1. Institute of Metabolism and Systems Research (IMSR), University of Birmingham , Birmingham B15 2TT , UK
2. Department of Endocrinology and Diabetes, University Hospitals Birmingham NHS Foundation Trust , Birmingham B15 2GW , UK
3. Clinical Biostatistics Unit, Hospital Universitario Ramón y Cajal de Investigación Sanitaria (IRYCIS), CIBER de Epidemiología y Salud Pública, Instituto de Salud Carlos III , Madrid 28034 , Spain
4. WHO Collaborating Centre for Global Women's Health, Institute of Metabolism and Systems Research (IMSR), University of Birmingham , Birmingham B15 2TT , UK
5. NIHR Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust and University of Birmingham , Birmingham B15 2TQ , UK
6. Medical Research Council London Institute of Medical Sciences (MRC LMS) , London W12 0HS , UK
7. Birmingham Women's and Children's NHS Foundation Trust , Birmingham B15 2TG , UK