Development of Diabetes in Adults With Cystic Fibrosis (CF)

In order to participate in the study, the CF group must meet all the following inclusion criteria 1. Male or female with a confirmed diagnosis of cystic fibrosis defined by 1. Clinical features consistent with a diagnosis of CF AND 2. Sweat chloride ≥60mmol/L by pilocarpine ionotophoresis; OR 3. Genotypic confirmation of CFTR mutation 2. Aged 18 - 50 years 3. Out-patients from the regional adult unit in Liverpool 4. Currently not known to be diabetic or on insulin 5. Clinically stable over the preceding 4 weeks i.e. no indication for iv antibiotics, steroids or hospital admissions 6. Hemoglobin value \>10g/dl The inclusion criteria for the normal population group is as follows: 1. Male or female with NO confirmed diagnosis of cystic fibrosis 2. Aged 18 - 50 years 3. Currently not known to be diabetic or on insulin 4. Clinically stable over the preceding 4 weeks i.e. no indication for iv antibiotics, steroids or hospital admissions 5. Hemoglobin value \>10g/dl In order to participate subjects must not meet any of the following exclusion criteria 1. Patients with known diabetes or on glucose lowering medications (insulin, oral agents) 2. On-going acute illness 3. Those on long-term oral steroids 4. Pregnant women 5. Those on immunosuppressive treatment 6. History of, or planned organ transplant 7. Clinically significant abnormal findings on haematology or clinical chemistry 8. Subjects with documented or suspected, clinically significant, alcohol or drug abuse. The determination of clinical significance will be determined by the investigator. 9. Current malignant disease 10. Any serious or active medical or psychiatric illness, which in eth opinion of the investigator, would interfere with subject treatment, assessment, or compliance with the protocol.