ObjectiveThis study aimed to determine the glycaemic profile of patients with cystic fibrosis using a continuous glucose monitoring system (CGMS), and to evaluate the associations of glycaemic abnormalities with sex, age, pubertal stage, CFTR gene mutations, nutritional status, lung function, oral glucose tolerance test, glycated haemoglobin concentrations, fasting insulin concentrations, C peptide concentrations and exocrine pancreatic function.Study designThis observational study evaluated CGMS data from 39 patients with cystic fibrosis who were treated at a referral centre. The patients were 10–19.9 years old, and were categorised according to whether they had normal results (27 patients) or glucose intolerance (12 patients) during the oral glucose tolerance test.ResultsThe maximum interstitial glucose concentration among individuals with normal oral glucose tolerance test results was 174.9±65.1 mg/dL (9.7–3.61 mmol/L), compared with 170.4±40.9 mg/dL (9.46–2.27 mmol/L) among individuals with glucose intolerance. The CGMS revealed that 18 of the 27 patients with normal oral glucose tolerance test results had peak interstitial glucose concentrations of >140 mg/dL (7.8 mmol/L), and that 4 of these individuals had peak levels of >200 mg/dL (11.1 mmol/L). None of the analysed clinical or laboratory characteristics predicted the occurrence of hyperglycaemic peaks on CGMS.ConclusionsThe present study revealed that CGMS could detect hyperglycaemia among patients with cystic fibrosis and ‘normal’ oral glucose tolerance test results, and that their clinical and laboratory characteristics were not useful in discerning between patients who did and did not exhibit these excursions.

Objective:To elucidate whether insulin is effective or not in patients with cystic fibrosis before the diabetes mellitus phase.Data source:The study was performed according to the Prisma method between August and September 2014, using the PubMed, Embase, Lilacs and SciELO databases. Prospective studies published in English, Portuguese and Spanish from 2002 to 2014, evaluating the effect of insulin on weight parameters, body mass index and pulmonary function in patients with cystic fibrosis, with a mean age of 17.37 years before the diabetes mellitus phase were included.Data synthesis:Eight articles were identified that included 180 patients undergoing insulin use. Sample size ranged from 4 to 54 patients, with a mean age ranging from 12.4 to 28 years. The type of follow-up, time of insulin use, the dose and implementation schedule were very heterogeneous between studies.Conclusions:There are theoretical reasons to believe that insulin has a beneficial effect in the studied population. The different methods and populations assessed in the studies do not allow us to state whether early insulin therapy should or should not be carried out in patients with cystic fibrosis prior to the diagnosis of diabetes. Therefore, studies with larger samples and insulin use standardization are required.

There are theoretical reasons to believe that insulin has a beneficial effect in the studied population. The different methods and populations assessed in the studies do not allow us to state whether early insulin therapy should or should not be carried out in patients with cystic fibrosis prior to the diagnosis of diabetes. Therefore, studies with larger samples and insulin use standardization are required.

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Background: Therapeutic progress and improvement on resources enabled the emergence of new comorbidities in cystic fibrosis (CF), such as cystic fibrosis-related diabetes (CFRD). About 20% of adolescents and 40-50% of adults are affected. CFRD and glucose intolerance reduce life expectancy in this population, highlighting the importance of early diagnosis and treatment. Up to 15% of CF patients have hypoglycemia during OGTT and its etiology remains unclear. Some authors associate hypoglycemia with CFRD onset, while others do not agree with this association. Objective: To determine whether abnormal CGM (hypo/hyperglycemia) can predict CFRD onset, pulmonary function and BMI decline in CF patients. Methods: Prospective single center study. All CF patients between 10-19yo from our outpatient clinic were screened for CFRD through OGTT following the World Health Organization (WHO) protocol. The enzymatic colorimetric method was used to classify them as per the ADA. Non-diabetic CF patients performed 3-day CGM, forced expiratory volume in the first second (FEV1), BMI and OGTT. All tests except for CGM were then reassessed after a long follow-up. The WHO’s 2006 curve was used to calculate the z scores for individuals ≤19yo and WHO cut-off values for >19yo. Oral corticoid use during data collection, pregnancy and solid organ transplantation were exclusion criteria. Results: Thirty-nine patients were recruited and 34 completed an average of 3.1 years (±0.51) follow-up. No clinical or laboratory variables could predict diabetes progression or hypoglycemic events. The cohort had an increase in mean BMI (17.80±3.65 vs 18.36±3.49; p=0.025) and a reduction in mean FEV1 (66.91±25.79% vs 56.32±29.57%; p=0.001) between the two evaluations. Patients who developed diabetes showed statistically significant worse FEV1 in the end of the follow-up (22.67±5 vs 59.58±28.9; p=0.041), and lower BMI at both start (14.37±1.23 vs 18.13±3.65; p=0.049) and end (14.81±0.66 vs 18.71±3.46; p=0.029) of follow-up. A logistic regression of the effect of time adjusted for independent variables for progression to CFRD was conducted. A higher possibility of evolution among participants with IGT (odds ratio [OR] 21.67; 95% confidence interval [CI] 7.03-67.36; p<0.01), and a lower possibility among participants with NGT (OR 1.84; 95% CI 1.06-3.19; p=0.031). Conclusion: CGM was not a useful tool to predict early diabetes onset in this population with the current cut-off values. However, the IGT group seems to be the riskiest group. The CF population has particular characteristics and may not have the same diagnostic criteria for DM as the non-CF population. More studies are necessary to determine the appropriate CGM cut-off values for CFRD.