Update on cystic fibrosis-related diabetes

The effect of a pre-meal snack and/or postprandial exercise on breakfast glycemic excursion in adults with cystic fibrosis: A pilot study

BACKGROUND & AIMS

Cystic fibrosis (CF)-related diabetes (CFRD), a common comorbidity in CF, is often preceded and characterized with elevated postprandial glycemic (PPG) excursions. In the general population, the consumption of a pre-meal protein snack and/or physical activity (PA) hinder the elevation of PPG levels. Our objective is to evaluate the effect of a pre-meal snack and/or post-meal PA on PPG excursions in CF.

METHODS

This is a double-blinded randomized controlled crossover interventional study in 14 adults with CF, with 4 interventions: placebo pre-meal snack + no PA (control: CTL), pre-meal soy snack + no PA (SK), placebo pre-meal snack + PA (PA), and pre-meal soy snack + PA (SK + PA). The pre-meal soy snack or placebo beverage (vanilla flavoured water) is served at 8 AM, followed by a standardized breakfast at 9 AM and, postprandially, 5 repeated bouts of 3-min walk every 30 min or sedentary activity. Blood glucose and insulin were measured every 15-30 min during the interventions.

RESULTS

Plasma glucose (PG) was higher 30 min after snack consumption compared to placebo beverage. One-hour post-breakfast, PG levels were lower during both PA interventions than with sedentary behavior. However, the overall 3 h post-breakfast glucose area under the curve (AUC) was similar between interventions. Post-breakfast 3 h insulin AUC was significantly lower during the SK + PA intervention compared to the sedentary behavior interventions.

CONCLUSION

Repeated short bouts of post-meal physical activity may positively impact PPG control in adults with CF, with or without the addition of a pre-meal soy snack. A pre-meal snack alone does not improve PPG.

Beyond insulin: Unraveling the complex interplay of ER stress, oxidative damage, and CFTR modulation in CFRD

CF-related diabetes (CFRD) is a prevalent comorbidity in people with Cystic Fibrosis (CF), significantly impacting morbidity and mortality rates. This review article critically evaluates the current understanding of CFRD molecular mechanisms, including the role of CFTR protein, oxidative stress, unfolded protein response (UPR) and intracellular communication. CFRD manifests from a complex interplay between exocrine pancreatic damage and intrinsic endocrine dysfunction, further complicated by the deleterious effects of misfolded CFTR protein on insulin secretion and action. Studies indicate that ER stress and subsequent UPR activation play critical roles in both exocrine and endocrine pancreatic cell dysfunction, contributing to β-cell loss and insulin insufficiency. Additionally, oxidative stress and altered calcium flux, exacerbated by CFTR dysfunction, impair β-cell survival and function, highlighting the significance of antioxidant pathways in CFRD pathogenesis. Emerging evidence underscores the importance of exosomal microRNAs (miRNAs) in mediating inflammatory and stress responses, offering novel insights into CFRD's molecular landscape. Despite insulin therapy remaining the cornerstone of CFRD management, the variability in response to CFTR modulators underscores the need for personalized treatment approaches. The review advocates for further research into non-CFTR therapeutic targets, emphasizing the need to address the multifaceted pathophysiology of CFRD. Understanding the intricate mechanisms underlying CFRD will pave the way for innovative treatments, moving beyond insulin therapy to target the disease's root causes and improve the quality of life for individuals with CF.

Metabolomics Panel Associated with Cystic Fibrosis-Related Diabetes toward Biomarker Discovery

The most prevalent comorbidity among cystic fibrosis (CF) patients is cystic fibrosis-related diabetes (CFRD). CFRD has been linked to one of the worse clinical outcomes and a higher mortality. Improved clinical results have been related to earlier diagnosis and treatment of CFRD. Therefore, the present study aimed to investigate the metabolome of human serum of patients with CFRD. This might aid in identifying novel biomarkers linked with the pathophysiology of CFRD and its diagnosis. The liquid chromatography-high-resolution mass spectrometry (LC-HRMS) metabolomics approach was utilized for serum samples from patients with CF (n = 36) and healthy controls (n = 36). Nine patients in the CF group had CFRD, and 27 were non-CFRD patients (nCFRD). A total of 2328 metabolites were significantly altered in CF compared with the healthy control. Among those, 799 significantly dysregulated metabolites were identified between CFRD and nCFRD. Arachidonic acid (AA), ascorbate, and aldarate metabolism were the most common metabolic pathways dysregulated in CF. l-Homocysteic acid (l-HCA) levels were significantly reduced in CF and CFRD compared to the control and nCFRD, respectively. In addition, gamma-glutamylglycine and l-5-hydroxytryptophan (5-HTP) had the highest discrimination between CFRD and nCFRD with AUC (0.716 and 0.683, respectively). These biomarkers might serve as diagnostic biomarkers and aid in understanding potential metabolic changes linked to CF and CFRD.

Pancreatic Crosstalk in the Disease Setting: Understanding the Impact of Exocrine Disease on Endocrine Function

The exocrine and endocrine are functionally distinct compartments of the pancreas that have traditionally been studied as separate entities. However, studies of embryonic development, adult physiology, and disease pathogenesis suggest there may be critical communication between exocrine and endocrine cells. In fact, the incidence of the endocrine disease diabetes secondary to exocrine disease/dysfunction ranges from 25% to 80%, depending on the type and severity of the exocrine pathology. Therefore, it is necessary to investigate how exocrine-endocrine "crosstalk" may impact pancreatic function. In this article, we discuss common exocrine diseases, including cystic fibrosis, acute, hereditary, and chronic pancreatitis, and the impact of these exocrine diseases on endocrine function. Additionally, we review how obesity and fatty pancreas influence exocrine function and the impact on cellular communication between the exocrine and endocrine compartments. Interestingly, in all pathologies, there is evidence that signals from the exocrine disease contribute to endocrine dysfunction and the progression to diabetes. Continued research efforts to identify the mechanisms that underlie the crosstalk between various cell types in the pancreas are critical to understanding normal pancreatic physiology as well as disease states. © 2024 American Physiological Society. Compr Physiol 14:5371-5387, 2024.

Early-phase insulin secretion during mixed-meal tolerance testing predicts β-cell function and secretory capacity in cystic fibrosis

Insulin secretion within 30 minutes of nutrient ingestion is reduced in people with cystic fibrosis (PwCF) and pancreatic insufficiency and declines with worsening glucose tolerance. The glucose potentiated arginine (GPA) test is validated for quantifying β-cell secretory capacity as an estimate of functional β-cell mass but requires technical expertise and is burdensome. This study sought to compare insulin secretion during mixed-meal tolerance testing (MMTT) to GPA-derived parameters in PwCF.

Methods

Secondary data analysis of CF-focused prospective studies was performed in PwCF categorized as 1) pancreatic insufficient [PI-CF] or 2) pancreatic sufficient [PS-CF] and in 3) non-CF controls. MMTT: insulin secretory rates (ISR) were derived by parametric deconvolution using 2-compartment model of C-peptide kinetics, and incremental area under the curve (AUC) was calculated for 30, 60 and 180-minutes. GPA: acute insulin (AIR) and C-peptide responses (ACR) were calculated as average post-arginine insulin or C-peptide response minus pre-arginine insulin or C-peptide under fasting (AIRarg and ACRarg), ~230 mg/dL (AIRpot and ACRpot), and ~340 mg/dL (AIRmax and ACRmax) hyperglycemic clamp conditions. Relationships of MMTT to GPA parameters were derived using Pearson's correlation coefficient. Predicted values were generated for MMTT ISR and compared to GPA parameters using Bland Altman analysis to assess degree of concordance.

Results

85 PwCF (45 female; 75 PI-CF and 10 PS-CF) median (range) age 23 (6-56) years with BMI 23 (13-34) kg/m2, HbA1c 5.5 (3.8-10.2)%, and FEV1%-predicted 88 (26-125) and 4 non-CF controls of similar age and BMI were included. ISR AUC30min positively correlated with AIRarg (r=0.55), AIRpot (r=0.62), and AIRmax (r=0.46) and with ACRarg (r=0.59), ACRpot (r=0.60), and ACRmax (r=0.51) (all P<0.001). ISR AUC30min strongly predicted AIRarg (concordance=0.86), AIRpot (concordance=0.89), and AIRmax (concordance=0.76) at lower mean GPA values, but underestimated AIRarg, AIRpot, and AIRmax at higher GPA-defined β-cell secretory capacity. Between test agreement was unaltered by adjustment for study group, OGTT glucose category, and BMI.

Conclusion

Early-phase insulin secretion during MMTT can accurately predict GPA-derived measures of β-cell function and secretory capacity when functional β-cell mass is reduced. These data can inform future multicenter studies requiring reliable, standardized, and technically feasible testing mechanisms to quantify β-cell function and secretory capacity.

Changes in glucose tolerance in people with cystic fibrosis after initiation of first-generation CFTR modulator treatment

BACKGROUND

Cystic fibrosis transmembrane conductance regulator (CFTR) modulators have been shown to have a beneficial effect on pulmonary function and nutritional status in patients with cystic fibrosis (CF), but the extent to which they affect glucose tolerance is not fully understood. In the current study, we evaluated the change in glucose tolerance and insulin secretion after first-generation CFTR modulator treatment in adults with CF.

METHODS

We performed a longitudinal observational study with an oral glucose tolerance test performed at baseline and after three and a half years of follow-up. The test comprised glucose, C-peptide and insulin measured at fasting, 1 h, and 2 h, and HbA1c at fasting. We compared changes in parameters of glucose tolerance and insulin secretion from baseline to follow-up.

RESULTS

Among 55 participants, 37 (67%) were treated with a first-generation CFTR modulator for a median of 21 months. Glucose levels were unchanged in both the treated and untreated group. In the treated group, C-peptide levels declined, yet no significant differences in glucose, insulin, and C-peptide levels were observed between the groups. HbA1c increased in both groups, while no significant change in the insulin sensitivity indices was detected in either group. However, homeostatic model assessment for insulin resistance tended to decline in the treated group, whilst tending towards an increase in the untreated group. The difference between the groups reached statistical significance (p = 0.040).

CONCLUSION

Treatment with first-generation CFTR modulators, mainly tezacaftor/ivacaftor, did not seem to be associated with glucose tolerance nor insulin secretion in adults with CF. However, CFTR modulators may still have a beneficial effect on insulin sensitivity.

The prevalence of vascular and metabolic complications after lung transplant in people with cystic fibrosis in a Dutch cohort

BACKGROUND

With improvements in care for people with Cystic Fibrosis (pwCF), total survival after Lung Transplantation (LTx) will be longer. Therefore, this population's up-to-date analysis of late-onset post-transplant metabolic and vascular complications will be more relevant in current clinical practice.

METHODS

We studied 100 pwCF who underwent an LTx between 2001 and 2020 at the University Medical Centre Utrecht, the Netherlands. The median age at transplant was 31 years and 55 percent was male. We assessed survival, the prevalence of metabolic complications (diabetes, renal damage, dyslipidemia, and metabolic syndrome), and vascular complications (hypertension, heart rhythm disease, micro-, and macrovascular disease). In addition, differences in risks for developing complications based on sex and overall survival were analyzed.

RESULTS

The prevalence of macrovascular disease raised to 15.9 percent 15 years post-LTx. The prevalence of diabetes increased from 63 percent at LTx to over 90 percent 15 years post-LTx and the prevalence of dyslipidemia increased from 21 percent to over 80 percent. Survival 1-, 2-, 5-, and 10 years post-transplant were 84, 80, 76, and 58 percent respectively. No significant differences were found based on sex.

CONCLUSION

This study shows that the prevalence of cardiovascular risk factors increases after LTx for CF, potentially leading to major complications. These data emphasize the necessity of regular check-ups for metabolic and vascular complications after LTx with specific attention to renal damage. Early recognition of these complications is crucial and will lead to earlier intervention, which could lead to improved prognosis after lung transplantation.

The Effects of Elexacaftor, Tezacaftor, and Ivacaftor (ETI) on Blood Glucose in Patients With Cystic Fibrosis: A Systematic Review

Cystic fibrosis (CF) is an autosomal recessive genetic disorder resulting from defects in the cystic fibrosis transmembrane conductance regulator (CFTR) protein, which in turn results in a multi-systemic disorder. There are numerous known CF alleles associated with different mutations of the CFTR gene, with the most common CF allele being a three-base-pair deletion known as ΔF508. One common manifestation of CF is glycemic dysregulation associated with decreased insulin secretion, often progressing into a distinct form of diabetes known as cystic fibrosis-related diabetes (CFRD). In the past decade, a class of drugs known as CFTR modulators has entered clinical practice. These drugs interact with the CFTR protein to restore its function, with different modulators (or combinations of modulators) suitable for patients with different CFTR mutations. Previous research has established that the modulator ivacaftor is effective in decreasing blood glucose and sometimes resolving CFRD in patients with certain CFTR mutations (class III mutations). However, early modulator therapies for individuals with the common ΔF508 mutation (e.g., a combination of the modulators lumacaftor and ivacaftor) have largely proven ineffective in improving glucose regulation. More recently, a combination therapy of three modulators, namely elexacaftor, tezacaftor, and ivacaftor (ETI), has entered clinical practice for patients with the ΔF508 mutation. However, it is not clear whether this therapy is effective in treating dysglycemia. We searched for studies of any design that examined the effects of ETI on measures of blood glucose. All available studies were observational studies comparing patients before and after initiating ETI therapy. Measures of daily-life blood glucose (those obtained with continuous glucose monitoring systems or by measuring glycated hemoglobin (HbA1c)) and post-prandial glucose spikes from oral glucose tolerance tests showed significant improvements in at least some studies. The majority of studies showed significant improvements from pre- to post-ETI in one or more blood glucose measures. While the interpretation of this evidence is complicated by the lack of randomized controlled trials, it appears that ETI therapy is associated with improved glucose regulation for at least some patients with the ΔF508 mutation.

Nutritional Care in Children with Cystic Fibrosis

Patients with cystic fibrosis (CF) are prone to malnutrition and growth failure, mostly due to malabsorption caused by the derangement in the chloride transport across epithelial surfaces. Thus, optimal nutritional care and support should be an integral part of the management of the disease, with the aim of ameliorating clinical outcomes and life expectancy. In this report, we analyzed the nutrition support across the different ages, in patients with CF, with a focus on the relationships with growth, nutritional status, disease outcomes and the use of the CF transmembrane conductance regulator (CFTR) modulators. The nutrition support goal in CF care should begin as early as possible after diagnosis and include the achievement of an optimal nutritional status to support the growth stages and puberty development in children, that will further support the maintenance of an optimal nutritional status in adult life. The cornerstone of nutrition in patients with CF is a high calorie, high-fat diet, in conjunction with a better control of malabsorption due to pancreatic enzyme replacement therapy, and attention to the adequate supplementation of fat-soluble vitamins. When the oral caloric intake is not enough for reaching the anthropometric nutritional goals, supplemental enteral feeding should be initiated to improve growth and the nutritional status. In the last decade, the therapeutic possibilities towards CF have grown in a consistent way. The positive effects of CFTR modulators on nutritional status mainly consist in the improvement in weight gain and BMI, both in children and adults, and in an amelioration in terms of the pulmonary function and reduction of exacerbations. Several challenges need to be overcome with the development of new drugs, to transform CF from a fatal disease to a treatable chronic disease with specialized multidisciplinary care.

Bone metabolism and incretin hormones following glucose ingestion in young adults with pancreatic insufficient cystic fibrosis

Background

Gut-derived incretin hormones, including glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide 1 (GLP-1), regulate post-prandial glucose metabolism by promoting insulin production. GIP, GLP-1, and insulin contribute to the acute bone anti-resorptive effect of macronutrient ingestion by modifying bone turnover. Cystic fibrosis (CF) is associated with exocrine pancreatic insufficiency (PI), which perturbs the incretin response. Cross-talk between the gut and bone ("gut-bone axis") has not yet been studied in PI-CF. The objectives of this study were to assess changes in biomarkers of bone metabolism during oral glucose tolerance testing (OGTT) and to test associations between incretins and biomarkers of bone metabolism in individuals with PI-CF.

Methods

We performed a secondary analysis of previously acquired blood specimens from multi-sample OGTT from individuals with PI-CF ages 14-30 years (n = 23). Changes in insulin, incretins, and biomarkers of bone resorption (C-terminal telopeptide of type 1 collagen [CTX]) and formation (procollagen type I N-terminal propeptide [P1NP]) during OGTT were computed.

Results

CTX decreased by 32% by min 120 of OGTT (P < 0.001), but P1NP was unchanged. Increases in GIP from 0 to 30 mins (rho = -0.48, P = 0.03) and decreases in GIP from 30 to 120 mins (rho = 0.62, P = 0.002) correlated with decreases in CTX from mins 0-120. Changes in GLP-1 and insulin were not correlated with changes in CTX, and changes in incretins and insulin were not correlated with changes in P1NP.

Conclusions

Intact GIP response was correlated with the bone anti-resorptive effect of glucose ingestion, represented by a decrease in CTX. Since incretin hormones might contribute to development of diabetes and bone disease in CF, the "gut-bone axis" warrants further attention in CF during the years surrounding peak bone mass attainment.

Association of Islet Amyloid Polypeptide to C-Peptide Ratio With Cystic Fibrosis-Related Diabetes: A Prospective Cross-sectional Study

OBJECTIVES

Early detection of cystic fibrosis (CF) related diabetes (CFRD) improves health outcomes and reduces CF-related mortality. The study aims to evaluate the ratio of islet amyloid polypeptide (IAPP) to C-peptide in CF patients with diabetes and without diabetes.

METHODS

Cross-sectional analysis was carried out in a prospective cohort of 33 participants (CF [n = 16] and CFRD [n = 18]). We examined the association of plasma IAPP:C-peptide ratio with clinical information, including glycated hemoglobin, and lung function markers.

RESULTS

The median (interquartile range) IAPP:C-peptide ratio was significantly (P = 0.004) higher in people with CFRD (4.8 [4.5]) compared with participants without CFRD (12.1 [19.7]). The ratio of IAPP to C-peptide significantly accounted for a 38% variation in the diabetes status in patients with CF (r2 = 0.399, P < 0.001). Islet amyloid polypeptide is strongly correlated with serum ferritin levels (r = 0.683, P = 0.005) and forced expiratory volume in CFRD, but not in nondiabetic participants with CF.

CONCLUSIONS

Islet amyloid polypeptide:C-peptide ratio could be a potential marker of CFRD in adults with CF. Further research requires validation of this marker in longitudinal cohort studies to confirm the capability of IAPP:C-peptide to predict CFRD.

Increased sputum lactate during oral glucose tolerance test in cystic fibrosis

Blood glucose levels exceeding 8 mM are shown to increase glucose levels in airway surface in cystic fibrosis (CF). Moreover, high levels of endobronchial glucose are proposed to increase the growth of common CF bacteria and feed the neutrophil‐driven inflammation. In the infected airways, glucose may be metabolized by glycolysis to lactate by both bacteria and neutrophils. Therefore, we aimed to investigate whether increased blood glucose may fuel the glycolytic pathways of the lung inflammation by determining sputum glucose and lactate during an oral glucose tolerance test (OGTT). Sputum from 27 CF patients was collected during an OGTT. Sputum was collected at fasting and one and two hours following the intake of 75 g of glucose. Only participants able to expectorate more than one sputum sample were included. Glucose levels in venous blood and lactate and glucose content in sputum were analyzed using a regular blood gas analyzer. We collected 62 sputum samples: 20 at baseline, 22 after 1 h, and 20 after 2 h. Lactate and glucose were detectable in 30 (48.4%) and 43 (69.4%) sputum samples, respectively. The sputum lactate increased significantly at 2 h in the OGTT (p = 0.024), but sputum glucose was not changed. As expected, plasma glucose level significantly increased during the OGTT (p < 0.001). In CF patients, sputum lactate increased during an OGTT, while the sputum glucose did not reflect the increased plasma glucose. The increase in sputum lactate suggests that glucose spills over from plasma to sputum where glucose may enhance the inflammation by fueling the anaerobic metabolism in neutrophils or bacteria.

New Concepts in the Pathogenesis of Cystic Fibrosis-Related Diabetes

CONTEXT

Cystic fibrosis-related diabetes (CFRD) is the most common extrapulmonary complication of cystic fibrosis (CF). Approximately 40% of people with CF who are older than 20 years have CFRD. Presence of CFRD is associated with poor health outcomes in people with CF.

OBJECTIVE

This review summarizes current knowledge on pathophysiology of CFRD.

METHODS

A PubMed review of the literature was conducted, with search terms that included CFRD, cystic fibrosis, cystic fibrosis related diabetes, and cystic fibrosis transmembrane conductance regulator (CFTR). Additional sources were identified through manual searches of reference lists. Pathophysiology of CFRD: The pathophysiology underlying development of glucose tolerance abnormalities in CF is complex and not fully understood. β-cell loss and functional impairment of the remaining β-cell function results in progressive insulin insufficiency. Factors that may contribute to development of CFRD include local islet and systemic inflammation, alterations in the incretion hormone axis, varying degrees of insulin resistance and genetic factors related to type 2 diabetes.

CONCLUSION

The prevalence of CFRD is expected to further increase with improving life expectancy of people with CF. Further research is needed to better understand the mechanisms underlying the development of CFRD and the impact of diabetes on clinical outcomes in CF.

The Changing Landscape of Nutrition in Cystic Fibrosis: The Emergence of Overweight and Obesity

Cystic fibrosis has historically been characterized by malnutrition, and nutrition strategies have placed emphasis on weight gain due to its association with better pulmonary outcomes. As treatment for this disease has significantly improved, longevity has increased and overweight and obesity have emerged issues in this population. The effect of excess weight and adiposity on CF clinical outcomes is unknown but may produce similar health consequences and obesity-related diseases as those observed in the general population. This review examines the prevalence of overweight and obesity in CF, the medical and psychological impact, as well as the existing evidence for treatment in the general population and how this may be applied to people with CF. Clinicians should partner with individuals with CF and their families to provide a personalized, interdisciplinary approach that includes dietary modification, physical activity, and behavioral intervention. Additional research is needed to identify the optimal strategies for preventing and addressing overweight and obesity in CF.

Cystic Fibrosis-Related Diabetes Mellitus and Pregnancy: A Retrospective Study

INTRODUCTION

Cystic fibrosis-related diabetes mellitus (CFRDM) is becoming a more common issue in pregnancy care as the life expectancy of females living with cystic fibrosis has improved, with an increasing number of pregnancies in this population. Despite the Republic of Ireland having the highest incidence of cystic fibrosis globally, there is limited Irish data on pregnancy outcomes for those with CFRDM. This study aimed to retrospectively review maternal and foetal outcomes of pregnancies affected by maternal CFRDM.

METHODS

The patient records of all women with CFRDM who attended the National Maternity Hospital Dublin for obstetric care between 2015 and 2019 were retrospectively reviewed.

RESULTS

A search of patient records identified 15 pregnancies in 12 women with CFRDM during the study period. CFRDM was diagnosed pre-conception in ten of the 15 pregnancies. Median neonatal weight at birth was lower in women with CFRDM diagnosed pre-conception compared to women diagnosed during pregnancy (2.8 vs. 3.02 kg). The median weight gain in women with CFRDM diagnosed pre-conception was 10.9 kg compared to 11.9 kg for those diagnosed during pregnancy. The majority of women (62.5%) with CFRDM diagnosed pre-conception delivered via caesarean section. Admission for CF exacerbations during pregnancy in women with CFRDM diagnosed pre-conception was very common (87.5%) compared with 75% of those diagnosed during their pregnancy.

CONCLUSION

Women diagnosed with CFRDM were likely to require caesarean section, to be treated with insulin, and to be frequently admitted to hospital for CF exacerbations. Our review highlights the importance of good glucose control, stable cystic fibrosis before pregnancy and a multidisciplinary team approach.

Understanding Cystic Fibrosis Comorbidities and Their Impact on Nutritional Management

Cystic fibrosis (CF) is a chronic, multisystem disease with multiple comorbidities that can significantly affect nutrition and quality of life. Maintaining nutritional adequacy can be challenging in people with cystic fibrosis and has been directly associated with suboptimal clinical outcomes. Comorbidities of CF can result in significantly decreased nutritional intake and intestinal absorption, as well as increased metabolic demands. It is crucial to utilize a multidisciplinary team with expertise in CF to optimize growth and nutrition, where patients with CF and their loved ones are placed in the center of the care model. Additionally, with the advent of highly effective modulators (HEMs), CF providers have begun to identify previously unrecognized nutritional issues, such as obesity. Here, we will review and summarize commonly encountered comorbidities and their nutritional impact on this unique population.

Cystic fibrosis transmembrane conductance regulator function in patients with chronic pancreatitis

BACKGROUND

Pathogenesis of chronic pancreatitis (CP) is still not entirely understood with many patients probably having more than 1 underlying etiology. Besides toxic-metabolic factors, genetics contribute to disease development. Mutations in cystic fibrosis transmembrane conductance regulator (CFTR) are shown to increase risk for CP. Activity of CFTR can easily be accessed in vivo by measurement of nasal potential difference (PD).

METHODS

We compared in this monocentric study 17 CP patients from the outpatient unit of our university hospital with 30 healthy controls regarding nasal PDs by using a superfusion protocol. Additionally, demographic and lifestyle data of all persons were recorded.

RESULTS

Seventeen patients (12% female, median age 48 years) with CP and 30 healthy volunteers (47% female, 25 years) were included in the study. Patients with CP had a significant higher proportion of CFTR dysfunction (P = .04). Furthermore, demographics differed between the 2 groups with CP patients being older (P < .001). There were differences in daily alcohol consumption (P = .001) and smoking habits (smokers vs nonsmokers: P = .01, pack years: P = .002).

CONCLUSIONS

PD measurement is an easily accessible way to show CFTR dysfunction as an etiological factor of CP. Cigarette smoking might impair CFTR function and therefore be 1 preventable cause of CP evolution.

The Changing Face of Cystic Fibrosis: An Update for Anesthesiologists

Cystic fibrosis (CF) is the most common fatal genetic disease in North America. While CF is more common among Whites, it is increasingly being recognized in other races and ethnicities. Although there is no cure, life expectancy has steadily improved, with the median survival exceeding 46 years in the United States. There are now more adults than children with CF in the United States. CF is caused by mutations in a gene that encodes the cystic fibrosis transmembrane conductance regulator (CFTR) protein, expressed in many epithelial cells. More than 2100 CFTR mutations have been linked to CF, and newer CFTR modulator drugs are being used to improve the production, intracellular processing, and function of the defective CFTR protein. CF is a multisystem disease that affects primarily the lungs, pancreas, hepatobiliary system, and reproductive organs. Anesthesiologists routinely encounter CF patients for various surgical and medical procedures, depending on the age group. This review article focuses on the changing epidemiology of CF, advances in the classification of CFTR mutations, the latest innovations in CFTR modulator therapies, the impact of the coronavirus disease pandemic, and perioperative considerations that anesthesiologists must know while caring for patients with CF.

Non-coding RNAs in diabetes mellitus and diabetic cardiovascular disease

More than 10% of the world's population already suffers from varying degrees of diabetes mellitus (DM), but there is still no cure for the disease. Cardiovascular disease (CVD) is one of the most common and dangerous of the many health complications that can be brought on by DM, and has become the leading cause of death in people with diabetes. While research on DM and associated CVD is advancing, the specific mechanisms of their development are still unclear. Given the threat of DM and CVD to humans, the search for new predictive markers and therapeutic ideas is imminent. Non-coding RNAs (ncRNAs) have been a popular subject of research in recent years. Although they do not encode proteins, they play an important role in living organisms, and they can cause disease when their expression is abnormal. Numerous studies have observed aberrant ncRNAs in patients with DM complications, suggesting that they may play an important role in the development of DM and CVD and could potentially act as biomarkers for diagnosis. There is additional evidence that treatment with existing drugs for DM, such as metformin, alters ncRNA expression levels, suggesting that regulation of ncRNA expression may be a key mechanism in future DM treatment. In this review, we assess the role of ncRNAs in the development of DM and CVD, as well as the evidence for ncRNAs as potential therapeutic targets, and make use of bioinformatics to analyze differential ncRNAs with potential functions in DM.

Analysis of multiple gene co-expression networks to discover interactions favoring CFTR biogenesis and ΔF508-CFTR rescue

BACKGROUND

We previously reported that expression of a miR-138 mimic or knockdown of SIN3A in primary cultures of cystic fibrosis (CF) airway epithelia increased ΔF508-CFTR mRNA and protein levels, and partially restored CFTR-dependent chloride transport. Global mRNA transcript profiling in ΔF508-CFBE cells treated with miR-138 mimic or SIN3A siRNA identified two genes, SYVN1 and NEDD8, whose inhibition significantly increased ΔF508-CFTR trafficking, maturation, and function. Little is known regarding the dynamic changes in the CFTR gene network during such rescue events. We hypothesized that analysis of condition-specific gene networks from transcriptomic data characterizing ΔF508-CFTR rescue could help identify dynamic gene modules associated with CFTR biogenesis.

METHODS

We applied a computational method, termed M-module, to analyze multiple gene networks, each of which exhibited differential activity compared to a baseline condition. In doing so, we identified both unique and shared gene pathways across multiple differential networks. To construct differential networks, gene expression data from CFBE cells were divided into three groups: (1) siRNA inhibition of NEDD8 and SYVN1; (2) miR-138 mimic and SIN3A siRNA; and (3) temperature (27 °C for 24 h, 40 °C for 24 h, and 27 °C for 24 h followed by 40 °C for 24 h).

RESULTS

Interrogation of individual networks (e.g., NEDD8/SYVN1 network), combinations of two networks (e.g., NEDD8/SYVN1 + temperature networks), and all three networks yielded sets of 1-modules, 2-modules, and 3-modules, respectively. Gene ontology analysis revealed significant enrichment of dynamic modules in pathways including translation, protein metabolic/catabolic processes, protein complex assembly, and endocytosis. Candidate CFTR effectors identified in the analysis included CHURC1, GZF1, and RPL15, and siRNA-mediated knockdown of these genes partially restored CFTR-dependent transepithelial chloride current to ΔF508-CFBE cells.

CONCLUSIONS

The ability of the M-module to identify dynamic modules involved in ΔF508 rescue provides a novel approach for studying CFTR biogenesis and identifying candidate suppressors of ΔF508.

Understanding the Pancreatic Islet Microenvironment in Cystic Fibrosis and the Extrinsic Pathways Leading to Cystic Fibrosis Related Diabetes

Cystic fibrosis (CF) is an autosomal recessive chronic condition effecting approximately 70 000 to 100 000 people globally and is caused by a loss-of-function mutation in the CF transmembrane conductance regulator. Through improvements in clinical care, life expectancy in CF has increased considerably associated with rising incidence of secondary complications including CF-related diabetes (CFRD). CFRD is believed to result from β-cell loss as well as insufficient insulin secretion due to β-cell dysfunction, but the underlying pathophysiology is not yet fully understood. Here we review the morphological and cellular changes in addition to the architectural remodelling of the pancreatic exocrine and endocrine compartments in CF and CFRD pancreas. We consider also potential underlying proinflammatory signalling pathways impacting on endocrine and specifically β-cell function, concluding that further research focused on these mechanisms may uncover novel therapeutic targets enabling restoration of normal insulin secretion.

Genetic syndromes with diabetes: A systematic review

Previous reviews and clinical guidelines have identified 10-20 genetic syndromes associated with diabetes, but no systematic review has been conducted to date. We provide the first comprehensive catalog for syndromes with diabetes mellitus. We conducted a systematic review of MEDLINE, Embase, CENTRAL, PubMed, OMIM, and Orphanet databases for case reports, case series, and observational studies published between 1946 and January 15, 2020, that described diabetes mellitus in adults and children with monogenic or chromosomal syndromes. Our literature search identified 7,122 studies, of which 160 fulfilled inclusion criteria. Our analysis of these studies found 69 distinct diabetes syndromes. Thirty (43.5%) syndromes included diabetes mellitus as a cardinal clinical feature, and 56 (81.2%) were fully genetically elucidated. Sixty-three syndromes (91.3%) were described more than once in independent case reports, of which 59 (93.7%) demonstrated clinical heterogeneity. Syndromes associated with diabetes mellitus are more numerous and diverse than previously anticipated. While knowledge of the syndromes is limited by their low prevalence, future reviews will be needed as more cases are identified. The genetic etiologies of these syndromes are well elucidated and provide potential avenues for future gene identification efforts, aid in diagnosis and management, gene therapy research, and developing personalized medicine treatments.

Islet Function in the Pathogenesis of Cystic Fibrosis-Related Diabetes Mellitus

Cystic fibrosis-related diabetes mellitus (CFRD) is the most common non-pulmonary co-morbidity in cystic fibrosis (CF). CF is caused by mutations in the cystic fibrosis transmembrane conductance regulator gene (CFTR), which leads to aberrant luminal fluid secretions in organs such as the lungs and pancreas. How dysfunctional CFTR leads to CFRD is still under debate. Both intrinsic effects of dysfunctional CFTR in hormone secreting cells of the islets and effects of exocrine damage have been proposed. In the current review, we discuss these non-mutually exclusive hypotheses with a special focus on how dysfunctional CFTR in endocrine cells may contribute to an altered glucose homeostasis. We outline the proposed role of CFTR in the molecular pathways of β-cell insulin secretion and α-cell glucagon secretion, and touch upon the importance of the exocrine pancreas and intra-pancreatic crosstalk for proper islet function.

Factors Influencing Lung Function in Patients with Cystic Fibrosis in Western Romania

PURPOSE

The aim of this cross-sectional study was to identify the major factors influencing pulmonary function in CF patients from western side of Romania.

PATIENTS AND METHODS

The study enrolled 51 patients with CF between the ages of 6 and 27.8 years who were monitored at regular visits to the National Cystic Fibrosis Centre and Pius Branzeu County Hospital in Timisoara, Romania, over a period of 2 years. The relationships between lung function, as measured by forced expiratory volume in 1 s (FEV1), with patient age, sex, body mass index (BMI), pancreatic insufficiency (PI), microbial infection, CF-related diabetes (CFRD), CF-associated liver disease (CFLD), and physical activity <30 min/day, were evaluated by multivariate regression analysis.

RESULTS

The results showed that FEV1 was 0.32% higher for each increase in percentile of BMI (95% confidence interval: 0.034-0.619). In addition, mean FEV1 was 1.52% lower with every year rise of age. PI and female sex increased the risk of impaired lung function (FEV1 <60%). The factors most closely correlated with pulmonary function in pediatric CF patients were current age (negative) and BMI (positive).

CONCLUSION

The findings of this study, in combination with what is known from other studies in CF, suggest that a better nutritional status and infection prophylaxis should be part of a comprehensive clinical management strategy for pediatric CF in Romania.

Cystic fibrosis-related diabetes (CFRD) and cognitive function in adults with cystic fibrosis

BACKGROUND

Being able to function cognitively is imperative for successful achievement in school, working life, and disease self-management. Diabetes is known to cause changes in brain structure and long-term cognitive dysfunction. This work investigated cystic fibrosis-related diabetes (CFRD) as a mechanism for cognitive impairment in people with CF. It was hypothesised that cognition would be poorer in adults with CFRD than in those with CF without diabetes (CFND) or in healthy controls.

METHODS

Cognitive performance was assessed using the Cambridge Neuropsychological Test Automated Battery which provides a comprehensive cognitive assessment with tests mapping onto specific brain regions. Demographic, clinical and self-reported health data were documented for all participants. CF specific clinical variables were recorded for the two CF groups.

RESULTS

Ninety-eight people with CF (49CFRD,49CFND) and 49 healthy controls were recruited. People with CF demonstrated deficits in aspects of verbal and spatial memory, processing speed and cognitive flexibility compared with healthy controls, with all areas of the brain implicated. Those with CFRD had additional difficulties with higher-level processes known collectively as 'executive function', which demand greater cognitive load and recruit the prefrontal cortex. Compared with healthy controls, those with CFND and CFRD had an estimated 20% and up to 40% reduction in processing speed respectively.

CONCLUSION

Managing CF requires higher order executive function. Impairments may be sufficient to interfere with self-care and the ability to perform everyday tasks efficiently. At which point in the CF disease trajectory these difficulties begin, and what may attenuate them, has yet to be determined.

Predicting Substance Use from Religiosity/Spirituality in Individuals with Cystic Fibrosis

Religiosity and spirituality predict lower alcohol and other substance use in community samples of adolescents and adults. However, the roles of religiosity and spirituality in substance use have not been examined in individuals with cystic fibrosis (CF). Adults with CF (n = 123) completed measures of spirituality, religiosity, and substance use. Clinical measures of illness severity (e.g., BMI and  %FEV₁) were obtained from participants' medical records. Substance use rates for alcohol, tobacco, and marijuana were lower in this sample than those seen in the general population. Of the measured BMMRS subscales, spiritual experiences and religious commitment were significant predictors of lower alcohol use. These results suggest that personal factors of religiosity and spirituality are more important for substance use in adults with CF than participation in religious service and events or adoption of religious practices.

Pancreas transplantation for cystic fibrosis: A frequently missed opportunity

Cystic fibrosis (CF) is an inherited autosomal recessive disorder. Despite optimized therapy, the majority of affected individuals ultimately die of respiratory failure. As patients with CF are living longer, extra-pulmonary manifestations may develop including pancreatic failure, which manifests as exocrine insufficiency, and CF-related diabetes (CFRD). Both of these can be managed through pancreas transplantation. Pancreas transplantation is usually performed in combination with another organ, most often with a kidney transplant for end-stage diabetic nephropathy. In the CF patient population, the two settings where inclusion of a pancreas transplant should be considered would be in combination with a lung transplant for CF pulmonary disease, or in combination with a liver for CF-related liver disease with cirrhosis. This report will discuss this topic in detail, including a review of the literature regarding combinations of lung/pancreas and liver/pancreas transplant.

Cystic fibrosis in disguise - the wolf in sheep's clothing, a case report

Background

Childhood hypoglycemia in combination with hepatomegaly is suspicious for inborn errors of metabolism. Cystic fibrosis typically presents with failure to thrive, pulmonary and gastrointestinal symptoms. Hepatic involvement and hypoglycemia can occur in a significant number of patients, although hepatomegaly is uncommon.

Case presentation

A 28 months old boy was presented with recurrent upper airways infections, progressive lethargy and weight loss. Clinically hepatomegaly was the main presenting feature and hypoglycemia (minimum 1.4 mmol/l) was noted as were elevated transaminases. The patient did not produce enough sweat to analyze it. Infectious causes for hepatitis were excluded and a broad metabolic work-up initiated. A therapy with starch was initiated to control hypoglycemia. In further course loose stools were reported and pancreatic elastase was found to be reduced. A further sweat test yielded pathological chloride concentration and genetic testing confirmed the diagnosis of cystic fibrosis.

Conclusions

Cystic fibrosis is a systemic disease and less common presentations need to be considered. Even in the age of CF-newborn screening in many countries CF needs to be ruled out in typical and atypical clinical presentations and diagnostics need to be repeated if inconclusive.

Cystic Fibrosis

Cystic fibrosis (CF) is one of the most commonly diagnosed genetic disorders. Clinical characteristics include progressive obstructive lung disease, sinusitis, exocrine pancreatic insufficiency leading to malabsorption and malnutrition, liver and pancreatic dysfunction, and male infertility. Although CF is a life-shortening disease, survival has continued to improve to a median age of 46.2 years due to earlier diagnosis through routine newborn screening, promulgation of evidence-based guidelines to optimize nutritional and pulmonary health, and the development of CF-specific interdisciplinary care centers. Future improvements in health and quality of life for individuals with CF are likely with the recent development of mutation-specific modulator therapies. In this review, we will cover the current understanding of the disease manifestations, diagnosis, and management as well as common complications seen in individuals with CF.

Continuous Glucose Monitoring as a Valuable Tool in the Early Detection of Diabetes Related to Cystic Fibrosis

Aims: We evaluated the impact of cystic fibrosis-related diabetes (CFRD) on lung disease and nutritional status. Study Design: The retrospective cohort study evaluated the subjects' medical records from 2004 to 2019. All participants older than 10 years diagnosed by a 30-minutely sampled OGTT formed OGTT-CFRD subgroup. The participants diagnosed with continuous glucose monitoring (CGM) (at least two peaks above 11.1 mmol/l and more than 10% of recorded time above 7.8 mmol/l) formed a CFRD-CGM subgroup. The participants without CFRD formed a non-CFRD group. The longitudinal follow-up was made 2 years before and 3 years after insulin therapy initiation. Results: Of 144 participants included, aged 10-55 years (44% males), 28 (19.4%) had CFRD. The HbA1c was significantly lower in the CGM-CFRD in comparison to the OGTT-CFRD subgroup (5.9 ± 0.62 and 7.3 ± 1.7% respectfully; p = 0.04). Subjects with CFRD were malnourished in comparison to non-CFRD, with significant improvements with insulin replacement therapy in regard to BMI Z-score (-1.4 ± 1.3 vs. -0.5 ± 1.2%, p = 0.04) and pulmonary exacerbation score (p = 0.02). In OGTT-CFRD subgroup there is an increase in FEV1 (62.7 ± 26.3 to 65.1 ± 21.7%, p = 0.7) and decrease in FVC (from 76.4 ± 24.2 to 71.2 ± 20%, p = 0.003) from diagnosis to second year of follow-up. In CGM-CFRD subgroup there was a decrease in FEV1 (from 58.2 ± 28.2 to 52.8 ± 25.9%, p = 0.2) and FVC-values (from 72.4 ± 26.5 to 67.4 ± 29.1%, p = 0.08).Chronic Pseudomonas aeruginosa infection was more prevalent in the CFRD group (p = 0.003). Conclusion: Continuous glucose monitoring is a useful tool for insight of glucose impairment and diagnosis of CFRD. Early recognition of CFRD and therapeutic intervention has favorable effects on clinical course of the disease.

Mechanisms of Post-Pancreatitis Diabetes Mellitus and Cystic Fibrosis-Related Diabetes: A Review of Preclinical Studies

Anatomical proximity and functional correlations between the exocrine and endocrine pancreas warrant reciprocal effects between the two parts. Inflammatory diseases of the exocrine pancreas, such as acute or chronic pancreatitis, or the presence of cystic fibrosis disrupt endocrine function, resulting in diabetes of the exocrine pancreas. Although novel mechanisms are being increasingly identified, the intra- and intercellular pathways regulating exocrine-endocrine interactions are still not fully understood, making the development of new and more effective therapies difficult. Therefore, this review sought to accumulate current knowledge regarding the pathogenesis of diabetes in acute and chronic pancreatitis, as well as cystic fibrosis.

Hypoglycemia in cystic fibrosis: Prevalence, impact and treatment

Hypoglycemia is a common and feared complication of insulin therapy. As in type 1 and type 2 diabetes, people with cystic fibrosis related diabetes are also at risk for hypoglycemia related to insulin therapy. Spontaneous hypoglycemia is also common in patients with CF without diabetes, who are not on glucose lowering medications. Spontaneous hypoglycemia in CF may also occur during or after an oral glucose tolerance test. In this review, we will discuss the definition, epidemiology, pathophysiology and impact of hypoglycemia, with a focus on people with cystic fibrosis. We will also review strategies to manage and prevent hypoglycemia.

Heterogeneous expression of CFTR in insulin-secreting β-cells of the normal human islet

Cystic fibrosis (CF) is due to mutations in the CF-transmembrane conductance regulator (CFTR) and CF-related diabetes (CFRD) is its most common co-morbidity, affecting ~50% of all CF patients, significantly influencing pulmonary function and longevity. Yet, the complex pathogenesis of CFRD remains unclear. Two non-mutually exclusive underlying mechanisms have been proposed in CFRD: i) damage of the endocrine cells secondary to the severe exocrine pancreatic pathology and ii) intrinsic β-cell impairment of the secretory response in combination with other factors. The later has proven difficult to determine due to low expression of CFTR in β-cells, which results in the general perception that this Cl⁻channel does not participate in the modulation of insulin secretion or the development of CFRD. The objective of the present work is to demonstrate CFTR expression at the molecular and functional levels in insulin-secreting β-cells in normal human islets, where it seems to play a role. Towards this end, we have used immunofluorescence confocal and immunofluorescence microscopy, immunohistochemistry, RT-qPCR, Western blotting, pharmacology, electrophysiology and insulin secretory studies in normal human, rat and mouse islets. Our results demonstrate heterogeneous CFTR expression in human, mouse and rat β-cells and provide evidence that pharmacological inhibition of CFTR influences basal and stimulated insulin secretion in normal mouse islets but not in islets lacking this channel, despite being detected by electrophysiological means in ~30% of β-cells. Therefore, our results demonstrate a potential role for CFTR in the pancreatic β-cell secretory response suggesting that intrinsic β-cell dysfunction may also participate in the pathogenesis of CFRD.

Overview of Atypical Diabetes

Although type 1 diabetes mellitus and, to a lesser extent, type 2 diabetes mellitus, are the prevailing forms of diabetes in youth, atypical forms of diabetes are not uncommon and may require etiology-specific therapies. By some estimates, up to 6.5% of children with diabetes have monogenic forms. Mitochondrial diabetes and cystic fibrosis related diabetes are less common but often noted in the underlying disease. Atypical diabetes should be considered in patients with a known disorder associated with diabetes, aged less than 25 years with nonautoimmune diabetes and without typical characteristics of type 2 diabetes mellitus, and/or with comorbidities associated with atypical diabetes.

[Abdominal manifestations in cystic fibrosis : Clinical review]

Cystic fibrosis (CF) is the most common fatal autosomal recessive disease in the Caucasian population. A mutation in the cystic fibrosis transmembrane regulator protein (CFTR) gene leads to the production of abnormally viscous mucus and secretions in the lungs of these patients. A similar pathology also occurs in other organs. In the abdomen, among others the gastrointestinal tract, the pancreas, and the hepatobiliary system are affected. The involvement of the pancreas leads to its exocrine and endocrine insufficiency. Hepatic manifestations include hepatic steatosis, focal biliary and multilobular cirrhosis, and portal hypertension. Biliary complications include cholelithiasis, microgallbladder, and sclerosing cholangitis. In the gastrointestinal tract, complications such as the distal intestinal obstruction syndrome, invaginations, chronic constipation, wall thickening, and fibrosis in the colon may occur. An important renal manifestation is nephrolithiasis. With currently rapidly increasing life expectancy of patients with cystic fibrosis, complications of extrapulmonary cystic fibrosis manifestations including hepatic and gastrointestinal malignancy could be an increasing cause of morbidity and mortality of these patients. It is therefore important for radiologists to know and recognize these clinical patterns and to monitor these manifestations in follow-up exams. Previous therapy of extrapulmonary manifestations has been largely symptomatic. Fortunately, the new CFTR modulators seem to represent an effective causal therapeutic approach here.

Incorporating Risk Stratification Into the Practice of Pediatric Preventive Cardiology

Atherosclerosis in its earliest stages is associated with the same traditional cardiovascular disease (CVD) risk factors as are associated with manifest CVD events in adulthood. Clustering of risk factors is associated with exponential increases in atherosclerotic burden from a young age. Some medical conditions and risk behaviours occurring in children can either increase the likelihood of higher levels of risk factors (such as chronic kidney disease) or the presence of risk factor clustering (such as obesity and cardiometabolic syndrome) or are associated with acquired coronary artery pathology (such as Kawasaki disease). This creates a milieu for-or increases the impact of-accelerated atherosclerosis that, in turn, increases the likelihood of premature CVD. This review highlights the importance of considering the total risk factor and risk-condition profile of pediatric patients. An algorithm is provided for stratifying patients into high-, moderate-, and at-risk categories, and practical examples are provided as to how the evaluation and management of 1 risk factor or risk condition might need to be intensified in the context of additional risk factors or risk conditions. For example, for treatment of an adolescent with familial hypercholesterolemia, the target low-density lipoprotein cholesterol level might be lowered by the concomitant presence of low high-density lipoprotein cholesterol or elevated lipoprotein(a) levels. As awareness of cardiovascular risk and atherosclerosis in pediatric patients increases, new at-risk conditions that warrant consideration are emerging. The identification and management of high-risk individuals is an important part of the overall practice of pediatric preventive cardiology.

PB. Transcriptomic and Proteostasis Networks of CFTR and the Development of Small Molecule Modulators for the Treatment of Cystic Fibrosis Lung Disease

Cystic fibrosis (CF) is a lethal autosomal recessive disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. The diversity of mutations and the multiple ways by which the protein is affected present challenges for therapeutic development. The observation that the Phe508del-CFTR mutant protein is temperature sensitive provided proof of principle that mutant CFTR could escape proteosomal degradation and retain partial function. Several specific protein interactors and quality control checkpoints encountered by CFTR during its proteostasis have been investigated for therapeutic purposes, but remain incompletely understood. Furthermore, pharmacological manipulation of many CFTR interactors has not been thoroughly investigated for the rescue of Phe508del-CFTR. However, high-throughput screening technologies helped identify several small molecule modulators that rescue CFTR from proteosomal degradation and restore partial function to the protein. Here, we discuss the current state of CFTR transcriptomic and biogenesis research and small molecule therapy development. We also review recent progress in CFTR proteostasis modulators and discuss how such treatments could complement current FDA-approved small molecules.

Thrombospondin-1: A Key Protein That Induces Fibrosis in Diabetic Complications

Fibrosis accompanies most common pathophysiological features of diabetes complications in different organs. It is characterized by an excessive accumulation of extracellular matrix (ECM) components, the response to which contributes to inevitable organ injury. The extracellular protein thrombospondin-1 (TSP-1), a kind of extracellular glycoprotein, is upregulated by the increased activity of some transcription factors and results in fibrosis by activating multiple pathways in diabetes. The results of studies from our team and other colleagues indicate that TSP-1 is associated with the pathological process leading to diabetic complications and is considered to be the most important factor in fibrosis. This review summarizes the molecular mechanism of increased TSP-1 induced by hyperglycemia and the role of TSP-1 in fibrosis during the development of diabetes complications.

Effects of aerobic interval training on glucose tolerance in children and adolescents with cystic fibrosis: a randomized trial protocol

BACKGROUND

Individuals with cystic fibrosis (CF) may develop CF-related diabetes (CFDR). This comorbidity is related to a poorer quality of life, microvascular complications, a decline in lung function, and an increase in exacerbations, as well as delayed growth and puberty. Evidence exists that physical exercise contributes to glycemic control in individuals with non-CF-related diabetes. This exercise is usually continuous with moderate intensity and long duration, which can cause muscle dyspnea and fatigue in CF individuals. Aerobic interval training (AIT) emerges as a safe and effective alternative for treating these individuals. The objective of this study is to evaluate the effects of AIT on glucose tolerance in children and adolescents with CF.

METHODS

This study will be a two-arm, prospectively registered, randomized controlled trial with blind assessors and twenty 6- to 18-year-old individuals with cystic fibrosis (CF) from two different Brazilian states. People with CF will be randomly allocated to either the experimental or control group using block randomization, stratified by puberty stage,. Participants from both groups will receive an educational intervention and will be asked to continue their usual daily treatment for the full duration of the study. Those in the experimental group will perform AIT on a cycle ergometer at home three times a week, for 8 consecutive weeks. The sample characterization will include an assessment of puberty stage, socioeconomic status, dyspnea, and anthropometry. The primary outcome will be the change in glucose tolerance, while the secondary outcomes will include lung function, exercise tolerance, respiratory muscle strength, quality of life, and CF exacerbations. All outcomes will be assessed at baseline, week 9, and week 17.

DISCUSSION

This is the first study to evaluate the effects of AIT on glucose tolerance in children and adolescents with CF. This study will serve as a basis for guiding clinical practice and decision-making in treating glucose intolerance and CF-related diabetes (CFRD) in children and adolescents with CF.

TRIAL REGISTRATION

ClinicalTrials.gov Protocol Registration System: NCT03653949. Registered on August 31, 2018.

Dietary intake in cystic fibrosis and its role in glucose metabolism

BACKGROUND

Dietary intervention in cystic fibrosis (CF) has historically focused on high-energy diets to address malnutrition, with little attention on diet quality. With increased survival, CF complications such as impaired glucose tolerance (IGT) and cystic fibrosis related diabetes (CFRD) have increased in prevalence. In the absence of consensus on the management of IGT, the role of dietary intake, specifically carbohydrate quality, requires consideration.

AIMS

The aims of this study were to: 1) determine nutritional quality of dietary intake at an adult CF clinic and compare this to the Australian Dietary Guidelines 2) explore relationships between dietary intake, including glycaemic index (GI) and glycaemic load (GL), and glucose response variables using continuous glucose monitoring (CGM).

METHODS

Adults attending a Sydney hospital were recruited to undergo CGM for five-seven days and record dietary intake using a food record over the CGM period. The relationship between variables of dietary intake, including GI and GL and variables of glycaemic response, including mean amplitude of glycaemic excursions (MAGE), percentage of time in hyperglycaemic and euglycaemic range, were determined.

RESULTS

Eighteen participants completed the study with 87 full days of dietary and CGM data. Dietary intake was higher than recommendations in the Australian Dietary Guidelines in relation to grains and protein foods and only slightly higher in saturated fat. Bivariate correlations showed dietary GI was significantly positively associated with percentage of time in hyperglycaemic range. Dietary GL was significantly associated with SD, MAGE and percentage of time in euglycaemic range on CGM. Results remained significant when controlled for energy intake in partial correlation analyses.

CONCLUSIONS

This study suggests GI and GL may be important dietary factors influencing glucose metabolism in CF. Further studies exploring low GI or GL diets as a dietary intervention in CF are the next step.

[Other specific types of diabetes and exocrine pancreatic insufficiency (Update 2019)]

The heterogenous catagory "specific types of diabetes due to other causes" encompasses disturbances in glucose metabolism due to other endocrine disorders such as acromegaly or hypercortisolism, drug-induced diabetes (e. g. antipsychotic medications, glucocorticoids, immunosuppressive agents, highly active antiretroviral therapy (HAART)), genetic forms of diabetes (e. g. Maturity Onset Diabetes of the Young (MODY), neonatal diabetes, Down Syndrome, Klinefelter Syndrome, Turner Syndrome), pancreatogenic diabetes (e. g. postoperatively, pancreatitis, pancreatic cancer, haemochromatosis, cystic fibrosis), and some rare autoimmune or infectious forms of diabetes. Diagnosis of specific diabetes types might influence therapeutic considerations. Exocrine pancreatic insufficiency is not only found in patients with pancreatogenic diabetes but is also frequently seen in type 1 and long-standing type 2 diabetes.

Dysregulated insulin in pancreatic insufficient cystic fibrosis with post-prandial hypoglycemia

BACKGROUND

Post-prandial and oral glucose tolerance test-related hypoglycemia is common in cystic fibrosis (CF); however, the underlying mechanisms are unclear.

METHODS

To understand the relationship of hypoglycemia with meal-related glucose excursion and insulin secretion, we analyzed plasma glucose, insulin, C-peptide, glucagon and incretins obtained during standardized mixed-meal tolerance tests (MMTT) in non-diabetic adolescents and young adults with pancreatic insufficient CF (PI-CF).

RESULTS

Hypoglycemia, defined as glucose <70 mg/dL, occurred in 9/34 subjects at 150 (range:120-210) minutes following initial meal ingestion. Hypoglycemia[+] and hypoglycemia[-] groups did not differ in gender, age, lung function, HbA1c, or BMI. While 11/14 hypoglycemia[-] individuals displayed normal glucose tolerance (NGT), only 2/9 hypoglycemia[+] had NGT. Peak glucose was higher in hypoglycemia[+] vs hypoglycemia[-]. Compared to hypoglycemia[-] NGT, hypoglycemia[+] exhibited lower early-phase insulin secretion (ISR-AUC_0-30min). ISR-AUC_120-180min was not different in hypoglycemia[+] vs hypoglycemia[-] with abnormal glucose tolerance (AGT); however, glucose-AUC_120-180min was lower in hypoglycemia[+] vs hypoglycemia[-] AGT. After adjusting for glucose-AUC, hypoglycemia[+] subjects tended to have higher ISR-AUC_120-180min than hypoglycemia[-] AGT. Glucagon concentration did not differ between groups. Lower GLP-1-AUC_30min and AUC_180min and higher GIP-AUC_30min were present in hypoglycemia[+] individuals.

CONCLUSION

Hypoglycemia is common in PI-CF following MMTT and is associated with early glucose dysregulation (higher peak glucose), more impaired early-phase insulin secretion (lower ISR-AUC_30min), and possibly late compensatory hyperinsulinemia. Further study is required to understand whether absence of glucagon difference in the hypoglycemia[+] individuals signals counterregulatory impairment, to delineate the role of incretins in hypoglycemia, and to determine the relationship of hypoglycemia to emergence of CFRD.

Hepatic enzyme ALT as a marker of glucose abnormality in men with cystic fibrosis

AIM

Cystic fibrosis (CF) patients are at high risk of developing CF-related diabetes (CFRD). In non-CF patients, liver disease, specifically steatosis and non-alcoholic fatty liver disease (NAFLD), is strongly associated with type 2 diabetes. We compared glycemic status and metabolic profiles in CF patients according to a biomarker of hepatic injury, alanine aminotransferase (ALT).

METHODS

We conducted a cross-sectional study among 273 adult CF patients recruited from the Montreal CF Cohort. A 2-hour oral glucose tolerance test (OGTT) was performed to collect glucose and insulin measures every 30 minutes. Fasting ALT levels and anthropometric measures were also obtained. Patients were categorized into 2 groups based on ALT cut-off of 25 U/L.

RESULTS

Patients in the high ALT group were mostly men (83%), had higher mean weight and BMI (p<0.001) and showed elevated glucose levels throughout OGTT (p≤0.01). When stratified by sex, only men with high ALT showed significantly higher weight (p<0.001), higher glycemic values at 60, 90 and 120 minutes of OGTT (p≤0.01), higher frequency of de novo CFRD (20.5% vs 8.2%, p = 0.04) as well as lower insulin sensitivity than men with normal ALT (p = 0.03). ALT levels were strongly associated with HOMA-IR in CFRD patients (p = 0.001, r2 = 0.28).

CONCLUSIONS

Adult CF men with higher ALT show an increased frequency of dysglycemia and de novo CFRD, lower insulin sensitivity and higher eight. Our data suggests that ALT levels could be an interesting tool to guide targeted diabetes screening, particularly among CF men. Prospective studies are needed to confirm these observations.

Incidence and risk factors of paediatric cystic fibrosis-related diabetes

INTRODUCTION

Cystic fibrosis-related diabetes (CFRD) is a common complication of cystic fibrosis (CF) directly linked to increased morbidity and mortality. Both the incidence of type I and type II diabetes has been shown to increase in the general population. In this study, we investigated the incidence and risk factors of CFRD in a paediatric CF population.

METHODS

Prospectively collected data from the Canadian CF Registry (CCFR) from 2000 to 2016 for patients ages 10 to 18 years was used to determine the incidence of CFRD. Risk factors for CFRD in the Canadian population were investigated using a nested case-control design. Conditional logistic regression analysis with a 4:1 control: case matching was used.

RESULTS

From 2000 to 2016, 2326 patients with CF aged between 10 through 18 years were included in the CCFR, during this time the overall incidence rate of CFRD was 2.1 cases per 100 patient-years (95% confidence interval 1.8 to 2.3). Incidence rates were stable in the Canadian cohort over three consecutive time periods 2000-2005, 2006-2010; 2011-2016. Worse lung function, female gender, history of allergic bronchopulmonary aspergillosis, Gastrostomy tube insertion and liver disease were statistically significant risk factors for CFRD.

CONCLUSION

The incidence of CFRD in the Canadian paediatric population has been stable over time, in contrast to the rising rates of Type 1 and Type 2 diabetes in the general paediatric population. The risk factor for CFRD in this contemporary population were consistent with previous studies.

Markers of bone turnover are reduced in patients with CF related diabetes; the role of glucose

BACKGROUND

Cystic fibrosis(CF) related diabetes(CFRD) and osteoporosis are prevalent in adult patients with CF. We aimed to evaluate if CFRD and markers of glucose metabolism and inflammation are associated with bone turnover in CF.

METHODS

Cross sectional study at the adult section at the Copenhagen CF Center from January-October 2017. Fasting blood samples, including bone turnover markers(BTMs) and cytokines, Dual-x-ray absorptiometry scan and oral glucose tolerance test were performed. Lung-transplanted participants and patients in antiosteoporotic treatment were excluded from analyses.

RESULTS

102 patients were included of whom 19 had a prior CFRD diagnosis. CFRD patients had lower procollagen type 1 N-terminal propeptide(P1NP) and C-Terminal cross-linked Telopeptide(CTX) levels compared to CF patients without diabetes (median[IQR]) 49.5 μg/l [29.6,57.1] vs 56.9 μg/l [38.2,74.3], p = .03 and 0.2 μg/l [0.1,0.3] vs 0.4 μg/l [0.3,0.6], p < .01, respectively. Fasting plasma glucose(FPG) was negatively associated with the bone formation markers P1NP and osteocalcin and bone resorption marker CTX. In multivariate linear regression FPG remained a significant predictor of P1NP -1.07 [-1.09;-0.01] and CTX -1.13 [-1.21;-1.06]. Bone mineral density Z-score was not different between patients with and without CFRD but FPG was negatively associated with hip and femoral neck Z-score. There was no consistent association between inflammatory cytokines and BTMs.

CONCLUSIONS

Bone turnover markers are reduced in CF patients with CFRD and negatively associated with glucose levels. Extra attention towards frequent hyperglycemia in CF patients should be taken when evaluating decreased BMD. Glycemia may be a future target for improving outcome in CFBD.