) compared with controls (75 +/- 22 kcal/d; P < 0.0001), with higher intake of total (saturated and monounsaturated) fats and lower intake of polyunsaturated FA (3.9 +/- 1.0% of total macronutrient intake vs 4.3 +/- 1.2%, P = 0.05). In CF patients, plasma and PL levels of linoleic and docosahexaenoic acids were lower, whereas those of arachidonic acid were similar compared with controls. The Shwachman score showed significant positive associations with plasma PL levels of arachidonic acid and total n-6 long-chain FA (r = 0.32, P = 0.05, and r = 0.35, P = 0.03, respectively). CONCLUSIONS: The data give suggestions that fat intake and CF-associated biomechanisms are bound in a vicious circle, concurring to create the clinical and biochemical picture of CF. The quantity and quality of fat supplementation in CF need careful attention to balance the fat supply with polyunsaturated FA.

Liver disease in cystic fibrosis.

Liver involvement in Cystic Fibrosis (CF) is much less frequent than both pulmonary and pancreatic diseases that are present in 80-90% of CF patients; liver disease (LD) affects only one third of CF patients, however, because of the decreasing mortality from extrahepatic causes, its recognition and management is becoming a relevant clinical issue. Recent observations suggest that clinical expression of LD in CF may be influenced by genetic modifiers; their identification is an important issue because it may allow recognition of patients at risk for the development of LD at the time of diagnosis of CF and early institution of prophylactic strategies. Oral bile acid therapy, aimed at improving biliary secretion in terms of bile viscosity and bile acid composition, is currently the only available therapeutic approach for CF-associated LD. However, the impact of this therapy on the natural history of LD remains to be defined and long-term effectiveness on clinically relevant outcomes should be further investigated. Liver transplantation should be offered to CF patients with progressive liver failure and/or with life-threatening sequelae of portal hypertension, who also have mild pulmonary involvement that is expected to support long-term survival. The 1-year survival rate after transplantation in CF patients is approximately 80%, with beneficial effects on lung function, nutritional status, body composition and quality of life in most cases.