Diabetes: a major co-morbidity of cystic fibrosis

[Continuous glucose monitoring system in the screening of glucose disorders in cystic fibrosis]

BACKGROUND

Diabetes mellitus (DM) is an increasing complication of cystic fibrosis (CF). It is associated with enhance morbidity. Continuous glucose monitoring system (CGMS) could detect glucose disorders earlier than other screening tests usually used.

AIMS

To compare oral glucose tolerance test (OGTT), HbA(1c) and CGMS in patients with CF and recent disorders of glucose homeostasis and to analyse changes in nutritional status and/or pulmonary function.

PATIENTS AND METHODS

Thirteen patients with CF (11-22 years, 7 males) were studied using OGTT, HbA(1c) and CGMS. All of them had newly diagnosed glucose disturbances. They were not receiving steroid therapy or had an underlying illness. In all subjects we compared: HbA(1c) levels (%), fasting and 2-hours glucose OGTT (mg/dl) and glucose CGMS values (overall, fasting, 2-hours post mean-meals and excursions >140mg/dl at any time). Furthermore, body mass index, forced expiratory volume in the first second (%) and forced vital capacity (%) were evaluated in the previous year and at the time of the study. We also analysed exocrine pancreatic function and CF-mutation.

RESULTS

Mean age at diagnosis of glucose disturbance was 16.4 years. All patients had insufficient exocrine pancreatic function and 11/13 presented DeltaF508 CF-mutation. Only one patient was diagnosed with DM using OGGT and 7/13 (53.8%) with CGMS. A total 77% of patients had poor nutritional status and/or pulmonary function at time of diagnosing the glucose disorder. Only 4 patients had abnormal HbA(1c) levels.

CONCLUSIONS

CGMS allows a better detection of glucose disorders than OGTT. Glucose homeostasis abnormalities are associated with a decrease in nutritional status and/or pulmonary function. HbA(1c) does not aid in the early diagnose of glucose disorders.

Dichotomy between postprandial glucose and lipid profiles in adults with cystic fibrosis: a pilot study

BACKGROUND

Cystic fibrosis (CF) patients present a high incidence of glucose tolerance abnormalities. Altered insulin secretion combined with recommended high-fat intake could be associated with dysregulation of glucose and lipid metabolism. We examined postprandial glucose and lipid profiles during an oral glucose tolerance test (OGTT) and following a standardized high-fat test meal (TM).

METHODS

Sixteen CF patients with normal glucose tolerance (NGT) or CF-related diabetes (CFRD) and 16 controls underwent a 4 h OGTT and a TM. We then measured plasma glucose, insulin, free fatty acid (FFA) and triglyceride (TG) concentrations.

RESULTS

CF patients presented higher glucose excursion compared to controls after the OGTT and TM. However, in CF patients, this excursion was significantly reduced in both amplitude and length after the TM. The TM provoked a comparable increase in TG levels in both groups whereas they remained stable during the OGTT. FFAs were suppressed similarly in both groups after both challenges.

CONCLUSION

CF is associated with abnormal glucose excursion in the presence of relatively normal lipid excursion. The rapid normalization of glucose values after a mixed meal should be further explored and, if confirmed, might have significant implications for CFRD diagnostic.

Treatment of allergic bronchopulmonary aspergillosis (ABPA) in CF with anti-IgE antibody (omalizumab)

Allergic bronchopulmonary aspergillosis (ABPA) results from IgE induced pulmonary response to aspergillus species. Recognition and management of ABPA is challenging in cystic fibrosis (CF) patients because changes in symptoms, lung function and chest radiograph are similar to that seen in CF related pulmonary infection. Standard therapy for ABPA includes systemic steroids and adjunctive use of antifungal agents. Little has been published regarding the use of monoclonal anti-IgE antibody in those with ABPA. We report a CF patient with her third exacerbation of ABPA who was treated with monoclonal anti-IgE (omalizumab) antibody; she had unfavorable side effects with prednisone therapy. This therapy resulted in improvement of pulmonary symptoms and lung function not achieved with antibiotics or prednisone alone.

No relationship between mean plasma glucose and glycated haemoglobin in patients with cystic fibrosis-related diabetes

AIM

Cystic fibrosis-related diabetes (CFRD) prevalence has increased dramatically with the improved life expectancy of patients with cystic fibrosis (CF). Glycated haemoglobin (HbA(1c)) is an important tool for monitoring blood glucose control but, unlike in type 1 and type 2 diabetes, a correlation between HbA(1c), fructosamine and mean plasma glucose has not been clearly established in CF. This study aimed to examine the relationship between mean plasma glucose and HbA(1c) or fructosamine in stable patients with CFRD.

METHODS

Fifteen type 1 diabetes and 13 CFRD patients (HbA(1c)<9.0%; no anaemia), matched for age and body mass index (BMI), provided 72 capillary blood glucose profiles taken 3days/month for three months. At the end of this time, HbA(1c) and fructosamine were measured. Mean plasma glucose was estimated using the Diabetes Control and Complications Trial (DCCT) conversion formula, and linear regressions carried out to establish its relationship with HbA(1c) and fructosamine.

RESULTS

In type 1 diabetes patients, mean plasma glucose correlated significantly with HbA(1c) (r=0.68; P=0.005). In CFRD patients, no correlation was found between mean plasma glucose and HbA(1c) (r=0.24; P=0.460). Also, no association was found between mean plasma glucose, representing the month before blood sampling, and fructosamine in either group.

CONCLUSION

Unlike in type 1 diabetes, HbA(1c) did not correlate with mean plasma glucose in CFRD subjects. Thus, having a normal HbA(1c) may not be sufficient to indicate a low risk of diabetes complications in CFRD. Further studies are required to explain such a discrepancy.

A teenage girl with cystic fibrosis-related diabetes, diabetic ketoacidosis, and cerebral edema

Diabetic ketoacidosis (DKA) is a potentially life-threatening complication of diabetes, most commonly associated with type 1 diabetes. Here, we report the case of a 17-yr-old girl with cystic fibrosis and a prior diagnosis of cystic fibrosis-related diabetes (CFRD) who presented with DKA in the setting of insulin omission and glucocorticoid use. During the course of treatment for DKA, her neurologic status declined and head computerized tomography confirmed cerebral edema. Recognition of DKA and cerebral edema allowed for timely treatment, and the patient recovered without sequelae. This is the first report of DKA complicated by cerebral edema that is attributable to CFRD.

[Growth hormone therapy for children with chronic diseases]

Growth disorders are commonly observed in children suffering from chronic diseases. The pathogenesis of growth failure is multifactorial. In chronic inflammatory diseases such as juvenile idiopathic arthritis and inflammatory bowel disease, growth is also affected by pro-inflammatory cytokines. Patients with chronic diseases might also become growth hormone (GH) deficient. However, normal or increased GH secretion with reduced plasma concentrations of insulin-like growth factor-I indicate a degree of GH insensitivity in some patients. Growth damage can increase with specific treatments, especially if glucocorticoids are used. GH therapy has been used to reduce the consequences of the disease and long-term steroid therapy in these patients. In this review, it is reported the encouraging results of GH treatment in growth-retarded children with chronic diseases, both in well defined indications as well in situations still under investigation.

Intensive care management of the patient with cystic fibrosis

Cystic fibrosis was previously thought to be a disease of childhood. With a better understanding of this condition along with improvements in therapy, patients with cystic fibrosis are now living well into adulthood. The aim of this article is to familiarize the intensive care unit physician with cystic fibrosis care, to discuss complications associated with cystic fibrosis specifically related to the intensive care unit, and to detail the current recommendations for the clinical management of the patient with cystic fibrosis. With advancing disease, the most severely affected organs are the lungs. Obstruction, infection, and inflammation contribute to the decline of pulmonary function, ultimately leading to death. Some patients may be eligible for lung transplantation, but choosing wisely will affect posttransplant survival. Because other organs are affected by the genetic defect and associated treatments, serious complications related to the liver, pancreas, intestines, and kidneys must be considered by the intensivist faced with a patient with cystic fibrosis. As practitioners, the fact that not all patients will survive and help our patients and families gracefully through the end-of-life process should be accepted.

Diabetes mellitus in patients with cystic fibrosis

Cystic fibrosis-related diabetes (CFRD) is the principal extra-pulmonary complication of cystic fibrosis, occurring in 15-30% of adult cystic fibrosis patients. The number of cystic fibrosis patients who develop diabetes is increasing in parallel with increases in life expectancy. The aim of this study was to review the physiopathology, clinical presentation, diagnosis and treatment of CFRD. A bibliographic search of the Medline and Latin American and Caribbean Health Sciences Literature databases was made. Articles were selected from among those published in the last twenty years. Insulin deficiency, caused by reduced beta-cell mass, is the main etiologic mechanism, although insulin resistance also plays a role. Presenting features of type 1 and type 2 diabetes, CFRD typically affects individuals of approximately 20 years of age. It can also be accompanied by fasting, non-fasting or intermittent hyperglycemia. Glucose intolerance is associated with worsening of nutritional status, increased morbidity, decreased survival and reduced pulmonary function. Microvascular complications are always present, although macrovascular complications are rarely seen. An oral glucose tolerance test is recommended annually for patients > or = 10 years of age and for any patients presenting unexplained weight loss or symptoms of diabetes. Patients hospitalized with severe diseases should also be screened. If fasting hyperglycemia persists for more than 48 h, insulin therapy is recommended. Insulin administration remains the treatment of choice for diabetes and fasting hyperglycemia. Calories should not be restricted, and patients with CFRD should be managed by a multidisciplinary team.

O diabetes melito na fibrose cística: uma comorbidade cada vez mais freqüente

O diabetes melito (DM) é a principal comorbidade relacionada à fibrose cística (FC) e costuma acontecer após os 15 anos de idade, associando-se ao aumento da morbimortalidade. Sua fisiopatologia inclui destruição do tecido exócrino, insuficiência endócrina e aumento da resistência insulínica, determinando inicialmente a alteração da cinética secretora da insulina, até o comprometimento de sua secreção total. A hiperglicemia pós-prandial é a alteração clínica mais precoce e sintomas do DM podem não ser reconhecidos. A investigação anual deve ser realizada por meio da glicemia de jejum ou de glicemias ao acaso e do teste oral de tolerância à glicose (OGTT). São reconhecidas duas categorias de diabetes relacionadas à FC: o DRFC sem hiperglicemia de jejum (HJ) (glicemia de jejum < 126 mg/dL e glicemia de 2 horas OGTT > 200 mg/dL) e DRFC com HJ (glicemia de jejum > 126 mg/dL). O tratamento inclui o manejo nutricional especializado e a correção da hiperglicemia. A insulinoterapia é recomendada para a categoria DRFC com HJ, não existindo ainda evidências do benefício de drogas secretagogas ou sensibilizantes da ação insulínica.

Use of sensor-augmented insulin pump in patient with diabetes and cystic fibrosis: evidence for improvement in metabolic control

Cystic fibrosis-related diabetes (CFRD) is a frequent complication of cystic fibrosis. We report the significant improvement of diabetes control and quality of life in a CFRD patient using the sensor-augmented insulin pump. The system gives the patient the highest degree of flexibility, which is required in CFRD since food intake and activity levels vary widely from day to day, depending on the rapid changes of health status.

Glucose tolerance, insulin secretion, and insulin sensitivity in children and adolescents with cystic fibrosis and no prior history of diabetes

OBJECTIVE

To determine the prevalence of abnormalities of glucose metabolism in pediatric outpatients with cystic fibrosis (CF).

STUDY DESIGN

Children and adolescents (n = 73, mean age 15.0 +/- 3.7 years) with CF not previously diagnosed with diabetes underwent 3-hour oral glucose tolerance testing. All subjects with CF were clinically stable and were not being treated for active infection. A reference group of young lean adults was used for comparison. Subjects were classified as having normal glucose tolerance (NGT) or abnormal glucose metabolism (AGM), including impaired glucose tolerance (IGT), impaired fasting glucose (IFG), or diabetes, by standard criteria. The insulinogenic index was calculated as a measure of beta-cell function, and insulin resistance was estimated with the homeostatic model assessment.

RESULTS

The reference group was significantly older than the patients with CF, but in the control subjects, the AGM and NGT were comparable in body mass index z-scores (-0.8 +/- 1.3, -0.6 +/- 1.1, -0.21 +/- 0.9 kg/m2). Thirty-eight percent of subjects with CF had AGM: 43% IGT, 29% IFG, 14% IGT/IFG, and 14% diabetes. In spite of distinct differences in glycemic response, the subjects with NGT and AGM had marked abnormalities of insulin secretion relative to the control subjects (Insulinogenic index 5.8 +/- 1.0, 5.3 +/- 0.8, and 53.5 +/- 10.0 uU/mL/mmol/L, respectively; P < .0001). Insulin sensitivity did not differ among the 3 groups, although there was a trend toward greater insulin resistance in the subjects with AGM (homeostatic model assessment: CF-NGT 1.5 +/- 0.2, CF-AGM 1.9 +/- 0.3, REF 1.3 +/- 0.1, P = NS).

CONCLUSION

Abnormalities in glucose metabolism are frequent in young patients with CF without a prior diagnosis of diabetes and are associated with marked defects in insulin secretion. Given the poor beta-cell function in patients with CF, even small reductions in insulin sensitivity may be an important determinant of AGM.

Glucose homeostasis and genotype-phenotype interplay in cystic fibrosis patients with CFTR gene deltaF508 mutation

OBJECTIVE

We sought to determine the clinical phenotype of adolescent/adult patients with cystic fibrosis, according to heterozygosity or homozygosity for cystic fibrosis transmembrane regulator (CFTR) deltaF508 mutation, and to analyze their characteristics according to glucose tolerance status.

RESEARCH DESIGN AND METHODS

A total of 76 cystic fibrosis patients with CFTR deltaF508 mutation (33 heterozygous and 43 homozygous) stratified according to normal glucose tolerance (NGT) (n = 51) or abnormal glucose homeostasis (AGH) (impaired fasting glucose, impaired glucose tolerance, or diabetes; n = 25) had their homeostasis model assessment (HOMA) of beta-cell function and of insulin sensitivity and hyperbolic product (beta-cell function x insulin sensitivity [B x S]) measured. Pancreatic exocrine insufficiency was inferred from pancreatine requirements. Clinical effects of insulin therapy on weight and lung function were recorded.

RESULTS

AGH was observed in 24 and 40% of heterozygous and homozygous subjects, respectively. AGH patients were older than NGT patients (mean +/- SD age 29 +/- 10 vs. 23 +/- 8 years, P = 0.006), and their beta-cell function was lower (93 +/- 49 vs. 125 +/- 51%, P = 0.011). Insulin sensitivity values were comparable in NGT and AGH patients. A lower B x S product was observed in AGH, although it was nonsignificant when adjusted for error propagation. Pancreatic insufficiency was observed in 52 and 100% of heterozygous and homozygous patients (P = 0.001).

CONCLUSIONS

Pre-diabetes and diabetes represent frequent comorbidities in CFTR deltaF508 mutation in the homozygous or heterozygous states. Impairment of insulin secretion, as shown by HOMA, is an important determinant when compared with the magnitude of compensation from insulin sensitivity. Given the high prevalence of abnormal glucose tolerance, screening for (pre-)diabetes is mandatory. Insulin supplementation in diabetic subjects with CFTR deltaF508 mutation seems a rational therapy for consideration, although this does not preclude that therapy directed toward insulin resistance could also interact.

Normal adiponectin levels despite abnormal glucose tolerance (or diabetes) and inflammation in adult patients with cystic fibrosis

RATIONALE

Circulating adiponectin levels are negatively associated with glucose intolerance, inflammation and central adiposity. Since these conditions are common in cystic fibrosis (CF), we examined whether adiponectin values are altered in these patients.

AIM

To determine if CF patients have altered adiponectin levels and if these levels correlate with glucose tolerance categories (normal, impaired glucose tolerance (IGT) and cystic fibrosis-related diabetes (CFRD)), insulin resistance or inflammatory markers such as fibrinogen and C-reactive protein (CRP).

METHODS

Oral glucose tolerance tests (OGTTs) were performed and adiponectin levels were measured in 90 CF patients not known to be diabetic and 15 healthy controls matched for age, sex and body mass index (BMI). Inflammatory markers, serum albumin concentrations and the clinical status of CF patients (i.e. pulmonary function) were also examined.

RESULTS

CF pathology was characterized by a high prevalence (43.5%) of glucose tolerance abnormalities: 26.5% of IGT and 17.0% of newly diagnosed CFRD. CF patients also presented systemic inflammation as revealed by a significant increase of fibrinogen (P=0.029) in all patients and higher CRP levels in CFRD patients compared to the controls (P<0.05). On the other hand, CF and control subjects had similar albumin serum concentration. While CF patients and controls had similar serum adiponectin values, women had significantly higher hormone levels than men (P<0.001). Adiponectin levels did not correlate with glucose tolerance, inflammatory markers or insulin resistance. On the other hand, they correlated positively with both total and HDL-cholesterol (P<0.001).

CONCLUSION

CF patients did not show any alterations in adiponectin levels despite insulin resistance, glucose intolerance and sub clinical chronic inflammation. Thus, CF appears to be one of the rare conditions in which discordance between adiponectin values and insulin resistance or inflammation is evident.

Increased glucose excursion in cystic fibrosis and its association with a worse clinical status

BACKGROUND

Abnormal glucose tolerance is a frequent co-morbidity in cystic fibrosis patients (CF), and is associated with a worse prognosis. The objectives are to investigate (a) the relative contribution of insulinopenia and insulin resistance (IR) for glucose tolerance and (b) the association between various glucose parameters and CF clinical status.

METHODS

Oral glucose tolerance tests were performed in 114 consecutive CF patients not known to be diabetic as well as 14 controls similar for age and BMI.

RESULTS

Abnormal glucose tolerance was found in 40% of patients with CF: 28% had impaired glucose tolerance (IGT) and 12% had new cystic fibrosis related diabetes (CFRD). Compared to control subjects, all CF patients were characterized by an increased glucose excursion (AUC). While reduced early insulin release characterised CF, IGT and CFRD patients also present IR thus both mechanisms significantly contribute to glucose tolerance abnormalities. Increased glucose AUC and reduced early insulin release but not glucose tolerance categories were associated with a reduced pulmonary function (FEV(1)).

CONCLUSION

In CF, early insulin secretion defect but also IR contribute to glucose intolerance. Early in the course of the disease, increased glucose AUC and reduced early insulin secretion are more closely associated with a worse clinical status than conventional glucose tolerance categories.

Combined en bloc liver pancreas transplantation for children with CF

Cystic fibrosis (CF) is an inherited genetic defect in epithelial chloride transport that results a multisystem disease affecting the sweat glands and the pulmonary and digestive systems. Although pulmonary disease remains the primary cause of morbidity and mortality in these patients, up to 8% may develop focal biliary cirrhosis and portal hypertension. Liver transplantation is an accepted therapy for these patients. About 85% of CF patients develop pancreatic exocrine insufficiency and up to 34% will develop diabetes requiring insulin. We describe a series of 9 patients who underwent liver transplantation (6 transplantation of liver only [LO], and 3 combined en bloc liver-pancreas [LP] transplantation) for CF-related liver disease at our institution,. All 9 patients had pretransplant pancreatic exocrine insufficiency requiring enzyme supplementation. Of the 9, 5 patients (55%) had preoperative insulin dependent diabetes, including all 3 patients who underwent liver pancreas transplantation. Liver-pancreas transplants were performed en bloc. One-year patient survival for both LO and LP patients was 100%. Five-year patient survival was 83% for the LO patients and 100% for the LP patients. All LP patients are off insulin and do not require pancreatic enzyme supplementation. All patients receiving LO continue to need exogenous pancreatic enzyme supplementation. In the 6 patients who received LO, 2 were insulin dependent prior to surgery, and they remain insulin dependent after transplant. Of the 4 patients who received LO who were not insulin dependent pretransplant, 3 have now developed insulin-dependent diabetes. Patients receiving LO were more likely to be diabetic and require exogenous pancreatic enzymes after transplant than those receiving LP (83% vs. 0%, P = 0.04, and 100% vs. 0%, P = 0.01, respectively). In conclusion, patients with CF and end-stage liver disease requiring liver transplantation may benefit from combined liver-pancreas transplantation.

Polymorphisms of TGF-beta1 in cystic fibrosis patients

There is a significant phenotypic variance among cystic fibrosis (CF) patients. Due to the role of TGF-beta1 in fibrotic processes we investigated its role in CF pathogenesis. TGF-beta 1 codons 10 and 25 were genotyped in 118 Czech CF patients and 268 controls by PCR-ARMS. Difference between CF and controls was found at codon 10, lower frequency of T/T homozygotes, and codon 25, higher frequency of G/C heterozygotes. We did not prove the association of TGF-beta1 polymorphisms and lung function in CF, however, the TT (codon 10)/GG (codon 25) genotype was preferentially associated with CF-related liver disease and diabetes. Independent of the TGF-beta1 genotype, production of cytokine was higher in patients than in controls with the notable exception of very low levels in Burkholderia cepacia complex colonized patients. In CF, both extremes, highest or lowest TGF-beta 1 production, were associated with impaired lung function.