1. Departments of Primary Care and General Practice (S.W., J.V.P., L.M.R., A.K.R., F.D.R.H.) Edgbaston, Birmingham B15 2TT, United Kingdom
2. The Regional Endocrine Laboratory (P.C.), University Hospital Birmingham National Health Service Foundation Trust, Birmingham B29 6JD, United Kingdom
3. Medicine (M.C.S., M.D.G., J.A.F.), University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
4. School of Life and Health Sciences (H.M.P.), Aston University, Birmingham B4 7ET, United Kingdom