Real-world data confirm elexacftor/tezacaftor/ivacaftor modulators halves sweat chloride concentration in eligible people with cystic fibrosis.

Sweat chloride concentration, a diagnostic feature in cystic fibrosis (CF), reflects CF transmembrane conductance regulator (CFTR) activity. CFTR modulator therapies, especially elexacaftor/tezacaftor/ivacaftor (ETI), has improved CF outcomes. We report nationwide, real-world data on sweat chloride concentration in people with CF (pwCF) with and without modulator therapies. All Danish pwCF with a minimum of one F508del allele were included. Sweat chloride measurements were stratified by genotype and modulator treatment. Differences were assessed using mixed-effects models. We included 977 sweat chloride measurements from 430 pwCF, 71% of which were F508del homozygous. Heterozygous and homozygous ETI-treated pwCF had an estimated mean sweat chloride concentration of 43 mmol/L (95% confidence interval: 39; 48) and 43 mmol/L (39; 47), respectively-48% and 59% lower than those without treatment. High variation in concentrations remained regardless of treatment status. Despite ETI treatment, 27% heterozygous and 23% homozygous pwCF had elevated concentrations (≥60 mmol/L). These real-world data confirm a substantial decrease in sweat chloride concentration during modulator treatment, especially ETI, where mean concentrations halved. However, large variation remained, including persistently high concentrations. These findings emphasize the potential of sweat chloride concentration as a treatment response biomarker and the need to explore its heterogeneity and relationship with clinical outcomes.

Identifying people living with cystic fibrosis in the Danish National Patient Registry: A validation study.

BACKGROUND: The Danish National Patient Registry (DNPR) serves as a valuable resource for scientific research. However, to ensure accurate results in cystic fibrosis (CF) studies that rely on DNPR data, a robust case-identification algorithm is essential. This study aimed to develop and validate algorithms for the reliable identification of CF patients in the DNPR. METHODS: Using the Danish Cystic Fibrosis Registry (DCFR) as a reference, accuracy measures including sensitivity and positive predictive value (PPV) for case-finding algorithms deployed in the DNPR were calculated. Algorithms were based on minimum number of hospital contacts with CF as the main diagnosis and minimum number of days between first and last contact. RESULTS: An algorithm requiring a minimum of one hospital contact with CF as the main diagnosis yielded a sensitivity of 96.1 % (95 % CI: 94.2 %; 97.4 %) and a PPV of 84.9 % (82.0 %; 87.4 %). The highest-performing algorithm required minimum 2 hospital visits and a minimum of 182 days between the first and the last contact and yielded a sensitivity of 95.9 % (95 % CI: 94.1 %; 97.2 %), PPV of 91.0 % (95 % CI: 88.6 %; 93.0 %) and a cohort entry delay of 3.2 months at the 75th percentile (95th percentile: 38.7 months). CONCLUSIONS: The DNPR captures individuals with CF with high sensitivity and is a valuable resource for CF-research. PPV was improved at a minimal cost of sensitivity by increasing requirements of minimum number of hospital contacts and days between first and last contact. Cohort entry delay increased with number of required hospital contacts.

Improved early growth in Danish children with cystic fibrosis from 2000-2022.

BACKGROUND: Improved growth in children with CF may have resulted from advances in treatment for cystic fibrosis (CF) over the past two decades, including the implementation of newborn screening in Denmark in 2016. This observational cohort study focuses on changes in early growth in Danish children with CF born between 2000 and January 2022. METHODS: Age, length/height, and weight data of children 0-5 years old were obtained from the Danish CF Cohort. Data were stratified to four birth cohorts born between 2000 and 2022. Weight-for-age (WAZ), length-for-age (LAZ), height-for-age (HAZ) and body-mass-index (BMZ) z-scores were computed using WHO growth curves. Cubic spline mixed effects models were used to evaluate growth over 5 years between birth cohorts. RESULTS: We included 255 children in the analyses. Cubic spline mixed effects models show that catch-up growth improved in birth cohorts over time, with the 2016-2022 birth cohort achieving growth reference curve values in WAZ, LAZ/HAZ and BMZ the earliest. The proportion of underweight and stunting observations among children born 2000-2004 decreased by the 2016-2022 birth cohort, while the proportion of overweight, low BMZ and high BMZ observations increased. CONCLUSION: Advances in care for young children with CF have led to improvements in growth - with the 2016-2022 birth cohort approaching potential for overweight. Nonetheless, low BMZ remains. Immediate, individualized nutrition care throughout early childhood remain crucial in mitigating malnutrition.

Metformin-induced changes of the gut microbiota in healthy young men: results of a non-blinded, one-armed intervention study.

AIMS/HYPOTHESIS: Individuals with type 2 diabetes have an altered bacterial composition of their gut microbiota compared with non-diabetic individuals. However, these alterations may be confounded by medication, notably the blood-glucose-lowering biguanide, metformin. We undertook a clinical trial in healthy and previously drug-free men with the primary aim of investigating metformin-induced compositional changes in the non-diabetic state. A secondary aim was to examine whether the pre-treatment gut microbiota was related to gastrointestinal adverse effects during metformin treatment. METHODS: Twenty-seven healthy young Danish men were included in an 18-week one-armed crossover trial consisting of a pre-intervention period, an intervention period and a post-intervention period, each period lasting 6 weeks. Inclusion criteria were men of age 18-35 years, BMI between 18.5 kg/m2 and 27.5 kg/m2, HbA1c < 39 mmol/mol (5.7%) and plasma creatinine within the normal range. No prescribed medication, including antibiotics, for 2 months prior to recruitment were allowed and no previous gastrointestinal surgery, discounting appendectomy or chronic illness requiring medical treatment. During the intervention the participants were given metformin up to 1 g twice daily. Participants were examined five times in the fasting state with blood sampling and recording of gastrointestinal symptoms. Examinations took place at Frederiksberg Hospital, Denmark before and after the pre-intervention period, halfway through and immediately after the end of intervention and after the wash-out period. Faecal samples were collected at nine evenly distributed time points, and bacterial DNA was extracted and subjected to 16S rRNA gene amplicon sequencing in order to evaluate gut microbiota composition. Subjective gastrointestinal symptoms were reported at each visit. RESULTS: Data from participants who completed visit 1 (n=23) are included in analyses. For the primary outcome the relative abundance of 11 bacterial genera significantly changed during the intervention but returned to baseline levels after treatment cessation. In line with previous reports, we observed a reduced abundance of Intestinibacter spp. and Clostridium spp., as well as an increased abundance of Escherichia/Shigella spp. and Bilophila wadsworthia. The relative abundance at baseline of 12 bacterial genera predicted self-reported gastrointestinal adverse effects. CONCLUSIONS/INTERPRETATION: Intake of metformin changes the gut microbiota composition in normoglycaemic young men. The microbiota changes induced by metformin extend and validate previous reports in individuals with type 2 diabetes. Secondary analyses suggest that pre-treatment gut microbiota composition may be a determinant for development of gastrointestinal adverse effects following metformin intake. These results require further investigation and replication in larger prospective studies. TRIAL REGISTRATION: Clinicaltrialsregister.eu 2015-000199-86 and ClinicalTrials.gov NCT02546050 FUNDING: This project was funded by Danish Diabetes Association and The Novo Nordisk Foundation.