Search

Background: Cystic fibrosis-related diabetes (CFRD) is a late cystic fibrosis (CF)-associated comorbidity whose prevalence is increasing sharply lifelong. Guidelines for glucose metabolism (GM) monitoring rely on the oral glucose tolerance test (OGTT). However, this test is neither sensitive nor specific. The aim of this study was to compare sensitivity and specificity of different methods for GM monitoring in children and adolescents with CF., Methods: Continuous glucose monitoring system (CGMS), used as the reference method, was compared with the OGTT, intravenous glucose tolerance test (IGTT), homeostasis model assessment index of insulin resistance (HOMA-IR), homeostasis model assessment index of β-cell function (HOMA-%B) and glycated haemoglobin A1C. Patients were classified into three groups according to CGMS: normal glucose tolerance (NGT), impaired glucose tolerance (IGT) and diabetes mellitus (DM)., Results: Twenty-nine patients (median age: 13.1 years) were recruited. According to CGMS, 11 had DM, 12 IGT and six NGT, whereas OGTT identified three patients with DM and five with IGT. While 13 of 27 had insulin deficiency according to IGTT, there was 19 of 28 according to HOMA-%B. According to HOMA-IR, 12 of 28 had insulin resistance. HOMA-%B was the most sensitive method for CFRD screening [sensitivity 91% (95% CI), specificity 47% (95% CI) and negative predictive value 89% (95% CI)]., Conclusions: OGTT showed the weak capacity to diagnose DM in CF and should no longer be considered as the reference method for CFRD screening in patients with CF. In our study, HOMA-%B showed promising metrics for CFRD screening. Finally, CGMS revealed that pathological glucose excursions were frequent even early in life.

Patients with cystic fibrosis have increased oxidative stress and impaired antioxidant systems. Moderate intake of docosahexaenoic acid (DHA) may favor the lowering of oxidative stress. In this randomized, double-blind, cross-over study, DHA or placebo capsules, were given daily to 10 patients, 5mg/kg for 2 weeks then 10mg/kg DHA for the next 2 weeks (or placebo). After 9 weeks of wash-out, patients took placebo or DHA capsules. Biomarkers of lipid peroxidation and vitamin E were measured at baseline, and after 2 and 4 weeks of treatment in each phase. The proportions of DHA increased both in plasma and platelet lipids after DHA supplementations. The lipid peroxidation markers did not significantly decrease, in spite of a trend, after the first and/or the second dose of DHA but plasma and platelet vitamin E amounts increased significantly after DHA supplementation. Our findings reinforce the antioxidant potential of moderate DHA intake in subjects displaying increased oxidative stress., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Objectives Bone disease is observed in at least 11% of CF patients. The underlying pathogenesis is multifactorial, including nutritional factors but also a direct impact of the CF transmembrane conductance regulator (CFTR) dysfunction. The objective was to compare bone microstructure between pediatric CF patients and healthy volunteers. Methods This is a cross-sectional study with bone geometry, volumetric density (vBMD) and microstructure assessement by DXA and high resolution scanner (HRpQCT) at the distal radius and tibia in children with CF compared to age- and gender-matched healthy volunteers (HV). Results Thirty four CF children (15 girls, 19 boys, 15±2 yrs, centile for weight −0.5±1.6 and height −0.6±1.2, 8 with a past of fracture) were included. Main respiratory parameters were: forced expiratory volume in one second: 89±21%; forced vital capacity: 95±17% and forced expiratory flow between 25–75% of FCV: 62±31%. Height, weight and lumbar spine areal BMD were not significantly different between CF and HV (respectively: 158±14 vs. 162±11 cm, 47±12 vs. 51±12 kg and 0.830±0.147 vs. 0.819±0.175 g/cm 2 ). At the radius, bone geometry, vBMD and trabecular microstructure were not different between CF and HV. However, at the tibia, CF had smaller bone cross-sectional area than HV (619±153 vs. 696±122mm 2 p = 0.01). vBMD, cortical thickness and trabecular microstructure were not impaired at the distal tibia. Conclusion In our study, bone microstructure in children with CF was rather reassuring. Given their mild lung disease and good nutritional status, it seems unlikely that CFTR defect plays by itself a major role in the bone disease observed in patients with CF. [ABSTRACT FROM AUTHOR]