1. Wellcome Trust Clinical Research Fellow, Institute of Metabolism and Systems Research, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
2. Department of Diabetes and Endocrinology, University Hospitals Birmingham NHS Foundation Trust, UK
3. West Midlands Adult CF Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
4. Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
5. University Hospitals of Leicester, Leicester, UK
6. Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK