Low-dose insulin therapy in patients with cystic fibrosis and early-stage insulinopenia prevents deterioration of lung function: a 3-year prospective study

Feasibility and accuracy of at-home glucose tolerance tests for cystic fibrosis related diabetes screening

BACKGROUND

Adult people living with Cystic Fibrosis (CF) undergo annual screening for CF-related diabetes. These tests represent a burden and can lead to undesirable effects resulting in low adherence. The objectives of this study were to 1) compare gold-standard in-hospital oral glucose tolerance testing (OGTT) with at-home options, and 2) evaluate acceptability of at-home options.

METHODS

A total of 34 adults living with CF undertook 3 types of OGTTs in standardized conditions within two weeks: 1) in a hospital using a 75 g glucose beverage, 2) at home with the same glucose beverage, and 3) at home using a standardized quantity of candy. Glucose levels were measured prior to the OGTT, after 1 and 2 hours. Concordance of glucose measurement, side effects and general appreciation were assessed across the three options.

RESULTS

Mean blood glucose was comparable among the three tests. Glucose tolerance categorization (normal, impaired glucose tolerance, or diabetes) was concordant with the hospital reference test in 59 % of participants for the glucose beverage and 75 % for the candies. Side effects were mild with all types of OGTTs, and 94 % of participants preferred the home options. Among the at-home OGTTs, the glucose beverage was preferred to the candy option.

CONCLUSIONS

Home-based OGTT could be an alternative to gold standard hospital-based OGTT testing, improving adherence to annual testing and reducing costs. However, the discrepancy between various OGTT testing methods could lead to diagnosis dilemma. This approach should be tested on a larger sample size.

The utility of glucose area under the curve from the oral glucose tolerance test as a screening tool for cystic fibrosis-related diabetes

BACKGROUND

Consistently abnormal glucose levels on oral glucose tolerance test (OGTT) are the most effective screening tool for cystic fibrosis-related diabetes (CFRD). However, some cystic fibrosis (CF) patients demonstrate abnormal glucose profiles not reaching levels required for CFRD diagnosis and are, therefore, left untreated. Since CFRD is associated with disease deterioration, early diagnosis and treatment are desirable.

AIM

To explore the association between the area under the curve of glucose (G-AUC) obtained during a five-point 2-h standard OGTT and CF disease severity parameters.

METHODS

All CF patients referred for an annual routine OGTT at the Hadassah CF Center between 2002 and 2018, were included. Disease severity parameters were correlated with the G-AUC.

RESULTS

Two hundred forty-two OGTTs were performed in 81 patients (mean age 19.7 ± 9.0 years); 54% were normal, 14% showed impaired glucose tolerance (IGT), 5% had values in the indeterminate range (INDET), 11% had both IGT and INDET and 16% were diagnosed with CFRD. A gradual increase in mean G-AUC was observed among the groups. In multivariate regression models, G-AUC ≥ 295 mg h/dl was independently associated with an increased number of pulmonary exacerbations (PEx). Not all the patients having this value met the CFRD definition.

CONCLUSION

Patients who do not fulfill the criteria for CFRD may have abnormal glucose metabolism identifiable by abnormally high G-AUC values, which may be associated with more PEx. The potential advantage of treating these patients with insulin and the subsequent reduction in PEx needs further investigation.

Cystic Fibrosis-Related Diabetes: Clinical approach and knowledge gaps

Cystic Fibrosis-Related Diabetes (CFRD) is a unique type of diabetes mellitus that shares some features with both type 1 and type 2 diabetes. Yet, its distinguishing feature of acute pulmonary complications associated with hyperglycemia and the catabolic metabolism associated with a relative insulin deficiency poses challenges to the application of traditional definitions and treatments for diabetes mellitus. People with CF (pwCF) undergo rigorous annual screening starting at age 10, a process that is challenging for patients and limited by sensitivity, specificity, and reproducibility. As pwCF continue to live longer, over 50% are expected to develop CFRD over their lifetime, including up to 20% of adolescents. Increasing numbers of people with CFRD will make this disease increasingly relevant to diabetes practitioners. Evidence-guided practice in CFRD care is limited by small and short studies. Our current understanding of CFRD may change significantly with the recent introduction of CF Transmembrane Regulator (CFTR) modulator medications. This review will explore current challenges in the diagnosis and management of CFRD, specifically highlighting knowledge gaps in the pathophysiology of CFRD, optimal screening methods, priorities for research and provide guidance with regards to screening, diagnosis, and treatment.

The Relationship Between Continuous Glucose Monitoring and OGTT in Youth and Young Adults With Cystic Fibrosis

CONTEXT

Early glucose abnormalities in people with cystic fibrosis (PwCF) are commonly detected by continuous glucose monitoring (CGM). Relationships between these CGM abnormalities and oral glucose tolerance testing (OGTT) in PwCF have not been fully characterized.

OBJECTIVE

This work aimed to determine the relationship between CGM and common OGTT-derived estimates of β-cell function, including C-peptide index and oral disposition index (oDI) and to explore whether CGM can be used to screen for OGTT-defined prediabetes and cystic fibrosis-related diabetes (CFRD).

METHODS

PwCF not on insulin and healthy controls aged 6 to 25 years were enrolled in a prospective study collecting OGTT and CGM. A subset underwent frequently sampled OGTTs (fsOGTT) with 7-point glucose, insulin, and C-peptide measurements. Pearson correlation coefficient was used to test the association between select CGM and fsOGTT measures. Receiver operating curve (ROC) analysis was applied to CGM variables to determine the cutoff optimizing sensitivity and specificity for detecting prediabetes and CFRD.

RESULTS

A total of 120 participants (controls = 35, CF = 85), including 69 with fsOGTTs, were included. CGM coefficient of variation correlated inversely with C-peptide index (Cpeptide30-Cpeptide0/Glucose30-Glucose0) (r = -0.45, P < .001) and oDIcpeptide (C-peptide index)(1/cpep0) (r = -0.48, P < .0001). In PwCF, CGM variables had ROC - areas under the curve ranging from 0.43 to 0.57 for prediabetes and 0.47 to 0.6 for CFRD.

CONCLUSION

Greater glycemic variability on CGM correlated with reduced β-cell function. However, CGM performed poorly at discriminating individuals with and without OGTT-defined CFRD and prediabetes. Prospective studies are now needed to determine how well the different tests predict clinically relevant nonglycemic outcomes in PwCF.

Perceptions of Diabetes Technology Use in Cystic Fibrosis-Related Diabetes Management

Background: Diabetes technologies are associated with improvements in glycemic control and health-related quality of life among people with type 1 diabetes (T1D). Use and perceptions of continuous glucose monitors (CGM) and insulin pumps within the cystic fibrosis (CF) community have not been well studied. Methods: A 30-item online survey addressing cystic fibrosis-related diabetes (CFRD) diagnosis, CGM and insulin pump use, and perceptions of diabetes technologies was sent to a CF community group, including people with CF (pwCF) and parents of children with CF (cwCF). Results: The response rate was 11% (n = 120; 83 pwCF, 35 cwCF). Sixty-one percent of pwCF and 34% of cwCF reported a diagnosis of CFRD. CGM use was reported by 75% (n = 47) of respondents with CFRD but was discontinued by 19% (n = 9), most commonly due to cost and increased worry about glycemia. Insulin pump therapy was reported by 29% (n = 18 of 62) of respondents with CFRD and was discontinued by 28% (n = 5), most commonly due to pain or skin irritation. Overall, 91% agreed or strongly agreed that CGM facilitated CFRD management. Eighty-one percent agreed with at least five of seven positive statements about CGM as compared with 22% for insulin pumps. Potential embarrassment over device wear, concerns about cost, and pain were commonly held negative perceptions of both technologies. Conclusions: As compared with T1D and despite perceived benefits, rates of sustained diabetes technology use are low in the CFRD community. Better insurance coverage to mitigate cost, better patient education, and confirmation that these technologies improve health and patient-reported outcomes may increase uptake.

Combined Indeterminate and Impaired Glucose Tolerance Is a Novel Group at High Risk of Cystic Fibrosis-Related Diabetes

BACKGROUND

Indeterminate glycemia (INDET) and impaired glucose tolerance (IGT) are independently associated with cystic fibrosis-related diabetes (CFRD) risk. We determined whether patients meeting both criteria have increased risk of diabetes in 2 separate adult cohorts.

METHODS

The Montreal Cystic Fibrosis Cohort (MCFC; n = 293 baseline and 198 for prospective analysis excluding subjects identified with incident CFRD at baseline) and the Lyon cystic fibrosis cohort [Determination of the Predictive Factors in the Reversibility or the Aggravation in the Disorders of the Glucose Metabolism in Cystic Fibrosis Patients (DIAMUCO); n = 144/105] are prospective observational cohorts.

RESULTS

In the MCFC and DIAMUCO cohorts, mean age was 25.5 ± 7.7 and 25.0 ± 8.6 years; body mass index, 21.7 ± 3.0 and 20.2 ± 2.2 kg/m2; percentage of forced expiratory volume expired in 1 sec, 73.2 ± 22.1 and 62.5 ± 21.9; and follow-up, 6.9 ± 3.8 and 2.4 ± 1.2 years, respectively. In the MCFC cohort, the IGT only and combined INDET and IGT (INDET + IGT) groups had greater risk of CFRD (P = 0.0109). In the DIAMUCO cohort, there was lower diabetes-free survival in the INDET + IGT group (P = 0.0105). In both cohorts, CFRD risk ranged from 17% in normal glucose tolerance patients up to 42% to 56% in patients with INDET + IGT.

CONCLUSION

Patients who meet combined criteria have a higher risk of developing diabetes probably justifying closer follow-up.

Diabetes outbreak during COVID19 lock-down in a prediabetic patient with cystic fibrosis long treated with glargine

BACKGROUND

Cystic Fibrosis Related Diabetes (CFRD) is a frequent comorbidity of patients with Cystic Fibrosis (CF). A worsening of clinical conditions appears before CFRD. It has been demonstrated a decline in pulmonary function and nutritional status also in patients with prediabetes. Few trials show that insulin may be beneficial in prediabetic CF patients, to date guidelines do not recommend for this condition.

CASE PRESENTATION

We report a case of a patient treated with insulin glargine at 13 years, due to glycemic intolerance, and with Lumacaftor/Ivacaftor at 15 years. A reduction of pulmonary exacerbations was observed after glargine therapy, also confirmed after the starting of Lumacaftor/ Ivacaftor in this patient. Pulmonary function improved only after the first year of glargine therapy, then a deterioration appeared due to the natural history of CF lung damage. During the COVID-19 lockdown, poor adherence to care contributed to diabetes mellitus onset needing high insulin requirements. After two weeks the patient returned to prediabetic condition and his previous dose of glargine.

CONCLUSIONS

our case highlights firstly that insulin glargine has contributed to preserve him from further clinical worsening due to prediabetes in the years before pandemic, secondly the negative impact of COVID-19 lockdown on the clinical course of a chronic disease as CF.

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.

Diabetes and Prediabetes in Children With Cystic Fibrosis: A Systematic Review of the Literature and Recommendations of the Italian Society for Pediatric Endocrinology and Diabetes (ISPED)

Cystic fibrosis related diabetes (CFRD) is a comorbidity of cystic fibrosis (CF) that negatively impacts on its clinical course. Prediabetes is an important predictor of either CFRD development and unfavorable prognosis of CF in both pediatric and adult patients. International guidelines recommend insulin only in case of CFRD diagnosis. Whether early detection and treatment of prediabetes may contribute to improve the clinical course of CF is still debated. A subgroup of pediatric diabetologists of the Italian Society for Pediatric Endocrinology and Diabetology (ISPED) performed a systematic review of the literature based on predefined outcomes: impact of pre-diabetes on clinical outcomes and on the risk of developing CFRD; diagnosis of diabetes and pre-diabetes under 10 years of age; effectiveness of therapy on glycemic control, impact of therapy on pulmonary function and nutritional status. Thirty-one papers were selected for the analysis data presented in these papers were reported in tables sorted by outcomes, including comprehensive evidence grading according to the GRADE approach. Following the grading of the quality of the evidence, the entire ISPED diabetes study group achieved consensus for the Italian recommendations based on both evidence and clinical experience. We concluded that in patients with CF, prediabetes should be carefully considered as it can evolve into CFRD. In patients with CF and prediabetic conditions, after complete evaluation of the OGTT trend, glucometrics, glycemic values measured during pulmonary exacerbations and/or steroid therapy, early initiation of insulin therapy could have beneficial effects on clinical outcomes of patients with CF and prediabetes.

Cystic Fibrosis Related Diabetes - An Update

Cystic fibrosis (CF) is the most common life-threatening inherited condition in the Caucasian population, where mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene result in a multifactorial syndrome, with pulmonary disease representing the largest contributor to morbidity and mortality. Life expectancy has improved and the recent development of disease-modifying CFTR modulator therapies is likely to further improve survival. However, increasing life expectancy brings new challenges related to the complications of a chronic disease including an increasing prevalence of cystic fibrosis related diabetes (CFRD), itself associated with increased morbidity and early mortality. This review provides an update as regards the underlying mechanisms, investigation and management of CFRD.

Cystic fibrosis-related diabetes: optimizing care with a multidisciplinary approach

Cystic fibrosis-related diabetes (CFRD) is a common complication of cystic fibrosis and can be present in over 50% of adults with the disease. CFRD is associated with poorer clinical outcomes, including accelerated pulmonary function decline and excess morbidity. The management of CFRD is complex and differs from that of type 1 and type 2 diabetes mellitus such that clinicians responsible for the care of people with CFRD must work closely with colleagues across a number of different specialities and disciplines. This review aims to discuss why a multi-disciplinary approach is important and how it can be harnessed to optimize the care of people with CFRD.

Combined Pancreatic Islet-Lung-Liver Transplantation in a Pediatric Patient with Cystic Fibrosis-Related Diabetes

BACKGROUND

Cystic fibrosis-related diabetes (CFRD) is the most frequent extrapulmonary complication of cystic fibrosis (CF).

METHODS

We report the first combined pancreatic islet-lung-liver transplantation in a 14-year-old adolescent. CFTR was analyzed by Sanger sequencing. Further genes were analyzed by high-throughput sequencing.

RESULTS

The patient was diagnosed with CF at the age of 14 months. Nine years later, after diagnosis of CFRD, the patient's BMI and lung function began to decline. Bilateral lung transplantation with simultaneous liver transplantation was performed at the age of 14.5 years. The first islet transplantation (IT) was carried out 10 days later. Six months later, C-peptide secretion after arginine stimulation showed peak values of 371 pmol/L (vs. 569 pmol/L before IT) and insulin doses had slightly increased (1.40 vs. 1.11 units/kg/day before IT). A second IT was performed at the age of 15 years, a third at 16 years. Two years after the first IT, arginine-stimulated C-peptide secretion increased to 2,956 pmol/L and insulin doses could be reduced to 0.82 units/kg/day. HbA1c decreased from 7.3% (57.4 mmol/mol) to 5.9% (41.0 mmol/mol).

CONCLUSION

IT following lung and liver transplantation, with injection of islets into a transplanted organ, is feasible. It improves C-peptide secretion, decreases insulin needs, and lowers HbA1c.

Pulmonary Function and Sleep Breathing: Two New Targets for Type 2 Diabetes Care

Population-based studies showing the negative impact of type 2 diabetes (T2D) on lung function are overviewed. Among the well-recognized pathophysiological mechanisms, the metabolic pathways related to insulin resistance (IR), low-grade chronic inflammation, leptin resistance, microvascular damage, and autonomic neuropathy are emphasized. Histopathological changes are exposed, and findings reported from experimental models are clearly differentiated from those described in humans. The accelerated decline in pulmonary function that appears in patients with cystic fibrosis (CF) with related abnormalities of glucose tolerance and diabetes is considered as an example to further investigate the relationship between T2D and the lung. Furthermore, a possible causal link between antihyperglycemic therapies and pulmonary function is examined. T2D similarly affects breathing during sleep, becoming an independent risk factor for higher rates of sleep apnea, leading to nocturnal hypoxemia and daytime sleepiness. Therefore, the impact of T2D on sleep breathing and its influence on sleep architecture is analyzed. Finally, the effect of improving some pathophysiological mechanisms, primarily IR and inflammation, as well as the optimization of blood glucose control on sleep breathing is evaluated. In summary, the lung should be considered by those providing care for people with diabetes and raise the central issue of whether the normalization of glucose levels can improve pulmonary function and ameliorate sleep-disordered breathing. Therefore, patients with T2D should be considered a vulnerable group for pulmonary dysfunction. However, further research aimed at elucidating how to screen for the lung impairment in the population with diabetes in a cost-effective manner is needed.

CF-related diabetes: Containing the metabolic miscreant of cystic fibrosis

Cystic fibrosis-related diabetes (CFRD) is associated with both an increase in morbidity and mortality in people with cystic fibrosis (CF). With increased screening and improved life expectancy of people with CF, the prevalence of CFRD is expected to rise further. The underlying pathophysiological mechanisms causing glucose intolerance and diabetes in patients with CF are not well understood but both functional and structural abnormalities in islet cells are likely to have key roles. Insulin therapy improves health outcomes in patients with CF. Future research is needed to better understand the mechanisms underlying the development of CFRD and to develop new screening and treatment strategies to minimize the detrimental impact of CFRD on health outcomes in people with CF.

Insulin therapy in patients with cystic fibrosis in the pre-diabetes stage: a systematic review

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.

Insulin therapy in patients with cystic fibrosis in the pre-diabetes stage: a systematic review

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.

Cystic fibrosis: an update for clinicians. Part 2: hepatobiliary and pancreatic manifestations

This paper, the second in the series, will build on the first and explore the importance of liver and pancreatic manifestations of cystic fibrosis (CF) and the effect on morbidity and mortality of this multifaceted genetic condition. It will also further develop the critical role of the gastroenterologist as part of the multidisciplinary group of clinicians and allied health staff in the effective management of patients with CF.

Cystic fibrosis related diabetes

Improved life expectancy in cystic fibrosis (CF) has led to an expanding population of adults with CF, now representing almost 50 % of the total CF population. This creates new challenges from long-term complications such as diabetes mellitus (DM), a condition that is present in 40 %-50 % of adults with CF. Cystic fibrosis-related diabetes (CFRD) results from a primary defect of insulin deficiency and although sharing features with type 1 (DM1) and type 2 diabetes (DM2), it is a clinically distinct condition. Progression to diabetes is associated with poorer CF clinical outcomes and increased mortality. CFRD is not associated with an increased risk of cardiovascular disease and the prevalence of microvascular complications is lower than DM1 or DM2. Rather, the primary goal of insulin therapy is the preservation of lung function and optimization of nutritional status. There is increasing evidence that appropriate screening and early intervention with insulin can reverse weight loss and improve pulmonary function. This approach may include targeting postprandial hyperglycemia not detected by standard diagnostic tests such as the oral glucose tolerance test. Further clinical research is required to guide when and how much to intervene in patients who are already dealing with the burden of one chronic illness.

New insights into cystic fibrosis-related diabetes in children

Cystic fibrosis-related diabetes (CFRD) is the most common complication of cystic fibrosis. It is associated with significantly increased morbidity and mortality in adults and children. Adolescents with cystic fibrosis have a much higher prevalence of diabetes than any other similar age population. Glucose abnormalities that precede diabetes are even more common, especially in children younger than 10 years. The pathophysiology of glucose metabolic abnormalities is poorly understood, but insulin insufficiency is clearly the main component. Findings from animal studies have provided insight into the pathophysiology of CFRD, and imply that carbohydrate metabolic abnormalities might begin at much younger ages than was previously thought in patients with cystic fibrosis, and might be related to the basic cystic fibrosis chloride channel defect. In this Review we explore present knowledge of CFRD in children and adolescents, and new data that indicate that the pathophysiology of CFRD begins in very young patients.

Diagnosis of cystic fibrosis-related glucose abnormalities: Can we shorten the standard oral glucose tolerance test?

Adult patients with cystic fibrosis (APCF) are at high risk of developing impaired glucose tolerance (IGT) and CF-related diabetes (CFRD) and thus an annual screening with a 2-h oral glucose tolerance test (OGTT) is recommended. This population would greatly benefit from a simplified and harmless alternative to the standard OGTT. Thus, we aimed to compare the diagnostic values of HbA1c and glycemias at interval time points during the 2-h OGTT for IGT and CFRD detection in APCF. To do so, we conducted a cross-sectional analysis of 194 APCF with normal fasting plasma glucose values (≤ 7.0 mmol · L(-1)) who underwent a 2-h OGTT. Receivers operating characteristic area under the curves (ROC-AUC) were analyzed to assess the diagnostic value of HbA1c and intermediate OGTT glycemias using 2-h OGTT glycemia as reference. For both IGT and CFRD diagnoses, ROC-AUC values obtained from glycemia at 90 min were significantly higher than HbA1c and remaining intermediate glycemias (p < 0.001). The best 90-min OGTT cut-off values for these diagnoses were >9.3 mmol · L(-1) (IGT) and ≥ 11.5 mmol · L(-1) (CFRD). A 90-min OGTT glycemia might be a simplified alternative to 2-h OGTT glycemia for earlier glucose tolerance abnormalities diagnosis in APCF. This finding should be confirmed in other APCF cohorts and its predictive value should be established prospectively.

Maintenance of nutritional status in patients with cystic fibrosis: new and emerging therapies

Poor clinical outcomes in cystic fibrosis are often associated with undernutrition. Normal growth and development should be achieved in cystic fibrosis, and nutritional counseling is paramount at all ages. Prevention and early detection of growth failure is the key to successful nutritional intervention. The advance in nutritional management is certainly one factor that has contributed to the improved survival in recent decades. This review outlines the major nutritional parameters in the management of the patient with cystic fibrosis, including recent advances in pancreatic enzyme replacement therapy and fat-soluble vitamin therapy. There are sections on complicated clinical situations which directly affect nutrition, for example, before and after lung transplantation, cystic fibrosis-related diabetes, and bone health.