Outcome of cystic fibrosis-related diabetes two years after lung transplantation.

BACKGROUND: Although transplantation is known to impair glucose tolerance, evolution of pre-existing diabetes after lung transplantation (LT) in cystic fibrosis (CF) has never been described. OBJECTIVES: We aimed to assess the outcome of CF-related diabetes (CFRD) after LT, with the hypothesis that suppressing chronic inflammatory foci may improve glucose tolerance in some patients. METHODS: In a retrospective study of 29 CF diabetic patients treated with insulin and undergoing LT, CFRD control was assessed 3 months before LT and 1 (n = 27) and 2 (n = 18) years after LT by measuring insulin dosage, fasting blood glucose and glycosylated hemoglobin (HbA1c) levels. Patients with HbA1c ≤7% and an insulin dose ≤1 UI/kg/day were defined as having controlled CFRD (group A). Other patients were assigned to group B. RESULTS: Before LT, 19 (65.5%) patients were in group A. At 2 years, 6 of 10 (60%) patients who were in group B prior to LT had moved into group A, which then comprised 77.8% of all patients. Insulin could have been stopped in 5 patients. Uncontrolled CFRD before LT (OR = 16) and a long delay between the diagnosis of CFRD and LT (OR = 1.3) were significant predictors of uncontrolled CFRD at 1 year. CONCLUSIONS: LT does not seem to worsen CFRD in some patients, suggesting that in some cases, glucose tolerance may be improved by the suppression of chronic pulmonary infection.

Calpain 10 and development of diabetes mellitus in cystic fibrosis.

Diabetes mellitus (DM) and abnormal glucose tolerance (IGT) are common in cystic fibrosis (CF). The loss of pancreatic beta-cells due to pancreatic fibrosis is thought to be one of the principal causes of diabetes in CF, but the aetiology of DM remains somewhat puzzling. Genetic factors may contribute to the development of CF related diabetes (CFRD). The purpose of this study was to investigate the role of polymorphisms in six genes on IGT or DM incidence. PCR and dHPLC were used to screen DNA samples for polymorphisms. Using 2-h oral glucose tolerance tests, 163 adult pancreatic insufficient CF patients have been subdivided in 3 groups: 54 NGT (normal glucose tolerance), 33 IGT and 76 CFRD. We found the first evidence for the association between CFRD and UCSNP-19 polymorphism in the CAPN10 gene. The UCSNP-19 genotype distribution differed significantly between NGT, IGT and CFRD groups. The difference reflected an increase in the 22 genotype (3 copies of 32-bp sequence) in IGT and CFRD patients (p=0.05). Odds ratio for the homozygote 22 versus homozygote 11 was 3.4 (p=0.02). All allele and genotype distributions for the other polymorphisms were similar in the three groups. In conclusion, our observations suggest that UCSNP-19 of CAPN10 may be involved in the pathogenesis of diabetes in CF.